Ice Station POLarstern (ISPOL):
Drifting Buoy Data Report
Petra Heil and Anthony P. Worby
Antarctic Climate & Ecosystems CRC
Australian Antarctic Division
Jennifer K. Hutchings
International Arctic Research Center
(Physical Science Group)
Jouko Launiainen and Milla Johansson
Finnish Institute of Marine Research
Christian Haas
Alfred Wegener Institute for Polar and Marine Research
William D. Hibler III
International Arctic Research Center
(Physical Science Group)
Antarctic Climate & Ecosystems
Cooperative Research Centre
Technical Report No. 1
Petra Heil and Anthony P. Worby
Antarctic Climate & Ecosystems CRC
Australian Antarctic Division
University of Tasmania
Private Box 80
Hobart, Tasmania 7050, Australia.
email: petra.heil@utas.edu.au
email: a.worby@utas.edu.au
Jennifer K. Hutchings
International Arctic Research Center (Physical Science Group)
University of Alaska, Fairbanks
930 Koyukuk Dr., P.O. Box 757335
Fairbanks, Alaska 99775-7320, USA.
email: jenny@iarc.uaf.edu
Jouko Launiainen and Milla Johansson
Finnish Institute of Marine Research
P.O. Box 33
FIN-00931 Helsinki, Finland.
email: jouko.launiainen@fimr.fi
email: milla.johansson@fimr.fi
Christian Haas
Alfred Wegener Institute for Polar and Marine Research
Postfach 120161
27515 Bremerhaven, Germany.
email: chaas@awi-bremerhaven.de
William D. Hibler III
International Arctic Research Center (Physical Science Group)
University of Alaska, Fairbanks
930 Koyukuk Dr., P.O. Box 757335
Fairbanks, Alaska 99775-7320, USA.
email: billh@iarc.uaf.edu
© Cooperative Research Centre for Antarctic Climate & Ecosystems 2005
ISSN: 1833-2404
ISBN: 1-921197-00-5
November 2005
Published by The Antarctic Climate & Ecosystems Cooperative Research Centre,
Hobart, Tasmania, Australia, 20 pp.
Established and supported under the Commonwealth
Governments Cooperative Research Centres Programme.
Ice Station POLarstern (ISPOL):
Drifting Buoy Data Report
Contents
Background and scientific objectives
Deployment overview
Site revisits
Recovery overview
Data availability
Instrument overview
Horizontal accuracy of ISPOL buoys
Intercomparison of atmospheric data collected by ISPOL buoys
Post ISPOL sea ice drift observations
Acknowledgements
References
Appendix I: Data products
Appendix II: Photo gallery
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Figures
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
2: ISPOL buoy array plus the remote Finnish buoy
3: Buoys in the Western Weddell Sea, 28 Nov. 2004 to 01 Jan. 2005
4: Two FIMR buoys with meteorological sensors before deployment
5: Buoys prior to deployment for calibration of meteorological sensors
6: Intercomparison of atmospheric pressure
7: Intercomparison of surface air temperature
8: Drift of four remaining buoys from late Dec. 2004 to mid June 2005
9: FIMR buoys: Buoys 1154 and 5892
10: AAD buoys: MetOcean buoy 20141 and Clearwater buoy 19035
11: AWI buoys: Buoys 14955 and 9803
12: IARC buoys: SiteM and buoy 5359
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10
11
12
14
15
16
19
19
19
20
Tables
Table
Table
Table
Table
Table
Table
1:
2:
3:
4:
5:
6:
Information on the deployment of the ISPOL sea ice buoys
Information on the recovery of the ISPOL sea ice buoys
Ice-floe revisits for ISPOL sea ice buoys
Data availability and sampling frequencies for the ISPOL buoys
Buoy manufacturers, GPS systems and nominal accuracy, sensors
Component and total horizontal position accuracy for ISPOL buoys
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9
11
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Antarctic Climate & Ecosystems CRC
1 Background and scientific objectives
Ice Station POLarstern (ISPOL) was a multi-national, interdisciplinary study coordinated by
the Alfred Wegener Institute for Polar and Marine Research, Germany, involving scientists
from different institutes and nations across a range of scientific disciplines. The ISPOL field
experiment, conducted onboard the M.S. Polarstern, was designed to investigate the role
of early summer physical and biological atmosphere-ice-ocean interactions in the western
Weddell Sea and their role in global processes. The ISPOL work complemented sea ice
and oceanographic observations and process studies performed previously during the US/
Russian Ice Station Weddell (ISW-1) [Gordon et al., 1993] from summer to early winter of
1992. ISPOL contributed to the goals of a number of international programs in Antarctica,
including the International Antarctic Zone (iAnZone) programme and Antarctic Sea Ice
Processes and Climate (ASPeCt) programme.
The scientific objective of the ISPOL buoy-array deployment was to collect spatially highresolution measurements of sea ice drift and deformation across a meso-scale region.
ISPOL had been planned as a 50-day drift station in the Western Weddell Sea. The start of
the drifting ice station was delayed, however, due to particularly heavy sea ice conditions,
so that the drift interval, originating at -68o 10’N, -54o 46’E, lasted a total of only 35 days
(28.11.2004—01.01.2005). During this time, the M.S. Polarstern was anchored to an ice
floe, referred to in this report as the ‘ISPOL floe’, and which was the primary site for in situ
experiments on the sea ice.
