Dataset: CTD profiles
Deployment: EN402

CTD cast profile data from MedFlux EN402 cruise

Principal Investigator:

Cindy Lee (Stony Brook University, SUNY Stony Brook)

BCO-DMO Data Manager:

Cynthia L. Chandler (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

MedFlux collaborative research project (MedFlux)

Current State:

Final no updates expected

Version Date:

2006-02-02

Data URL:

https://www.bco-dmo.org/dataset-deployment/453425/data

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Description

CTD profile data including pressure, temperature, salinity, dissolved oxygen, potential temperature, density and fluorometric chlorophyll a

Methods & Sampling

Dataset acquisition description

Data Processing Description

Dataset Processing Description

MedFlux cruise: EN402 March 2005
CTD profile data processing notes

31 January 2006: Prepared for OCB data system by Terry McKee (PO Dept, WHOI) and Cyndy Chandler, OCB DMO (WHOI).

DMO Notes Summary:

Original data contributed: 19 September 2005 on CD-ROM by Cindy Lee
Processed: January 2006 by TMcKee (PO Dept., WHOI) and OCB DMO

Data were recovered from Seabird raw data files and are reported as 0.5 dbar pressure sorted profiles. No comparison has been done with any in-situ data. Use with caution.

Details of CTD data processing steps:

Seabird processed CTD downtrace data files (*.cnv) were contributed on the CD-ROM that was generated during the cruise and the OCB DMO extracted the data from those files. Data had been processed during the cruise using the standard set of Seabird utilities, to generate final 0.5-decibar pressure sorted downtrace files for all CTD casts. The only additional processing done by the OCB DMO, was to reformat the at-sea-processed .cnv files (.5db bin-averaged) found in the "list" directory. The *.cnv files had been output in binary format, so we used the SBEDataProcessing program, "Translate", to convert the data to ASCII format. Also, MATLAB Physical Properties of Seawater routines were used to calculate and add several derived oceanographic parameters.

EN402 CTD shipboard data processing notes:

Modified from 402CTDprocessing.doc file contributed on post-cruise data CD-ROM.

CTD001 a Benthos Altimeter was installed.

CTD002-011 a WET Labs ECO Fluorometer was installed and Altimeter removed.

Datcnv

X Process scans to end of file. Scans to skip over 0. Binary output, up& down, Both bottle & data to list. Scans marked with bottle confirm bit. Scan range offset 0. Scan range duration 2. Do not merge separate header file.

Scan Count, Time Elapsed (s), Pressure Digiquartz (db), Depth seawater (m), Temp 1, Temp 2, Temp Diff, Cond 1, Cond 2, Cond Diff, V0, V1, V3, Beam Attenuation Seatech, Beam Transmission Seatech, Fluorescence Seatech, Fluorescence WETLab ECOFL, V4, Oxygen V SBE43 1, V6, Oxygen V SBE43 2, Pump Status, Latitude, Longitude, Bottles Fired.

Filter for SBE9, old manual.txt suggests Low pass filter B = 0.15s for pressure

Low pass filter A = 0.03s for conductivity

New SBEDataProcessing_5.32a.pdf suggests only .15 for pressure

Used: B=0.15 for Press, Depth. A=0.03 for Cond 1 & 2 & Diff

AlignCTD for

Cond 0.073s (secondary only)

Temp 0

DO 4 (2 at 25C, 5 at 0C) V4, Oxy V pri, V6, OxyV sec

CellTM for 9+ w/TC duct & pump running at 3000rpm. Correct both pri & sec conductivity values

alpha = 0.03

1/beta = 7

LoopEdit (not done for EN402)

Fixed minimum velocity of 0.25m/s. X Exclude scans marked bad.

Derive

Depth (sw m), Salinity 1 & 2 (PSU), Density 1 & 2 (sigma-t, Kg/m^3), Descent Rate (m/s), Oxygen 1 & 2 (ml/l)

BinAvg

Pressure, 0.5, X Incl #scans/bin, X exclude scans marked bad, skip over 0, Process Downcast only, X Incl surface bin 0, 0, 0

ASCII_Out

Output header & data files, 60 lines/pg, label top of file, semicolon, Julian days, all variables.

BottleSum

Show Min/Max for Avgd variables, all and salinity, density, oxygen (ml/l) derived

Processing Summary Files:

Final CTD station 11 header record showing history of processing steps:
EN402_ctd011_hdr.txt

CTD Configuration report stations 1 - 11:
CTDConReport402.txt

Depth [ sw_dpth.m ]: depth=sw_dpth(data.prs,43); % latitude fixed at 43 ° N
Density [ sw_dens.m ]: sigma-t=sw_dens(data.ctdsal1,data.ctdtmp1,data.ctdprs,0)-1000;
Potential Density [ sw_pden.m ]: sigma_0=sw_pden(data.ctdsal1,data.ctdtmp1,data.ctdprs,0)-1000;
Potential Temperature [ sw_ptmp.m ]: potemp=sw_ptmp(data.ctdsal1,data.ctdtmp1,data.ctdprs,0);

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0622754	NSF Division of Ocean Sciences

Instruments

CTD Sea-Bird 9

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird 9

Acronym: CTD SBE 9

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/130/

Generic Description:

The Sea-Bird SBE 9 is a type of CTD instrument package. The SBE 9 is the Underwater Unit and is most often combined with the SBE 11 Deck Unit (for real-time readout using conductive wire) when deployed from a research vessel. The combination of the SBE 9 and SBE 11 is called a SBE 911. The SBE 9 uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 and SBE 4). The SBE 9 CTD can be configured with auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorometer, altimeter, etc.). Note that in most cases, it is more accurate to specify SBE 911 than SBE 9 since it is likely a SBE 11 deck unit was used. more information from Sea-Bird Electronics

Sea Tech Fluorometer

Supplied Description:

Instrument Type

Generic Name: Sea Tech Fluorometer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/113/

Generic Description:

The Sea Tech chlorophyll-a fluorometer has internally selectable settings to adjust for different ranges of chlorophyll concentration, and is designed to measure chlorophyll-a fluorescence in situ. The instrument is stable with time and temperature and uses specially selected optical filters enabling accurate measurements of chlorophyll a. It can be deployed in moored or profiling mode. This instrument designation is used when specific make and model are not known. The Sea Tech Fluorometer was manufactured by Sea Tech, Inc. (Corvalis, OR, USA).

