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ICES CM 1997/C:3
Hydrography Committee
REPORT OF THE
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WORKING GROUP ON OCEANIC HYDROGRAPHY
TexeI, The Netherlands
21-23 April 1997
This report is not to be quoted without prior consultation with the
General Secretary. The document is areport of an expert group
under the auspices of the International Council for the Exploration of
the Sea and does not necessarily represent the views of the Council.
International Council for the Exploration of the Sea
Conseil International pour l'Exploration de la Mer
Palregade 2-4 DK-1261 Copenhagen K Denmark
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TABLE OF CONTENTS
Section
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Page
1.
OPENING
1
2
Review of Membership
1
3
Remarks from the ICES Oceanography Secretary
1
4
Results from Standard Sections and Stations
2
5
Report FormaL
6
Progress in National and International Projects in North Atlantic
7
Developments in GOOS
6
8
NANSEN Project Report
6
9
Trans-Atlantic ADCP Survey Proposal
7
10
Oceanographic Instrumentation
7
11
Overview of Instrument Calibration Procedures and Quality Assurance
7
12
Satellite Altimentry in Circulation Studies
7
13
Ocean Climate Forecasting
8
14
Second Decadal Symposium Proposal
8
15
Any Other Business
9
16
Place, Date and Topics ofNext Meeting
9
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Annex A: Agenda
11
Annex B: List of Participants
12
Annex C: Recommendations
13
Annex D: Membership List
14
Annex E: Northwest Atlantic Sections
:
18
Annex F: Results from Icelandic Waters
38
Annex G: West Greenland Seetions
45
Annex H: The State ofFaroese Waters in 1996
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Seetion
Page
Annex I: Results from the Scottish Standard Sections
.49
Annex J: Norwegian Sections
65
Annex K: Results from Spanish Sections
75
Annex L: Results from Barents Sea
84
Annex M: Report on WOCE Seetion AlE
89
Annex N: Further Changes in Norwegian Sea Deep Water
92
Annex 0: An Overview of VEINS
95
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ii
1.
Opening
Following the opening remarks by the Chairman, Johan van Bennekom of the Netherlands
Institute of Oeean Scienees welcomed the \VG members to Texel and to the Institute, and
explained the loeal arrangements associated with the meeting. The agenda (Annex A) was
diseussed and modified to include additional presentations that are of interest to the \VG, as
well as to make allowanees for members who eould not join the meeting on the first day. List
of participants is given in Annex B.
2.
Review of Membership
The latest list of the \VG members provided by the ICES Seeretariat was reviewed by the
attendees, and eorreetions and additions were made to provide addresses, telephone and FAX
numbers and the e-mail addresses (Annex D). However, it was obvious that the Seeretariat
had not revised the member list to refleet the 1997 nominations from the member countries.
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3.
Remarks from the leES Oceanographic Secretary
Due to the pressures and eommitments the Oceanography Secretary was not able to attend the
meeting. The following text was provided subsequent to the meeting at the request of the
\Vorking Group.
The Oeeanography Secretary, Dooley, reported that the past year had seen a signifieant
inerease in the size of the data bank by almost 60,000 profiles. However there was a notable
drop in the number of ehemical data (nutrient and oxygen) reeeived, largely because a number
of the major sources of data had been concentrating on developing relational database systems
for CTD data only. This in turn was resulting in the devclopment of more robust quality
control systems in support of CTD data which was in part producing data of higher quality.
However this was also placing extra pressure on the data centre because of re-submissions of
old, but newly quality-controlled data. Because of this the total amount of data received
during the past years exceeded weIl over 100,000 profiles. Unfortunately, sources of data
remained relatively static, with data being mainly acquired from government laboratories.
University departments continue to be poor contributors, and this remains a major
shortcoming in the usefulness of the databank. At the request of the EC-MAST, the data
centre was asked to review the fraction of University data in the publie domain, and this
produced rather telling statistics. For example, in the case of the University of Bergen which
is a rather prolifie eollector of oceanographie data, only 6% of the data collected since the
1960s have been made available. It is hoped that involvement in MAST Projects (see next
paragraph) will help to nurture eontaets with University departments and therefore improve
data flow and enhance the overall quality of the Databank.
The Data Centre is currently eontracted via EC MAST to manage the data sets of two major
MAST projects, viz ESOP-II and VEINS, both of which are projects based on the
oceanography of the Nordic Seas. The data centre also provides input to the TASC project and
is responsible for the compilation of the ESOP-l data set fOf subsequent merging with ESOPII data. The data management structure for these projects is closely based on routine
proeedures which are being adapted to accommodate the broader range of parameters that are
being collected, particularly in ESOP-II.
.
"f',;'
,-*' \ ,
The Data Centre web-site continues to expand slowly, but its basic structure remains as
described last year. The web-presence has resulted in a significant increase in the number of
requests for qata, with the balance shifting significantly from the provision of raw data to the
provision of gridded products, especiaIly the provision of statistics on varying space and time
scales. It is expected that the more common types of requested products will be made
available from the website.
The ICES Inventory of Oceanographic Activities, which was devised by the working group
more that 15 years ago, continues to be produced on an annual basis. Many (>60 per year)
requests for changes/additions reflect the continued interest in this producL However, because
of changing commitments and priorities in the Secretariat it is likely that this and some other
services may have to be discontinued soon.
4.
Rcsults from Standard Seetions and Stations
Narayanan reported results from the N\V Atlantic (Annex E). In general there have been
warmer winter conditions. Air temperatures monitored at five sites have revealed normal or
warmer than normal conditions. These temperatures seem to mark an end to the recent cooling
trend. The warming appears weH correlated with changes in the NAO. Less sea ice was
produced due to weaker N\V winds and warmer winter temperatures. A good index of climatic
conditions is the area of sub-zero temperature water on the shelf. Standard sections off Seal
Island, Bonavista and the Flemish Cap aIl reveal a warming trend, associated with possible
freshening. Station 27 also reveals this trend. Rossby questioned whether density had been
examined in order to describe changes in the dynamics of the upper ocean. Narayanan
explained that geostrophic currents across the standard transects were computed, but showed
considerable variability.
Malmberg presented results from Icelandic waters (Annex F). Conditions have been generaIly
mild. Although salinities were low north and east of Iceland, this was not associated with cold
temperatures as would normaIly be expected. Satellite imagery demonstrated SST features
around Iceland very weIl. 1996 was not an ice year, but the salinity of the East Iceland Current
was rather low. Malmberg noted that the NAO should be used with some caution in this area,
since local variations in atmospheric pressure patterns were common.
No member from Denmark was present at the meeting. However, Buch from the Royal
Danish Administration of Navigation and Hydrography provided a written report summarising
the observations from west Greenland (Annex G). Consistent with the above-normal air
temperatures at NuuklGodthaab, the upper layer temperatures in the west Greenland coastal
waters were also above normal.
Hansen (Annex H) presented results from standard sections and stations around Faroe Islands.
The decrease of salinity in the Atlantic water in the Faroe Bank Channel has now stabilised
after beginning in the late 1980s and reaching a maximum rate in 1993/94. The temperature
and salinity of this \Vater is a good indicator of conditions in the North Atlantic Currcnt. These
changes have been associated with rather small changes in temperaturc. On thc shclf
temperatures havc incrcascd sincc the cold ycars 1993, 1994 and 1995.
TurreIl presented results from the Faroc Shetland Channel (Annex I). Past CTD data has been
recalibrated, hcnce values and time series presented may differ slightly from previously
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quoted values. There was a problem with some of the definitions used to derive indices from
the five water masses observed within the Channel, hence they should be used with some
caution. North Atlantic Water (NAW) at the shelf edge has demonstrated a warming since
1987. Salinity has shown great variability since the arrival of the salinity anomaly in the mid1970s. This variability appears correlated with the NAO index. There may be an underlying
increasing trend since the mid-1970s, with salinities now approaching 1960 values. In the socalled Modified North Atlantic \Vater there has been a cooling since 1960, unlike the general
warming observed in NA\V. There has been arecent enhanced freshening since 1991, with an
underlying freshening trend evident since 1960. Salinities are beginriing to approach values
observed in the mid-1970 anomaly years. Salinity continues to decline in all intermediate and
deep-water masses. In the North Sea, salinity has been variable, but weIl correlated with that
of the NAW. The most Fair Isle Munken section shows extremely anomalous salinity in the
Arctic Intermediate I North Icelandic \Vater, with a density distribution displaced towards the
Faroese shelf.
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Blindheim presented results from Norwegian seetions in the Barents and Norwegian Seas
(Annex J). The general trends in both temperature and salinity are decreasing. Temperatures in
the Barents Sea have been above the long-term mean during 1989-1995, with warmest
conditions in 1991/92. During 1996 temperatures fell to below the long term mean. The
colder conditions are also reflected in the sea ice records, with relatively large ice coverage
during the winter 1995-96. In the Norwegian Sea there was an increase in temperature and
salinity between 1994 and 1995. From 1995 to 1996 all sections demonstrated cooling and
freshening, with some local variability. In the North Sea relatively cold temperatures were
found following the cold and dry winter of 1995/96. Time series in the Skagerrak reveal that
deep-water renewal occurred in 1991 after a long period without deep water exchange. There
was a further supply of deep water in the winter of 1996.
Osterhus reported on the oceanographic time series of Ocean \Veather Station «Mike». The
time series has not been updated since last year. However, considerable effort was made to
quality control and analyse the existing long time series with the purpose of publishing the
data on CD-ROM, and the results in refereed journals.
•
Lavin presented results from Spanish standard seetions (Annex K). Air temperatures have
closely followed changes in the NAO index. Results from the standard sections reveal a strong
seasonal cycle, with evidence of regular upwelling. Winter salinities appear to be decreasing.
There was evidence of a stronger poleward current during 1995/96. Nutrient records
demonstrate peaks during the upwelling seasons. At 10m depth the warming that was evident
from 1991-1995 has now stopped. Also the salinity decrease observed between 1991 and 1994
has now reversed. A correlation of salinity variability between two stations at 70m depth at La
Coruna and Santander revealed a significant correlation with a lag of 60 days implying a
poleward flow of 10 crn/s. Current meter data confirmed this ~ean transport.
Piechura presented results from the Barents Sea (Annex L). Conditions were very variable,
with the intrusion of cold, fresh bottom water, termed Barents Polar Water (BPW). Variable
mixing with Atlantic water was observed. Coldest temperatures were recorded in 1995. On the
Svalbaard shelf water there was strong evidence of cold, dense bottom water cascading off the
shelf.
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Meinke presented results from the Greenland-VK trans-Atlantic section (Annex M). The
differences between occupations in 1991 and 1995 were discussed, with particular reference
to changes in the Labrador Sea \Vater. Implications to transport within intermediate waters of
the North Atlantic were discussed. The volume budget of these intermediate waters did not
appear at first to balance.
Further discussions took placc on thc standard section data. Rossby presented new Pathfinder
SST images and noted these were extremely useful new products. Van Aken presented results
from an analysis of altimeter data revealing patterns in cddy kinetic energy in the northeast
Atlantic.
5.
Report Format
During the 1996 \VG meeting, it was decided that an overview of thc status of thc physical
environment is to bc prepared after thc 1997 meeting, and presented at thc annual science
congress. Following the presentations on the standard sections and stations, thc format and
authorship of thc overvicw report was discussed at lcngth. Thc group recommended that onc
of the individua1s who reported on thc sectionslstations together with a team he/shc selected
from thc group bc given thc editorship of thc overview report. Turrell from Scotland was
nominated as the chairman for the editorial group for the 1997 and 1998 reports. Other
members of thc editorial group are Narayanan and Lavln.
•
An abstract was prepared for the ICES Annual Science Congress in Baltimore. It was also
agreed that all relevant texts and figures associated with the presentations on standard sections
and stations will be submitted to the Chairman before the end of May, so that preparation of
the report and the overview paper can proceed in a timely fashion.
6.
Progress in National and International Projects in North Atlantic
Bennekom presented rcsults from his analysis of time series of temperature, salinity and
nutrients collected from the Norwegian Sea (Annex N). He has added data from several
cruises from the region to his time series of hydrographie properties of thc deep water in thc
Norwegian Sea. By applying corrections for thc standard water batches, as published by A.
Mantyla, Bennekom was able to upgradc thc quality of thc deep salinities to a satisfactory
level. The rcsults show a constant salinity of 34.910 C±O.OOl) sincc 1981, indicative of a
stagnant situation in the deep Norwegian Sea. It was hypothesized that such salinity
characteristics arc caused by thc disappearancc of deep convection in the Greenland Sea, a
sourcc for thc flushing of Norwegian Sea deep layers. Osterhaus added that thc concurrent
change in temperature of the deep water in the Norwegian Sea, also presented by Bennekom,
can be modelIed with a simple model containing isopycnal mixing and a realistic geothermal
heat flux, without any lateral exchange with thc Greenland Sea. This stagnant schemc for thc
deep Norwegian Sea is further supported by thc build-up of dissolved silica gradients and the
reduction ofthe 3H concentration in accord with radioactive decay.
Van Aken prcscnted rcsults [rom an ongoing program to study the circulation in the Bay of
Biscay and the roIe of currents and mixing in maintaining the observed distribution of
temperature and salinity. An impressive mix of hydrography, moorcd currcnt meters and
WOCE-type surface drifters are being used. The boundary currents are castward along the
Spanish coast, and north along the shelf break west of France. Thc interior circulation is less
4
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clear and must await detailed analyses. The spreading north of Mediterranean waters to Cape
Finisterre beyond which two regions of high salinities, straight north and cast aIong the
Spanish coast suggest two pathways of spreading, but the relative roIes of advection and
mixing need to be sorted out. The current meters at the depth of the salinity maximum indicate
a northward flow aIong the sIope, but the high eddy kinetieenergies suggest significant
mixing. In addition there is strong cvidence for enhanced diapycnal mixing along the
boundary by breaking internal waves.
Mcincke summarised the German trans-Atlantie sections that will take place this summer
aIong WOCE lines Al and A2. The first crosses the subpolar gyre, and the second crosses the
ocean at 48°N, just south of the Subpolar Front. These sections follow the same Iines as the
two taken during the International Geophysical Year (IGY) in the late 1950s. This will be the
third occupation of the Al and A2 Iines respectively since 1993. Meincke also reported that a
major WOCE symposium will be held in Halifax May 25-29, 1998. A North Atlantie WOCE
workshop is also being planned.
•
Malmberg discussed the surface circulation around Iceland as observed with \VOCE-type
surface drifters. These have been most valuable in highlighting the variability of the surface
flow underscoring the need for additional observations to obtain a more quantitative measure
of the mean flow and eddy activity. More drifter studies are planned for this coming summer.
A lively discussion took place about the nature of the surface flow along the southern and
eastern coasts of Iceland, as weIl as along the Iceland-Faeroes ridge. In particular, the WG
focused on how and/or what fraction of the warm waters from the North Atlantie
CurrentlSubpolar Front make their way north into the Nordic Seas along 1) the Reykjanes
Ridge, 2) west of Rockall Bank, and 3) through the Faeroes-Shetland ChanneI. These
questions are expected to be resolved from the direct measurements of velocity in the North
Atlantie \VOCE.
Blindheim reported that Norway plans to continue repeat hydrographie seetions along the Bear
Island \Vest and Svinoy sections. These sections were first taken in 1958 during the first IGY.
•
Meincke detailed the plans for the upcoming VEINS program "Variability of Exchange in the
Nordie Seas" (Annex 0). The immediate objective is to conduct a program of flux
measurements between the Nordie Seas and the Arctie in the north, and the North Atlantie in
the south with a view towards implementing a longer term system of critical measurements to
understand low-frequency variability of the Nordie Seas. The program, scheduled to start this
year, will be a three-year pilot program to monitor in- and outflows using a mixture of moored
current meter and ADCP measurements and hydrographie surveys. As an integral part of the
program, a concurrent modelling activity will provide the framework for the analysis and
assimilation of the observations and their dynamical interpretation. Significantly, the model
will rely heavily upon boundary flux and surface forcing conditions to understand the interior
circulation and its variability. A significant objective of the modelling cffort will bc to identify
the minimum (Le. cost-cffective) set of critical measurements needed to monitor the Nordie
Seas and their variability on a long-term basis.
Dickson reported on activities to monitor the overflow and southward transport of Denmark
Strait Overflow Waters along the East Greenland continental slope. A ten-year plan is
envisaged with funding for the immediate years probable. Participation from Finland,
Germany and the UK for current meter measurements is anticipated. Past current meter
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measurements indicatc astonishingly steady southward velocities. Dickson emphasised thc
importance of determining the thickness and location of the overflow waters, otherwise it will
be difficult t~ obtain a quantitative understanding of the low-frequency variability of the
overflow waters.
