Upper Ocean Water Properties and Currents along Paired Sections
in the Northern California Current, September 1999-2003
Jane H. Fleischbein
Adriana Huyer
P. Michael Kosro
Robert L. Smith
Jennifer J. Wetz
and
Patricia A. Wheeler
College of Oceanic and Atmospheric Sciences
Oregon State University
Corvallis OR 97331-5003
Data Report 204
Reference 2006-1
January 2006
Table of Contents
Introduction
1
Sampling
1
Vertical Distributions
2
Offshore Profiles
2
Characteristic Diagrams
2
Acknowledgements
2
References
2
List of Tables and Figures
Table 1. CTD and biochemical (BC) sampling along paired
NH- and CR-Lines, September 1999 to 2003.
Figure 1. Shelf and coastline geometry in the region of the
section pair, showing the standard CTD stations of each
section, and the location of Cape Blanco, Columbia River
estuary, and the 50, 200 and 2000 m isobaths.
Figure 2. Six-hourly values of the coastal upwelling index at
45°N, 125°W (black) and 42°N, 125°W (red) in late
summer and early autumn (15 August through 15 October)
of 1999-2003. Long vertical lines indicate 1 September and
1 October. Short vertical lines indicate dates of
hydrographic sampling on the NH-line (black) and the CRline (red). (Data from http://www.pfeg.noaa.gov.)
Figure 3. Upper-ocean distributions of temperature (C).
Figure 7. Upper-ocean distributions of geostrophic velocity
(cm s-1, positive northward) relative to 500 dbar. Values
inshore of the 500 m isobath were calculated by the method
of Reid and Mantyla (1976).
Figure 8. Upper-ocean distributions of northward (alongshore)
component of ADCP velocity (cm s-1).
Figure 9. Upper-ocean distributions of eastward (onshore)
component of ADCP velocity (cm s-1).
Figure 10. Upper-ocean distributions of Brunt-Vaisala
frequency (cycles per hour); values were calculated at 10 m
intervals as the least-squares fit over a 10-m centered bins;
the shallowest value is at 9.5 m. Light contour is at 3 cph;
heavy contours are at intervals of 6 cph.
Figure 11. Upper-ocean distributions of spiciness (kg m-3),
calculated from T-S characteristics following Flament
(2002).
Figure 4. Upper-ocean distributions of salinity (psu).
Figure 5. Upper-ocean distributions of potential density
anomaly (σθ, kg m-3).
Figure 6. Upper-ocean distributions of geostrophic velocity
(cm s-1, positive northward) relative to 150 dbar. Values
inshore of the 150 m isobath were calculated by the method
of Reid and Mantyla (1976).
Figure 12. Upper-ocean distributions of oxygen saturation (%).
Contour interval is 10 %; the 50 % and 100% contours are
heavy and the 105% contour is dashed. Saturation
percentage was calculated from CTD oxygen concentration
data calibrated by Winkler-titrated samples from a few
stations on each cruise, using the algorithm from the
Scripps PACODF library.
Figure 13. Upper-ocean distributions of fluorescence voltage
(V). Contours: dashed at 0.5 V; thin at 1, 3; heavy at 2, 4;
full scale is at 15 V in 2002 and at 5.0 V in other years.
Fluorometer calibration is believed to remain about the
same within each cruise though it may vary from cruise to
cruise.
Figure 14. Upper-ocean distributions of total nitrate (µmol/l).
Figure 15. Upper-ocean distributions of phosphate (µmol/l).
Figure 16. Upper-ocean distributions of silicate (µmol/l).
Figure 17. Upper-ocean distributions of chlorophyll (mg/m ).
Contours are at 0.5 (dashed), 1, and 2, 4, 8 (heavy), 12 and
3
16 mg/m .
3
Figure 18. Offshore profiles of surface temperature and
salinity.
Figure 19. Offshore profiles of steric height (J/kg) of the sea
surface relative to 150 dbar and 500 dbar.
Figure 20. Offshore profiles of surface density and of surface
mixed layer depth, defined as the depth at which potential
density exceeds the surface value by 0.01 kg m-3.
Figure 21. Offshore profiles of surface density and of surface
mixed layer depth, defined as the depth at which potential
density exceeds the surface value by 0.1 kg m-3.