A range of scientific projects were carried out during ISPOL and are described in detail
in the official voyage report (Haas et al., in prep.). Here we present data and auxiliary
information on the sea ice drift and deformation experiment, which was a collaborative
research program involving the International Arctic Research Center (IARC) at the University
of Alaska Fairbanks, the Antarctic Climate & Ecosystems CRC (ACE CRC), the Australian
Antarctic Division (AAD), the Finnish Institute of Marine Research (FIMR) and the Alfred
Wegener Institute (AWI), with buoy contributions from each.
A meso-scale array of 26 drifting ice buoys was deployed for about 30 days during late
November and December 2004 to estimate the characteristics of the sea ice drift and
dynamics in the Western Weddell Sea. Sea ice drift was obtained from the horizontal GPSderived location measurements, which were made at all buoys but collected at various
temporal resolutions and different spatial accuracies. Auxiliary instruments were attached to
some of the sea ice drifters, including temperature probes for air and sea ice temperatures,
and air pressure sensors. Four of the buoys were left in the ice pack after the end of the
ISPOL field phase to record the large-scale drift in the region around the ice station from
late summer into winter.
Twenty-three of the sea ice buoys were deployed in a staggered set of triangular arrays. It
was planned for the outer edges of the largest triangular array to measure approximately
76 km upon deployment (Figure 1). Two more buoys were deployed outside the main array
(Figure 2). One of these was deployed near the ‘ISPOL floe’ for intense study of atmospheric
changes during ISPOL. The other was deployed about 100 km to the north of the buoy array
to provide data on synoptic weather systems and to aid measurements taken by helicopterdeployed instrumentation. These included remote sea ice thickness measurements using
an inductive electromagnetic probe and ice-floe characterisation using digital aerial
photography.
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Antarctic Climate & Ecosystems CRC
Data reported here are available via an accompanying CD-Rom, through the International
Programme for Antarctic Buoys [IPAB; http://www.awi-bremerhaven.de/IPAB], or directly
from the investigators.
The scientific interpretation of these data will be published elsewhere, including reports
on how these data supplement other investigations, such as the estimation of floe-size
distribution using digital aerial photography.
2 Deployment overview
The drifting buoy array was deployed on the 28 November 2004 (Day-of-Year [DoY] 333)
using two helicopters. Ice and snow thickness measurements (Table 1) were taken at each
deployment location if possible (although equipment failure prevented some data being
collected). Buoy locations were labelled alphabetically from A to Y (Figure 2 [right panel]).
Figure 1: Deployment plan for the ISPOL buoy array. [Mauve hexagons: IARC buoys; blue triangles:
FIMR buoys; green squares: AWI buoys; red diamonds: AAD buoys.]
Figure 2: (Left) Snapshot of the actual ISPOL buoy array plus the remote Finnish buoy on the 7th
December 2004 after all buoys had been deployed. AWI buoy 14955 (site D) had ceased
operation by this time. [Mauve hexagons: IARC buoys; blue triangles: FIMR buoys; green
squares: AWI buoys; red diamonds: AAD buoys.] (Right) Naming convention for the buoys
applied to buoys in the ISPOL array (right). Notes: Due to technical problems, buoy K was
deployed late. Its deployment position was hence adjusted westward to compensate for the
drift of the buoys deployed previously. Both buoys deployed at site D failed. No data have
been obtained for this site, hence they are not displayed in these plots.
ISPOL Drifting Buoy Data Report
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ISPOL Drifting Buoy Data Report
AWI
19021
20139
5892
52292
V
W
X
Y
18848
19020
53536
Q
19035
N/A
P
U
N/A
O
T
53541
N
19228