An important challenge for the future is to better document and understand the role of the
ocean in mitigating andlor controlling climate and its variability. A new international
cooperative effort, CLIVAR, seeks to address these questions in a systematic way. Dickson
discussed one particular aspect of low frequency variability, namely a hypothesis that thermal
anomalies can be injected into the ocean at high latitudes, circulate around the North Atlantic
and reappear at high latitudes to provide a kind of decadal locking oscillator mechanism.
Although the feedback mechanism as such is highly conjectural at this point, increasing
evidence shows with considerable confidence that perturbations injected into the Labrador Sea
waters at its source appear some five years later in the western subtropical gyre at Bermuda
documenting adefinite pathway for water mass propagation, not merely wave propagation
(which would require much less time).
Lavfn reported on the multi-disciplinary program, CANIGO (Canary Islands Azores Gibraltar
Observations), involving 45 partners and 12 countries, designed to understand the CanaryAzores-Gibraltar system and its interaction with the northeast Atlantic Ocean. CANIGO is
implemented through four subprojects and the field work has already started.
A
comprehensive management plan has also been implemented to ensure coordination among
the components and to assure timely delivery of the results.
•
Lavfn also reported on a 3-year Spanish program in the Bay of Biscay, planned to commence
in 1998. This program is primarily biological in nature, with emphasis on fluxes, especially
carbon.
Hagen reported on the Baltic activities with emphasis on the MESODYN projecL MESODYN
program is a cooperative venture with institutes in Kaliningrad and Petersburg, and covers
four areas, the Arkana and Bornholm Basins, the Stolpe furrow, and the east Gotland Basin.
The research emphasis will be on a) vertical mixing and fluxes, b) oceanographic events and
c) horizontal currents. The observation program is designed to provide fine resolution data for
input into the numerical models.
7.
Devclopments in GOOS
None of the members present at the meeting had sufficient information on GOOS to report on
the progress of GOOS implementation. However, every one agreed that ICES is capable of
providing considerable assistance in the data management component of GOOS. Narayanan
reported that she has been asked to attend the IGOOS meeting in Paris this summer as one of
the Canadian delegates, and volunteered to provide an overview at the next 'VG meeting.
8.
NANSEN Project Report
Hansen reported progress towards the final publication of results from the north AtlanticNorwegian Sea exchanges (NANSEN) projecL Twelve papers from the 1991 theme session
were now edited and on the point of submission for publication in the ICES Co-operative
6
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Research Report series together with a synopsis of the aims and history of the project by
Hansen, Osterhus, Dooley, Gould and Rickards.
9.
Trans-Atlantic ADCP Survey Proposal
Rossby (US) infonned the Working Group on behalf of his Norwegian colleague Osterhus
about the status of the plarining for a VOS-ADCP line between Fair Isle and Kap Farvel.
Negotiations are underway with the Danish Royal Arctic Line, which operates the Greenland
supply vessels at 3 weeks interval. The vessel under consideration is already equipped with a
surface TS-recorder. The route is optimal for scientific reasons, since the data will support the
monitoring of the upper limb of the global thennohaline conveyor belt circulation. A similar
project along the New York-Bennuda line crossing the Gulf Stream has already proven to be
highly successful. The \Vorking Group appreciates this activity.
10.
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Oceanographic Instrumentation
Lundberg infonned the WG about a revival of the use of underwater cables for transport
measurements. After initial trials with a demobilized telephone cable between Sweden and the
Island of VEN using CarbonlCopper electrodes, latest experiments with dedicated cables and
more sensitive Silver/Silverchloride electrodes have resulted in useful measurements in the
Skagerrak area. Present improvements concern the analysis of the data, in particular if a
baroclinic structure of the flow field has to be considered.
Osterhous reported on experiments in cooperation with RD Instruments to use an acoustic
Doppler Current profiler (ADCP) package to measure ambient noise, to detennine wind speed
and rain fall rate. Such measurements in the past utilised hydrophone packages, and not
ADCPs. Report on the results ofthis experiment can be found on the RD Instruments' WW\V
horne page.
Overview of Instrument Calibration Procedures and Quality
Assurance
11.
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The successive inter-calibration exercises of ICES Marine Chemistry WG and later the
QUASIMEME initiative (European Community (EC) Bureau of Reference) have been
successful in achieving a progressive reduction in community error for nutrient analysis.
However, QUASIMEME procedures are not adapted for use by seep-sea oceanographers. The
\VGGH invites Dr. David \Vells to advise on how QUASIMEME might best meet the
specialised needs of deep-sea oceanography.
The WG was also advised that new quality assurance (QA) literature was available in the fonn
of the \VOCE QA manual and aseries of handbook on methods, protocols, archiving and QA
that were currently being issued in support of EC MAST Programs Though aimed at specific
projects, these have a general reference.
12.
Satellite Altimetry in Circulation Studies.
Availability of altimctry data on CD-roms was notcd (van Akcn) and a numbcr of projects
utilising this were mentioned. A combination of altimetry and moored bottom pressure or
7
inverted echo-sounder has great potential in certain areas, especially slope regions (Rossby).
During the discussion, a concern was raised that students are being less and less familiarised
with observational techniques (as compared to modelling) which may have an significant
impact on large programs in the upcoming years.
13.
Oeean Climate Foreeasting
The discussion initially focused on the Norwegian approach to forecasting which is a part of
the annual environmental report of the Marine Research Institute in Bergen. This approach is
mainly based upon statistical" prediction supplemented by other information and each
prediction is evaluated in next year's report. New initiatives at prediction of fisheries will
require reliable prediction of environmental changes. There was some discussion as to how
appropriate prediction schemes arc at the present stagc. Clearly, there is a demand (Dickson),
but different oceanic systems havc different predictability and the time for which prediction
may be realistic varies from onc region to another (van Aken). In Canada, the index from
station 27 may be useful for prediction a few months ahead and the areal cxtent of 4°C water
seems to be a good indcx for salmon (Narayanan). Cod growth is also strongly related to
temperature and temperaturc may predict weight at agc e.g. at thc Faroes (Dickson).
14.
Seeond Deeadal Symposium Proposal
Thc item on a «second decadal symposium» on time series of physical and chemical
observations in thc ocean and related biological investigations, along the lines of the Aland
Symposium in 1991, was introduced by Dickson. The symposium aims to give decadal
information on environmental conditions during the nineties in relation to longer observation
periods, with emphasis on the ICES area in thc north Atlantic, but not exclusively so. The \VG
members unanimously cndorsed the proposal and put forward thc suggestion that some longterm contributors of time series from thc ICES community be honoured as weIl at this
occasion, which is within thc spirit of ICES and the Annales Biologiques.
It was decided to recommend to hold the symposium in Edinburgh, Scotland, in August 2001.
The Chief Executives ofthe Marine Laboratory, Aberdeen and thc CEFAS Laboratory,
Lowestoft, has agreed to provide partial financial support for the cvent. Thc dates have been
chosen so that the Symposium immediately precedes thc Edinburgh International Festival and
the main venuc is expected to be thc Royal Museum of Scotland, Chambers Street, with a
Symposium Dinner, at participant's expensc, in thc main exhibition hall of thc Museum.
Thc WG thanked Dickson and Meinke for volunteering to bc the convenors of the symposium
and Turrell and Drinkwater (Bedford Institutc of Oceanography, Canada) for agreeing to act as
thc editors of thc proceedings.
Thc WG discussed thc possibility of NAFO participating in thc Symposium, since NAFO has
a keen interest in the north Atlantic, and through its environmental committee, does review
the state of thc ocean at annual and decadal time scales. Furthermorc, many of thc scientists
who arc involvcd in such studies in leES arc also participants in NAFO. Thc WG proposcs to
invcstigate this possibility further.
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15.
Any Other Business
Blindheim informed the WO that the lOoth anniversary of the Kola Meridian Section will be
in 1999, and that a special I-day symposium is being planned to mark this event. The
Knipovich Polar Research Institute of Marine Fisheries and Oceanography (PINRO) has
offered to host the 1999 Oceanic Hydrography \VO meeting if the meeting can be scheduled
to commencc thc day after the symposium. Blindheim also offered to assist in making thc
travel arrangements for thc members. Thc WO members were unanimous in their decision to
accept the offer, and thanked Blindheim and the Russian colleagues for providing such an
opportunity.
•
Rossby expressed an interest to be informed of research cruise plans in the ICES area for the
upcoming years. He and his US colleagues arc planning to conduct a very largc drifter
program in thc north Atlantic, and arc looking for opportunities to piggy-back on existing
cruises. Thc WO agrecd that it is a good idea to make such information availablc and
requested the ICES Secretariat to investigatc the possibility of posting the cruisc schedules on
the ICES WWW page, if it is not already available at any of thc other sites in a consolidated
form.
Narayanan reminded the WO members of thc April 28 th deadline for submitting abstracts to
ICES. Ideas for themc sessions for 1999 and onwards werc also discussed. The WO
recommends four topics for thc Themc Sessions for thc upcoming years:
1.
2.
3.
4.
The Physical Environment of thc ca/anlls fin11larchiclls
The Aanderaa Current Meter: Thc contribution of Ivar Aanderaa
to modem oceanography.
The usc of ADCP in fisheries research
Thc shelf-edgc, slope or Eastern boundary currents in the European margin.
Thc WO has identified potential convenors for thc themc sessions. The Chairman was asked
to contact them to confirm their acceptance.
•
The members feIt that the mandate of the Oceanic Hydrography WO may be modified as a
result of the new organizational structure. The WO supported Dickson's suggestion that
Narayanan contact thc new Chairman of the Oceanography Committee for the Terms-ofReference of Oceanic Hydrography WO.
16.
PIace, Date and Topics of Next Meeting
The WO accepted an invitation from Lavfn to have the 1998 meeting at Instituto Espafiol de
de Oceanograffa, Santander, Spain, on 27, 28 and 29 April.
The following topics are proposed for the next meeting:
a) Update and review results from Standard Sections and Stations
b) Progress in national and international projects in north Atlantic WaCE, VEINS,
CLIVARJACSYS, OLOBEC, OMEX, ESOP2, TASC, CANIGO, and others
c) Shelf-edge, slope or Eastem boundary currents
d) Assess the developments in GaaS
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e) Review the progress of ships-of-opportunity vessel-mounted ADCP surveys
f) oceanographic instrumentation
g) Second Decadal Symposium
Justifications:
a)
b)
c)
d)
e)
f)
g)
This is a standard item to enable the group to closely monitor the ocean conditions.
The materials presented under this item will be utilised to prepare an overview of the
state-of-the-environment in north Atlantic at the Annual Science Congress.
This agenda item will provide an opportunity for the WG to be informed of programs
in the ICES area. Since many planned and funded activities are now being coordinated
via funded proposals, such information is necessary to take advantage of national and
international funds and to establish collaborations among members.
A number of programs are underway in the eastern Atlantic, Iberian Basin, Bay of
Biscay, etc. This agenda item will provide an opportunity to review the results from
these programs.
GGOS is still in design stage. Most ICES member countries will be formally involved,
one way or another, in GOOS activities. In order to acquire an ICES-wide perspective
of national contributions and intentions, the \VG wishes to keep these activities under
close scrutiny. All members will provide GOGS status reports to the chairman.
Vessel-mounted ADCPs, properly managed, have been shown to provide valuable
information on the ocean currents. The WG wishes to be informed of the progress on
the ADCP installation on commercial ships crossing the north Atlantic, and discuss
opportunities far other installations.
Rapid technological developments as weIl as new applications of existing ones
continue to enhance our capabilities for measuring oceanographic parameters.
However, there are many drawbacks if incorrectly used. This item therefore serves to
inform members and the ICES community on the present status of the operational use
of any new equipment.
This item is to review the progress on the second decadal symposium planning.
•
lO
•
Annex A: leES Working Group on Oceanic
Hydrography
Texei, Netherlands, April 21-23, 1997
Agenda
•
1. Opening
2. Review of Membership
3. Remarks from the ICES Oceanographic Secretary
4. Results from Standard Seetions and Stations
5. Report Format
6. Progress in National and International Projects in North Atlantic
7. Developments in GOOS
8. NANSEN Project Report
9. Trans-Atlantic ADCP Survey Proposal)
10. Oceanographic Instrumentation
11. Overview of Instrument Calibration Procedures and Quality Assurance
12. Satellite Altimetry in Circulation Studies
13. Ocean Climate Forecasting
14. Second Decadal Symposium Proposal
15. Any Other Business
16. Place, Date and Topics of Next Meeting
11
•
12
Annex B: List of Participants
J. Blindheim
E. Ha~en
H. Van Aken
A. J. van
Bennekom
R. R. Dickson
B. Hansen
A. Lavin
S. Narayanan
P. Lundber~
S. A. Malmberg
J. Meincke
S.Osterhus
J. Piechura
T. Rossby
W. Turrell
Norway
Germany
Netherlands
Netherlands
UK
Denmark
Spain
Canada
Sweden
Iceland
Germany
Norway
Poland
USA
UK
•
•
12
.
~
Annex C: Recommendations
1)
This will be the second in aseries of such Symposia held to review the physical,
chemical and biological changes of thc decade and to set these changes into the context
of longer-term variability; the first, on thc decade of thc 1980's, was held at
Mariehamn in the Aland Islands in June 1991. These symposia were initiated by
Council in 1987 as a means of continuing the essential purposc of the old Annales
Biologiques series in recording the hydrobiological character of each decade across the
ICES Area. As with the Mariehamn Symposium, the Proceedings will be published in
the ICES Marine Science Symposium Series, with, Turrell and Drinkwater as Editors,
and will form a Festschrift in honour of individuals who have maintained and
supported the time-series on which the Symposium is based. The Chief Executives of
the Marine Laboratory, Aberdeen and the CEFAS Laboratory, Lowestoft, is providing
partial financial support for thc event. Thc dates havc been chosen so that thc
Symposium immediately precedes thc Edinburgh International Festival and the main
venue is cxpected to be the Royal Museum of ScoHand, Chambers Street, with a
Symposium Dinner, at participant's expense, in thc main exhibition hall of thc
Museum.
•
•
Working Oroup on Oceanic Hydrography recommends that a Symposium on
«Hydrobiological Variability in thc ICES Area, 1990-1999» bc held in Edinburgh,
Scotland on 8-10 August 2001, with Dr. R.R.Dickson of the CEFAS Laboratory,
Lowestoft and Professor Jens Meincke of the Institut fur Meereskunde of the
University of Hamburg as the Co-Convenors for the symposium.
2)
The WO recommends that the following theme sessions be included in the ICES
Annual Science Congress in the upcoming years.
a) The Physical Environment of the calanus finmarchicus,
b) Thc Aanderaa Current Meter: The contribution of Ivar Aanderaa
(1940-1996) to modem oceanography,
c) Thc usc of ADCP in fisheries research,
d) The shelf-edge, slope or Eastem boundary currents in the European margin.
3)
Thc Working Oroup on Oceanic Hydrography will meet at Institute Espanol de
Oceanografia, Santander, Spain, on 27, 28 and 29th of April 1998 to:
a) Update and review results from Standard Seetions and Stations
b) Progress in national and international projects in north Atlantic \VOCE, VEINS,
CLIVARlACSYS, OLOBEC, OMEX, ESOP2, TASC, CANIGO, and others
c) Shelf-edge, slope or Eastern boundary currents
d) Assess the developments in OOOS
e) Review the progress of ships-of-opportunity vessel-mounted ADCP surveys
f) oceanographic instrumentation
g) Second Decadal Symposium
13
A nnex D•• M emb ers lp
Name
DrH.M. van
Aken
DrG. Becker
Mr AJ. van
Bennekom
~
DrJ.
Blindheim
DrE. Buch
Ms H. Cavaco
Address
Netherlands
Institute for
Sea Research
Bundesamt f.
Seeschiffahrt
und
Hydrographie
Netherlands
Institute for
Sea Research
Institute of
Marine
Research
Farvandsv:esen
et Overgaden
o.
IPIMAR
M J. Citeau
Mr.E.
Colboume
ORSTOM
Dept. of
Fisheries &
Oceans
DrC. Afonso
Dias
Dr R.R.