Figure 22. T-S characteristics of all CTD stations. Shelf
stations are plotted in red.
Figure 23. Superimposed groups of T-S characteristics. Upper
row: NH (black) on CR (red). Lower row: CR (red) on NH
(black).
Figure 24. Detail of T-S characteristics in the permanent
halocline. Shelf stations are plotted in red.
Figure 25. Oxygen-salinity characteristics of all CTD stations.
Shelf stations are plotted in red.
Figure 26. Detail of oxygen-salinity characteristics in and
below the permanent halocline. Shelf stations are plotted in
red.
Figure 27. Nitrate-phosphate relations for all rosette samples.
Shelf stations are plotted in red.
Figure 28. Silicate-phosphate relations for all rosette samples.
Shelf stations are plotted in red.
Figure 29. Nitrate-salinity relations. Shelf stations are plotted
in red.
Figure 30. Nitrate-salinity relations for samples with salinities
≥ 32 psu. Shelf stations are plotted in red.
Figure 31. Nitrate-salinity relations for samples with salinities
≥ 32 psu: CR data (red) superimposed on NH data (black).
Figure 32. Phosphate-salinity relations. Shelf stations are
plotted in red.
Figure 35. Silicate-salinity relations. Shelf stations are plotted
in red.
Figure 33. Phosphate-salinity relations for samples with
salinities ≥ 32 psu. Shelf stations are plotted in red.
Figure 36. Silicate-salinity relations for samples with salinities
≥ 32 psu. Shelf stations are plotted in red.
Figure 34. Phosphate-salinity relations for samples with
salinities ≥ 32 psu: CR data (red) superimposed on NH data
(black).
Figure 37. Silicate-salinity relations for rosette samples with
salinities ≥ 32 psu: CR data (red) superimposed on NH data
(black).
Upper Ocean Water Properties and Currents along Paired Sections
in the Northern California Current, September 1999-2003
whose separation increases with distance from shore; the most
offshore station, NH-85, is at 126.05ºW, 157 km from shore.
The CR-line at 41.9ºN off Crescent City, California,
lies 300 km farther south and spans a narrower shelf; this line
was originally sampled during the 1981-1984 SuperCODE
experiment (Huyer et al., 2002). The CR-line originally
consisted of nine CTD stations with the most offshore at
125.3ºW. This section was extended in 2000 by adding two
stations (at 125.7ºW and 126.0ºW). Beginning in September
2000, the station CR-9 at 125.3ºW was dropped in favor of
CR-9a at 125.4ºW.
Sampling along both sections included CTD/rosette
casts at standard stations (Table 1), and continuous operation of
an Acoustic Doppler Current Profiler; results of the concurrent
zooplankton sampling are not included in this report.
Details of CTD data collection, calibration and
processing are available in a series of data reports (Fleischbein
et al., 1999; 2001; 2002; 2003). Accuracy of the processed data
is estimated to be better than ±0.01ºC for temperature, ±0.003
psu for salinity, ±1 dbar for pressure, and ±0.2 ml/l for
dissolved oxygen. A SeaTech fluorometer was also mounted
on the CTD/rosette frame.
Biochemical sampling was conducted at most stations
(Table 1). Water samples from the upper 150 m were analyzed
to determine concentrations of inorganic nutrients (nitrate,
phosphate, silicate, nitrite, ammonium), phytoplankton biomass
(chlorophyll-a), particulate organic carbon and nitrogen, and
dissolved organic carbon and nitrogen. Samples were collected
with 5-L Niskin bottles on a 12-bottle rosette, with samples
Introduction
As part of the U. S. GLOBEC NorthEast Pacific
Program we made repeated seasonal hydrographic surveys in
the northern California Current system (Figure 1) between July
1997 and September 2003. These surveys included sampling
along a pair of hydrographic sections, one north (at 44.6ºN)
and one south (at 41.9ºN) of Cape Blanco (Figure 1) in
September of five years (1999-2003). The coastal upwelling
associated with the California Current experiences maximum
upwelling during summer, and usually continues through much
of September; upwelling is usually stronger at 42ºN than at
45ºN (Figure 2). One purpose of this report is to show
differences and similarities between the coastal upwelling
domains north and south of Cape Blanco. We present graphical
summaries of the physical oceanographic and biochemical
observations along both sections, principally in the form of
zonal sections (0-160 km from shore, 0-150 m depth). We also
show offshore profiles of a few selected properties, and some
characteristic diagrams (T-S, oxygen-S, etc.). Similar reports
showing results for mid-summer and for spring have already
been published (Fleischbein et al., 2005a, b).
