CalCOFI 9910NH CTD Data Processing Notes 2021

CalCOFI 9910NH was processed using SBE Data Processing Suite 7.23.2 without
issue. Using our current CalCOFI protocol, the cruise generated high quality
clean data. The Beckman/YSI oxygen sensor, when calibrated with bottle O2 samples,
generated decent data. Underestimating surface oxygen on the downcast can still
be a issue, observed in the bottle vs sensor data profiles. Also, on many casts
the oxygen sensor is relatively noisy even when smoothed using wfilter. The 
sensor does follow the bottle sample measurements but there is some back-forth
"noise" in the data, deemed insignificant. 

It is noted that casts 029-030 had dual O2 sensors listed in the .con files.
Also casts 032-072 also seemed to have dual O2 sensors or at least another
sensor on V5/6. Casts 029-057 were processed using 9910030.con since 032-057
listed only one O2 sensor in the .con files. An additional sensor was present.
I do not have console ops notes & nothing is written in the .hdr files. So
this cruise was processed as only having one O2 sensor although it changed
three times: 001-028, 029-057, 058-072. Refer to the O2 sensor vs bottle
oxygen plot in the Metadata folder for clarification. All other sensors were
not changed during the cruise and behaved well. There was a fluorometer 
sensitivity change noted on casts 053. It appears to have been switched back
on cast 056 for the remainder of the cruise. Refer to the FlV vs Chl-a plot
in the Metadata folder for clarification.

So these data were processed in 4 sets: Casts 001-028; 029-052,056-057, 637; 053-055 
(Fluorometer sensitivity changed); & 058-072.
Casts 637 (deep cast on sta 037) was to 2000m so any shallow-depth sensors were 
removed. The PAR, rated only to 1000m, was removed after cast 028 and remained 
offline for the rest of the cruise. So it may not have been necessary to remove
any sensors for the two deep casts.
Cast 072 was also a deep cast to 1500m with no bottle samples. 

Sensor configuration had flurometer on V0, transmissometer on V1, altimeter on
V2, PAR on V3 (casts 001-028), O2 on V4/5, V6/7 were open on casts 001-028 then
secondary O2 on 029-030, sPar on V15. The secondary O2 sensor serial #'s & 
calibrations were questionable. So, although the asc files include secondary O2,
only the primary were bottle corrected. The values of the secondary O2 later in
the cruise do not look right ie too high. So either the calibrations are off or
there's some other correction that needs to be applied.

Data flagged files:
Fluorometer looks bad/questionable on casts 053 & 055. On cast 053, data below
125m are flagged bad "9"; on cast 055 data below 125m are flagged questionable "8"
Noisy O2 data were not flagged since the profiles follow bottle data pretty closely.

JRW 07/23/2021