Dickson
IPIMAR
The Centre for
Environment,
Fisheries and
Oceans
IS
POB
P.O. Box 59
City
1790 AB Den
Burg, Texel
Country
The
Netherlands
Email
aken@nioz.nl
Postfach 30 12
20
20305
Hamburg
Germany
gerd.becker@
m2.hamburg.bs
h.d400.de
P.O. Box 59
1790 AB Den
Burg, Texel
the Netherlands
P.O. Box 1870
Nordnes
5024 Bergen
Vandet 62b
Postboks 1919
Avenidade
Brasilia
B.P.1386
P.O. Box 5667
Avenida de
Brasilia
Aquaculture
Science
Telephone
Tel.(31)-222369416
Telefax
Fax (31)-222319674
bennekom@ni
oZ.nl
Tel.(31 )-222369392
Fax (31)-222319674
Norway
johan.blindhei
m@imr.no
Tel.(47)-55238500
Fax (47)-55238584
1023
Copenhagen K
Denmark
farvebu@unidh
p.uni-c.dk
1400 Lisbon
Portugal
Dakar
St-John's, NF
AIC5Xl
Senegal
Canada
1400 Lisbon
Portugal
Lowestoft
NR330HT
Suffolk United
Kingdom
•
Eugene@
pisces.nwafc.nf
.ca
Tel. (709)-7226106
Fax (709)-7723207
r.r.dickson@ce
fas.co.uk
Tel.(44)-1502524282
•
Fax (44)-1502.
513865
•
•
Institute of
Oceanography
Somerset
Campo Grande
1700 Lisbon
Portugal
United
Kingdom
Waterfront
Campus
European Way
Seestrasse 15,
18119
Southampton
S0143ZH
United
Kingdom
Warnemünde,
Germany
Noatun, FR110 T6rshavn
2100
Copenhagen 0
20305
Hamburg
Faroe Islands
Denmark
Denmark
Germany
Koltermann@b
sh.d400.de
39080
Santander
Spain
a1acia.lqavin@
st.ieo.es
Pa1aegade 2-4
Dr E. Fahrbach
A1fredWegenerInstitut für
Po1ar- und
Meeresforschu
ng
University of
Lisbon
Hydrographie
Department
AUNTON
Southampton
Oceanography
Centre
Institut für
Ostseeforschun
Co1umbusstrass
e
Mr N. Gooding
Dr WJ. Gou1d
-
Denmark
ICES
Prof A.F. Fiuza
DrE. Hagen
VI
TA12DN
DrN.K.
H0ierslev
Mr K.P.
Koltermann
MsA.Lavfn
Fiskiranns6kna
rstovan
Geofysisk
Afdeling .
Bundesamt f.
Seeschiffahrt
und
Hydrographie
Instituto
Espaiiolde
Oceanograffa,
Laboratorio de
Santander
P.O. Box 3051
Juliane
Mariesvei 30
Postfach 30 12
20
Apdo 240
Tel.+45 33 15
4225
Fax +453393
4215
Tel.(49)3815197150
Fax (49)3815197440
Te1.298-15092
Fax 298-18264
Tel.(34)-42275033
Fax (34)-42275072
Germany
g
DrB. Hansen
harry@ices.dk
1261
Copenhagen K
27668
Bremerhaven
Dr. H. Doo1ey
Error!
Bookmark not
defined.
john.gould@so
c.soton.ac.uk
eberhard.hagen
@iowarnemunde.de
bogihan@frsJo
nkh@gfy.ku.dk
MC. Leroy
IFREMER
MrH.Loeng
Institute of
Marine
Research
Fysisk
Oceanografi/S
MF
Hydrographie
Department
TAUNTON
Marine
Research
Institute
Institut für
Meereskunde
der Universität
Hamburg
Marine
Environmental
Data Service
Institut für
Ostseefischerei
ProfP.
Lundberg
MrK.
McClean
DrS.A.
Malmberg
-
Prof J.
Meincke
0\
DrS.
Narayanan
Mr R. Oeberst
Prof J.
Olafsson
Mr S. Osterhus
MmeA.
Pichon
Marine
Research
Institute
University of
Bergen
Geophysical
Institute
EPSHOMSSH
Rue de l'IIe
d'Yeu BP 1105
P.O. Box 1870
44311 Nantes
Cedex 03
Nordnes, 5024
France
Bergen
Norway
harald.loeng@i
mr.no
Stockholms
Universitet
S-10691
Stockholm
Sweden
peter@misu.su.
se
Tel.(46)-8161735
Fax (46)-8157956
Somerset TAl
2DN
United
Kingdom
P.O. Box 1390
Skulagata4
121 Reykjavik
Iceland
svam@hafrojs
Tel.(354)-5520240
Fax (354)-5623790
Troplowitzstras
se 7
22529
Hamburg
Gerrnany
meincke@ifm.
uni-hamburg.de
Tel.(49)-4041235985
Fax (49)-4041234644
200 Kent St.
Station 1202
Ottawa,
Ontario
Canada KIA
OE6
Narayanan@ott
med.meds.dfo.
ca
Tel. 613-9900265
Fax 613-9934658
An der
Jägerbäk 2
18069
RostockMarienehe
121 Reykjavik
Germany
Ieeland
svam@hafrojs
Tel.(354)-5520240
Fax (354)-5623790
Allegaten 70
5007 Bergen
Norway
svein@regn.gfi
.uib.no
B.P.426
29275 Brest
Cedex
France
P.O. Box 1390,
Skulagata 4
•
•
Dr J. Piechura
DrM.Rhein
Prof T. Rossby
MrM.Stein
Dr W. TurreII
MrJ.P.
Vitorino
MrW.
Walczowski
Polish
Academyof
Sciences
Institut für
Meereskunde
an der
Universität
Kiel
Graduate
Schoolof
Oceanography
Bundesforschu
nganstalt f.
Fischerei
Marine
Laboratorv
Instituto
Hidrografico
Polish
Academyof
Sciences
,
Institute of
Oceanology
P.O. Box 6
Düsternbrooker
Weg 20
uI. Powstancow
Warszawy 55
81-712 Sopot
Poland
piechura@iopa
n.gda.pl
24105 Kiel
Germany
mrhein@ifm.un
i-kieI.de
University of
Rhode Island
Kingston R.I.
02881
USA
Institut für
Seefischerei
PalmaiIIe 9,
22767
Hamburg
Aberdeen
AB119DB
1296 Lisbon
Germany
uI. Powstancow
Warszawy 55
P.O. Box 101,
Victoria Road
Rua das Trinas
49
Institute of
Oceanology
P.O. Box 68
Tel.(48)-58517281 ext.313
Fax (48)-58512130
tom @rafos.gso
.uri.edu
Tel.(401)-8746521
Fax (401)-8746728
United
Kingdom
Portugal
turreIIb@marla
b.ac.uk
TeI.(44)-01224-876544
Fax (44)-01224-295511
81-712 Sopot
Poland
waIczows@iop
an.gda.pl
Annex E: Northwest Atlantic Sections
Savi Narayanan, Marine Environmental Data Service
Fisheries and Oceans
1202-200 Kent St., Ottawa, Canada
Introduction
In the following, the meteorological and oceanographic conditions that prevailed in
1966 off the Canadian east coast have been described. The data presented here were
collected by a number of researchers in Canada and compiled into time series for the
standard sections and stations (Fig. 1). Colbourne in Newfoundland, and Drinkwater,
Petrie, Prinsenberg and Peterson at Bedford Institute of Oceanography provided the time
series and diagrams for this presentation.
l\'leteorological Conditions
Air temperatures are monitored at Godthaab in Greenland, Iqaluit on Baffin Island,
Cartwright on the Labrador Coast, S1. John's in Newfoundland, and Sable Island on the
Scotian Shelf. The monthly air temperature anomalies at these sites relative to their
1961-90 mean (Fig. 2) clearly indicate the predominance of warmer-than-normal
conditions in 1996. At alt sites, the temperatures were either near normal or above
during the winter months as weIl as towards the end of the year. The net effect was that
the annual temperature anomalies at all sites were positive consistent with the
moderating trend which began in 1994 (Fig. 3).
The oceanographic conditions in the north Atlantic is closely linked with the large-scale
atmospheric circulation. It has been shown that the difference between the winter sea
level pressures between Azores and Iceland (referred to as the North Atlantic Oscillation
(NAO) index) is associated with the winter westerly winds over the northern North
Atlantic. Over the Labrador Shelf, a negative NAO index is associated with weak
northwest winds, warm air temperatures, and limited ice cover. The annual NAO index
anomaly (Fig. 4) for 1996 was strongly negative, reversing the trend of very high
positive anomalies of previous years.
The above normal air temperatures during the late fall of 1995 had the effect of slowing
the ice formation. Ice advancement was slower and ice was more broken up than usual
because of the warmer conditions for most of the winter and weaker northwest winds.
Consequently, the total ice cover south of 55°N on the Labrador Shelf, frequently used
as an index of the ice conditions in Newfoundland, was considerably lower in 1996 than
the previous years (Fig. 5).
Oceanographic Conditions
The area along cross-shelf transects off Newfoundland and Labrador, occupied by subzero temperature waters (referred to as the cold intermediate layer, or CIL), has been
shown to be significantly correlated with the air temperatures and ice cover, and thus is
an index of climate variability in the region. Recognizing the usefulness of this index in
monitoring the climate variability, the Department of Fisheries and Oceans occupies a
18
•
..
.series of cross-shelf transects in the July/August period of every year. The resulting
temperature transects are used to derive the CIL areas and the anomalies relative to their
61-90 means. The anomalies from the three standard sections, Seal Island, Bonavista
and Flemish Cap (Fig. 6) were all negative in 1996, thus continuing with the general
warming trend.
The temperature and salinity transects from the three standard sections are given in Figs
7, 8, 9. On the southem Labrador Shelf (Seal Island), the upper layers were slightly
colder and saltier, where as the intermediate and bottom layers were warmer and fresher
than normal. On the Newfoundland Shelf (Bonavista) as weil as on the Grand Banks
(Flemish Cap), the conditions were similar in that except for a thin layer at the surface,
the water was fresher and warmer than normal.
•
Data from the fixed stations off the Canadian East Coast confirm the continuation of the
warming trend in the northwest Atlantic. At station 27 located off St. John's,
Newfoundland (Fig. 10), the entire water column was warmer and fresher than normal
for almost the whole year' The low pass filtered time series of temperature at standard
depths (Fig. 11) elearly indicate that the doldrums of early 1990s is over and that the
conditions are improving. The salinity anomalies on the other hand were considerably
negative at the beginning of this decade, became near normal in 1993 and 94, but
reversed to negative at most depths. The heat and salt contents in the water column as
estimated by the vertically integrated temperatures and salinities at Station 27 also show
similar trends (Fig. 12).
The deep-water temperatures on the Scotian Shelf have also been bound to have
significant coherence at low frequencies horizontally from Laurentian Channel to midAtlantic Bight. Episodic intrusions of the warm slope water have been hypothesized as
the primary source of this variability. The time series that has been assembled from
Emerald Basin (Fig. 13) elearly indicate a number of such events, the recent one being at
the end of 1991 when the bottom temperature increased from about 70 C to 10 0 C.
Consequently, for the past 5 years, the bottom waters in the basin have been warmer
than normal.
At Prince 5, a long term monitoring station in Bay of Fundy, the temperatures at both
the surface and bottom were near normal and salinities weil below normal (Fig. 14).
19
-------------------------
-----
---
I
2COm ~,
5COm
\"
58'
'~,
I
I.
'1\
-.._~
~~
s ... l Xaland
~;,
..,:;
.
54i
52'
"
(
n·
~.Bonavl.t&..
~;
I,' --0.........".-:~.\
: ..
Station :t7'
.
.
50'
48'
\
'l'il------------.:. 1'1em1.h
Cap
."
48'
44'
42'
•
40'
70'
65'
SO'
55'
60'
\
45'
\\
Cabot
Slrait
',,-
"
;..:'.: . <.
\ ,
~.., "
'"
~
,
(>.,~. \
-,,\ "'., \,
'\ q '\
" "'",- ,
._';..o..c.:..---+-----....:\-"..::~:..-..: .--..:.I- 450
\
\
..--;'
c:::;v--
..
J-- ,'_•• Emerald
.
~.
Basin
.
...-....
'
••._ ...... OZOO"'··..-
--
Sable Is.
Georges
Bank
......
·--------1----------+---------.140°
Fig.1
Standard Stations and Sections • East Coast of Canada
20
•
•
..
Iqaluit
Godthaab
8
8
U 6
0'
~
!!. 4
e.
4
i!
2
i'
e;:,
e
-i
2
"
0
:3
•
!.
E
~ 0
E
I-
6
·2
-2
J
F
M A
M
J
J
A
S
0
N
J
D
F
Cartwright
M
A
M
J
J
A
S
0
N
D
St. John's
8..------------------,
8..----------------,
0'
6
-
4
l
!
::J
i!
!.
2
E 0
~
JF
MAMJJASOND
JF
-4
MAMJ
JASOND
Sable Island
8..-----------------,
U
6
-
4
i!
2
~
0
g'
c
!:3
!.
Fig. 2
Monthly air temperature
anomalies relative to
61-90 mean: 1996
JF
21
MAMJ
J
ASOND
Godthaab
Iqaluit
4,.----------------,
4
0' 2
CI
GI
e.
e
-8::;,
0
E
~ -2
t-
-44------...--------.----1
1930
1980
1880
-4
1880
Cartwright
4-r---------------,
0'2+---------~___;-____:_-__i
0'
CI
g'
GI
e.
~
e 0
::;,
~
f-t..--;--.I
•
2 -t---------------~
e.
0 + - - - - - - -.........~.t-7_;'t_+
8-
E
~
1980
St. John's
4-r--------------...,
e::;,
1930
"
+-:~~~-#-__;_;;N~.J_,.~Hn..5ri.'__l
8-
-2
E
+--------------J---._---J
~
-4+--..,.---.---.---.----...-~
-4+---...----._-....----,---....--~
1880
1900
1920
1940
1960
-2 + ' - - - - - - - - - - - - - - - - 1
1880 1900 1920 1940 1960 1980 2000
1980. 2000
Sable Island
4,--------------,
0' 2 - t - - - - - - - - - - . , . . . . . - - - - - - I
CI
GI
e.
~
::;,
~
O-t----':-'~
8-
Fig. 3 Annual and 5-yr running
means of air temperature
anomalies at selected
E
~ -2 - t - - - - - - - - - - - - - - - - j
-4+---r--__.--~-_.__-__.-__I
sites
1880 1900 1920 1940 1960 1980 2000
22
•
•
.
I
I
,
I
I
--_.--- - Fig. 4
20
15
co
~
10
5
c:
0
~ -5
c
c. -10
-I
cn
-15 .
-20
1880
-
G)
(,)
--------------------.-----_.-.- '--l
NAO Index Anomalies
_._-----_._._-
.....
:~
.
"
"
"
G)
'
~
N
w
.._··· ...
1900
1920
1940
Year
.
.,
- '-~'
...
.!
,
"
.. ..
1960
1980
-----
2000
.
Newfoundland Shelf lee Coverage
450-r------------------------.
•
400
350
300
,-....
cn
E ] 250
~
~
• ::s
~ .8 200E-..-
150
100
50
O-+--....L-l-'r-U-u...l..L....u..J..f-lL..l...L..U.-.~...lJ..L.L...Ll..-:u.J.J,.J...L.J..JU.L..JU_.I.Ir..u....u....u..LL....Lt_.LI..-lI-....u.-uL...l+_&.l-I--~
1960
1965
1970
1975
1980
1985
1990
Fig. 5 Time series 01 the monthly mean ice area off Newfoundland
and Labrador (between 450 N-550 N)
24
1995
2000
.
•
Seallsland
-g
30
E 20
~ 100
-;; -1 0
..--------------------~
.
: : .. : . : . : .. : : . : : : : . : : : : : : . : . : :
! -20
4(
.
~
:
: : : . : : : : : .. : : : : : : : : : :
,
V: ::::
.
-30 +----..-~---.-------r-----------I
1950
1960
1970
1980
1990
2000
Bonavista
_
30
E 20
.---------------------~
,
~ J ::::::::::::::::::::::::
e -20
lIl(
'.'
.
:!SrV::: : : : .: : : : : .: :: :
.
-30 -t----..------,----....-----'--.---~
1950
1960
1970
1980
1990
2000
Flemish Cap
E
i
-e
30 - - r - - - - - - - - - - - - - - - - - - - - - - - ,
20
.
1~ ~~::.::.:.::: .. ::::::::::::.:.::.:: .. :~:::~~:~:~:::
CG
-10
lIl(
-20 . . . . . . . . . . . . . . . . . . .. .