Sampling
The NH-line at 44.6ºN off Newport, Oregon, lies about
130 km south of the mouth of the Columbia River, and spans a
relatively wide shelf. This line was sampled seasonally from
1961 to 1971 (Smith et al., 2001), and then sporadically until
July 1997 when GLOBEC resumed sampling of the NH-line
until the fall of 2003. The NH-line consists of 12 CTD stations
-1-
taken at about 150 m, 100 m, and at 10 m intervals in the upper
70 m. Analytical methods have been described by Corwith and
Wheeler (2002) and by Hill and Wheeler (2002). The following
plots in this data report include only nutrient and chl-a data.
Sampling protocols, analytical information and tabulated
values of nutrient and chl-a are available in the data report by
Wetz et al. (2004).
Upper-ocean currents were measured along each
section by a shipborne acoustic Doppler current profiler
(ADCP). On most cruises the ADCP system was narrowband,
150 kHz, with 8-m bins, manufactured by RD Instruments.
ADCP data were collected in 2.5 min ensembles and processed
using the University of Hawaii CODAS system (Firing,
Ranada and Caldwell, 1995). Profiles were screened manually
for bottom interference, corrected for gyrocompass errors with
data from an Ashtech 3DF GPS-based system, calibrated for
transducer and gyrocompass alignment, and processed to
absolute currents by referring to differential GPS data. Kosro
(2002) estimates high-frequency noise (due to tides and inertial
currents) to be about ±8 cm/s.
Offshore Profiles
Offshore profiles (Figure 18-21) are shown for a few
selected parameters: surface temperature and salinity, steric
height, and mixed layer depth (determined from two separate
criteria).
Characteristic Diagrams
T-S diagrams (Figures 22-24) include all available data,
i.e., from depths below 150 m (to 1000 m) as well as above 150
m. To facilitate comparison and interpretation, we show the TS diagrams superimposed as well as separately. We also show
oxygen-salinity (Figures 25-26), nutrient-phosphate (Figures
27-28) and nutrient-salinity diagrams (Figures 29-37).
For most characteristic diagrams, we distinguish from
“shelf” data (NH-1 to NH-15 and CR-1 to CR-3) from offshore
data (all remaining stations). For some T-S and nutrientsalinity relations we show two versions: one with a wide
salinity range (30-35 psu), and one with a narrow salinity range
(32 to 34.5 psu).
Acknowledgements
We are grateful to all those who participated in
collecting these data, including the captain, crew and especially
the marine technicians of R/V Wecoma and R/V New Horizon.
We are supported by the National Science Foundation through
Grant OCE 0000733 and OCE 0434810. The LTOP
hydrographic data collection and analysis are supported by the
U.S. GLOBEC NorthEast Pacific Program, funded jointly by
NSF and NOAA.
Vertical Distributions
The upper-ocean distributions (surface to 150 m depth)
are shown for fifteen parameters: temperature, salinity,
potential density, geostrophic velocity (relative to both 150
dbar and 500 dbar), ADCP measured current (northward and
eastward components), buoyancy frequency, spiciness,
dissolved oxygen saturation, fluorescence voltage, nitrate,
phosphate, silicate, and chlorophyll (Figures 3-17). For each
parameter, distributions are shown for both sections in each
fall.
References
Corwith, H.L. and P.A. Wheeler. 2002. El Niño related
variations in nutrient and chlorophyll distributions off
Oregon. Progr. Oceanogr., 54, 361-380.
-2-
observation program off Oregon, 2001. College of Oceanic
and Atmospheric Sciences, Oregon State University, Data
Report 187, Ref. 2002-3, 168 pp.
Fleischbein, J., A. Huyer, and R. L. Smith, 2003.
Hydrographic data from the GLOBEC long-term
observation program off Oregon, 2002 and 2003. College
of Oceanic and Atmospheric Sciences, Oregon State
University, Data Report 192, Ref. 2003-2, 296 pp.
Hill, J.K. and P.A. Wheeler. 2002. Organic carbon
and nitrogen in the northern California Current
system during July 1997: comparison of offshore,
river plume, and coastally upwelled water. Progr.