AAD
N/A
M
S
IARC
N/A
L
FIMR
FIMR
AAD
AAD
AAD
AAD
AAD
IARC
IARC
IARC
IARC
IARC
IARC
IARC
IARC
N/A
N/A
I
N/A
9803
H
IARC
K
53538
G
AAD
IARC
J
20141
F
IARC
53540
53537
E
AWI
14955
D
IARC
AWI
53539
8064
FIMR
C
1154
A
Institution
B
PTT
Site
A,G,T,P
A,G,T,P
A,G,T,P
A,G
A,G
A,G
A,G
A,G
A,G
G
G
A,G
G
G
G
G
G
A,G
A,G
A,G,T,P
A,G
A,G
A,G
A,G
A,G
A,G,T,P
Sensors
04.12.2004 (1100)
30.11.2004 (1400)
28.11.2004 (1030)
28.11.2004 (1100)
28.11.2004 (1130)
28.11.2004 (1300)
28.11.2004 (1230)
28.11.2004 (1200)
28.11.2004 (1545)
28.11.2004 (1600)
28.11.2004 (1530)
28.11.2004 (1210)
28.11.2004 (1630)
28.11.2004 (1700)
07.12.2004 (1445)
30.11.2004 (1445)
28.11.2004 (1745)
28.11.2004 (1125)
28.11.2004 (1115)
28.11.2004 (1500)
28.11.2004 (1700)
18.12.2004 (1800)
28.11.2004 (1615)
28.11.2004 (1100)
28.11.2004 (1030)
28.11.2004 (0915)
Deployment Date &
time (UT)
-68.146
-67.322
-68.773
-68.635
-68.655
-68.545
-68.542
-68.538
-68.428
-68.432
-68.423
-68.430
-68.370
-68.370
-68.317
-68.312
-68.308
-68.310
-68.310
-68.212
-68.210
-68.227
-68.210
-68.210
-68.210
-62.210
Latitude
(°N)
-55.487
-56.008
-56.042
-55.855
-56.212
-55.668
-56.035
-56.418
-55.465
-55.852
-56.198
-56.552
-55.957
-56.115
-55.853
-55.780
-56.048
-56.400
-56.747
-55.157
-55.472
-56.235
-55.865
-56.198
-56.552
-56.902
Longitude
(°E)
N/A
0.61
1.81
1.78
1.65
1.79
1.79
2.17
0.72
1.71
0.28
N/A
2.09
3.13
N/A
0.89
0.68
N/A
N/A
0.85
0.78
N/A
1.56
N/A
N/A
N/A
Zic
(m)
N/A
-0.10
+0.14
+0.07
+0.07
+0.12
+0.06
-0.10
0.00
0.00
-0.07
-0.07
0.00
0.00
N/A
0.00
-0.08
-0.12
0.00
0.00
0.00
N/A
-0.06
0.00
0.00
-0.05
FB
(m)
Ice State
N/A
0.11
0.16
0.40
0.38
0.13
0.32
0.65
0.15
0.70
0.84
0.38
0.30
0.37
0.15
0.21
0.52
0.85
0.30
0.21
0.15
N/A
0.50
0.55
0.35
0.90
Zsn
(m)
Vast, ridged (RH: 3.5 m). Site of Finnish met station.
Vast, heavily ridged (RH: 3 m); 500m from large lead; in area of lower
concentration (80%).
~1 km across, level area with nearby ridges (RH: 3 m); narrow lead
~200 m east of buoy.
Vast, ridged (RH: 2 m); narrow lead ~1k m east of buoy.
Vast, ridged (RH: 2 m); narrow lead ~1k m west of buoy.
500 m ø; OW of 50 m width all around; deployed in small drift.
Large level area on ridged floe; narrow lead ~500 m east of buoy.
Ridged (RH: 3 m); snow drifts up to 1 m; buoy in heavily ridged area.
100 m ø level area on heavily ridged floe (RH: 2–3 m).
Heavily ridged (RH: 2 m); buoy in flat area; lead to the west 500m.
Large floe; heavily ridged; buoy deployed 300 m from large lead in 2
directions.
500 m by 500 m; heavily ridged edges (RH: 1–3 m); buoy in flat area
50 m across.
500 m by 500 m; ridged (RH: 1–2); buoy deployed in flat area 100 m
across.
Vast, heavily ridged (RH: 1–2 m); buoy deployed in flat area 200 m
across.
~1 km wide (RH: 1–2 m); 300 m wide lead to north; buoy in level area.
Vast (RH: 1–2 m); buoy in level area 50 m across.
Vast (~1 km sq.); buoy is almost centred on floe.
Vast (E–W), ~1 km N-S (RH: ~0.5 m); buoy at east end.
Leads to the N, S & W (RH: ~1 m); buoy deployed 100 m of western
edge of floe.
Vast, narrow lead ~1k m east, and ~3 km west; buoy in small
hummock.
Vast, very heavy ridges (RH: 3–4 m); buoy in small level area.
Vast, highly deformed (RH: to 1 m); buoy deployed 100 m east of large
lead.
Vast (RH: 0.5–1.0 m); OW 1 km distant; buoy in small snow drift.
Vast, heavily ridged (RH: 1–2 m); buoy 500m east of lead.
About 500 m by 500 m (RH: ~0.5 m).
Vast, heavily ridged (RH: 1–2 m); buoy in small (10 m by 10 m) level
area.
Floe Description
Table 1: Information on the deployment of the ISPOL sea ice buoys. Instrumentation deployed on the buoys include GPS receivers (G), Argos transmitters
(A), air temperature sensors (T) and air pressure sensors (P). PTT denotes the Argos transmitter number. Only buoys equipped with an Argos
transmitter have been issued with a PTT. Zic is the thickness of the ice floe, Zsn the thickness of the overlying snow, and negative freeboard (FB)
indicates flooding. RH is the ridge height, OW stands for open water and ø stands for ice-floe diameter.