.
-30 -+-----,----...------.------,-------/
1950
1960
1970
1980
1990
2000
Fig. 6
eil area anomalies relative to 61·90 average
25
j
0~~~~~~T:l
-,.~~üI "~
o
o
..
.rP
0
,;)
",
o
_0
:IN
---:rll"lo
~N
0-
Wo
/j
°0
O"l
o
,..,lI"l
\
JJ ___
o
o
~
JULY 1996 SEAL ISLAND T(t.1PE:RATURE
gl--~-.-----,----.--..,.---r--.----r---,-.L.---,---.---r--.---~
1l"l0
25
50
75
100 125 150 175
DISTANCE
0~~:--~77~~",~~~~T-7T7T.;:::=::~~0::::-1
o
lI"l
o
o
o
Il"l
o
_0
:IN
---:rll"lo
~N
0-
..... 0
°0,..,
o
lI"l
O"l
o
o
~
.....
JULY 1996 SEAL ISLAND TEt.1P ANOI.IALIES
g+--...--r----..--,--..,.--.------,,..---,----r'---,--..,.--.---....:.....,.-~
Il"l
0
25
50
75
100 125 150 175 200 225 250 275 300 325 350
DISTANCE (KM)
Fig. 7a The vertical distribution of temperature and temperature anomalies
along the standard Seal Island transect tor the summer (July) ot 1996.
26
•
O..-----r-r--r---------------=:::::0'7.77TJTrr---------,
o
10
o
o
o
10
o
_0
~N
......,
o
:r1O
.... N
a..
Wo
°0
r<')
o
10
r<')
o
o
~
o
Il'l
~
JULY 1996 SEAL ISLAND SALINITY
8+--..,--"-T""---.----r--.----.--.---.,...--""T"--..,--.,-----,-----r----1
1l'l0
25
50
75 100 125 150 175 200 225 250 275 300 325 350
DISTANCE (KM)
O~~~~~~:::J
o
10,
o
o
o
10
o
_0
~N
......,
o
:r1O
.... N
a..
Wo
,..,
°0
o
,..,
Il'l
o
o
~
o
Il'l
~
JULY 1996 SEAL ISLAND SALINITY ANOt.AALIES
8+--...,..--..,--"-T""---.----r---r----.--.----r'---r--...,..--..,----,---~
10
25 50
75 100 125 150 175 200 225 250 275 300 325 350
0
DISTANCE (KM)
Fig. 7b The vertical distribution 01 salinity and salinity anomalies along the
standard Seallsland transect for the summer (July) of 1996.
27
o
o
o
If)
o
....... 0
:(N
'-'"
o
::I:1f)
li:
N
Wo
°0
t")
o
ll")
t")
o
o
~
o
ll")
~
JULY 1996 BONAVISTA TEI.4PERATURE
o
O+--,..--r--.----,,----,---,---,----,.----,.-~-___.._-__r-~-_l
ll")0
o
25
50
75
100 125 150 175 200 225 250 275 300 325 350
B§~~~~~~~~D~IS~TgA~NC;E=(K=M::)~-~:_:_~T::::::::;--1
o
ll")
'-/l{.
o
o
ll")
o
....... 0
:(N
'-'"
o
:I:ll")
..... N
Q.
Wo
°0
.... :::--- .. ,~ .• /~
;1
o
/
:
....
~c·
~ 0J l'~
)
~
---------,'----0:
"'-.. -, "
~,~
I :'
~
~
\
t")
o
ll")
t")
o
o
~
o
ll")
~
o
JULY 1996 BONAVISTA TEI.4P ANOMALIES
o+--,..--.--,----,---,----,.----,.--.---.--....l...r---.----.---.,...--J
ll") 0
25 50
75 100 125 150 175 200 225 250 275 300 325 350
DISTANCE (KM)
Fig. 8a The vertical distribution of temperature and temperature anomalies
along the standard Bonavista transect for the summer (July) of 1996.
28
·.
O,-------:,.--------y---~------....._-_r_'__..,,..__r_--..,
o10
o
o
o
10
o
_0
:iN
.....,
o
:I: 10
t-N
Q.
...... 0
°0
I"l
o
10
I"l
o
..,
o
..,
o
10
o JULY 1996 BONAVISTA SALINITY
o+---.----.----.----.---,---....._--r---r"--r"-Lr---r"--r"--,--~
IOD
o
10
I"l
o
o
..,
o
..,
10
JULY 1996 BONAVISTA SALINITY ANOMALIES
25
50
75
100 125 150 175 200 225 250 275 300 325 350.
DISTANCE (KM)
Fig. 8b The vertical distribution of salinity and salinity anomalies along the
standard Bonavista transect for the summer (July) of 1996.
29
·.
O~--"-r,;----r-------~----r--r--r---,.----:-----,r-----=:>---.
o
QJ
o
-
N
o
,.....ID
:::1......
o
:r:O
'-N
a..
GRAND BANK
l.l
O~
N
oQJ
N
o
N
I"')
o
<D
I"')
GRAND BANK
oQJ
N
o
N
I"')
o
<D
I"')
o
O+---r---r---r--~-,.--,.--,.--.---l-.--L-.---r---r--~-l.~--I
~O
Fig.9a The vertical distribution of temperature and temperature anomalies
along the standard Flemish Cap transeet for the summer (July) of 1996.
30
o,.--,..------,----------r--r-r-r-----,-------r---r,-,
o.....
o
00
o
N
o
_co
2'-'
o
:rO
~N
a..
GRAND BANK
Lo.I
0 O
.....
N
o
00
N
o
N
I"l
o
co
I"l
o JULY 1996 SALINITY
o-l---.,......--.---r---,----,---,--.--r-..L-!.r--'-.,......--r----.----,--L-,.--!
..... 0
50
100
150·200
750
o
.....
o
00
o
N
o
_co
2'-'
o
:ro
~N
a..
GRAND BANK
Wo
0 .....
N
o
00
N
oN
FUI.IISH CAP
I"l
o
co
I"l
o
JUL Y 1996 SAlINITY ANOI.IAUES
O+----.---.,......--.---.---.----.-----,r---r--'--..--~.,----.---r---.---l--,-----l
..... 0
50
100
150
200
250
300 350 400 450
DISTANCE (KI.I)
500
550
600
650
700
750
Fig. 9b The vertical distribution of salinity and salinity anomalies along the standard
Fremish Cap transect for the summer (Jury) of 1996.
31
C! ...u...,
..::.S..:..:TA..:.;T..:.;IO:.;N.:--:2:.:.7_..:..1.:..99:..:6:-...:T.::.E;,::M.:-P....:A:.;:N..:.;O:.;M;,::A..::L:.:.Y
-.
000 1.4
0°
w":
o
°
a.. •
.. 'l!,':::'::·!!:·':·:':·'·!!::·:::::Ä::::::)!;:::::"~'::::.~~ :...:::,l(.:::....•Ä-,::::)(::::.-Ä..::..::..~ ...
:::i-
w'
1-
U
0
t"i +---<---'-.1...-.-.1...-.-'----'-'-----'---'---'---'---'---0....1.- ---11.4
20
~~
.-.-:::::!!:::::::."J!:'::::::!::::::::~~:'.'.'.''-~'-'-'-'-~:~:::::·:Ä ..::::;;;.::....:~::::::;r;( ..
..:o..::::::!!.
~I
1-
0 +--..L_--'-_'-----'-_-'--..L~--'--'-----'----'----J'----.j
U...,
0°
w":
o
°
a.. •
:::iw l
1-
0
u...,
+-_i.-_'-----'_--'-_----'-_-'-_.....I.-_....I.-_-'--_.L.----J'---I
0°
w":
o
•
°
a.. .
~I
I-
lf?
u
~ ci
Li')
J'F'M'A'M'JIJ'A'SI.OIN'D
:n:····..·:n:··..·..):(··.. ···~······.Ä
••••• ••• _
_
~
.
:n:···..··):(·.. ····Ä
075 M
)!(· .. •.. -):(
·Ä
_
.
a.. .
:::i l
w
°
I-lt)
+---'-_-'--_'---'-_--'--_.1._--'-_'----r!--.L.._-'---'_---.j
U -
~ ci .. ~;:::. ::~::::::~::::::~:~~:::~.::::::~::: ::~ ~. ~::~~
.' ..'
lt)
a.. .
100 M
~:~ .-:::~.:..-::::..
w'° +-_-'-_'-----'_--'_----'-_-'-_.....I.-_....I.-_i.-_.l...-._'---I
:::i
I-lt)
u
150 M
~ ci ...~:::. . ::~::::::~::::::~:::::::~::::::~:::::::~::::: . :~::::::.-~::::.-: . ~:::::::)1:::::::~ ...
a.. •
w°
lt)
:::i
l
I-lt)
+-_.l...-._'-----'_--'-_----'-_-'-_.....I.-_....I.-_i.-_'------''---I
u
olt)
~ lt)
ci
a.. .
175 M
.. ~
:._..:
J
r
~ ~ ::: ~ :::::..~.:::::::~: :::!!".::::::~::::::}1.-:::::::n: m.~::::::~ ..
w'°
:::i
l-
MA
MJ
JAS
MONTH
0
ND
Fig. 1Oa Time series of the monthly temperature anomalies at Station 27 at standard
depths during 1996.
32
•
..
STATION 27 1996 SALINITY ANOMALY
~
000 t.1
>-"ot.
.-
ZO
:J"ot
< .
(/)0
I
~
020 t.1
>-"ot.
.-
ZO
:J"ot
< .
(/)0
:··.::;::::::X:::::::j::::::;Jt:·······)!(·······)!.,··: ::::~::::··,)i,::::::.'i!...:·::::.Si..·.::·.:·.Ä···
···)(·..
I
~
030 M
•
>-"ot.
.-
ZO
:J"ot
< .
(/)0
I
~
050 t.1
>-"ot.
.-
ZO
:J"ot
< .
(/)0
··)::(:::::.:;:::::::)l;::::::Ä::::::~::::::Ä::::::;::::::Ä::::
. . .;:::::::~ ..._"'~ . _. . :~ ..
I
~
J
I
F
I
MI A
I
MI J
I
J
I
AIS 10 I NI D
075 M
>-"ot.
.-
ZO
:J"ot
< .
(/)0
I
C'!
100 M
>-"ot.
.ZO
:J"ot
··A::::::·7!.···.-·-··_··Ä·...:::::~:::::::)(:::::::;:::::::;;:::::::;:::::::~:::: ....:Ä::::::·Ji.::::::."ji,···
<t •
(/)0
I
C'!
150 M
.- .
>-~
ZO
:J~
<t
•
...ji,.-:::::.Ji.::...-:...11......::.:"ii..:.:..'.::'-ji'.::':.:"ii...:'.:::'.:;.'.::':.::;;.:::'.:'.;;.::::::"iic::::::-;;::::::
n'"
(/)0
I
C'!
>-"ot.
.ZO
:J~
<t
•
175 M
··"){:.-..:.-.-~·········.-·1(·.-::·:·:ii·::·:·::ii:.·:::::··~·::::::~···::·:·:;i;·:::·:·:ii·'-'-'-'-'-'-~·.:·:'-.·.·;:·.:·.:·.-~···
(/)0
I
Fig. 10b Time series of the monthly anomalies at Station 27 at standard depths during 1996.
33
..
STATION 27
TEt.4P ANOt.4ALY TIt.4E SERIES
u,...;,--------------------------,
°
0
°
..... ..;
o
°
0..
•
~i
1-
0
U,...;i1r--;---+----~-----------l-----,r---l
0
..... °
..;
o
o•
0..
~i
1-
10
u~t_---..:-..:.----L-----f---...:.-L1Hl----~
0
10
~ci
0..
10
•
:::l0
..... 1
I-II'J
~ -r------------------..:.------1
U
0
10
~ci
•
10
?i o
..... 1
I-
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
STATION 27 SALINITY ANOt.4ALY T1t.4E SERIES
II'J-r---------------------------,
000 M
>-10
I.
:zO
:JIO
« ,
Vl<j'
II'J_t_----------------~-~f------l
>-10
~ci
:JIO
;;;0I
o+---------------------------.j
ID
>-N
~ci
:JN
;;;0I
~-t--------------------------l
I- .
:z0
>-N
:JN
« .
VlO
I
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
',rAP
Fig. 11 Time series of monthly temperature and salinny anomalies at Station 27 at standard
depths from 1970 to 1996. The heavy Iines are the low-passed filtered time series.
34
•
------ - - - - - - - - 1
..
~
-
S27 0-175 M DEPTH AVERAGED TEMP
lI')
,
........
u~
,0
e"
WlI')
Q
•
,
-0
o..N
:i ,
~O
N
ci
I
lI')
ci
I
55
58
61
64
67
70
73
76
79
82
85
88
91
94
97
~
N-,----------------------------.,
S27 0-50 M DEPTH AVERAGED SALINITY
I")
~
N
I")
N
N
I")
::>C!
(/)N
0..1")
•
I>-~
- _
zl")
::::;\0
-0(
•
(/);;)
"'f
55
58
61
64
67
70
73
76
79
82
85
88
91
94
97
YEARS
Fig. 12 Time series of the vertically averaged (0-176 m) Station 27 temperature and the vertically
averaged (0-50 m) summer (July-Sept.) Station 27 salinity. The dashed Iines are the three
year running means.
35
..
Temperature
14 . , . - - - - - - - - - - - - - - - - - - - - ,
u
12
~
+------------1~---------f
c
-~ 10
-
... ------------:-6III"&,l--t'~~
~
E 8 + - - -........-"1
~-=-----J ~-'f'-~& r-----'--\-t----1
(1)
~ 6 +------1~-_V'__I---------___I
(1)
I-
4+---...---...---...---...---,------i
1960
1940
1950
1970
1980
1990
2000
•
Temperature Anomaly
5-r----------------------,
-4+--------------;~-----___l
()
0)3-+------------11----------1
~2+-------------:-1I-.-..-----..~--+L~
~
~
1 +------.----~-.
0
~-_V'm4l~-~~+_=_-=--..:..-_l
E
-1 +-----V-..~HllI.-_a~-+-.·_...--_at--_I
~ -2 +------1~~_W_----+----.:...-_I
E -3
(1)
I-
-t-------.l
1940
Fig. 13
-'W-~--------____f
-4 ; - - - - - - - - - - . . - - - - - - - - - _ 1
-5 -+---..,---...---,.---...---...------f
1950
1960
1970
1980
1990
2000
Emerald Basin, 250 M temperature and temperature
anomaly
36
•
Temperature: OM
Temperature: 90 M
2r----------------.
2-r----------------,
•
u
u
~
~
f
t
~
...!
0
::l
i
~
•
0
~
I-
·2
1920
1940
1960
1980
-2
1920
2000
. ..
-'--.::.
.:..-
• -
~
0(
•
~
•
0
2000
0.4 -+-....- - - - - - - - - - - - - - 1
~
I
::: '
I.
~ 0.2
'ii 0.2 t--7--'----:---fr--...---tf--\c-":-........- - i
8c:
1980
0.6,--------------,
~-----------____.
0.4 +-_...L
1960
Sallnlty: 90 M
Sallnlty: 0 M
0.6
1940
E
oc:
t-~....IIIP."r-.,--:.-\:1H_;J't:-..,....-t:if"li::--t
0(
~
c:
c
0 +---:-..J.---'-#Ä-"':-r-iF-~-"~
~ -0.2 -f----.-----f----'--'o--,/--~-L
. .4-.--l
~ -0.2 -j---:=------7-w--'---,~--'i---.r\..._1
. ..
~
·0.4
-0.4 - + - - - - - - - - - - - - - - - ' - 1
-0.6 +----.-----.------.-----1
1920
1940
1960
1980
2000
-0.6 +-----,.----.------,.----1
1920
1940
1960
1980
2000
Fig. 14 The annual and 5-yr running means of the temperature
and salinitiy anomalies for Prince 5
37
..
Annex F: Results from Icelandic Waters
Svend-Aage Malmberg, l\1arine Research Institute,
P. O. Box 1390, Skulagata 4, Reykjavik, leeland
Introduction
The sea around Iceland is divided into various sectors, such as thc Iceland Basin to the
south, the Irminger Sea to the west, the Denmark Strait bet\veen Northwest Iceland
and Greenland, and thc Iceland and Norwegian Seas north and east of thc country.
These seas are all part of the Atlantie Ocean; the area south of the submarine ridges
between Greenland and Scotland being part of the North Atlantie, while the area north
of the ridges is part of the Nordie Seas.