Oceanogr., 53, 369-387.
Kosro, P. M. 2002. A poleward jet and an equatorward
undercurrent observed off Oregon and northern California
during the 1997-98 El Niño, Progr. Oceanogr., 54, 343360.
Reid, J. L., and A. W. Mantyla, 1976. The effect of geostrophic
flow upon coastal sea elevations in the northern North
Pacific Ocean. J. Geophys. Res., 81, 3100-3110.
Smith, R. L., A. Huyer and J. Fleischbein. 2001. The coastal
ocean off Oregon from 1961 to 2000: Is there evidence of
climate change or only of Los Niños? Progr.
Oceanography, 49, 63-93.
Wetz, J. J., J. Hill, H. Corwith and P. A. Wheeler. 2004.
Nutrient and extracted chlorophyll data from the GLOBEC
Long-Term Observation Program, 1997-2004. Data Report
193, COAS Ref. 2004-1, 135 pp.
Firing, E., J. Ranada and P. Caldwell. 1995. Processing ADCP
data with the CODAS software system, version 3.1.
Honolulu, HI: University of Hawaii.
Flament, P. 2002. A state variable for characterizing water
masses and their diffusive stability: spiciness. Progress in
Oceanography, 54, 491-500.
Fleischbein, J., A. Huyer, P. M. Kosro, R. L. Smith and P. A.
Wheeler. 2005a. Upper ocean water properties and
currents along paired sections in the northern California
Current, summer 1998-2003. College of Oceanic and
Atmospheric Sciences, Oregon State University, Data
Report 201, Ref. 2005-4, 41 pp.
Fleischbein, J.H., A. Huyer, P. M. Kosro, R. L. Smith, J. J.
Wetz, and P. A. Wheeler. 2005b. Upper ocean water
properties and currents along paired sections in the northern
California Current, spring 1998-2003. College of Oceanic
and Atmospheric Sciences, Oregon State University, Data
Report 203, Ref. 2005-6, 42 pp.
Fleischbein, J., J. Hill, A. Huyer, R. L. Smith and P. A.
Wheeler. 1999. Hydrographic data from the GLOBEC
long-term observation program off Oregon, 1997 and 1998.
College of Oceanic and Atmospheric Sciences, Oregon
State University, Data Report 172, Ref. 99-1, 288 pp.
Fleischbein, J., A. Huyer, and R. L. Smith, 2001.
Hydrographic data from the GLOBEC long-term
observation program off Oregon, 1999 and 2000. College
of Oceanic and Atmospheric Sciences, Oregon State
University, Data Report 183, Ref. 2001-3, 290 pp.
Fleischbein, J., A. Huyer, and R. L. Smith, 2002.
Hydrographic data from the GLOBEC long-term
-3-
Table 1. CTD and biochemical (BC) sampling along paired NH- and CR-Lines, September 1999 to 2003.
NH-1
NH-3
NH-5
NH-10
NH-15
NH-20
NH-25
NH-35
NH-45
NH-55
NH-65
NH-85
CR-1
CR-2
CR-3
CR-4
CR-5
CR-6
CR-7
CR-8
CR-9
CR-9a
CR-10
CR-11
-124.100
-124.130
-124.177
-124.295
-124.412
-124.528
-124.650
-124.883
-125.117
-125.367
-125.600
-126.050
-124.300
-124.400
-124.500
-124.600
-124.700
-124.800
-125.000
-125.200
-125.333
-125.400
-125.667
-126.000
22-25 Sept 1999
Stn Max BC
No Depth
1
20
2
46
3
57
x
4
76
5
86
x
6
136
7
285
x
8
426
x
9
694
x
10 1008
11 1008
x
12 1008
x
21
35
x
22
61
23
127
x
24
496
x
25
655
x
26
688
27
826
x
28 1006
29 1005
x
7-10 Sept 2000
Stn Max BC
No Depth
1
24
2
43
3
52
x
4
76
5
90
x
6
139
7
280
x
