CalCOFI's Seabird 911+ CTD includes dual Temperature, Conductivity, and Oxygen sensor arrays that are separately plumbed & pumped. Data from these sensors are labeled Temp1, Salt1, Ox1, & Temp2, Salt2, Ox2 respectively (refer to the index below for units). The "FinalQC" version of the CTD csvs also include oxygens in umol/kg (Ox1uM, Ox2uM) and data-quality code columns. Data codes (flags) may be use to identify bad (datacode "9") or questionable (datacode "8") data.

CalCOFI collects seawater samples using 24-10L metal-free bottles mounted on an epoxy-coated rosette. The seawater samples are analyzed at-sea then undergo a series of additional data-processing, calibration, & data-quality steps on shore. Initial merging & comparison of CTD & bottle data generates the "prelim" CTD csvs used for point-checking. Once bottle data have been gone through CalCOFI's data quality control protocols, the final bottle data are merged with 1m-binavg CTD sensor data from the same cast, same depths. CTD salinities deeper than 350m are subtracted from matching bottle (depth) salinities. These differences are averaged into offsets for both primary and secondary CTD salinities and applied to all CTD salinities. Bottle-corrected CTD salinities are reported as Salt1_Corr (primary), Salt2_Corr (secondary), and SaltAve_Corr (ave of both).

Oxygen bottle samples are plotted versus the corresponding CTD primary (Ox1) and secondary (Ox2) oxygen sensor data. Regression coefficients to correct CTD oxygens are derived for both sensors in ml/L and uM/kg - 4 plots total. The bottle-corrected CTD sensor data are reported in the Ox1_CruiseCorr (ml/L) and Ox1uM_CruiseCorr (uM/Kg) and Ox2_CruiseCorr and Ox2_uM_CruiseCorr data columns.

One-meter binavg CTD fluorometer voltages are plotted versus the corresponding depth chlorophyll bottle samples to derive regression coefficients. These are applied to the 1m binavg fluorometer voltages from 0-200 meters, estimating chlorophyll-a  & reported as EstChl_CruiseCorr.

A plot of 1m binavg ISUS voltages versus nitrate (NO3) using all the nitrate bottle samples generates regression coefficients. These are applied to the 1m binavg ISUS voltage to derive estimated nitrate data, reported as EstNO3_CruiseCorr

In addition to cruise-corrected CTD data, there are station-corrected data. These data are bottle-corrected CTD data that use the bottle data from only the matching station. These data are generated using CalCOFI-developed software that dynamically calculates the correction coefficients and applies them automatically to CTD sensor data. These data are usually the best data since this method adjusts for station-to-station variablilty in the sensor behavior such as sensor drift. These data are reported as "StaCorr": Ox1_StaCorr, Ox2_StaCorr, EstChl_StaCorr, EstNO2_StaCorr. The coefficients applied dynamically for each station may be different and are tabulated in each cruises CTD metadata file "DBcoeff.csv".

Please note that the FinalQC format with additional data quality code columns was adopted in 2015. CTD data files with the 82-column format are labeled "FinalQC". Cruise files labeled "Final" are being reprocessed to add the data-quality columns, data codes, & O2s in uM/Kg. When updated, they will be relabled "FinalQC".  Note that most data values, particularly T & S, should remain unchanged - only the format is changing and data-flags added.
QCodes: blank or "0" code = good data; "8" = questionable data; "9" = bad data