Iceland is situated at the meeting place or fronts of warm and cold ocean currents,
which meet at this point because of thc geographical position and the submarinc
ridgcs, which form a natural barrier against thc main ocean currents around thc
country. To thc south thcsc eurrents arC warm (6-8°C; Irminger Current) and to thc
north thc sea is eold (-I-2°C; East Greenland and East Icelandie Currents). At the
eontinental shelf there is a eoastal eurrent which flows clockwise around the country
and is created by thc mixing of thc ocean eurrents with fresh water from thc land.
•
Finally, there arc also deep and bottom currents in thc sea around Iceland, principally
thc overflow of deep cold water from the Nordie Seas south over thc submarinc ridges
into thc North Atlantic.
Hydrographie Conditions
a) North Icelandic 'Vaters 1924·1995
Aseleeted hydrographie station in North Icelandie waters (S-3, Figs 1, 2) has been
used to characterizc the hydrographie conditions from year to year. At these stations,
Atlantie watcr (t>4°C; S>34,9) dominated during thc periods 1924-1964, 1972-1974,
in 1980, 1984-1987 and 1991-1994. The latc sixties as weIl as shorter periods
thereafter (1975-1979, 1982, and 1988) were prominently characterized by Polar
influenee, frequently manifested by thc appearanee of sea icc and Polar water and by
somc biological eonsequences in North Icelandie waters. During the years 1981-1983,
1989-1990 and most severely in 1995 thc hydro-biological eonditions werc extremely
unfavorablc and of neither Atlantie nor Polar charaeter, but with a relatively
homogenous water of an Arctie character (t=0-3°C; S-34,8-34,9). A continuous
temperature recording in the sea at thc island Gfmscy in North Icelandic waters during
the years 1987-1996 (Fig. 3) reveals the hydrographie eonditions in North Icelandic
waters as low winter/spring temperatures in 1988 and 1995 and relatively high
temperatures in 1987 and 1991-1994 with an unusual interruption in fall 1993 when
the Atlantic inf10w into these waters was totally hampcred for some time in the
Denmark Strait area.
38
•
..
b) South Icelandic Waters 1971-1996
In the warm waters south of Iceland periods of relatively high and low salinities occur.
Noteworthy were the low salinities observed in the mid-seventies (Great Sa1inity
Anomaly), and again at least in 1988 and after 1992 (Fig. 2). Along with low
salinities in the area low temperatures are also generally observed.
Conditions in 1996 (Figs 4, 5)
•
Following extreme cold conditions in Icelandic waters in winter and spring 1995
temperatures rose again in winter 1995-1996 and remained in 1996 near the average
all around Iceland, but salinities was rather low. Thus sa1inity in the East Icelandic
Current was in spring below 34,7 indicating apolar character of the current (Fig. 2).
In spring 1996 Atlantic water reached the Siglunes section in North Icelandic waters at
depths below 100 m, but the surface waters were influenced by freshwater from land.
During summer and fall a layer of low salinity polar water penetrated the surface
waters north of Iceland. However, in the deeper layers Atlantic water had reached the
Langanes section northeast of Iceland at that time. The nutrient concentrations in
1996, during the spring survey, were high in the waters all around Iceland except of
the north coast where the spring bloom was over. The zooplankton biomass was high
in these waters except off the south coast in 1996, though a downward trend is
indicated by the long-time series both in South and North Icelandic waters. The
Atlanto-Scandian herring was observed at the eastem and southem boundaries of the
cold East Icelandic Current, in spring 1996 as in 1994 and 1995.
•
39
•
•
1924 '26'36 ':57'47 ':12
198:1
19:1:1
1960
1970
197:1
1980
1990
196:1
1995
IO· r-r-,-.,.---r-,-r-r-,-.,.---r-,-r--r-,--r--r---r-r-r-,-.,.---r---r--rr-r--r-.,.---r---r-r-r--r-,---r---r--rr-r-r-,-,.--r"-T-,-r--r-,-.,.--r-""""'-r--1 10·
'oe
,
5°
,,
I
\ ","
'"
,
~.
T. 2.BO·
I
O·
O·
S·34.99
35.0
S
350
I
I
I
ATLANTIC WATER
34.5
345
POLAR WATER
34.0
340
1924 '26':56 ':57 '47 ':12
1955
1960
1965
1970
1975
1980
198:1
1990
1995
..
o
FRAvlK
·0
tJl
ü5
(j)
tJl
lö
•
-J
o
lö
-J
tJl
lö
(Xl
o
<Il
Gi
r
tJlC
0 2
3
lö
VI
(Xl
tJl
•
rr1
<Il
t
~~
~
C
::0
~
<Il
rr1
1
< 1/
-0
OGl
O<ll
3 lD
t>
2
~
tJl
.....
N
tJl
3
lö
w
o
rr
(')
tJl
VI
VI
.tJl
""-J
üi
~
o
tJl
SELTA
Fig. 2
Salinity deviations in spring at
a) 100 m depth in the Irminger Current south oflceland (1971-1996);
b)
50 m depth in North Icelandic waters (1961-1996);
c) 25 m dcpth in the East Icelandic Current (1961-1996).
41
..
l.C
o
C1l
~
I\)
CD
.....
CD
Q)
......,
.....
CD
Q)
Q)
.....
CD
Q)
~-~----------
=-:::~E=r-=~
CO
.....
CD
CD
~
--~=~===:;;::=:.....:~
o
•
~~
.....
CD
CD
.....
.....
CD
CO
~
l\)
.....
CO
CO
..
tu
~
OE-
.....
CD
CO
-
~---­
~
,:::..
......
CD
CD
U1
.....
==------------::==~==-==
~
CD
CD
0'>
Fig. 3
Annual and seasonal variations in sea surface temperature (Oe) at Grimsey, North Iceland, in
1987-1996.
42
e
.
.
'"
"j
'"~
'"0:
'"
'" q
"l
"I
'"~
'"0:
III
0
N
N
u:
~
q
q"
".
".
N
•
Fig. 4
'""I q
Sea temperature (oe) at 50 m depth in Icelandic waters in
a) OctoberlNovember 1995,
b) Febmary 1996,
c) May/June 1996,
d) August 1996.
43
...~. :
•
.-Je:
",'---'--...L-'---.l-"..--'--.l-.-J-_",i.--L---'---"-.l-",
['--~-r-r -~-"'+-i ~-,-~-':;~~~q
~
er
.
•
Fig. 5
Salinity (S) at 50 m dept in Icelandic waters in
a) OctoberlNovember 1995,
b)
February 1996,
c) May/June 1996,
d) August 1996.
44
.
.
Annex G: West Greenland Sections
Erik Buch, Farvandsvresen et Overgaden o.
Vandet 62b Postboks 1919,
1023 Copenhagen K, Denmark
The climatic conditions at Westgreenland has for most of the 1990'es been
characterized by long periods with negative temperature anomalies in the atmosphere.
Especially during wintertime this tendency has been very pronounced. I 1996 however
slightly positive temeprature anomalies were experienced during wintertime while
weak negative anomalies characterized the summer, Fig. 1.
Temperatur anomali ved Nuuk I Godthaab
•
5
o
-5
-10
-15
1980
L-~~~_~....1-~_~~~---I_~~~_~..I.-~~_~~--'
•
1985
1990
1995
2000
Fig.l Monthly mean air temperature anomalies from Nuuk for the period 1980 to 1996
The Westgreenland Standard Seetions were surveyed during the period 24 June - 6
July 1996.
The mild climate was reflected in the temperature conditions of the surface layer; Fig.
2.
The surface layer off Southwest Greenland was dominated by inflow of Atlantic
water. Off Cape Farewell and Cape Desolation extraordinary high surface
temperatures and salinities (T>7°C, S> 34.8 psu) were observed. Polar Water was only
observed very dose to coast.
45
..
Scatterplot (FYL.STA 5v*58c)
3.0
2.5
·.
··
2.0
1.5
..
1.0
0.5
O.~9'-50~~~1-l96-0~~~19...1.7-0~~~1-9..L.8~0~~~1-9.L-90~~~2-l000
-0-
TEMP
RUN_MEA3
YEAR
•
Fig.2. Mean Temperature on top of Fylla Bank, Medio June 1950-96
Observed values
- - - - - 3 years running mean
0-----0
The deeper layers were also dominated by inflow of water of Atlantic Origin, quite
large volumes of water with temperatures above 5°C was observed. Pure Irminger
Water (T>4.5°C, S>34.93 psu) was present at the three southemmost sections, while
modified Irminger Water (T>4.5°C, 34.88<5<34.93) could be traced as far north as
between the FyllaBand and the Sukkertop Bank seetions. Subatlantic Water
(3.5<T<4.5, 34.5<S<34.88) was in 1996 present on all seetions.
•
46
Annex H: The state of Faroese waters in 1996
Bogi Hansen, Fiskirannsoknar stovan
P.O. Box 3051, Noatum, FR-I10 Torshavn
Faroe Islands, Denmark
•
Figure 1 shows the four standard sections that
are operated by the Faroese Fisheries
Laboratory (Fiskiranns6knarstovan) and are
usually occupied by CTD observations at least
four times a year. The sections cover the
Atlantic water inflow to the Nordic Seas
between Iceland and Scotland. Since the end of
the eighties, this water has freshened
considerably and also become somewhat
cooler. This is best illustrated by average
characteristics for the 100 - 300 meter depth
layer in the Faroe Bank Channel (white circle
on Fig. I), which is considered to represent
water of generally pure Atlantic origin,
deriving from the North Atlantic Current (Fig.
1).
Figure 2 shows observed
alinity and
. deseasoned" temperature for this layer during
the la t two decades. Since the mid-seventies
("Great") salinity anomaly, the salinity of this
water increased and generally exceeded 35.25
until the decrease in the early nineties. Figure 2
includes CTD observations from 6 cruises in
1996 and one in February 1997. It appears that
the salinity decrease has stagnated; but there is
no clear evidence for increasing salinities
again, although the observations from the latest
years have not showed salinities as small as those
observed in 1993 and 1994.
Fig. 1. The bottom topography around the Faroe
Islands is indicated with the shallow areas shaded.
The main flow in the upper layers is by arrows and
the Iceland-Faroe Front by a dotted curve. The four
standard sections (N, E, Sand W) are shown by
thick lines and the white circle indicates the area in
the Faroe Bank Channel from which the data in Fig.
2originate.
9.5 , - - - - - - - - - - - - - - - - - - ,
"Deseasoned" Temperature 100·300m
depth in the Faroe Bank Channel
9.0
35.30
35.25
8.5
35.20
8.0
35.15
1975
Salinity 100·300m depth in
the Faroe Bank Channel
1985
1995
7.5 +---"'T'""---"'T'""---"'T'""---~-----I
1975
1985
1995
Fig. 2. Salinity (Ieft) and temperature (right) averaged over the 100 - 300 m layer in the middle of the
Faroe Bank Channel (white circle on Fig. I) based upon CTD observations. Temperature has been
"deseasoned' by subtracting the typical seasonal variation. Filled circles connected by bold lines on Jeft
graph show annual averages of salinity while thick horizontal Iines on right graph show temperature over
two 5-year periods and the period 1996 - Feb. 1997.
47
..
The observations of temperature in the 100 - 300 m layer of the Faroe Bank Channel (righthand graph
on Fig. 2) make a fairly noisy time series even though the data in Fig. 2 have been "deseasoned". The
five-year averages shown in figure 2 indicate that the 1991-95 period was slightly colder than the 198690 period while the average temperature for the 1996-97 observations had increased. The large
variability reduces the significance of these conclusions. The coastal observations of sea surface
temperature (Fig. 3), on the other hand, clearly indicate a warming of the waters on the shelf in 1996,
but no analysis is available to establish how much, if any, of this is due to warming of the surrounding
oceanic waters.
.-rl
9
Oyrargj6gv
..."'0"
Mykinesh61m ur
~
U
-.
=
~
"
8
~~
Fig. 3. Annually averaged coastal observations
of sea surface temperature in the Faroes at two
fairly close locations: Mykinesh61mur 1914 1969 and Oyrargj6gv 1991 - 1996.
V
:::
t:~
~
~
-.
"1:
~
T.'
ij
7
~:
1910
1930
1950
1970
•
1990
•
48
.
~
Annex I: Results from the Scottish Standard Sections
Bill Turrell, Marine Laboratory
P.O. Box 101, Victoria Road, ,
Aberdeen, Scotland, ABl19DB
Introduction
The two standard Faroe-Shetland Channel sections (NoIso (Faroe) -Flugga (Scotland)
and Fair Isle (Scotland) - Munken (Faroe» have been occupied by the Marine
Laboratory Aberdeen on three occasions since April 1996; May/June 1996, October
1996 and March/April 1997. In addition the North Sea JONSIS section was also
occupied during these surveys (Fig. 1).
•
The results presented here are based on the definitions of time series presented in a
section below. These definitions are not ideal, and are being further developed.
However they may be used to give an indication of ocean climate change in the areas
monitored by Scottish standard seetions until April 1997.
Summary of Results
Smface Waters
North Atlantic \Vater (NA W) at the Scottish shelf edge (Fig. 2) has been warming
.since 1987 at a rate of O(0.5°C/decade). This is arecent more rapid warming imposed
on a warming trend which commenced in 1966 and has continued at a rate of
O(0.3°C/decade). Salinity of NA\V has demonstrated great variability since the end of
the low salinity anomaly (GSA) years in the late 1970s, and this variability may be
related to the NAO index. There has possibly been a gradual overall salinity increase
since the GSA period with salinities now approaching 1960 values. The most recent
change is a more rapid rise at a rate of O(0.2/decade) since 1993.
•
Modified North Atlantic \Vater (MNA\V) has demonstrated quite different changes
compared to those of NA\V (Fig. 3). There has been a general cooling of MNA\V
since 1960 at a rate of O(0.3°C/decade). Salinity has also decreased since 1960 at a
rate of O(0.02/decade), with a more rapid decrease evident since 1991. Salinities are
beginning to approach those values observed during the GSA period.
Intennediate Waters
Trends in temperature cannot be determined in intermediate waters using the present
definitions, but salinity continues to decrease (Fig. 4). In the Arctic Intermediate /
North Icelandic \Vater (AIINIW) salinity has decreased at a rate of O(O.OI5/decade)
since 1975. The salinity of Norwegians Sea Arctic Intermediate \Vater (NSAIW) also
continues to decrease at a rate of O(0.02/decade). This decrease commenced in 1975
and is twice the rate of the decrease in the bottom water.
Bottom Water
49
,.
Faroe Shetland Channel Bottom Water (FSCBW) again still demonstrates the salinity
decline at a rate of O(O.Ol/decade). The warming observed at 1100 dbar which
commenced in 1990 has now stopped (Figs 5 and 6).
In the North Sea the salinity variability in the past has been weIl correlated with that
of NA\V, with a possible 1 year lag. However, unlike NAW, the salinity of Fair Isle
Current \Vater (FICW) has more recently demonstrated a differing trend, with FICW
salinity decreasing since 1973, while NA\V salinity is generally increasing (Fig. 7).
Also unlike NA\V, FICW demonstrated a cool episode in the mid 1990s which has
nowended.
The properties of Coolcd Atlantic \Vater (CA\V) which typifies water lying within the
central northern North Sea below the seasonal thermocline, are more closely tied to
those of NA\V (Fig. 8). Hence CA\V does demonstrate the gradual warming seen in
NA\V since 1970, and the more recent salinity variability seen in NAW is reflected in
that of CA\V. One difference noted is that while the salinity of NA\V has risen since
1993, CA\V salinity has declined. This may imply reduced oceanic inflow to the North
Sea presently.
•
Dramatic Change in March 1997
A final result of some note is the great change observed within the Fair Isle Munken
line during the March/April 1997 cruise. Figure 9 shows the contoured sections of
tcmpcrature along the two standard sections. These two lines were survcyed 4 days
apart duc to scverc weather halting operations. The northerly Nolso - Flugga line was
surveyed first (23-24 March 1997), followed by the Fair Isle Munken line (27-29
March 1997). As can be seen the isotherms in thc southern section are displaced
upwards against the Faroesc slopc. This implies an incrcascd southerly transport
against thc slopc. The es characteristics of AIINI\V (Fig. 10) are significantly altered.
NSIW is no Ionger marked as a salinity minimum. It is now represented as an
inflection, but of lower temperature than in lune 1996. AIINIW is now seen as a
salinity minimum, with salinities 0.12 less than in lune 1996. This represents a
significant reduction in intermediate water salinity. Its cause is not yet known, but
may be connected with thc increased southerly transport of intermediate water
associated with thc upward displacement of the Fair Isle Munken isotherms.