8
430
x
9
680
x
10 1006
11 1005 x
12 1007 x
21
35
x
22
64
23 130
x
24 500
x
25 651
x
26 686
27 811
x
28 1006
29 1007 x
30
31
1006
1005
4-9 Sept 2001
Stn Max BC
No Depth
1
25
2
44
3
56
x
4
78
5
88
x
6
138
7
281
x
8
426
x
9
696
x
10 1005
11 1006
x
12 1005
x
21
36
x
22
62
23
130
x
24
505
x
25
630
x
26
692
27
838
x
28 1006
29
30
x
-4-
1005
1006
x
x
28 Sept -1 Oct 2002
Stn Max BC
No Depth
1
2
3
4
5
6
7
8
9
10
12
19
20
21
22
23
18
17
16
41
53
74
87
134
272
435
684
1005
1006
1014
35
63
132
495
646
689
802
1005
15
14
13
1002
1007
1006
x
x
x
x
x
x
x
x
x
x
x
x
x
x
26-29 Sept 2003
Stn
Max BC
No Depth
1
26
2
44
3
55
x
4
77
5
87
x
6
136
7
280
x
9
430
x
10
680
x
11
1005
12
1006 x
13
1006 x
14
35
x
15
62
16
130
x
17
500
x
18
650
x
19
691
20
811
x
21
1005
22
23
24
1005
1005
1005
x
x
Columbia
River
m
46
200
45
Latitude (N)
Newport
50 m
NH
44
43
Cape Blanco
42
CR
Crescent City
2000
m
41
127
126
125
124
Longitude (W)
123
122
Figure 1. Shelf and coastline geometry in the region of the section pair, showing the standard CTD stations of each
section, and the location of Cape Blanco, Columbia River estuary, and the 50, 200 and 2000 m isobaths.
-5-
42N
45N
300
0
1999
Offshore Ekman Transport (m 3/100 m)
-300
300
0
2000
-300
300
0
2001
-300
300
0
2002
-300
300
0
2003
-300
15
15
1
August
September
15
1
October
Figure 2. Six-hourly values of the coastal upwelling index at 45°N, 125°W (black) and 42°N, 125°W (red) in late summer and early
autumn (15 August through 15 October) of 1999-2003. Long vertical lines indicate 1 September and 1 October. Short vertical lines
indicate dates of hydrographic sampling on the NH-line (black) and the CR-line (red). (Data from http://www.pfeg.noaa.gov.)
-6-
Sep 99
16
Depth (m)
0
50
Sep 00
Sep 01
15
15
16
Sep 03
10 17
14
16
15
9
10
8
NH
8.5
8.5
100
8
8
8
150
15
0
50
10
9.5
13
10
10
15
8.5
9
CR
8.5
-80
Distance (km)
8
11
12
10
9
8
150
-160
7.5
13
9
100
7.5
8
17
11
Depth (m)
Sep 02
8
8
0
Figure 3. Upper-ocean distributions of temperature (C).
-7-
8
Sep 99
32
31.6
0
Depth (m)
Sep 00
31.6
32.2
Sep 02
32
32
Sep 03
33
33
32.2
32
32.8
50
32.8
NH
33
100
150
33.9
33.9
0
50
33.8
32.6
33
33
33
32.2
32.8
33
Depth (m))
Sep 01
33.4
CR
100
33.8
33
34
33.9
150
-160
-80
Distance (km)
33.9
34
33.9
0
Figure 4. Upper-ocean distributions of salinity (psu).
-8-
Sep 99
23
Depth (m)
0
24
Sep 00
Sep 01
24
25
25
Sep 02
24
Sep 03
25
24
25
50
NH
26
100
26.25
26.25
26.25
26.25
26.25
150
25
0
25
26
24
25
Depth (m)
25.25
25
50
26
26
26
100
26.25
26.25
150
-160
-80
Distance (km)
26
26.25
26.25
0
Figure 5. Upper-ocean distributions of potential density anomaly (σθ, kg m-3).
-9-
26.25
CR
Sep 99
0
20
Sep 00
-30
Sep 01
Sep 02
-10
-30
Sep 03
-30
-30
Depth (m)
0
50
0
0
0
100
NH
0
0
0
150
0
-10
20
-20
-10
-20
Depth (m)
0
-10
50
0
0
CR
0
0
100
0
0
150
-160
0
-80
0
Distance (km)
Figure 6. Upper-ocean distributions of geostrophic velocity (cm s-1, positive northward) relative to 150 dbar. Values inshore of the 150
m isobath were calculated by the method of Reid and Mantyla (1976).
