Dataset: GP15 CTD ODF

Name: CTD profiles from the ODF rosette on the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15) from September to November 2018
Published: 2020-07-22
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.778168.2

Spatial Extent: N:56.0585 E:-151.9879 S:-20 W:-156.9627

Temporal Extent: 2018-09-24 - 2018-11-23

Project:

US GEOTRACES Pacific Meridional Transect (GP15) (U.S. GEOTRACES PMT)

Program:

U.S. GEOTRACES (U.S. GEOTRACES)

Principal Investigator:

Karen L. Casciotti (Stanford University)

Co-Principal Investigator:

Gregory A. Cutter (Old Dominion University, ODU)

Phoebe J. Lam (University of California-Santa Cruz, UCSC)

Contact:

Karen L. Casciotti (Stanford University)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2020-07-22

Restricted:

Validated:

Yes

Current State:

Final no updates expected

CTD profiles from the ODF rosette on the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15) from September to November 2018

Abstract:

CTD profiles from the ODF rosette on the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15) from September to November 2018.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2020-07-22	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.778168.2	2020-08-04

Methods & Sampling

The description below is excerpted from the GP15 Cruise Report (PDF). Refer to cruise report for more information, including the complete problem report and CTD processing details.

The 36-place Scripps Ocean Data Facility (ODF) rosette was used to sample water for less contamination-prone elements. Casciotti (Stanford, co-cruise leader), along with Marty Fleisher (LDEO) and Colette Kelly (Stanford) were responsible for managing the water budget and overall sampling of the ODF rosette. The ODF group was responsible for maintenance and calibration of the rosette bottles and instrumentation.

Cast types included 'Demi' station casts to 1000 m, shallow casts to 400-1000m, intermediate casts from 400-2000 m, and deep casts to within 40 m of the bottom. At each full and super station, an additional cast of the ODF rosette was conducted to sample large volumes for pigments, Radium, and Thorium isotopes (PigRaTh). On the PigRaTh casts, eight depths were selected to match the shallowest eight pump depths. Another four depths were chosen for resolution of Th-234, and a surface bottle was tripped for a 13th sample depth. The surface bottle was used primarily to sample dissolved gases at the sea surface, rather than drawing from the towfish or the ship's underway system. Surface bottle sampling also occurred at demi stations (13 depths sampled instead of 12).

CTDO/rosette casts were performed with a package consisting of a 36 bottle rosette frame, a 36-place carousel and 36 Bullister style Niskin bottles with an absolute volume of 10.6L. Underwater electronic components primarily consisted of a SeaBird Electronics housing unit with Paroscientific pressure sensor with dual plumbed lines where each line has a pump, temperature sensor, conductivity sensor, and exhaust line. A SeaBird Electronics membrane oxygen sensor was mounted on the "primary" line. A reference thermometer, transmissometer, chlorophyll-a fluorometer and backscatter meter, oxygen optode, altimeter and for some casts, a monocore were also mounted on the rosette.

Data Processing Description

The description below is excerpted from the GP15 Cruise Report (PDF). Refer to cruise report for more information, including the complete problem report and CTD processing details.

Shipboard CTD data processing was performed after deployment using SIO/ODF python CTD processing software v. 0.3. CTD acquisition data were copied onto a OS X system, and then processed. CTD data at bottle trips were extracted, and a 2-decibar down-cast pressure series created. A number of issues were encountered during GP15 ODF that directly impacted CTD analysis. Issues that directly impacted bottle closures, such as slipping guide rings, were detailed in the Underwater Sampling Package section of the ODF report.

_FLAG_W columns follow the WOCE Hydrographic Program (WHP) quality flag definitions.

The WHP quality codes for the water bottle itself are:
1 = Bottle information unavailable.
2 = No problems noted.
3 = Leaking.
4 = Did not trip correctly.
5 = Not reported.
6 = Significant discrepancy in measured values between Gerard and Niskin bottles.
7 = Unknown problem.
8 = Pair did not trip correctly. Note that the Niskin bottle can trip at an unplanned depth while the Gerard trips correctly and vice versa.
9 = Samples not drawn from this bottle.
(Flags 6, 7, and 8 apply primarily to large volume samplers.)

The WHP bottle parameter data quality codes are:
1 = Sample for this measurement was drawn from water bottle but analysis not received. Note that if water is drawn for any measurement from a water bottle, the quality flag for that parameter must be set equal to 1 initially to ensure that all water samples are accounted for.
2 = Acceptable measurement.
3 = Questionable measurement.
4 = Bad measurement.
5 = Not reported.
6 = Mean of replicate measurements (Number of replicates should be specified).
7 = Manual chromatographic peak measurement.
8 = Irregular digital chromatographic peak integration.
9 = Sample not drawn for this measurement from this bottle.

The WHP CTD data quality codes are:
1 = Not calibrated.
2 = Acceptable measurement.
3 = Questionable measurement.
4 = Bad measurement.
5 = Not reported.
6 = Interpolated over >2 dbar interval.
7 = Despiked.
8 = Not assigned for CTD data.
9 = Not sampled.

BCO-DMO Processing:
- parsed file headers to obtain STNNBR, CASTNO, DATE, TIME, LATITUDE, LONGITUDE, and DEPTH;
- concatenated data files for separate casts into one dataset;
- 2020-07-22: joined to GP15 event log to obtain EVENTNO (matching values on STNNBR + CASTNO); added ISO8601 date/time format.