Time Series Definitions
Time series from 5 characteristic water masses which occupy the Faroe Shetland
Channe1 are prcsented in Figs 2 - 6 and for 2 North Sea water masses in Figs 7 and 8.
The methods employed to define the water masses, and to derive the time series are
described below. Please note that these are preliminary definitions and may alter.
Surface Waters:
North Atlamic Water (NAW) (Fig. 2) - Thc temperature and salinity at the
50
•
.
'
. ..
standard pressure level which exhibits the maximum salinity w~thin an
individual survey of the most southeasterly two stations, on both standard
sections, on the Scottish side of the Channel.
The criteria was designed to produce the characteristics of the North Atlantic
water lying within the Slope Current at the Scottish shelf edge. North Atlantic
Water is typificd by a salinity maximum on a 8-S diagram. This water most
probably originates west of the UK, in the Rockall Trough, and hence may be
most closely related to North East Atlantic Water (NEAW).
Modified Nortlz Atlalltic Water (MNA W) (Fig. 3) - The temperature and salinity
at the standard depth which exhibits the maximum salinity within an
individual survey of the first two stations, on both standard sections, on the
Faroese side of the Channel.
•
These criteria were defined in order to characterise Modified North Atlantic
\Vater, the water mass which composes much of the surface waters of the
Channel, and encompasses the anti-cyclonic flow of warm, surface water
around the Faroe plateau. These waters most probably originate in the subtropical gyre, west of Rockall, and hence may more cIosely follow conditions
in areas influcnced by the North Atlantic Current. This water again is
identified on a 8-S diagram as a salinity maximum for waters on the Faroese
side of the Channe 1.
Removal 0/ seasonal cycles: As the surveys over the past century have been
done at quite different times of the year, the effect of the seasonal cycle in the
surface waters has been removed using the monthly mean t and S derived over
the period 1960-1990. These means have been calculated for each individual
station and at each standard pressure level, and subtracted from the individual
observations resulting in plots of t and S anomaly from the mean seasonal
cycle.
Intermediate Waters:
Arctic /lltennediate / Nortlz Icelandic Water (A/IN/lV) (Fig. 4) - The average
salinity at standard pressures which exhibit potential temperatures in the range
3.5°C::;; 8 ::;; 5.5°C, at stations 7 - 10 along the standard sections. These stations
lie between the centre of the Channel and the Faroese plateau.
This criteria is designed to examine the mean characteristics of water hugging
the Faroese slope, whose characteristics fall within the stated potential
temperature range on a 8-S curve. \Vithin this range an inflection in the slope
of the curve is generally observed, indicating the presence of AIINI\V formed
North of Iceland and along the northem slopes' of the Iceland - Faroe Ridge.
The water circulates around Faroe, partly leaving the Faroe Shetland Channel
through the Faroe Bank Channel, and partly recirculating back into the
Norwegian Sea. The water which satisfies this criteria generally lies within the
51
.. .
pressure range 300-400 dbar. The AJ/NI temperature time series cannot be
used due to the present definition employed.
Nonregian Arctic Sea Illtennediate Water (NSA1W) (Fig. 4) - The salinity at
the standard pressure which exhibits the minimum salinity within an individual
survey of both standard sections, within the temperature range 0 K ::; e::; 1 K.
Obviously the time series of temperature for this definition has little meaning.
This criteria is designed to examine the characteristics of the intermediate
water mass created north of the Arctic front in the Iceland and Greenland Sea,
which then subducts beneath the front forming a largc salinity-minimum layer
throughout the Norwegian Sea. Thc salinity minimum marking this water has
not always been apparent due to changing properties of thc water mass, but it
has always been marked as a silicate minimum, and has been located between
thc stated temperatures.
Deer Waters:
Standard PresslIre Levels (Figs 5-6) - Mcan potential temperature and salinity
at a standard pressure levels, averaged over all values on that pressure level
recorded during an individual survey of both ~t~dard sections.
This method of deriving time series for the bottom waters in the Faroe
Shetland ChanneI acknowledges that thc characteristics of the water have
changed considerably during the century, sometimes displaying the
characteristics of true Norwegian Sea Deep water, while at other times being
occupied by predominantly intermediate water.
North Sea Waters:
Fair Isle Cllrre1lt Water (FICW) (Fig. 7) - The mean temperature and salinity
at all standard pressures, averaged over the first two stations at the west end
(Scottish) of the JONSIS standard section.
This criteria captures thc characteristics of water entering the North Sea
through the Fair Islc Channel. This water originates west of Scotland, and is a
mixture of coastal water and Atlantic water that has come onto the shelf from
the Slope Current.
Cooled Atlalltic Water (CA W) (Fig. 8) - The mean temperature and salinity at
all standard pressures below 50 dbar, averaged over the first six stations at the
east end (Norwegian) of the JONSIS standard section.
This criteria is designed to examinc the characteristics of the cool dense lens of
52
•
. ,.
..
Atlantic water which forms in the eentre of the North Sea during the summer
months. During period of vertical stratifieation in the northem North Sera, this
water mass retains the eharacteristies of the mixed North Sea during the
previous winter, until the dense lower layer is eventually eroded through
autumnal wind mixing, and again takes on the properties of the northem North
Sea as a whole. Thus it generally represents water of Atlantic origin, modified
by mixture with North sea coastal waters to a varying extent.
Removal of seasonal cycles: As the surveys over the observational period have
been done at quite different times of the year, the effeet of the seasonal eyde in
the surfaee waters has been removed using the monthly mean t and S derived
over the period 1970-1990. These means have been ealculated for eaeh
individual station and at eaeh standard pressure level, and subtraeted from the
individual observations resulting in plots of t and S anomaly from the mean
seasonal eyde.
All plots show individual cruise values, along with the results of applying a two year running mean
filter.
53
.,
.
..
Table 1. Characteristic e and S of different surface water masses during 1995 1997. Values are anomalies after the seasonal cycle has been removed (See text
for exphlnation).
FICW
MNAW
NAW
CAW
oeC)
S
o (OC)
S
O(°C)
S
O(°C)
S
Sep95
-0.32
0.004
0.18
-0.008
n/a
n/a
n/a
N/a
Nov95
-0.47
0.038
n/a
n/a
0.54
0.056
0.49
-0.054
Jun 96
0.64
0.055
-0.26
0.003
0.52
-0.098
0.45
-0.013
Oct96
-0.23
0.069
-0.86
-0.028
-0.35
0.040
-0.02
0.048
Mar 97
0.26
0.030
-0.03
-0.060
n/a
n/a
n/a
N/a
Table 2. Characteristic e and S of different intermediate water masses during
1995 - 1997. Values have been obtained manually from es diagrams and not
using the automated methods described ahove.
NSAIW
AIINIW
Nolso Flugga
•
Nolso F1ugga
Fair Isle Munken
Fair Isle 1funken
o (0C)
S
o (OC)
S
o (0C)
s
e (0C)
S
Sep95
2.27
34.915
2.01
34.910
0.18
34.879
0.03
34.882
Nov95
1.93
34.901
1.64
34.895
0.32
34.875
0.18
34.883
Jun 96
3.49
34.941
3.42
34.903
0.05
34.892
-0.04
34.892
Oct 96
3.17
34.898
3.02
34.933
-0.12
34.888
0.13
34.887
Mar 97
2.82
34.857
3.28
34.847
-0.29
34.889
-0.55
34.899
Table 3. Characteristic e and S at three pressure levels during 1995 - 1997.
Values have heen obtained using the automated methods described above.
800 dbar
1000 dbar
1100 dbar
o (0C)
S
o (0C)
S
o (0C)
S
Sep95
-0.38
34.897
-0.60
34.903
-0.67
34.907
Nov95
-0.42
34.899
-0.72
34.910
-0.64
34.911
Jun 96
-0.52
34.908
-0.76
34.916
-0.79
34.916
Oct96
-0.61
34.904
-0.77
34.909
-0.79
34.911
Mar97
-0.38
34.898
-0.70
34.906
-0.72
34.906
54
•
•
•
..
• ..
60.5
Q)
"'0
:J
..... 60.0
co
...l
59.5
59.0
58.5
58.0
57.5
-7
-6
-5
-4
-3
-2
o
-1
Longitude
Figure 1
55
1
2
3
4
5
..
..
NORTH ATLANTIC WATER
-ro
~
>.
E
0
c
1.00
0.50
0.00
<{
...
Q)
-...8:::J
ro
-0.50
E
Q)
-1.00
•
I-
-1.50
1960
1970
1980
1990
2000
1990
2000
Year
co
r--I
0.10
-
0.05
E
0.00
!/l
!/l
a.
>.
ro
0
c
<{
-ro
>.
'e
I"'I
~!"!
1'11
.
! 1: .I
,
-0.05
,
Cf)
-0.10
1960
1970
1980
Year
Figure 2
56
••
MODIFIED NORTH ATLANTIC WATER
-~
>-
aJ
E
0
c
oe:(
Q)
.....
:J
2.00
1.50
1.00
0.50
0.00
~
-0.50
a.
-1.00
.-
-1.50
Q)
E
Q)
-2.00
1960
1970
1980
1990
2000
Year
0.15
-""
CX)
I
~
0.10
i
l/)
l/)
a.
>-
0.05
(Q
E
0
c
oe:(
•
-
0.00
>-
'e:
(Q
-0.05
Cf)
-0.10
1960
1970
1980
Year
Figure 3
57
1990
2000
. .
ARCTIC INTERMEDIATE I NORTH ICELANDIC WATER
35.20
35.15
co
r-....
I
35.10
l/)
l/)
-a.
>-
35.05
'e
cu
Cf)
35.00
34.95
34.90
1960
1970
1980
Year
1990
2000
NORVVE:GIAN SEA INTERMEDIATE WATER
34.95
co
r-....,
l/)
l/)
.9;
>c
34.90
;!::
(ij
Cf)
34.85 - t - - - , - - - - r - - . . - - - , - - - - r - - . . - - - , - - - - - - ,
1960
1970
1980
Year
Figure 4
,
58
1990
2000
•
,
. -
FAROE SHETLAND CHANNEL SOTTOM WATER - 800 dbar
0.00
-0.10
q
-0.20
~
-0.30
~
Q)
-0.40
E
-0.50
:J
a.
Q)
•
I-
-0.60
-0.70
-0.80
-+---r----,.-----r-~-...t._.,,___-r__-+_____,
1960
1970
1980
1990
2000
Year
34.93
-rn
co
34.92
,
!'
l/)
l/)
a.
>-
34.91
'c
Cf)
34.90
34.89 -+---r----,.-----r----r---,,----r---r---,
1960
1970
1980
Year
Figure 5
59
1990
2000
1 .
FAROE SHETLAND CHANNEL BOTIOM WATER -1100 dbar
-0.50
-:::.c::
Q)
....
CI]
....
Q)
-
-0.60
:J
-0.70
0.
E
Q)
I-
-0.80
-0.90 -t---..,.---r----,---..,.---r----,----r---,
19.60
1970
1980
1990
2000
Year
34.93
co
34.92
""",
lf)
lf)
-
0.
34.91
34.90
34.89
-t----r-----,r--~-.,...-~--r---.----,
1960
1970
1980
Year
Figure 6
60
1990
2000
•
.
,
FAIR ISLE CURRENT WATER
2.00
-~
>-
tU
E
0
c:
«
1.50
1.00
0.50
A
Q)
~
::l
"tU
0.00
1
~
•
Q)
0-
E
Q)
I-
-0.50
-1.00
-1.50
1960
1970
1980
1990
2000
Year
-E
00
t--
eh
l/)
0-
>-
g
«
•
~
'e
tU
Cf)
0.30
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
-0.10
-0.15
-0.20
-0.25
-+----r---,r--"r--J.....-r--~-___,r__-_r_-_,
1960
1970
1980
Year
Figure 7
61
1990
2000
1 .
COOLED ATLANTIC WATER
2.00
-
-.
1.50
>-
1.00
~
('0
E
0
c::
oe:(
Q)
'-
::J
0.50
0.00
tii
'-
-0.50
a.
E
Q)
-1.00
I-
-1.50
f
•
Q)
-2.00
1960
1970
1980
1990
2000
Year
ro
,
I"'-
0.20
0.15
l/)
l/)
a.
0.10
>-
('0
E
0
c::
0.05
-
0.00
('0
-0.05
oe:(
>-
•
'e
Cf)
-0.10
1960
1970
1980
Year
Figure 8
62
1990
2000
• f
.
.
NOLSQ-FLUGGA 0497S
0
200
........
ro
400
~
.0
"0
........
600
~
~
Cf)
Cf)
~
800
Q.
1000
1200
o
50
100
150
Distance (km)
Figure 9
63
200
250
300
'Tl
FAIR ISLE MUNKEN SECTION
1"
-
7.0 --------
o
-------------------------------------
---------_
.. ---------- ---------------------------------------------- ---------- -----------------6.0 __---.rr·
----------
5
. 5.0
4.0
-
,
t>
0
~
~
-
---------
~
Q)
~
. . . '.
3.0
~
~
.... ~
.-
'
."
• "-
.jiljI- .'
+ +
.......
...
~. -II"
I' ...
...... .:.
..:
'!"
....
'" '
~
Mt'+
..'io
.. -'-;'.-_.....
to:~.
_.:C1':~~
~~__ -:;
•• ~ ••. .+.:t . ~
"'-0(->••.~:#
.-------I , , ,
34.80
I
I
I
-' --I
I
,
34.84
I
,
,
I
;
~--; .....;t.~--+-
......'
•••• _",
iJt+"
+ +
I
•
34.88
,
,
.T.
----
+
#
;'
--------------------------------------
.
•
+
-----------_ ...
•••
------------
I , , , , I ,
•
-----------------------------
--
0.0
, .
"
'
"'.. "......
-...
...•
-------
,_,
:I: .. 'lL.
.te:. '\: •• !
~
••
•
' ~", ----------------------,
. ,... ..r..._--------------
Oln
----1:'.;".-,.-------;;,..
~ .' ~
_-.'2. . 1.0 ---- 1 9
-2.0
•
•
•
• ~ .-~-----~.i+....,.
,,_ ..----tU;.'
I
,
2.0
-1.0
~. "
••
;:
'
.' : ,
__----.rr.l ,.:0;-.-0:..:.,.'.,'
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------------------------------------~:;,
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June 1996
•
March I April 1997
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Salinity
e
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-
...
Annex J: Norwegian Sections
Johan Blindheim, Institute of Marine Research
P.O.Box 1870, Nordnes
5024 Bergen, Norway
Thc location of Norwegian standard sections arc indicated in Fig. 1. Thc intention
with this set of sections is to monitor thc flow of wann water from thc North Atlantic,
into thc Nordic Seas. An important reason for this monitoring is the rather
considerablc effect of inter-annual temperaturc fluctuations on thc state and
development of thc commercially important fish populations in the area
•
•
The transport of Atlantic water enters the Nordic Seas Mainly through thc FaroeShetland channel and to a considerable extent, also in thc current brancl1 which passes
north of thc Faroes. Important branches divert from thc main current along thc
continental shelf break, into thc important fishing areas in thc North Sea and the
Barcnts Sea. The standard sections are repeated to monitor fluctuations in this system.
Thc ßarents Sea
The Barents Sea is a shelf sea covering an area of approximately 1.4 x 10 6 km2 where
the mean depth is about 230 m. The bottom topography strongly influences
distribution and movements of thc water masses. Around thc Central Bank, in about
thc middlc of thc area, the inflow of Atlantic water, thc North Capc Current, splits into
a main southern branch and a northern onc which is somewhat smaller. Thc Barents
Sea is characterised by considerablc inter-annual fluctuations in water mass properties,
particularly in heat content and consequently, icc coveragc. These fluctuations are
monitored in threc sections which are repeated regularly; the Fuglpy-Bjprnpy Section,
between 19°E and 20 0 E [rom thc Norwegian coast to Bear Island, the Vardp-N
Section, along 31°13'E, and thc Sem Islands-N Section along 37°20'E. Timc series of
temperature and salinitiy, averaged between 50 and 200 m depth across the main
Atlantic inflow in thesc sections are shown in Fig. 2
In general, thc temperature in thc Barents Sea has been abovc the long tenn mean
during the period 1989-1995, with warmest conditions in 1991-1992. During 1996 thc
temperatures havc decreased and arc now below thc long tenn mean. This decreasc
was larger in thc two castern sections than in the western part of thc Barcnts Sea. Also
in salinity there has been a similar decrease, falling from a maximum in 1991-1992 to
present values below the long tenn mean.