-10-
Sep 99
0
30
Sep 00
-30
-30
0
0
Depth (m)
Sep 01
Sep 02
Sep 03
-20 -30
-10
-30
-10
50
0
0
0
0
100
NH
0
150
0
-10
30
-30
-20
-10
Depth (m)
-20
50
CR
0
100
-10
0
0
0
0
0
0
150
-160
-80
0
Distance (km)
Figure 7. Upper-ocean distributions of geostrophic velocity (cm s-1, positive northward) relative to 500 dbar. Values inshore of the 500
m isobath were calculated by the method of Reid and Mantyla (1976).
-11-
Sep 99
Sep 00
Sep 01
Sep 03
0
-10
Depth (m)
30
-20
0
0
10
0
150
0
0
0
0
0
-20
20
30
0
-10
0
-40 30
-20
10
50
0
CR
0
-20
0
0
0
0
150
-160
NH
-10
0
100
0
Depth (m)
0
0
50
100
-30
0 -20
-80
Distance (km)
0
Figure 8. Upper-ocean distributions of northward (alongshore) component of ADCP velocity (cm s-1).
-12-
Sep 99
Sep 00
Sep 01
Sep 03
0
Depth (m)
-10
-10
50
0
-10
-20
0
-10
0
0
0
NH
0
100
0
0
0
0
0
0
150
20
0
0
Depth (m)
10
50
30
0
0
0
-20
0
0
40
0
-10
30
100
0
0
150
-160
-80
Distance (km)
0
0
0
Figure 9. Upper-ocean distributions of eastward (onshore) component of ADCP velocity (cm s-1).
-13-
CR
Sep 99
0
18
Sep 00
Sep 01
18
6
Sep 02
18
3
3
Depth (m)
6
3
6
12
12
50
NH
6
100
6
3
3
6
3
50
6
3
3
150
0
6
6
3
Depth (m)
Sep 03
6
3
12
3
3
3
12
3
12
3
6
6
6
6
100
CR
6
6
3
150
-160
3
3
3
-80
0
Distance (km)
Figure 10. Upper-ocean distributions of Brunt-Vaisala frequency (cycles per hour); values were calculated at 10 m intervals as the
least-squares fit over a 10-m centered bins; the shallowest value is at 9.5 m. Light contour is at 3 cph; heavy contours are at intervals
of 6 cph.
-14-
Sep 99
Depth (m)
0
-0.6
0
50
100
Sep 00
Sep 01
0.2
0
-1
-1
-1
NH
-0.2
-0.2
-0.2
-0.2
0
150
0.4
0
0
0
0.4
-0.6
0
-0.4
-0.4
Depth (m)
Sep 03
0
0.2
-0.8
-0.8
Sep 02
0
50
-0.6
-0.2
-0.2
0
100
0
150
-160 -120 -80 -40
Distance (km)
-1
0
CR
0
-0.2
0
Figure 11. Upper-ocean distributions of spiciness (kg m-3), calculated from T-S characteristics following Flament (2002).
-15-
Apr 99
Depth (m)
0
Apr 00
100
Mar 01
50
100
90
90
90
Apr 03
110
100
NH
100
50
50
50
50
40
150
30
40
100
100
90
50
40
40
120
105
100
100
0
Depth (m)
Apr 02
90
105
90
CR
90
100
50
50
50
50
40
50
40
40
150
-160
-80
0
Distance (km)
Figure 12. Upper-ocean distributions of oxygen saturation (%). Contour interval is 10 %; the 50 % and 100% contours are heavy and
the 105% contour is dashed. Saturation percentage was calculated from CTD oxygen concentration data calibrated by Winkler-titrated
samples from a few stations on each cruise, using the algorithm from the Scripps PACODF library.
-16-
Sep 99
Depth (m)
0
Sep 00
1
1
1
50
Sep 02
Sep 03
2
4
0.5
Sep 01
0.5
0.5
0.5
0.5
NH
5
100
4
3
150
2
5
0
0.5
1
Depth (m)
0.5
4
2
1
1
0.5
50
2
0.5
0
0.5
CR
100
150
-160
-80
0
Distance (km)
Figure 13. Upper-ocean distributions of fluorescence voltage (V). Contours: dashed at 0.5 V; thin at 1, 3; heavy at 2, 4; full scale is
at 15 V in 2002 and at 5.0 V in other years. Fluorometer calibration is believed to remain about the same within each cruise though it
may vary from cruise to cruise.
