Processing Steps |
- Parameter or Variable: CTD pressure; Abbreviation: pr; Unit: dbars; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: CTD; Analyzing instrument: Sea-Bird SBE-911plus CTD system; Detailed sampling and analyzing information: A detailed and more complete description is available in the cruise report at: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf. CTD/rosette casts were performed with a package consisting of a 24-place, 10-liter rosette frame (AOML white frame), a 24-place water sampler/pylon (SBE32) and 24, 10-liter Bullister/Niskin-style bottles. This package was deployed on all stations/casts. Underwater electronic components consisted of a Sea-Bird Electronics (SBE) 9 plus CTD with dual pumps and the following sensors: dual temperature (SBE3), dual conductivity (SBE4), dual dissolved oxygen (SBE43), and a Simrad 807 altimeter. The CTDs supplied a standard Sea-Bird format data stream at a data rate of 24 frames/second. The SBE9plus CTD was connected to the SBE32 24-place pylon providing for single-conductor sea cable operation. Power to the SBE9plus CTD, SBE32 pylon, auxiliary sensors, and altimeter was provided through the sea cable from the SBE11plus deck unit in the computer lab. Shipboard CTD data processing was performed automatically at the end of each deployment using SEABIRD SBE Data Processing version 7.21h and AOML Matlab processing software.; Uncertainty: Pressure sensor calibration coefficients derived from the pre-cruise calibrations were applied to raw pressure data during each cast. Residual pressure offsets (the difference between the first and last submerged pressures) were examined to check for calibration shifts. On deck pressure before the start of each cast was recorded. The on deck pressure before and after the cast were stable at 1.67 +/- 0.081 db, and 1.68 +/- 0.087 db respectively. Near surface pressure values (which are taken as the near-surface pressure at the markscan and the last fired bottle pressure) showed relatively small variability (4.41+/- 0.40 db before and 4.54+/- 0.33 db after).; Method reference: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf.; Researcher name: Molly Baringer; Researcher institution: Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration.
- Parameter or Variable: CTD temperature; Abbreviation: te; Unit: degree C; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: CTD; Analyzing instrument: Sea-Bird SBE-911plus CTD system; Detailed sampling and analyzing information: A detailed and more complete description is available in the cruise report at: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf. CTD/rosette casts were performed with a package consisting of a 24-place, 10-liter rosette frame (AOML white frame), a 24-place water sampler/pylon (SBE32) and 24, 10-liter Bullister/Niskin-style bottles. This package was deployed on all stations/casts. Underwater electronic components consisted of a Sea-Bird Electronics (SBE) 9 plus CTD with dual pumps and the following sensors: dual temperature (SBE3), dual conductivity (SBE4), dual dissolved oxygen (SBE43), and a Simrad 807 altimeter. The CTDs supplied a standard Sea-Bird format data stream at a data rate of 24 frames/second. The SBE9plus CTD was connected to the SBE32 24-place pylon providing for single-conductor sea cable operation. Power to the SBE9plus CTD, SBE32 pylon, auxiliary sensors, and altimeter was provided through the sea cable from the SBE11plus deck unit in the computer lab. Shipboard CTD data processing was performed automatically at the end of each deployment using SEABIRD SBE Data Processing version 7.21h and AOML Matlab processing software.; Uncertainty: Temperature sensor calibration coefficients derived from the pre-cruise calibrations were applied to raw primary and secondary temperature data during each cast. Calibration accuracy was examined by comparing T1-T2 over a range of station numbers and pressures (bottle trip locations) for each cast. For the entire cruise, only one set of temperature sensors were used, both tracked each other extremely nicely. The median temperature difference between the two sensors was 0.0006 degrees Celsius with a pseudo standard deviation of 0.006 degrees Celsius.; Method reference: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf.; Researcher name: Molly Baringer; Researcher institution: Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration.
- Parameter or Variable: Potential temperature; Abbreviation: th; Unit: degree C; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Calculated; Sampling instrument: CTD; Analyzing instrument: Sea-Bird SBE-911plus CTD system; Researcher name: Molly Baringer; Researcher institution: Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration.