82-Column CTD + Bottle CSV Format (color key & data code index at bottom)
Count (Excel Column) Field Description Format
1 (A) Project Cruise; usually CalCOFI Text, variable
2 (B) Study YYMMSS (year month ship) Cruise designation Text, 6 char
3 (C) Ord_Occ Order Occupied Integer
4 (D) Event_Num CTD-at-Depth event number Integer
5 (E) Cast_ID Study+Order Occupied+up or downcast Text, YYMM_###D or U
6 (F) Date_Time_UTC Date Time UTC; downcast = start time; upcast=time @ 1st bottle tripped DD-MMM-YYYY HH:M:SS
7 (G) Date_Time_PST Date Time PST: downcast = start time; upcast=time @ 1st bottle tripped DD-MMM-YYYY HH:MM:SS
8 (H) Lat_Dec GPS Decimal Latitude: downcast = start lat; upcast=lat @ 1st bottle tripped R7.5; ##.#####
9 (I) Lon_Dec GPS Decimal Longitude: downcast = start lon; upcast=lon @ 1st bottle tripped R8.5; -###.#####
10 (J) Sta_ID CalCOFI Line and Station Text; LLL.L SSS.S
11 (K) Line CalCOFI Line R4.1; LLL.L
12 (L) Sta CalCOFI Station R4.1; SSS.S
13 (M) Depth 1 Meter Binavg Depth (meters) R7.3; #.###
14 (N) Pressure 1 Meter Binavg Pressure (db) R7.3; #.###
15 (O) PrQ Pressure Sensor Data Quality I1
16 (P) Temp1 1° Temperature (deg C)  R6.4; ##.####
17 (Q) Temp1Q 1° Temperature Data Quality Code I1; see key below
18 (R) Temp2 2° Temperature (deg C)  R6.4; ##.####
19 (S) Temp2Q 2° Temperature Data Quality Code  I1
20 (T) TempAve Average Temperature, deg C; (1°+2°)/2 R6.4;# #.####
21 (U) Salt1 1° Salinity (PSU) R6.4; ##.####
22 (V) Salt1Q 1° Salinity Data Quality Code I1
23 (W) Salt1_Corr 1° Salinity, Bottle-corrected (PSU) R6.4
24 (X) Salt2 2° Salinity (PSU) R6.4
25 (Y) Salt2Q 2° Salinity Data Quality Code I1
26 (Z) Salt2_Corr 2° Salinity, Bottle-corrected (PSU) R6.4
27 (AA) SaltAve_Corr Average Corrected Salinity; (1°+2°)/2 R6.4
28 (AB) Ox1 1° Oxygen; ml/L R6.5
29 (AC) Ox1Q 1° Oxygen Data Quality Code I1
30 (AD) Ox1_CruiseCorr 1° Oxygen, cruise-corrected; ml/L R6.5; see key
31 (AE) Ox1_StaCorr 1° Oxygen, sta-corrected;  ml/L R6.5; see key
32 (AF) Ox2 2° Oxygen; ml/L R6.5
33 (AG) Ox2Q 2° Oxygen Data Quality Code I1
34 (AH) Ox2_CruiseCorr 2° Oxygen, cruise-corrected; ml/L R6.5
35 (AI) Ox2_StaCorr 2° Oxygen, sta-corrected;  ml/L R6.5
36 (AJ) OxAve_StaCorr Average Oxygen (ml/L); (1°+2°)/2 R6.5
37 (AK) Ox1uM 1° Oxygen; uM/Kg  
38 (AL) Ox1uM_CruiseCorr 1° Oxygen;cruise-corrected;uM/Kg  
39 (AM) Ox1uM_StaCorr 1° Oxygen;sta-corrected; uM/Kg  
40 (AN) Ox2uM 2° Oxygen; uM/Kg  
41 (AO) Ox2uM_CruiseCorr 2° Oxygen;cruise-corrected;uM/Kg  
42 (AP) Ox2uM_StaCorr 2° Oxygen;sta-corrected; uM/Kg  
43 (AQ) OxAveuM_StaCorr Average Oxygen (ml/L); (1°+2°)/2  
44 (AR) FluorV Fluorometer Voltage (V) R5.4
45 (AS) FluorQ Fluorometer Data Quality Code I1
46 (AT) EstChl_CruiseCorr Estimated Chlorophyll, cruise-corrected R6.4
47 (AU) EstChl_StaCorr Estimated Chlorophyll, sta-corrected R6.4
48 (AV) ISUSV ISUS Voltage R5.4
49 (AW) ISUSQ ISUS Data Quality Code I1
50 (AX) EstNO3_CruiseCorr Estimated Nitrate, cruise-corrected R5.4
51 (AY) EstNO3_StaCorr Estimated Nitrate, sta-corrected R5.4
52 (AZ) SigThetaTS1 Sigma-theta T1S1 R6.4
53 (BA) SigThetaTS1Q Sigma-theta T1S1 Quality Code I1
54 (BB) SigThetaTS2 Sigma-theta T2S2 R6.4
55 (BC) SigThetaTS2Q Sigma-theta T2S2 Quality Code I1
56 (BD) BAT Beam Attenuation Coefficient R5.4
57 (BE) XMiss % Light Transmission R6.4
58 (BF) TransQ Transmissometer Quality Code I1
59 (BG) pH pH Sensor R6.4
60 (BH) pHQ pH Sensor Quality Code I1
61 (BI) SPAR Surface PAR #.##E+##
62 (BJ) SPARQ Surface PAR Quality Code I1
63 (BK) PAR Remote PAR #.##E+##
64 (BL) PARQ Remote PAR Quality Code I1
65 (BM) PoT1 Potential Temperature R6.4
66 (BN) PoT2 Potential Temperature R6.4
67 (BO) DynHt Dynamic Height R5.4
68 (BP) SVA Specific Volume Anomaly R6.3
69 (BQ) OxSat1 Oxygen Saturation R5.4
70 (BR) OxSat2 Oxygen Saturation R5.4
71 (BS) BTL_Depth Bottle Depth (meters) I4
72 (BT) BTL_Temp Bottle Temperature (deg C); usually 1°T R5.3
73 (BU) SaltB Bottle Salinity (PSU) R6.4
74 (BV) OxB Bottle Oxygen (ml/L) R4.3
75 (BW) OxBuM Bottle Oxygen (umol/KG) R6.2
76 (BX) Chl-a Bottle Chlorophyll R4.3
77 (BY) Phaeo Bottle Phaeopigments R4.3
78 (BZ) NO3 Bottle Nitrate R3.1
79 (CA) NO2 Bottle Nitrite R3.2
80 (CB) NH4 Bottle Ammonium R3.2
81 (CC) PO4 Bottle Phosphate R4.2
82 (CD) SIL Bottle Silicate R5.2
Color Codes for this table (background color indicates data source)
Color Data Type Source
White CTD Cast Information CTD "At Depth" Metadata
Green CTD Data 1m binavg CTD Data, Seasave processed
Yellow Bottle-corrected CTD Data 1m CTD Data, Seasave processed, bottle corrected
Blue Bottle Data Final, processed bottle data
Purple Data Quality

Data Quality Codes and Comments:

  • 0 or blank = Good Data
  • 1 = use Primary sensor data (dual sensors)
  • 2 = use Secondary sensor data (dual sensors)
  • 8 = data questionable
  • 9 = bad or missing data


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