-17-
Sep 99
Sep 00
0.5
0
Depth (m)
Sep 02
5
0.5
10
Sep 01
Sep 03
10
0.5
0.5
50
NH
100
30
30
30
30
30
150
0
5
5
10
Depth (m)
50
150
-160
5
10
20
100
10
5
10
0.5
CR
20
25
30
30
-80
Distance (km)
30
30
0
Figure 14. Upper-ocean distributions of total nitrate (µmol/l).
-18-
30
0
Sep 99
Sep 00
0.5
0.5
Sep 01
Sep 02
0.5
Sep 03
1
0.5
Depth (m)
1
1
50
3
2
2
2
100
3
NH
2
2
2.5
2.5
150
0
0.5
1
1
Depth (m)
1
50
1
1
1.5
CR
1.5
100
150
-160
2
2
2
-80
Distance (km)
2
2
0
Figure 15. Upper-ocean distributions of phosphate (µmol/l).
-19-
Sep 99
Sep 00
0
Depth (m)
20
NH
30
30
50
40
40
10
30
40
10
5
10
5
20
20
30
30
-80
Distance (km)
CR
10
30
40
150
-160
20
40
5
10
100
60
50
0
Depth (m)
5
20
30
150
50
10
10
20
40
Sep 03
5
10
50
100
Sep 02
5
5
10
Sep 01
40
40
40
0
Figure 16. Upper-ocean distributions of silicate (µmol/l).
-20-
30
20
40
Sep 99
0
Sep 00
8
2
0.5
0.5
Depth (m)
Sep 01
Sep 02
2
1
Sep 03
1
0.5
4
1
0.5
0.5
50
NH
100
20
16
12
150
0
0.5
1
8
8
1
Depth (m)
>0.5
8
1
>0.5
2
8
4
1
0
50
0.5
0.5
100
150
-160
-80
Distance (km)
0
Figure 17. Upper-ocean distributions of chlorophyll (mg/m ). Contours are at 0.5 (dashed), 1, and 2, 4, 8 (heavy), 12 and 16
3
mg/m .
3
-21-
CR
Sep 99
Sep 00
Sep 01
Sep 02
Surface Salinity
Surface Temperature
20
NH
16
12
CR
8
36
34
32
30
160
80
Distance (km)
0
Figure 18. Offshore profiles of surface temperature and salinity.
-22-
Sep 03
Sep 00
Sep 01
Sep 02
Sep 03
100
Geopot Anom (0/150)
Geopot Anom (0/500)
Sep 99
NH
80
CR
60
40
20
160
80
Distance (km)
0
Figure 19. Offshore profiles of steric height (J/kg) of the sea surface relative to 150 dbar and 500 dbar.
-23-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Mixed Layer Depth (m)
60
40
CR
20
NH
Surface σθ
0
27
24
21
160
80
Distance (km)
0
Figure 20. Offshore profiles of surface density and of surface mixed layer depth, defined as the depth at which potential density
exceeds the surface value by 0.01 kg m-3.
-24-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Mixed Layer Depth (m)
80
60
CR
40
NH
20
Surface σθ
0
27
24
21
160
80
Distance (km)
0
Figure 21. Offshore profiles of surface density and of surface mixed layer depth, defined as the depth at which potential density
exceeds the surface value by 0.1 kg m-3.
-25-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
18
NH
1-15
Temperature
p
(C)
( )
15
12
9
NH
20-85
6
3
18
CR
1-3
Temperature
p
(C)
( )
15
12
9
CR
4-11
6
3
31
32 33 34
Salinity (psu)
35
Figure 22. T-S characteristics of all CTD stations. Shelf stations are plotted in red.
-26-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
18
NH
Temperature
p
(C)
( )
15
12
9
CR
6
3
18
NH
Temperature
p
(C)
( )
15
12
9
CR
6
3
31
32 33 34
Salinity (psu)
35
Figure 23. Superimposed groups of T-S characteristics. Upper row: NH (black) on CR (red). Lower row: CR (red) on NH (black).