- Parameter or Variable: CTD salinity; Abbreviation: sa; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Calculated from conductivity measurements.; Sampling instrument: CTD; Analyzing instrument: Sea-Bird SBE-911plus CTD system; Detailed sampling and analyzing information: A detailed and more complete description is available in the cruise report at: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf. CTD/rosette casts were performed with a package consisting of a 24-place, 10-liter rosette frame (AOML white frame), a 24-place water sampler/pylon (SBE32) and 24, 10-liter Bullister/Niskin-style bottles. This package was deployed on all stations/casts. Underwater electronic components consisted of a Sea-Bird Electronics (SBE) 9 plus CTD with dual pumps and the following sensors: dual temperature (SBE3), dual conductivity (SBE4), dual dissolved oxygen (SBE43), and a Simrad 807 altimeter. The CTDs supplied a standard Sea-Bird format data stream at a data rate of 24 frames/second. The SBE9plus CTD was connected to the SBE32 24-place pylon providing for single-conductor sea cable operation. Power to the SBE9plus CTD, SBE32 pylon, auxiliary sensors, and altimeter was provided through the sea cable from the SBE11plus deck unit in the computer lab. Shipboard CTD data processing was performed automatically at the end of each deployment using SEABIRD SBE Data Processing version 7.21h and AOML Matlab processing software.; Uncertainty: Conductivity sensor calibration coefficients derived from the pre-cruise calibrations were applied to raw primary and secondary conductivities. Comparisons between the primary and secondary sensors and between each of the sensors to check sample conductivities (conductivity calculated from bottle salinities) were used to derive conductivity corrections. For the entire cruise, only one set of conductivity sensors were used, both tracked each other extremely nicely. The two sensors show a median difference of 0.00092 S/m and a pseudo standard deviation of 0.00064 S/m.; Quality flag convention: WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value.; Method reference: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf.; Researcher name: Molly Baringer; Researcher institution: Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration.
- Parameter or Variable: Dynamic height (cm); Abbreviation: ht; Unit: cm; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Calculated; Sampling instrument: CTD; Researcher name: Molly Baringer; Researcher institution: Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration.
- Parameter or Variable: Specific weight, gamma; Abbreviation: ga; Unit: N/m^3; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Calculated; Sampling instrument: CTD; Researcher name: Molly Baringer; Researcher institution: Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration.
- Parameter or Variable: CTD oxygen; Abbreviation: ox; Unit: micromol/kg; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: CTD; Analyzing instrument: Sea-Bird SBE-911plus CTD system; Detailed sampling and analyzing information: A detailed and more complete description is available in the cruise report at: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf. CTD/rosette casts were performed with a package consisting of a 24-place, 10-liter rosette frame (AOML white frame), a 24-place water sampler/pylon (SBE32) and 24, 10-liter Bullister/Niskin-style bottles. This package was deployed on all stations/casts. Underwater electronic components consisted of a Sea-Bird Electronics (SBE) 9 plus CTD with dual pumps and the following sensors: dual temperature (SBE3), dual conductivity (SBE4), dual dissolved oxygen (SBE43), and a Simrad 807 altimeter. The CTDs supplied a standard Sea-Bird format data stream at a data rate of 24 frames/second. The SBE9plus CTD was connected to the SBE32 24-place pylon providing for single-conductor sea cable operation. Power to the SBE9plus CTD, SBE32 pylon, auxiliary sensors, and altimeter was provided through the sea cable from the SBE11plus deck unit in the computer lab. Shipboard CTD data processing was performed automatically at the end of each deployment using SEABIRD SBE Data Processing version 7.21h and AOML Matlab processing software.; Uncertainty: Two SBE43 dissolved O2 (DO) sensors were used on this cruise. Both sensors tracked each other very well, with no noted problems. The DO sensors were calibrated to dissolved O2 check samples by matching the up cast bottle trips to down cast CTD data along isopycnal surfaces, calculating CTD dissolved O2, and then minimizing the residuals using a non-linear least-squares fitting procedure. The fitting determined calibration coefficients for the sensor model conversion equation and proceeded in a series of steps. Each sensor was fit in a separate sequence. The first step was to determine the time constants for the exponential terms in the model. These time constants are sensor-specific but applicable to an entire cruise. Once the time constants had been determined, casts were fit individually to O2 check sample data. The resulting calibration coefficients were then smoothed and held constant during a refit to determine sensor slope and offset. Calibration accuracy was examined by comparing O1-O2 over a range of station numbers and pressures (bottle trip locations) for each cast. For the entire cruise, only one set of oxygen sensors were used, both tracked each other extremely nicely. The two sensors show a median difference of -2.96 micro-mol/kg and a pseudo standard deviation of 1.21 micro-mol/kg.; Method reference: http://www.aoml.noaa.gov/ocd/gcc/GOMECC2/Cruise_Report.pdf.; Researcher name: Molly Baringer; Researcher institution: Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration .
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