Figure 3 shows the distribution of temperaturc at 100m depth in 1992, which was a
relatively warm year, and in 1996 which was considerably colder. As seen in thc
figure, thc temperaturc decrease was particularly largc in the frontal zone in the central
Barents Sea.
During thc winter 1995-1996 the ice coverage was relatively large, with the ice bordcr
lying between 74°N and 75°N during the winter. During summer the whole Barents
Sea \vas ice [ree. The icc index given in Fig. 4 which is based on thc icc coveragc for
,
65
"
\:. ','
.'~
,:,. :
..
. .
the whole year, indicates slightly more ice than average.
Thc Nopvcgian Sea
Figure 5 shows the fluctuations in tcmperature and salinity in the scctions Svin~y­
NW, Gims~y-N\V and Ss:5rkapp-\V (West Spitsbergen) which are situated in the
southem, central and northem Norwegian Sea, respectively (Fig. 1). As in the Barents
Sea, the entries also in this figure are mean values of temperature and salinity,
avcragcd betwccn 50 and 200 macross the core of the Atlantic inflow off the shelf
break. They are based on measurements taken in the period late July - early
September.
In the Svin~y-NW Section there was an incrcase in temperature and salinity from
1994 to 1995 so that the summer situation in 1995 was very dose to the average for
the period since 1978. The salinity was dose to the long term average also in the two
sections furt her north while the temperatures in 1995 were above the mean, with
increasing anomalies toward north. From 1995 to 1996 all three sections showed
decrease in both temperature and salinity.
•
The figure shows that some of the variations appears elearly in all three sections, as
for example the period with high values in both temperature and salinity around 1990.
This period showcd, however, also local differences. Hence, in the northem
Norwegian Sea this warm period had a longer duration and larger temperature
anomalies than further south. The large temperature decrease from 1995 to 1996 in the
Ss:5rkapp-\V Section shows that this period with locally high temperatures now is
broken.
All three sections in the Norwegian Sea also show a general decreasing salinity trend
over most of the observational period. In the Svin~y-N\V Section a similar decrease is
dear also in temperature. This is a feature which is observed also in longer time
series in the Norwegian Sea and in the Faroe-Shetland area since about 1960, affecting
the upper part of the water column, into the upper layers of the deep water.
Thc North Sea and Skagerrak
The North Sea is mainly a shallow shelf sea where about 2/3 of the area is shallower
than 100 m. Greater depths occur in the Norwegian Trench where the depths exceed
700 m in Skagerrak. Most ofthe water masses in the North Sea flow in from the North
Atlantic while some is runoff from land. The vertical mixing during the winter
reaches the bottom in the shallow areas with small temperature differences between
surface and bottom as consequence. The summer warming results in a weIl developed
thermoeline at depths varying between 20 and 50 m.
The circulation in the North Sea is largely cyelonic, and almost all of the water passes
through Skagerrak before it leaves the area in the Norwegian Coastal current. Interannual fluctuations around this mean situation influences the whole ecosystem in the
North Sea. The most important forcing mechanisms for such dimatic variability are
fluctuations in inflow of Atlantic water, wind conditions, heat exchange with the
atmosphere and fresh water discharge from land.
66
•
..
..
The winter 1995/96 was relative1y cold and dry over Europe. As a result, particularly
the southern North Sea was up to 3°C colder than normal during the winter. This
remained as cold bottom water during the following summer, with bottom
temperatures about 1,5°C below the long term mean.
Figure 6. shows time series of temperature and salinity in the north western North Sea
(Position A) and over the western slope in the Norwegian Trench (Position B), both
located on a section from Utsira toward west along 59°17'N (Fig. 1). The
measurements at A are taken to represent the "winter water" in the western branch of
the Atlantic inflow. The observations in Fig. 6 B show the conditions in the core of
the Atlantic inflow from the Norwegian Sea which follow the western slope of the
Norwegian Trench. The figure show that the temperature is in general 1o_2°C lower
on the North Sea plateau than in the inflow in the Norwegian Trench. After a warm
period on the plateau around 1990, there has been a eooling and freshening trend sinee
1993. This is somewhat in contrast to Fig. 6B where the two last years have been
relatively warm.
•
Figure 7 shows series of temperature, salinity and oxygen content at 600 m depth in
the Skagerrak Deep. The time series show that deep water renewal occurred in 1991
after a long period without deep water exchange. At the end of this period the oxygen
coneentration in the deep water was at the lowest since the observations were
initiated. This period with stagmint and warm water lasted until 1994 when colder
water with higher oxygen eontent sank into the basin from the North Sea plateau.
Further supply of new bottom water during the winter of 1996 brought the temperature
further down.
Coastal 'Vater
•
At 8 fixed stations along the cost, temperature and salinity are observed at standard
depths 2-4 times monthly. Fig. 8 shows the temperature and salinity trends at the fixed
station "Skrova" for the period 1936 - 1996, averaged over the first quarter, Jan. Mar., at 10m depth and over the third quarter at 150 m depth. While the observations
in the surface layer are rather vulnerable to IoeaI effects, the observations at 150 m are
more reflecting the oceanic conditions and the variations in the Norwegian Atlantic
Current. The high temperatures and salinities of the very warm period around 1990
reached a maximum in 1991, but the following cooling and freshening culminated in
1994. The seasonaI trend at the same depths is also shown in the figure.
Figure 9 shows similar graphs for the fixed station at "Utsira". Averages for the first
quarter at 10m depth and for the third quarter at 150m depth. Also at this station the
observations at 150m depth reflects the conditions in the Norwegian Atlantic Current,
but here in the flow which diverts into the North Sea. The warm period around 1990 is
indicated also in this time series.
.
67
. .
0'
•
Standard seelion
Standard station
20'
40'
75·
•
60'
Fig. l. Hydrographie standard seetions and fixed oeeanographie stations
68
:1· ., ~'&'-'-'
.Fugl~ya.Bjllm~ya
fcAf
5
~
-.
'-'.
•
\. I
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f 4
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•
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.i 3 ' \ ' /,.,.,r
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i
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1'\Vard~N/ ".
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•
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.,.~.
'-'" i j
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2
._'-._..
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\ j'" /
.\_. .,,'
o ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
1964
•
35. 20
35. 15
1969
:!l
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1979
j'
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• /
! \-', 'I
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.
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".6
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•
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<'
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1994
...
",
Vard0
:,..:::
\
1989
•
tJ;".
35.10 ~.. • ,\ "''',
3505 .•/
•
35.00
1984
1
1 ./\.. Fuglllya-Bj0m0ya
.
~
1974
T
,/
. ...
.1\'-.-,'.
::[ ,~~~~~~:~,~:~,:," ,-.'I"" ,:
1964
1969
1974
1979
1984
1989
1994
Fig. 2. Mean temperature and salinity between 50 and 200 m depth in the seetions
Fugloya-Brornoya. Vardo - N and Sem Islands - N. Observations from August/September.
1964 - 1996,
)(XX)
1100
I(XX)
•
SOl
.:
~
~
1.11
·soo
·1000
·1100
.)(XX)
1910
Im
1914
1976
1978
1980
1981
1984
1986
1988
1990
199)
1994
1996
1,
Fig, 3, !ce index for the period 1970 - 1995. Positive indices represent less ice than average.
69
•
•
Fig. 4. Di~trihlltion of temperature at 100m depth In thc Barents Sea during AugustSeptember in 1992 (upper panel) and 1996 (lower panel)
70
--- -
•
19U
1911
1971
1913
~-------------
1993
19"
1993
19"
Fi~, 5. Tempcralure and salinity. obsen'ed in Jul)'/AugUSI. in the core of the Atlanlic ....ater in
!he seclions S~ Ino)·l"W. Glmsoy·NW and Sorkapp. W. A\eraged bellloeen 50 and 200 m
depth
.• ~
•
j .• ./"-.
t: ,
-'"
Jv..
I \.
'\r\\ 7 V'J\['
~:I_ _---....
·f'. ~~. I\I\~
V-l I:
"::1
....
C":\
r
'\I
_
Fi~ 6. TempcrJlure and s~"nity near the bollom an the north weSlern Nonh Sea (A) and in the
core of the AllJnllC waler <BI o"er !he western slopc of !he NOt""'egian Trench during!he
summers of 1970·1996. Locallons of A and B in Fig I.
71
7.00
6.30
t
2
6.00.
3.SO t-1hJ.Hr---:+---l4r-F----rt~_Wct_+-F_lr
:
~
.
E 3.00
... 450
4.00
3.SO +-.~~~~~~~~~~~~~~
ll~~~~Q~~MWn~~~W~~~a~nW%
•
33.30
33.20
~
~
35.10
33.00
34.90
34.80 +-.~~~~~~~~~~~~~~~
~~~~MQ~~MronuM~~~MMnron~%
7.50
7.00
l:
6.30
~
~ 6.00
HlI---,l;It-----~\_\IiI~IJ_t_:lJ_lI1A-It_+w:
0 550
3.00
4.50
+-~~~~~~~~~~~~~~~~
~~~~roQ~~Mron~~~~~M~a~n~%
Fig. 7. Variations in temperaturc. salinity and dissolved oxygen in the bottom water at 600 m
depth in Skagerrak. 1952 - 1996. Position indicated by C in Fig. 1.
72
•
'.00
)JO
'.00
""
2.00!....~
~~~
__
1936 1"1 1946 1911 I~ '''1 19M 1971 1976 1..1 1916 1"1 I'"
....
"D
".".
'"
)'14
t- ,u 1I-'/-\+\j-\A1H-~+--A-H-t--i4t-4J1-+4--l+
•
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>U>b_~
__
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1936 ''''1 1946 IßI 1954 '''11166 .". I'"
__
",
~~
".~------------~
Itl6 1...1 1946 19511956 1'" I," 1t71 197' 1911 I"" .991 1996
1911 I," 19911",
Skron
10m. 1996
Skrovs
150m, 1996
""
15.1
•
"D
'"
,.,
)),1
'"" +-;-.....F....-;;M~A ......M...."...."....--:;A~',.,....,O'""'N--.-;;D~
Jlj
+-;,.......,F,........""M.......,A,...--M"....-,,~,...,
"""-A"'-',"""''''D~N~O~
Fig 8. (Uppe panel) Time series of temperature and salinity for the period 1936 - 1996 at the
fixed station "Skrova". The figure shows plots of means for the first quarter (Jan.-Mar.) at 10
m depth and of means for the third quarter at 150 m depth.
(Lower panne!) Seasonal trends of temperature and salinity at 10 m and 150 m depth at
"Skrova". Seasonal mean values with standard deviation are also shown.
73
YtrtUtsn
YlleVtln
IOm.l.tvvta.l
150m. 3. tvuta]
l.JO
)~M2l-.-I",-"-,l-I",-,,,-,""',,,,-:-lm~l:':m~'tI2~I:,:,,,~,",:::-'
...lO
1>Jl1
lI.lO
".70
•
150m,
YtreUliin.
10m, 1996
YtftUUIn.
'OJXl
• .lO
.'"
1.lO
i ''''
'.lO
.. ''''
@
1.lO
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j
3 u.o)
:
W.9O
lI.lO
)<.70
"'"
.....
lO.lO
...lO
11
A
Fig 9. (Upper panel) Time series of temperature and salinity for the period 1942 - 1996 at the
fixed station "Utsira". The figure shows plots of means for the first quarter (Jan.-Mar.) at 10
m depth and of means for the third quarter at 150 m depth.
(Lower pannel) Seasonal trends oftemperature and salinity at 10 m and 150 m depth at
··Skrova". Seasonal mean values with standard deviation are also shown.
74
•
Annex K: Results from Spanish Sections
Alicia Lavfn and J.M. Cabanas, Instituto Espafiol de Oceanograffa
Laboratorio de Santander
Apdo 240, 39080 Santander, Spain
The Standard Sections sarnpled by the Instituto Espafiol de Oeeanografia are given in
Fig. 1. In Bay of Biscay and Atlantic waters there are 4 sections, situated in Santander
(43.5°N, 3.78°W), Asturias (43.5°N, 6°\V), La Corufia (43.4°N, 8.3°\V) and Vigo
(42. 1oN, 9°W), which are sampled monthly.
•
•
The meteorologieal conditions in the North of the Iberian Peninsula have become mild
after a warm period. In annual mean air temperature (according to the Spanish Instituto
Nacional de Meteorologia) 1995 was one of the warmest year of the period 1961-1996,
and in 1996 mean temperature fell by 0.9°C. Anomalies in annual mean temperature
relative to 1961-90 mean, are shown in Fig. 2 for the period 1961-1996. The anomaly
temperature patterns of the Centro Meteorologico de Santander consistently follow
those ofthe NAO Index.
Contours of temperature and salinity at stations 2, 4 and 6 for the period (November
1991-Deeember 1996) for the Santander Seetion are presented in Figs 3, 4 and 5. The
seasonal cycle in temperature is clearly marked, mainly over the central part of the shelf
(st 4) and shelf-break (st 6) in the upper layers and throughout the water column at the
inner station (st 2) due to mixing. Stratification develops between April-May and
Oetober-November, and during the remaining period the water column is mixed over
the shelf and shelf-break. Salinity contours show high salinity at the beginning of
winter, duc to the poleward current, and sporadically in spring-summer duc to seasonal
upwelling events. Low salinity appears in autumn, when the seasonal picnocline is
broken, in summer in the upper layers, due to advection of warm surfaee water, and in
spring, due to river overflow.
Nitrate distributions at stations 2,4, and 6 are presented in Fig. 6. High values appear in
the mixed period and, due to upwelling events, in the stratified part of the year.
Inereasing trends in temperature and decreases in salinity detected from 1991 to 1995
have stopped (Figs 7a and b). This change in temperature trend in the upper waters
(10m) is related to a decrease in air temperatures. The decreasing trend in salinity
oceurred in the relaxed part of the high salinity anomaly that moved around the North
Atlantic at the end of the 80's, and arrived in the Bay of Biscay during 1991-1992, and
eontinued until 1994-1995 before changing.
Temperature, salinity and nitrate distribution at stations 14b, 13a and lla in the Vigo
section are shown in Figs 8, 9, 10, 11 from inside the ria de Vigo to outside. Poleward
current salinity increase is clearly detected in autumn 95 and winter 96.
To study distribution of properties along the shelf from the western part of the Iberian
Peninsula to the Northern part, we have computed the correlation hetween salinity
eonditions in La Coruna and Santander, in the former ease at any station on the shelf at
72m depth, and in the latter, at 100m depth. Monthly data were fitted by cubic splines
75
to fortnightly data to compare the two series. Salinity at 70m depth is signifieantly
eorrelated with time between La Corufia and Santander, with a maximum eorrelation of
0.63 for a lag of 2 months (Fig. 12). In the opposite direetion eorrelation is lower and
diminishes with time. We think this eorrelation and lag provide indications on the
direetion and mean speed of the shelf-edge current from the western part of the Iberian
Peninsula to the northern part~
These results are eoherent with a year of eurrent measurements sampled at 75m depth
over the shelf-break in Asturias (43.5° N, 6°W). In the stratified period, when a
pienoeline develops and winds are mainly easterly, eurrent direetion ehanges frequently
from eastward to westward and speed is quite low, but in autumn and winter, when
water is homogeneous, the direetion is predominantly eastward and monthly mean
veloeities are around 20 ern/s. This is the sign of the poleward eurrent. These eurrent
measurements eorrespond to the Feb 95-Feb 96 period, and in winter 96 an important
flow of the poleward eurrent is marked by the high salinity and temperature in the
seetions deteeted throughout the area, but with greater intensity in Vigo.
•
76
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Figure 2. Anomalies in annual mean temperature relative to the 1961-1990 mean. Centro
Meteorol6gico de Santander. Instituto Nacional de Meteorologia.
77
..
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Figure 1. Location ofthe Sections
IKEAN AIR TEMPERATURE ANOMAL!
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91
Figure 3. Distribution ofTemperature and Salinity at station 2 (Santander Section).
•
92
~3
Figure 4. Distribution ofTemperature and Salinity at station 4
•
11.00
•
•
STATION 6
NUTRIENTS
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0.50
0.00
'"
z
o
;:
;:
lI)
SUMl
91
Figure 5. Distribution ofTemperature and Salinity at station 6 (Santander Section).
jWIN
SUM
92
96
Figure 6: Nitrate distributions at stations 2, 4 and 6 (Santander Section).
..