Antarctic Climate & Ecosystems CRC
N/A
53536
18848
19228
19035
19020
19021
20139
5892
52292
P
Q
R
S
T
U
V
W
X
Y
53541
N/A
O
M
N
N/A
N/A
L
N/A
N/A
I
N/A
9803
H
K
53538
G
J
20141
53540
F
IARC
14955
D
53537
8064
C
E
AWI
53539
B
ISPOL Drifting Buoy Data Report
FIMR
FIMR
AAD
AAD
AAD
AAD
AAD
AAD
IARC
IARC
IARC
IARC
IARC
IARC
IARC
IARC
IARC
AWI
IARC
AAD
IARC
AWI
IARC
1154
A
Institution
PTT
Site
31.12.2004 (0900)
01.01.2005 (1700)
01.01.2005 (1115)
28.12.2004 (1455)
01.01.2005 (1100)
28.12.2004 (1415)
28.12.2004 (1520)
01.01.2005 (1050)
28.12.2004 (1530)
27.12.2004 (1700)
26.12.2004 (1545)
30.12.2004 (1530)
26.12.2004 (1645)
26.12.2004 (1500)
28.12.2004 (1500)
28.12.2004 (1740)
27.12.2004 (1630)
30.12.2004 (1600)
29.12.2004 (1810)
28.12.2004 (1830)
28.12.2004 (1600)
20.12.2004
06.12.2004
30.12.2004 (1430)
30.12.2004 (1500)
Recovery
Date & time (UT)
-67.561
-67.092
-68.603
-68.598
-68.512
-68.428
-68.555
-68.423
-68.255
-68.557
-68.628
-68.385
-68.558
-68.567
-68.228
-68.242
-68.465
-68.263
-68.293
-67.925
-68.152
-68.152
-68.185
Latitude
(°N)
-55.572
-56.517
-56.313
-55.005
-56.513
-55.843
-56.218
-56.717
-55.582
-56.203
-56.612
-56.803
-56.437
-56.580
-55.783
-55.963
-56.463
-56.678
-57.023
-55.622
-55.737
-56.487
-56.865
Longitude
(°E)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.62
1.08
0.71
2.20
2.42
2.47
1.73
N/A
1.88
>2
N/A
N/A
N/A
1.75
>2
Zic
(m)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
-0.13
0.00
-0.05
0.00
-0.15
-0.13
-0.01
N/A
+0.08
0.00
N/A
N/A
-0.05
0.00
0.00
FB
(m)
Ice State
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.10
0.50
0.25
0.30
0.32
0.40
0.30
N/A
0.42
0.85
N/A
N/A
0.20
0.55
0.25
Zsn
(m)
Broken up into many small floes. Redeployed on ISPOL floe at the end
of ISPOL.
Floe was ~1 km diameter.
Redeployment of PTT19020 on this floe at end of ISPOL.
Buoy found horizontal.
Required cutting of temperature sensor to remove.
Buoy found at 50° lean from vertical.
Surrounding floes 20–500m diameter.
Extensive flooding, vast floe remaining.
Redeployment of PTT19035 on this floe at end of ISPOL.
Buoy did not work, hence retrieved.
Failed shortly after deployment.
FIMR Remained after end of ISPOL.
Comments
Table 2: Information on the recovery of the ISPOL sea ice buoys. Zic is the thickness of the ice floe, Zsn the thickness of the overlying snow cover, and
negative freeboard (FB) indicates flooding.
Antarctic Climate & Ecosystems CRC
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Antarctic Climate & Ecosystems CRC
3 Site revisits
Site revisits were planned to monitor changes in the ice floes throughout the interval of drift
of the ISPOL ice station. Due to adverse weather conditions and limitations on helicopter
availability due to requirements of other projects, however, only a few buoys were revisited
after their deployment.
Table 3: Details of ice-floe revisits for ISPOL sea ice buoys.
Site
PTT
Deployment
Revist1
Revisit2
A
1154
28.11.2004
12.12.2004
16.12.2004
12.12.2004
F
20141
28.11.2004
07.12.2004
I
N/A
28.11.2004
12.12.2004
L
N/A
28.11.2004
12.12.2004
M
N/A
28.11.2004
12.12.2004
O
N/A
28.11.2004
12.12.2004
P
N/A
28.11.2004
12.12.2004
T
19035
28.11.2004
12.12.2004
W
20139
28.11.2004
16.12.2004
Y
52292
04.12.2004
Various*
Revisit 3
17.12.2004
*For information on the ice-floe revisits at the Finnish meteorological station (site Y) please
contact Dr. J. Launiainen [FIMR] directly.
4 Recovery overview
The recovery of drifting buoys from the ISPOL array commenced on 27 December 2004
(DoY 362). Buoy recovery was undertaken using two helicopters, and where possible ice
and snow thickness measurements were taken (Table 2). A total of four buoys were left on
the sea ice after the end of the ice station to collect data on the long-term drift within the
Western Weddell Sea from summer through to winter as described in section 9.
5 Data availability
Data collected using the ISPOL buoys discussed here are available on the attached CD-Rom.
Table 4 summarises the data intervals and sampling frequency for each of the buoys. Note
that data from the non-Argos IARC buoys, although collected at 10 seconds intervals, are
made available here at 30 minute intervals. Data from IARC buoys on the Argos system
are provided at the sampling frequency (10 minutes). See Appendix I for file naming
conventions and the data formats.
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Table 4: Details of the data availability and sampling frequencies for the ISPOL buoys. After the end
of the ISPOL experiment buoys 19020 and 19035 were redeployed at the location of buoys
20139 and 20141, respectively, and buoy 5892 was redeployed on the ISPOL ice floe. These
3 buoys, together with buoy 1154, which was left on the ice floe where it was originally
deployed, were left behind to provide information on the long-term drift (see section 9).
For the three relocated buoys I indicates the phase when they were part of the ISPOL buoy
array, II indicates the phase their post ISPOL deployment.