-27-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Temperature (C)
12
NH
1-15
9
NH
20-85
6
Temperature (C)
12
CR
1-3
9
CR
4-11
6
32
33
34
Salinity (psu)
Figure 24. Detail of T-S characteristics in the permanent halocline. Shelf stations are plotted in red.
-28-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Dissolved Oxygen
yg (ml/l)
(
)
10
8
NH
6
1-15
4
NH
2
20-85
0
Dissolved Oxygen
yg (ml/l)
(
)
10
8
CR
6
1-3
4
CR
2
4-11
0
31
32 33 34
Salinity (psu)
35
Figure 25. Oxygen-salinity characteristics of all CTD stations. Shelf stations are plotted in red.
-29-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Dissolved Oxygen (ml/l)
10
8
NH
6
1-15
4
NH
2
20-85
0
Dissolved Oxygen (ml/l)
10
8
CR
6
1-3
4
CR
2
4-11
0
32
33
34
Salinity (psu)
Figure 26. Detail of oxygen-salinity characteristics in and below the permanent halocline. Shelf stations are plotted in red.
-30-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Nitrate (µM)
40
NH-5,15
20
NH-25 to -85
0
Nitrate (µM)
40
CR-1,3
20
CR-4 to -11
0
0
2
4
Phosphate (µM)
Figure 27. Nitrate-phosphate relations for all rosette samples. Shelf stations are plotted in red.
-31-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Silicate (µM)
150
100
NH-5,15
NH-25 to -85
50
0
Silicate (µM)
150
100
CR-1,3
CR-4 to -11
50
0
0
2
4
Phosphate (µM)
Figure 28. Silicate-phosphate relations for all rosette samples. Shelf stations are plotted in red.
-32-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Nitrate (µM)
40
NH-5,15
20
NH-25 to -85
0
Nitrate (µM)
40
CR-1,3
20
CR-4 to -11
0
30
32
34
Salinity (psu)
Figure 29. Nitrate-salinity relations. Shelf stations are plotted in red.
-33-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Nitrate (µM)
40
NH-5,15
20
NH-25 to -85
0
Nitrate (µM)
40
CR-1,3
20
CR-4 to -11
0
32
33
34
Salinity (psu)
Figure 30. Nitrate-salinity relations for samples with salinities ≥ 32 psu. Shelf stations are plotted in red.
-34-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Nitrate (µM)
40
NH
CR
20
0
32
33
34
Salinity (psu)
Figure 31. Nitrate-salinity relations for samples with salinities ≥ 32 psu: CR data (red) superimposed on NH data (black).
-35-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
(µM)
Phosphate (uM)
4
NH-5,15
2
NH-25 to -85
0
(µM)
Phosphate (uM)
4
CR-1,3
2
CR-4 to -11
0
30
34
32
Salinity (psu)
Figure 32. Phosphate-salinity relations. Shelf stations are plotted in red.
-36-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Phosphate (µM)
4
NH-5,15
2
NH-25 to -85
0
Phosphate (µM)
4
CR-1,3
2
CR-4 to -11
0
32
34
Salinity (psu)
Figure 33. Phosphate-salinity relations for samples with salinities ≥ 32 psu. Shelf stations are plotted in red.
-37-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Phosphate (µM)
4
NH
2
CR
0
32
34
33
Salinity (psu)
Figure 34. Phosphate-salinity relations for samples with salinities ≥ 32 psu: CR data (red) superimposed on NH data (black).
-38-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Silicate (µM)
150
100
NH-5,15
NH-25 to -85
50
0
Silicate (µM)
150
100
CR-1,3
CR-4 to -11
50
0
30
32
34
Salinity (psu)
Figure 35. Silicate-salinity relations. Shelf stations are plotted in red.
-39-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Silicate (µM)
150
100
NH-5,15
NH-25 to -85
50
0
Silicate (µM)
150
100
CR-1,3
CR-4 to -11
50
0
32
33
34
Salinity (psu)
Figure 36. Silicate-salinity relations for samples with salinities ≥ 32 psu. Shelf stations are plotted in red.
-40-
Sep 99
Sep 00
Sep 01
Sep 02
Sep 03
Silicate (µM)
(uM)
150
100
NH
CR
50
0
32
33
34
Salinity (psu)
Figure 37. Silicate-salinity relations for rosette samples with salinities ≥ 32 psu: CR data (red) superimposed on NH data (black).
-41-