A
22
21
!s:ATION 4
(10m)
I
20
19
18
17
·e
16
15
14
13
12
11
1993
1992
1991
1996
1995
1994
B
SALINITY
35.80
35.75
35.70
35.65
•
1\
N\
\ 11./\
J
\ I
35.60
YY
~
35.55
35.50
,
V,\
\
35.45
35.40
I
X
1
IA
1\
IM
(\
j
\.J
) y~
1/
35.35
35.30
1991
1992
1993
1994
1995
1996
Figure 7. A: Temperature at 10 m depth at station 4. B: Salinity at 50 m depth at station 4
(Santander Section)
80
•
•
20.0
16.0
MI.
Sp
Oe
Mt
Jn
Sp
Meses
00
1994
Oe
Mt
Jn
1995
36.00
Sp
1994
Oe
MI.
Sp
Oe
1994
1996
Jn
Sp
Meses
Oe
Mt
Jn
1995
Sp
Oe
1996
35.S0
Jn
Sp
meses
1995
Oe
MI.
Jn
Sp
Oe
1996
Jn
Sp
1994
Figure 8. Distribution ofTemperature and Salinity at station 14b (Vigo Section).
Oe
1995
MI.
Jn
Sp
Oe
1996
Figure 9. Distribution ofTemperature and Salinity at station l3a (Vigo Section).
I1
9
DIIA
Oie
1996
M:u
Jun
Sept
Oie
1996
Mar
Jun
Sept
00
N
DI3A
Oie
Mar
Sept
Die
1996
Mu
Jun
Sept
EI-Iß
Oie
Figure 10. Distribution ofTemperature and Salinity at station Ila (Vigo Section).
•
Mar
Sept
Oie
1996
Mar
Jun
Sept
Figure I J. Nitrate distributions at stations 14b, 13a and 11 a. (Vigo Section)
•
•
o. 65
~----------
-----------------_._-_._..
0.6
..
~
. .. . .. .. - - - - - - - - . -
-----Coruna-Santander
..
- - - Santander-Coruna
. ..
.. .
. ..
0.35 -
.. .
..
..
. .. .
0.3 .\----+------jf-----+-----+----1-----+---t----l
o
1
2
4
5
6
7
8
3
n° of 1ag5 (1=15 days)
Figure 12. Correlation between salinity conditions at 70 m depth in La Coruiia and Santander.
...
Annex L: Results from Barents Sea
J. Piechura, Polish Academy of Sciences
Institute of Oceanography, P.O. Box 6
Düsternbrooker, ul. Powstancow, 'Varszawy 55
81-712 Sopot, Poland
Inflow of the Barents Sea 'Vaters
Every summer since 1987 (except 1990) the Institute of Oceanology has conducted
oceanographic research in the area between Norway and Spitsbergen from the board of R.V.
"Oceania". 1987 salinity data were found too high and were rejected.
Quite substantial, interannual variations of physical properties and transport were observed.
\Ve would like to caIl more attention to variability of the Barents Sea \Vater Dow into the
Greenland Sea, especiaIly in the Sorkapp region. Most probably this is the Barents Polar
\Vater (BPW). In the most cases the BPW transported with the Sorkapp Current which is
mainly the surface current penetrates into the layer 200-400m just above the bottom of the
small plateau to the south of the South Cape (Figs 1, 2, 3). Temperature and salinity of
these waters Ductuated from below minus 1°C and 34.86 psu (summer 1995) to nearly
3.5°C and 35.00 psu (summer 1991). High temperature and salinity were recorded also in
the summers of 1994 and 1996 and 10w TS in 1992. Data also show different stages of
penetration and different volume of cold, less saline waters from the Barents Sea. In 1989
and 1995 the large volume of "new" BPW is seen while 1991 and 1994 they were weIl
mixed with Atlantic water and only traces can be seen in temperature distribution mainly.
In 1992 only smaIl amount of BPW was recorded.
Different type of water Dows into the Greenland Sea in the bottom layer of Storfjord and
Storfjordrenna (Fig. 4).
There are two large bodies of very dense winter waters on the transect along the axis of the
Storfjordrenna. One of them - is 10cated in the north-eastern part of the Storfjdrenna
between stations 06 and 09. Its temperature is as low as -2°C, the salinity is dose to 35 spu
and the density over 28.16. The other body is located at the opposite end of the transect, Le.
between stations IA and 02; the temperature in its core is -1.8°C and the density is 28.1228.14. Salinity rises to nearly 35 psu but only in a very thin bottom layer. The salinity
increase in the western part of the lens is more probably due to the Atiantic waters located
in the intermediate layer to the west. Intrusions of low salinity water are observed in the
upper part of these cold water lenses: <34.84 psu in western and <34.76 psu in eastern.
Density distribution suggests eddy - type circulation which cause redistribution of dense
waters and complicates picture.
84
•
FI·~.1.Area of investigations in Norwegian - Barents Seas Confluence Zone.
Transect "0" and northern part of Transect "15" - bold lines.
85
FIg.Z Potential temperature fC} and salinity [psu} distributions
at the northern part of transect 15°E.
1988
Potential temperature tCj
N4
1.14
0
L4
50
l00(l<m}
75'
K4
200
200
4~
4~
600
600
800
750
50
1989
Salinity [psuj
76'N
N4
800
750
100 f'mI
---=.::....
-
-
75'
- --':
200
•
4~
600
50
0
700
(l<m)
1.14
'~
«0
~
50
100
ftomJ
75'
200
200
4~
4~
600
600
750
1.14
800
0
50
1992
Potential temperature rC}
l00(l<m)
50
700
(l<m)
750
Salinity [psu}
76'N
L4
150
75'
200
200
~
.~
>5...
600
0
.
5..0
800
0
Salinity [psuj
, --- ~q....
6.•
800
750
l00(l<m}
76'N
K4
L4
.0
50
1991
Potential temperature tCl
N4
0
750
800
0
86
50
l00(l<m}
750
600
800
•
.
H3·~LlOf"'f<iPotential temperature [C} and salinity [psu} distributions
at the northem part of transect 15°E.
1994
Potential temperature tCj
M4
L4
Salinity [psuj
76"N
K4
75"
200
800
o
N4
150
50
Potential temoerature tCI
M4N
M4
L.ß.t
L4
K4t
o
1995
50
Salinity [psuj
76"N
K4
150
75"
200
40ci
----J
600
o
50
1996
Potential temoerature tCI
M4N
M4
L4M
L4
K4t
200
----j
75"
200
40ci
---+600
o
Salinity [psuj
76'N
K4
600
800
50
loo(l<mJ
150
87
.
AREX'95 Confluence Zone
Transect '0'
Salinity [psul
Potential temperature {"Cl
L4
02
01
04
03
05
07
06
08
09
Sigma- Theta
\.
I
/
;'
.I
...0"""'-'
,
/~,
.\
""0
300
/\ "
,/
o
20
40
60
80
'00
"""'
88
120
140
160
180
400
.
~
.
Annex M: Report on WOCE Section AlE
Jens Meincke, Institut für Meereskunde der Universität Hamburg
Troplowitzstras, se 7, 22529, Hamburg, Germany
The ongoing work on the WOCE-section AlE (Fig. 1) is reported here. This section has
been repeated 5 times since 1991 with approximately 65 CTD-Stations betwcen Kap
Farvel and Porcupine Bank (SW-Ireland). The most prominent change has been
observed with the eastward spreading of Labrador Sea Water. By means of Fig. 2 it is
demonstrated, that the LSW formed during 1988/98 convection event has reached the
European continental slope in 1995, i.e. 3 times faster than expected from carlier
published work. The present analysis focusses on the changes of Atlantic waters and the
overflows. The section will be continued, however at a reduced repetition rate after
1997.
N
54°
•
52°
WOCEA1/E
Figure 1
89
.
A
e :
o.or oe: /
Je.!.'!; V~ ir '1(
H:
-0./0, -0 Je
~ 34.64
~C'l 34.ffi
-'"
::; 34.88
~ 34.70
~
c:n
34.72
34.74U-ll~aSi-..-;.-L~-J.-~~~~~~~~;:;:;;;;.~=~
c:;
.......=.;;;.;.J.----L.
34.64
~cn 3US
•
-"
::; 34.58
~ 34.70
S
ü) 34.72
~ 34.64
~~at~
-'"
;;; 34.68
g
34.70
•
ü) 34.72
34.74
~ 34.64
~
cn
-'"
34.ffi
::; 34.68
~ 34.70
S
ü) 34.72
34.74 42
40
38
II
34
32
])
28
Fig.2 a) Difference ofPotential Temperatures against Sigma 1.5 along the WOCE AlE -Sections in 1992,
1994,1995 and 1996 against 1991. Hatched: Warmer against 1991
90
A
S~
C.OI r s"I rt ID<,'L
L'
t.. '11
34.14
•
;::; 34.68
~ 34.70
<r.
34.72
34.14
Fig 2 b) A '
SW),but
Agend
' Ity.6:Hatched'
for Salin'
Sea Water (~a).
an d'
mtemational
p rOJec~
.range covers the Lab rador
altem
Progre~s'salt'
m natIonal
ler .against
1991
. The density
91
01
•
Annex N: Further Changes in Norwegian
Sea Deep Water
Mr. A.J. van Bennekom
Netherlands Institute for Sea Research
P.O. Box 59, 1790 AB Den Burg, Texel
The Netherlands
Presented at the 1997 OHWG meeting as a follow-up to the 1996 OHWG discussion
Table 1 shows that applying the corrections to the salinity of Standard Sea Water
batchcs (Mantyla JPO 17:547, 1987 and DSR 41: 1387, 1994) improvcs thc consistency
of the salinity time series in adiabatic NSDW. It strengthcns thc conclusion of Svein
Osterhus (OHWG 1996 meeting) that during the last 15 years the salinity of adiabatic
NSDW did certainly not incrcase. Thc decreasc of 0.001 PSU is not significant in view
of measurement accuracy.
Salinities of NSDW before 1981 were higher than at prcscnt. It is difficult to find
pcrtincnt statistics in Iitcraturc; 34.92 is oftcn givcn for dcep watcr from thc Norwcgian
Sca, bascd on "Amaucr Hanscn" cruises in 1935 and 1936, tabulatcd by Mosby.
•
Preliminary data from a 1996 Johan Hjort cruise (Francisco Rey) show that the changes
in NSDW properties further proceeded slightly sincc 1994: Dccreasc in potential
tcmperaturc and thickness of thc adiabatic laycr and incrcasc in silicic acid
concentration.
Thc scenario for thc changcs in NSD\V and GSD\V sccms to bc: Ncarly total ovcrturn
of GSDW was last found in 1971 and since than thc depth of overturn in the Greenland
Sca progressivcly dccreased. Bchaviour of NSD\V is lagging bchind. Production of
new GSD\V cnhanccs the flow of bottom watcr through the Norwcgian Sca, dctcctablc
from thc disappcarancc of gradients in silicic acid concentration in bottom watcrs.
Throughflow of NSDW gradually diminished until about 1990, when it virtually
stoppcd. Stagnancy of NSDW is shown by a re-appearance of a near-bottom H4 Si04
gradient (Fig. 1).
Silicic acid measured on board by F. Rey and mcasured 14 days later at NIOZ (van
Bennekom and Bakker) in sampies fiItercd on board and sent by post, wcre the same
(average difference 0.002 ~M for 23 sampIes).
92
•
,
..
•
Table 1. Properties of Adiabatic Norwegian Sea Decp Water (> 2500 m depth),
around 65 N; 5 W (SW Norwegian Sea)
Compilation by A.J. van Bennekom from data reports.
Salinity corrected for SSW batches (Mantyla, JPO. 17: 547, 1987 & DSR 41: 1387, 1994)
Sal.
Annauer Hansen
1935,4 Stt.
•
t)
Ox, Jlmollkg Si, Jlmollkg
Corrected
34.92
±O.005
34.912
±0.002 ?
1972 Geosecs 3)
Stl9
34.912
198 I,TTOINAS
St 143
34.907
82-00 I, Hudson
St 116
34.910
34.909 3
(34.910 - 34.911)
!982, Meteor 4)
St284
34.909
1987, Tydeman
St3
34.910
34.910
(34.910 - 34.911)
3
?
34.910
(PI03 5); -0.0002/3)
-1.14
±0.006
302±2 2)
-1.043
302
14.1
-1.052
305
l3.1
-1.055
297-8
13.0
-1.048
299 2•4)
13.05
-1.052
300.2
12.7
300.9
-1.033
34.909 5
34.9095
(34.909 -34.910)
(P1l9 5»
-1.028 to
34.909 to
1996, Johan Hjort
-1.032
34.910
Stl266
(preliminary data; Pers. Comm. Francisco Rey, IMR, Bergen, Norway)
1994, Pelagia
St4
13.0
13.14
±0.02
Häkon Mosby (1966) Oceanographical Tables, Annauer Hansen in the Norwegian Sea,
1935, Geophysical Institute Bergen University, Norway, 118 pp.
2) From mllL with the conversion factor 44.66, and p 1.026 at pickling temperature.
3) A. Bainbridge (1981) Geosecs Atlantic Expedition, voll, Hydrographie Data, IDOENSF, Washington, 121 pp. Salinity slightly less accurate than others, pers. comm.
A. Mantyla
4) G.A. Becker (ed.)(l986) Data Report FS "METEOR" Reise nr 61, 150 pp.
Not the same position; about 200 km east of the other stations. St 285 more north
(central Norwegian Basin) gives S =34.914 at the same E>, Ox =298 and Si = 13.15.
5) Batch of Standard Sea Water used for salinity calibration; correction not known for
P119, probably very small
t)
93
Silicic acid profiles S. Norw. Sea
15
14
i'
-"g
~
"C
13.5
CJ
~CII
~
13
/
12.5
12
1500
/
~
14.5
/ V/
~
L
V
./
v
/
v
//
~
_/ /
-*-1972
-+-1987
-'-1994
-X-1996
....,........ ~
-x
L--
-
t'-
~
V~ E::-/
/ V1700
1900
2100
2300
2500
2700
2900
3100
3300
3500
depth (m)
•
•
.•
t.
, ..
::
"
Annex 0: An Overview ofVEINS
Jens Meincke, Institut für Meereskunde der Universität Hamburg
Troplowitzstras, se 7, 22529, Hamburg, Germany
The scope and the aims of the EU-MAST III Project VEINS (Variability of Exchanges
in the Northern Seas) is presented here.
The overall objective of the project is to measure and model the variability of fluxes
between the Arctie Ocean and the Atlantie Ocean with a view on implementing a longer
term system of critical measurements needed to understand the high-Iatitude oceans
steering role in decadal climate variability.
•
Exchanges between the North Atlantie and the Arctie Ocean result in the most dramatie
water mass conversions in the \Vorld Ocean: \Varrn and saline Atlantie waters flowing
through the Nordie Seas into the Arctie Ocean are separated by cooling and freezing into
shallow fresh waters (and ice) and saline deep waters. The outflow from the Northern
Seas to the south provides the initial driving of the global thermohaline circulation celI,
the one to the north is of major impact to the large scale circulation of the Arctie Ocean.
Measuring these fluxes is a major requirement to quantify the turnover-rates within the
large circulation cells of the Arctie and the Atlantie Oceans and a basic condition to
understand the role of these ocean areas in climate variability on interannual to decadal
scales.
For this purpose a consortium of 18 institutions with long standing experience in high
latitude observations and modelling with obtain 3 year synoptie time series of water and
property transports in the key passages from the Arctie Ocean through the Nordie Seas
into the Atlantie Ocean. These measurements will provide integral information on the
water mass formation processes in the Northern Seas and on the forces driving the
cireulation between the different basins. This makes them especially suitable for the
validation of large seale circulation models.
Its results will be used to develop an efficient observational design to measure time
series resolving up to deeadal time scales, which are considered to be the most crucial
measurements for advancing our predictive capabilities for shorter term climate
changes.
Figure I shows the areas, which VEINS will cover.
The \Vorking Group notes the importance of the VEINS Project for the general aims of
ICES-activities in the Northern Seas. It is evident, that this study of a predictive
capability for longer term physical changes in Atlantie \Vater inflow and deep water
outflow is of direct relevance to estimates of productivity-changes for the most
prominent fishing grounds in the Northern North Atlantie. It is therefor recommended,
to closely monitor the progress of VEINS by holding a theme-session on VEINS-results,
preferably during the 1999 Statutory Meeting.
95
't
N
80 0
GREEN LAND
,
Figure 1. Areas which VEINS will cover
96
'..
.....