Institute
PTT
Site
Start date
End date
Sampling
frequency
18848
R
28.11.2004
01.01.2005
30 minutes
19020 (I)
U
28.11.2004
01.01.2005
30 minutes
01.01.2005
14.01.2005
30 minutes
19020 (II)
AAD
19021
V
28.11.2004
28.12.2004
30 minutes
19035 (I)
T
28.11.2004
28.12.2004
30 minutes
30 minutes
19035 (II)
AWI
FIMR
28.12.2004
06.06.2005
19228
S
28.11.2004
28.12.2004
30 minutes
20139
W
28.11.2004
01.01.2005
60 minutes
20141
F
28.11.2004
28.12.2004
60 minutes
8064
C
28.11.2004
30.12.2004
60 minutes
9803
H
28.11.2004
30.12.2004
60 minutes
14955
D
28.11.2004
06.12.2004
60 minutes
1154
A
28.11.2004
19.08.2005#
60 minutes*
52292
Y
04.12.2004
01.01.2005
60 minutes*
5892 (I)
X
30.11.2004
01.01.2005
60 minutes
01.01.2005
19.08.2005#
60 minutes
5892 (II)
IARC
53536
Q
30.11.2004
27.12.2004
10 minutes
53537
E
28.11.2004
28.12.2004
10 minutes
53538
G
28.11.2004
29.12.2004
10 minutes
53539
B
30.11.2004
30.12.2004
10 minutes
53541
N
29.11.2004
26.12.2004
10 seconds
N/A
I
28.11.2004
27.12.2004
10 seconds
N/A
J
30.11.2004
28.12.2004
10 seconds
N/A
K
07.12.2004
28.12.2004
10 seconds
N/A
L
28.11.2004
26.12.2004
10 seconds
N/A
M
28.11.2004
26.12.2004
10 seconds
N/A
O
28.11.2004
26.12.2004
10 seconds
N/A
P
28.11.2004
26.12.2004
10 seconds
# Buoy was still transmitting data as of 11 October 2005.
* Acquisition of meteorological data started 10minutes prior to each full UTC hour
(XX:50:00).
ISPOL Drifting Buoy Data Report
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Antarctic Climate & Ecosystems CRC
Figure 3: Drift of all ISPOL buoys in the Western Weddell Sea from 28 November 2004 through to
01 January 2005. [Mauve: IARC buoys; blue: FIMR buoys; green: AWI buoys; red: AAD
buoys.] Deployment positions are indicated by a star.
The sea ice concentration around the outer sides of the ISPOL buoy array (marked by buoys
A–F–W) was determined from aerial photography to be approximately 96% immediately
after deployment on the 28 November 2004. Subsequent flights showed a net decrease in
ice floe size, and a slight increase in the percentage of open water and brash around the
outer edge of the ISPOL array. By the end of the field phase, the ice concentration within
the north-eastern part of the deformation array was close to 90%.
Preliminary analysis indicates that the general drift of sea ice within the ISPOL experimental
region appears to be coherent, but there was a marked velocity gradient from East to West
(Figure 3). The buoy-drift data show that the sea ice responded to synoptic forcing and also
to tidal movement.
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6 Instrument overview
Technical information on the GPS positioning units and the meteorological sensors deployed
on the ISPOL drifting buoys is summarised in Table 5.
Table 5: Details of buoy manufacturers, GPS systems and nominal accuracy, as well as auxiliary
sensors, such as air temperature sensors (Tair), air pressure sensors (Pair) and internal
ice-snow temperature sensors (Tint), for the various ISPOL buoys identified by their
PTT numbers. Within the table different buoy types are separated by a horizontal line.
#
Manufacturer information for the air temperature used on buoy 5892 was not available.
*Seven of the IARC buoys were not equipped with Argos transmitters, hence do not have
a PTT.
Sensors
Institute
Buoy Type
PTT
GPS Type
AAD
Clearwater
18848
EZ ice
19020
Jupiter
GPS
Engine
marker
MetOcean
19021
19035
19228
20139
Ice Beacon
20141
AAD
AWI
FIMR
FIMR
IARC
IARC
Denk
8064
Manufacturer
9803
Sea ice
weather buoy
Met Ocean
14955
Ice Beacon
52292
MetOcean
Ice Beacon
Oceanetic
Measurements
(Model 406)
5892
Custom made
-
1154
53536
53537
53538
53539
53541
-*
-
Jupiter
GPS
Engine
Trimble
(LassenSQ)
Jupiter
GPS
Engine
Jupiter
Hor. accuracy
(quoted by the
manufacturer)
Pair
Tair
Tint
< 20m
-
-
-
-
-
-
Vaisala
YSI44006
-
PTB-201A
Thermistor
-
(0.1° C)
-
-
-
< 20m
< 6m (50%)
(0.25 hPa
acc.)
-
&
-
-
-
< 9m (90%)
-
-
-
< 20m
Vaisala
14A1002-C3
YSI44006
#
-
-
-
PTB-100
< 6.2m
Garmin
16N
< 100m
Garmin
16N
< 100m
Vaisala
PTB-220A
-
Figure 4: Two FIMR buoys with
meteorological sensors before
their ISPOL deployment.
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7 Horizontal accuracy of ISPOL buoys
Prior to deployment all ISPOL drifting sea ice buoys were positioned on a single sea ice floe
(Figure 5) adjacent to the M.S. Polarstern with their positioning devices and meteorological
sensors activated for approximately 18 hours. This was primarily motivated by the need to
calibrate the buoy’s air pressure and temperature sensors (see Figure 4). The buoys were
placed across an area of about 6m by 3m. Where available these data have been used to
compare the positional accuracy between the buoys (Table 6).