Sea Tech Transmissometer

Supplied Description:

Instrument Type

Generic Name: Sea Tech Transmissometer

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0003/

Generic Description:

The Sea Tech Transmissometer can be deployed in either moored or profiling mode to estimate the concentration of suspended or particulate matter in seawater. The transmissometer measures the beam attenuation coefficient in the red spectral band (660 nm) of the laser lightsource over the instrument's path-length (e.g. 20 or 25 cm). This instrument designation is used when specific make and model are not known. The Sea Tech Transmissometer was manufactured by Sea Tech, Inc. (Corvalis, OR, USA).

Sea-Bird SBE 43 Dissolved Oxygen Sensor

Supplied Name: SBE 43 Dissolved Oxygen Sensor

Supplied Description:

Instrument Type

Generic Name: Sea-Bird SBE 43 Dissolved Oxygen Sensor

Acronym: SBE-43 DO

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0036/

Generic Description:

The Sea-Bird SBE 43 dissolved oxygen sensor is a redesign of the Clark polarographic membrane type of dissolved oxygen sensors. more information from Sea-Bird Electronics

Wet Labs ECO-AFL/FL Fluorometer

Supplied Description:

Instrument Type

Generic Name: Wet Labs ECO-AFL/FL Fluorometer

Acronym: ECO AFL/FL

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0172/

Generic Description:

The Environmental Characterization Optics (ECO) series of single channel fluorometers delivers both high resolution and wide ranges across the entire line of parameters using 14 bit digital processing. The ECO series excels in biological monitoring and dye trace studies. The potted optics block results in long term stability of the instrument and the optional anti-biofouling technology delivers truly long term field measurements.
more information from Wet Labs

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Pmax	pressure; maximum recorded	decibars	prmax
press	pressure; from CTD	decibars	press
lon	longitude; negative denotes West	decimal degrees	lon
lat	latitude; negative denotes South	decimal degrees	lat
temp	temperature; from CTD; ITS-90; from primary T0 sensor	degrees Celsius	temp
potemp	potential temperature; ITS-90; from primary T0& C0 sensors	degrees Celsius	potemp
sal	salinity; from CTD; PSS-78 (PSU);from primary T0 & C0 sensors	dimensionless	sal
time	start time of event (GMT)	hhmm	time
sta	station number	integer	sta
sigma_t	sigma T (density); from primary T0 & C0 sensors	kilograms/meter^3	sigma_t
sigma_0	sigma theta (potential density); from primary T0 & C0 sensors	kilograms/meter^3	sigma_0
depth	depth; calculated from CTD pressure	meters	depth
fluor_ECO	fluorescence; WET Labs ECO sensor	milligrams/meter^3	chl_a_fluor
O2_ml_L	oxygen; dissolved from SBE CTD	milliliters/liter	O2_ml_L
trans	light transmission	percent	trans
cond	conductivity from CTD; from primary C0 sensor	Siemens/meter	cond
fluor_chla	fluorescence; Seatech sensor rescaled; units are numerically equivalent to chlorophyll-a concentrations	unknown ?? micrograms/liter ??	chl_a_fluor
date	start date of event (GMT)	YYYYMMDD	date
event	unique sampling event number	YYYYMMDDhhmm	event

Database

Contribute Data

Dataset: CTD profiles
Deployment: EN402

Dataset acquisition description

Dataset Processing Description

MedFlux cruise: EN402 March 2005
CTD profile data processing notes

DMO Notes Summary:

Details of CTD data processing steps:

EN402 CTD shipboard data processing notes:

Datcnv

Used: B=0.15 for Press, Depth. A=0.03 for Cond 1 & 2 & Diff

AlignCTD for

Cond 0.073s (secondary only)

Temp 0

DO 4 (2 at 25C, 5 at 0C) V4, Oxy V pri, V6, OxyV sec

LoopEdit (not done for EN402)

Derive

BinAvg

ASCII_Out

BottleSum

Processing Summary Files:

The OCB DMO derived some parameters using MATLAB Physical Properties of Seawater Toolbox:

Database

Contribute Data

Dataset: CTD profilesDeployment: EN402

Dataset acquisition description

Dataset Processing Description

MedFlux cruise: EN402 March 2005 CTD profile data processing notes

DMO Notes Summary:

Details of CTD data processing steps:

EN402 CTD shipboard data processing notes:

Datcnv

Used: B=0.15 for Press, Depth. A=0.03 for Cond 1 & 2 & Diff

AlignCTD for

Cond 0.073s (secondary only)

Temp 0

DO 4 (2 at 25C, 5 at 0C) V4, Oxy V pri, V6, OxyV sec

LoopEdit (not done for EN402)

Derive

BinAvg

ASCII_Out

BottleSum

Processing Summary Files:

The OCB DMO derived some parameters using MATLAB Physical Properties of Seawater Toolbox:

Dataset: CTD profiles
Deployment: EN402

MedFlux cruise: EN402 March 2005
CTD profile data processing notes