During the 2002 cruises four production line versions (#43020, #43166, #43262, and #43134) of the Sea-Bird SBE 43 oxygen sensor were used. Sensor #43020 belongs to STAG. As mentioned in the previous section, sensor #43166 was repaired and calibrated at Sea-Bird in January 2002; the sensor was repaired again in March and August 2002 after failing during HOT-135 and HOT-138 respectively. In both cases the sensor head assembly was replaced. The sensor failed again during HOT-140, and Sea-Bird replaced the sensor with a new sensor #43325 in October 2002. Sensor #43262 was acquired in March 2002 and failed during HOT-143, the sensor’s lid and membrane assembly was replaced and the electrolyte reservoir was re-backfilled at Sea-Bird in February 2003. Sensor #43134 was acquired in January 2002 and performed correctly during 2002 cruises.
One YSI Inc. probe (#13251) was also used during HOT-134.
Three sets of calibration parameters were usually obtained per HOT cruise, corresponding to the casts at Stations 1, 2 and 8. Table 4.14 shows the mean and standard deviation for the calibrated CTD oxygen minus water sample residuals for each cruise. Cruises HOT-142 and 143 had problems with the oxygen titration equipment, deeming the samples unreliable (Fitzgerald, 2003), thus the values for these cruises are not included in the table.
Table 4.14a: CTD-Bottle dissolved oxygen per cruise at Station Kahe (µmol kg-1). Cruises 142 and 143 oxygen samples not reliable (see text).
|
|
0 to 1500 dbar
|
|
Cruise
|
Sensor
|
Mean
|
SD
|
HOT-134 |
43020 |
0.00 |
0.37 |
HOT-135 |
43134 |
0.02 |
1.65 |
HOT-136 |
43134 |
0.01 |
0.82 |
HOT-137 |
43134 |
0.01 |
1.14 |
HOT-138 |
43134 |
-0.01 |
1.78 |
HOT-139 |
43262 |
-0.30 |
1.33 |
HOT-140 |
43262 |
0.00 |
0.74 |
HOT-141 |
43262 |
0.00 |
0.89 |
HOT-142 |
43262 |
- |
- |
HOT-143 |
43134 |
- |
- |
Table 4.14b: CTD-Bottle dissolved oxygen per cruise at Station ALOHA (µmol kg-1). Cruises 142 and 143 oxygen samples not reliable (see text).
|
|
0 to 4800 dbar |
500 to 4800 dbar |
||
Cruise |
Sensor |
Mean |
SD |
Mean |
SD |
HOT-134 |
43020 |
0.01 |
0.71 |
-0.01 |
0.68 |
HOT-135 |
43134 |
-0.02 |
0.68 |
-0.02 |
0.64 |
HOT-136 |
43134 |
0.01 |
0.80 |
0.02 |
0.69 |
HOT-137 |
43134 |
0.02 |
0.98 |
0.04 |
0.73 |
HOT-138 |
43134 |
0.08 |
0.91 |
0.02 |
0.75 |
HOT-139 |
43262 |
0.01 |
0.68 |
0.02 |
0.61 |
HOT-140 |
43262 |
0.04 |
0.86 |
0.07 |
0.63 |
HOT-141 |
43262 |
0.07 |
0.89 |
0.05 |
0.81 |
HOT-142 |
43262 |
- |
- |
- |
- |
HOT-143 |
43134 |
- |
- |
- |
- |
Table 4.14c: CTD-Bottle dissolved oxygen at Station HALE-ALOHA (µmol kg-1)
|
|
0-1500 dbar |
|
Cruise |
Sensor |
Mean |
SD |
HOT-134 |
43020 |
0.00 |
0.57 |
HOT-135 |
43134 |
0.00 |
1.12 |
HOT-136 |
43134 |
0.00 |
0.77 |
HOT-137 |
43134 |
0.00 |
0.98 |
HOT-139 |
43262 |
0.00 |
0.85 |
HOT-140 |
43262 |
0.00 |
0.51 |
Figure 4.15 shows the CTD oxygen data quality for every 2-dbar bin in each cast at Station ALOHA for cruises 134 through 143.
Figure 4.15. CTD oxygen data quality per cast (vertical bars) and per 2-dbar bin at Station ALOHA during HOT cruises 134 through 143. The tick marks along the x-axis separate different casts. Casts from the same cruise are separated by vertical black lines.