Figure 5: ISPOL buoys prior to their deployment for the calibration of the FIMR meteorological
sensors on the 27 November 2004.
There is no difference in accuracy between longitudinal or latitudinal positions (Table 6). For
the AAD buoys, the horizontal position accuracy provided by the Clearwater buoys is slightly
better than that provided by the MetOcean buoys. The accuracy for three of the thirteen
IARC buoys using the Garmin GPS is similar to the AAD’s Clearwater buoys; each of the
latter exhibits a horizontal accuracy better than 40m. The spatial accuracy for the AWI and
FIMR buoys is slightly less than that of the AAD buoys, with exception of FIMR buoy 5892.
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Table 6: Component and total horizontal (4 hor) position accuracy for ISPOL buoys as compared
to GPS position of the M.S. Polarstern. GPS receiver models are Jupiter GPS (JG), Jupiter
GPS Engine (JGE), Trimble’s Lassen-SQ (TL-SQ), and Garmin’s 16N (G16N). See Table 5
for specifications of the GPS units. Note that IARC buoys without a PTT number have been
identified by the ISPOL site, at which they were subsequently deployed.
Platform
18848
19020
19021
19035
19228
20139
20141
8064
9803
14955
1154
52292
5892
53536
53537
53538
53539
53541
IARC(M)
IARC(O)
IARC(P)
GPS Type
Number
reports
Δx
(m)
Δy
(m)
Δ hor
(m)
JGE
JGE
JGE
JGE
JGE
JGE
JGE
TL-SQ
TL-SQ
TL-SQ
JGE
JGE
JG
G16N
G16N
G16N
G16N
G16N
G16N
G16N
G16N
20
21
22
18
20
18
23
10
12
9
15
30
12
62
71
75
34
26
36
12
36
23.7
18.4
18.8
19.4
22.6
30.8
26.2
79.3
54.5
93.9
195.9
56.7
17.7
33.6
52.8
45.3
28.3
22.4
31.7
11.6
26.1
20.6
20.2
26.6
12.1
12.9
15.8
73.6
90.5
63.6
128.4
212.8
23.9
13.7
75.0
89.9
84.2
56.6
36.3
21.1
20.0
19.3
31.4
27.3
32.5
22.9
26.0
34.6
78.1
120.4
83.8
159.1
289.2
61.5
22.4
57.8
48.4
55.1
54.1
33.5
38.1
23.1
32.5
8 Intercomparison of atmospheric data collected by ISPOL buoys
As noted in the previous section, all ISPOL buoys were placed on a sea ice floe close to the
M.S. Polarstern prior to their deployment to allow an intercomparison of the meteorological
sensors installed on some of the buoys. These data also provided a means to check that
intstrument calibration had not been compromised by shipping or handling.
8.1 Air pressure
Air pressure onboard the M.S. Polarstern is measured in the meteorological station at a
height of 16m. The pressure data provided in the M.S. Polarstern meteorological data
stream are already reduced to sea-level pressure. The air pressures taken at the buoys are
not reduced to sea level as instrument height is generally within 1m of sea surface.
Our intercomparison shows that all air pressure sensors track reasonably well with the
shipboard system. Pressure readings taken at AAD buoys 20139 and 20141 are biased
towards pressure readings lower than those recorded onboard the M.S. Polarstern, while
FIMR buoys 1154 and 52292 are biased towards pressure readings higher than those from
the ship’s meteorological system. The data included on the attached CD-Rom have not been
corrected for any offset noted here.
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Antarctic Climate & Ecosystems CRC
FIMR PPT 1154
FIMR PPT 52292
1004
1006
1002
1004
Surface pressure (hPa)
Surface pressure (hPa)
1000
998
996
994
1000
998
996
992
990
332
1002
332.2
332.4
332.6
332.8
333
333.2
333.4
333.6
994
332.6
333.8
332.8
333
333.2
Time (DoY(2004)
333.4
333.6
333.8
334
Time (DoY(2004)
FIMR PPT 5892
1006
Surface pressure (hPa)
1004
1002
1000
998
996
994
332.6
332.8
333
333.2
333.4
333.6
333.8
334
Time (DoY(2004)
AAD PPT 20141
1004
1002
1002
1000
1000
Surface pressure (hPa)
Surface pressure (hPa)
AAD PPT 20139
1004
998
996
994
992
990
332
998
996
994
992
332.2
332.4
332.6
332.8
333
333.2
Time (DoY(2004)
333.4
333.6
333.8
990
332
332.2
332.4
332.6
332.8
333
333.2
333.4
333.6
333.8
Time (DoY(2004)
Figure 6: Intercomparison of atmospheric pressure as measured onboard the M.S. Polarstern (red,
all panels) with that measured by FIMR buoy 1154 (blue; upper left panel), FIMR buoy
52292 (blue; upper right panel), FIMR buoy 5892 (blue; middle left panel), and with that
measured by AAD buoy 20139 (blue; lower left panel) and AAD buoy 20141 (blue; lower
right panel) just prior to their deployment. Time is in UT.