Data Files

File
GP15_CTD_ODF.csv (Comma Separated Values (.csv), 14.43 MB) MD5:83ac06d61e3b97159994a58dd436be67 Primary data file for dataset ID 778168

Supplemental Files

File
Rinko III Calibration Sheet filename: ARO-CAV0296_170410.pdf (Portable Document Format (.pdf), 843.57 KB) MD5:da29b7ebfd29c76299d1deccf151db23 Calibration sheet for the RINKO III deployed on the GEOTRACES PMT cruise.
Rinko III Manual filename: RinkoIII_Manual.pdf (Portable Document Format (.pdf), 5.03 MB) MD5:fa44761dbe044f0f8994902bafda7cdd Rinko III Manual for instrument deployed on GEOTRACES PMT cruise

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1657781
NSF Division of Ocean Sciences	OCE-1657944
NSF Division of Ocean Sciences	OCE-1658318

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
RR1814	GP15 GP15 Leg1 33RR20180918 PMT US GEOTRACES PMT	2018-09-18	R/V Roger Revelle	Gregory A. Cutter (Chief Scientist) Karen L. Casciotti (Co-Chief Scientist) Phoebe J. Lam (Co-Chief Scientist)	data info
RR1815	GP15 GP15 Leg 2 33RR20180918 PMT US GEOTRACES PMT	2018-10-24	R/V Roger Revelle	Gregory A. Cutter (Chief Scientist) Karen L. Casciotti (Co-Chief Scientist) Phoebe J. Lam (Co-Chief Scientist)	data info

Instruments

CTD Sea-Bird

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird

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

Generic Description:

Conductivity, Temperature, Depth (CTD) sensor package from SeaBird Electronics, no specific unit identified. This instrument designation is used when specific make and model are not known. See also other SeaBird instruments listed under CTD. More information from Sea-Bird Electronics.

Niskin bottle

Supplied Name:

Supplied Description:

CTDO/rosette casts were performed with a package consisting of a 36 bottle rosette frame, a 36-place carousel and 36 Bullister style Niskin bottles with an absolute volume of 10.6L.

Instrument Type

Generic Name: Niskin bottle

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/

Generic Description:

A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc.

Rinko III ARO-CAV Oxygen Sensor

Supplied Name:

Supplied Description:

A RINKO III (ARO-CAV) optical dissolved oxygen sensor was deployed on this cruise. See the following documents for more information:

ARO-CAV0296_170410.pdf (calibration certificate provided by ODF)
RinkoIII_Manual.pdf (Rinko manual provided by ODF)

Instrument Type

Generic Name: Rinko III ARO-CAV Oxygen Sensor

Acronym: RINKO III

Generic Description:

The RINKO III is a fast-response optical dissolved oxygen (DO) and temperature sensor. The DO sensor is coated with photostimulable phosphor (PSP) on the outside of the pressure-resistant acrylic optical window, measuring phosphorescence quenching phase shift. The excitation blue LED pulse generates a red phosphorescence pulse, which in turn has an inverse correlation with the oxygen partial pressure in the water. It is an analogue output version. It has a response time of less than 1 second in air, enabling dissolved oxygen measurements with continuous profiling at high speeds. The dissolved oxygen sensor has a non-linear accuracy of +/-2% of full scale (at 1atm, 25 deg C) and the temperature sensor +/-0.02 deg C. It has a pressure rating of 7000 m. This device is made by JFE Advantech Co. Ltd.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
EXPOCODE	Expedition code	unitless	EXPOCODE
SECT_ID	Section ID	unitless	cruise_name
INSTRUMENT_ID	Instrument ID number from CTD file header	unitless	instrument
EVENTNO	Event number; obtained from the cruise event log	unitless	event
STNNBR	Station number; from CTD file header	unitless	station
CASTNO	Cast Identifier; from CTD file header	unitless	cast
DATE	Date from CTD file header; format: yyyymmdd	unitless	date
TIME	Time from CTD file header; format: HHMM	unitless	time
LATITUDE	Latitude from CTD file header; positive values = North	decimal degrees	lat
LONGITUDE	Longitude from CTD file header; positive values = East	decimal degrees	lon
DEPTH	Bottom depth; from CTD file header	meters (m)	depth_w
Event_Descrip	Event description; obtained from the cruise event log	unitless	ev_type
CTDPRS	Sample/sensor pressure	decibars	press
CTDPRS_FLAG_W	WHP quality flag for CTDPRS	unitless	q_flag
CTDTMP	Temperature from CTD sensor in the ITS-90 convention	degrees Celsius	temp
CTDTMP_FLAG_W	WHP quality flag for CTDTMP	unitless	q_flag
CTDSAL	Practical salinity from CTD sensor on the PSS-1978 scale	psu	sal
CTDSAL_FLAG_W	WHP quality flag for CTDSAL	unitless	q_flag
CTDOXY	Concentration of dissolved oxygen from sensor on CTD	micromoles per kilogram (umol/kg)	O2
CTDOXY_FLAG_W	WHP quality flag for CTDOXY	unitless	q_flag
CTDRINKO	Voltage from RINKO dissolved oxygen sensor	volts	O2_v
CTDRINKO_FLAG_W	WHP quality flag for CTDRINKO	unitless	q_flag
CTDXMISS	Transmissometer	volts	trans_v
CTDXMISS_FLAG_W	WHP quality flag for CTDXMISS	unitless	q_flag
CTDFLUOR	Fluorescence from CTD sensor	volts	fluor
CTDFLUOR_FLAG_W	WHP quality flag for CTDFLUOR	unitless	q_flag
ISO_DateTime_UTC	Date and time (UTC) formatted to ISO8601 standard: YYYY-MM-DDThh:mmZ	yyyy-MM-dd'T'HH:mm'Z'	ISO_DateTime_UTC

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Dataset: GP15 CTD ODF