8.2 Air temperature
Surface air temperature readings taken at the buoys and the meteorological station onboard
the M.S. Polarstern are also compared. Air temperatures measured at the buoys were taken
about 1m above sea level. Onboard the M.S. Polarstern temperatures were taken at 14m
above sea level.
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The intercomparison of surface air-temperature data from buoy-mounted sensors with
those on board the M.S. Polarstern reveals that temperature readings taken at FIMR buoys
1154 and 5892 and also those taken at AAD buoys 20139 and 20141 deviated, on a daily
cycle, towards warmer temperature readings. Maximum deviations are around local noon,
indicating a possible problem relating to the radiation shield of the buoys’ temperature
sensor. In general, all air temperatures recorded on the buoys are above those taken at the
M.S. Polarstern. Buoy-derived temperature data need to be closely screened before being
used in any analysis or modelling study.
FIMR PPT 52292
−1
−1
−2
−2
Surface temperature (
Surface temperature (
o
C)
0
o
C)
FIMR PPT 1154
0
−3
−4
−5
−3
−4
−5
−6
−6
−7
−7
332
332.2
332.4
332.6
332.8
333
333.2
333.4
332
332.2
332.4
Time (DoY(2004)
332.6
332.8
333
333.2
333.4
333
333.2
333.4
Time (DoY(2004)
FIMR PPT 5892
0
−2
Surface temperature (
o
C)
−1
−3
−4
−5
−6
−7
333
333.2
333.4
333.6
333.8
334
334.2
334.4
Time (DoY(2004)
AAD PPT 20141
−1
−1
−2
−2
Surface temperature (
Surface temperature (
o
C)
0
o
C)
AAD PPT 20139
0
−3
−4
−5
−6
−4
−5
−6
−7
332
−3
−7
332.2
332.4
332.6
332.8
Time (DoY(2004)
333
333.2
333.4
332
332.2
332.4
332.6
332.8
Time (DoY(2004)
Figure 7: Intercomparison of surface air temperature as measured onboard the M.S. Polarstern
(red,all panels) with that measured by FIMR buoy 1154 (blue; upper left panel), FIMR buoy
52292 (blue; upper right panel), FIMR buoy 5892 (blue; middle left panel); and with that
measured by AAD buoy 20139 (blue; lower left panel) and AAD buoy 20141 (blue; lower
right panel) just prior to their deployment. Time is in UT.
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9 Post ISPOL sea ice drift observations
Of the four buoys remaining on the ice after the end of the ISPOL ice station, two (FIMR
1154 and FIMR5892) carried meteorological sensors. Individual buoys in the post ISPOL
phase were positioned to represent the drift of the “ISPOL” floe and the three corner points
(named A, F and W in Table 1) of the ISPOL buoy array. To accomplish this, FIMR5892 was
moved south-eastward on 01 January 2005 onto the ISPOL ice floe, and the 2005 drift
trajectory of FIMR5892 captures the track of the ISPOL ice station from summer into winter
and beyond. AAD buoys 19020 and 19035 were relocated to the ice floes at the southern
and eastern corners of the ISPOL deformation triangle shortly before the termination of the
ISPOL drift camp. There they replaced the two AAD buoys carrying meteorological sensors
at sites W and F, respectively.
Figure 8: Drift of four remaining buoys in the Western Weddell Sea from late December 2004
through to mid June 2005. (Note: Buoys 1154 and 5892 continued data transmission as
of 21 October 2005.) [Red: FIMR 1154; green: FIMR 5892; blue: AAD19020 (II); mauve:
AAD19035 (II).] Bathymetric contours [at 600, 700, 800, 900, 1000, 2000, 3000, 4000
and 5000m] are also shown.
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At the time of preparation of this report FIMR 5892 and 1154 were still operating. Figure
8 shows the drift of those remaining four buoys from January to June 2005. The two
remaining AAD buoys had battery packs designed for a total working life of 6 months, and
have since ceased data transmission: Buoy 19020 ceased transmission on 14.01.2005,
presumably due to damage sustained by ice deformation. Buoy 19035 ceased transmission
on 06.06.2005.
Acknowledgements
Dr. Victoria I. Lytle (now at the WCRP/SCAR CliC International Project Office, Norway)
is thanked for her input in project planning and design of the buoy array. Adrienne Tivy,
Carl Hoffman and Sascha Willmes are thanked for their assistance with the preparation,
deployment and recovery of the drifting buoys during ISPOL. The helicopter crew are
thanked for their support, as are the crew of the M.S. Polarstern. Professor Michael Spindler
(Chief Scientist during ISPOL) is thanked for his support of the ISPOL buoy project. AWI is
thanked for the opportunity to realise the drifting buoy experiment as part of ISPOL. Drs.
Ian Allison (AAD and ACE CRC) and Robert A. Massom (ACE CRC) are thanked for their
reviews of this report. Some figures in this report were compiled with GMT public domain
software (Wessel and Smith, 1995).
The AAD component of this project is supported by the Australian Antarctic Science grants
#742, #2559 and #2678; and assisted by the Australian Government’s Cooperative
Research Centre Programme through the ACE CRC. IARC buoys used in this project were
funded through an IARC/JAMSTEC grant. The Finnish buoys were funded by the Finnish
Antarctic Research Program (FINNARP).
Photo credits: Photos used in this report where contributed from the AWI (through Christian
Haas), the FIMR (through Milla Johansson) and the AAD (through Anthony Worby).
References
Gordon, A.L., and Ice Station Weddell Group of Principal Investigators and Chief Scientists,
Weddell Sea Exploration from Ice Station, Eos, Transactions of the American Geophysical
Union, 74 (11), 16 March 1993, 121–128, 1993.
Haas, C., G. Dieckmann, and M. Schröder (Eds.), The Expedition ANTARKTIS XXII/2 of
RV “Polarstern” in 2004/2005: Ice Station POLarstern (ISPOL), Rep. on Polar Res.,
in preparation. Wessel, P., and H.F. Smith, New version of the generic mapping tool
released, EOS Trans. AGU, 76, 379, 1995.
This report may be accessed via the ACE CRC, the ISPOL or the IPAB internet pages.
General information on ISPOL may be found at http://www.ispol.de and information on
IPAB may be accessed via http://www.awi-bremerhaven.de/IPAB.
Information on ISW-1 may be found at:
http://psc.apl.washington.edu/ISWphotogallery/ISW description.html
http://www.ldeo.columbia.edu/res/fac/physocean/ISW
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Appendix I: Data products
Digital data from the ISPOL buoy array are included in the CD-Rom attached to this
document. The naming convention identifies each data file as part of the ISPOL 2004
experiment and provides labels for the contributing research institute (AAD, AWI, IARC
or FIMR), the buoy PTT or (for the IARC buoys) the deployment label, and the nominal
temporal resolution (30 or 60 min), at which the data are available. For each buoy
deployment there is a data file:
ISPOL2004_AAD19020_1_30min.dat
ISPOL2004_IARCstationI_30min.dat
ISPOL2004_AAD19020_2_30min.dat
ISPOL2004_IARCstationJ_30min.dat
ISPOL2004_AAD19021_30min.dat
ISPOL2004_IARCstationK_30min.dat
ISPOL2004_AAD19035_1_30min.dat
ISPOL2004_IARCstationL_30min.dat
ISPOL2004_AAD19035_2_30min.dat
ISPOL2004_IARCstationM_30min.dat
ISPOL2004_AAD19228_30min.dat
ISPOL2004_IARCstationN_30min.dat
ISPOL2004_AAD20139_60min.dat
ISPOL2004_IARCstationG_30min.dat
ISPOL2004_AAD20141_60min.dat
ISPOL2004_IARCstationO_30min.dat
ISPOL2004_AWI14955_60min.dat
ISPOL2004_IARCstationP_30min.dat
ISPOL2004_AWI8064_60min.dat
ISPOL2004_IARCstationQ_30min.dat
ISPOL2004_AWI9803_60min.dat
ISPOL2004_FIMR1154_60min.dat
ISPOL2004_IARCstationB_30min.dat
ISPOL2004_FIMR52292_60min.dat
ISPOL2004_IARCstationE_30min.dat
ISPOL2004_FIMR5892_1_60min.dat
ISPOL2004_IARCstationG_30min.dat
ISPOL2004_FIMR5892_2_60min.dat
Due to the different parameters sampled by the ISPOL buoys there are three different data
formats for the buoy files.
For data files containing only position information from an ISPOL buoy the format is as
follows:
PTT
YY MM DD HH MN
DoY
Lat
Lon
The appropriate fortran format statement is: I5,1x,I4,4(1x,I2),3(1x,F8.4)
For data files containing position and meteorological information from a FIMR MetOcean
buoy during ISPOL the format is as follows:
PTT
YY MM DD HH MN
DoY
Lat
Lon
Pres Tair Tint
The appropriate fortran format statement is: I5,1x,I4,4(1x,I2),3(1x,F8.4),3(1x,F6.1)
For data files containing position and meteorological information from an AAD MetOcean
buoy during ISPOL the format is as follows:
PTT
YY MM DD HH MN
DoY
Lat
Lon
Pres Tair
The appropriate fortran format statement is: I5,1x,I4,4(1x,I2),3(1x,F8.4),2(1x,F6.1)
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Appendix II: Photo gallery
Figure 9: FIMR buoys: Buoy 1154 (left) and buoy 5892 (right).
Figure 10: AAD buoys: MetOcean buoy 20141 (left) and Clearwater buoy 19035 (right).
Figure 11: AWI buoys 14955 (left) and 9803 (right). The grey tube houses the Argos transmitter and
the GPS antenna, the brown tube contains an external battery pack.
ISPOL Drifting Buoy Data Report
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Antarctic Climate & Ecosystems CRC
Figure 12: IARC buoys deployed at siteM (no Argos PTT; left) and 53539 (right).
20
ISPOL Drifting Buoy Data Report
Core Participants
Australian Antarctic Division
University of Tasmania
CSIRO Marine & Atmospheric Research
Australian Bureau of Meteorology
Supporting Participants
Alfred Wegener Institute for Polar and Marine Research
Australian Greenhouse Office
Australian National University
National Institute of Water and Atmospheric Research
Silicon Graphics International
Tasmanian Department of Economic Development
Address
ACE CRC
Private Bag 80
Hobart, Tasmania Australia 7001
P +61 3 6226 7888
F +61 3 6226 2440
E enquiries@acecrc.org.au
www.acecrc.org.au
Established and supported under the
Australian Government’s Cooperative
Research Centres Programme