Total alkalinity, pH on seawater scale, oxygen, temperature, salinity, nutrients and other measurements collected from discrete samples and profile observations during the R/V Sarmiento de Gamboa OVIDE-16 cruise (EXPOCODE 29AH20160617) in the North Atlantic Ocean from 2016-06-17 to 2016-07-31 (NCEI Accession 0190728)

INVESTIGATOR:

Fiz F. Pérez

- Institute of Marine Research Vigo (IIM)

PACKAGE DESCRIPTION: This dataset includes discrete sample and profile data collected during the R/V Sarmiento de Gamboa OVIDE-16 cruise (EXPOCODE 29AH20160617) in the North Atlantic Ocean from 2016-06-17 to 2016-07-31. These data include total alkalinity, pH on sea water scale, oxygen, temperature, salinity, nutrients and chlorofluorocarbons. The instruments used to collect these data include alkalinity titrator, CTD, Niskin bottles and spectrophotometer. The International GO-SHIP Global Ocean Carbon and Repeat Hydrography Program carries out a systematic and global re-occupation of select WOCE/JGOFS hydrographic sections to quantify changes in storage and transport of heat, fresh water, carbon dioxide (CO2), and related parameters. The objectives of the OVIDE-16 cruise are fulfilled in spite of the problems derived from the installation of the new signal transmission cable. This operation delayed the departure by one week. However, this delay was recovered thanks to the speed of the ship, the constant adaptation of the cruise planning to the weather forecasts and the excellent reliability of the CTD and box- corer operations. A total of 138 CTD stations and 66 sediment sampling were done. In addition, the recovery and new deployment of two ASFAR-ARGO systems were done, as well as the deployment of five meteorological floats and nine ARGO floats.

CITE AS: Pérez, Fiz F.; Lherminier, Pascale; Alonso-Pérez, Fernando; Steinfeldt, Reiner (2019). Total alkalinity, pH on seawater scale, oxygen, temperature, salinity, nutrients and other measurements collected from discrete samples and profile observations during the R/V Sarmiento de Gamboa OVIDE-16 cruise (EXPOCODE 29AH20160617) in the North Atlantic Ocean from 2016-06-17 to 2016-07-31 (NCEI Accession 0190728). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/nasz-v279. Accessed [date].

DATA PACKAGES RELATED TO THIS ONE:

Section OVIDE

IDENTIFICATION INFORMATION FOR THIS DATA PACKAGE:

NCEI ACCESSION: 0190728

NCEI DOI: https://doi.org/10.25921/nasz-v279

EXPOCODE: 29AH20160617;

CRUISE ID: OVIDE_2016, BOCATS;

SECTION/LEG: WOCE A01W; WOCE A25;

TYPES OF STUDY:
Discrete measurement;Profile;

TEMPORAL COVERAGE:

START DATE: 2016-06-17

END DATE: 2016-07-31

SPATIAL COVERAGE:

NORTH: 63.5

WEST: -43.4

EAST: -9.3

SOUTH: 40.2

GEOGRAPHIC NAMES:

North Atlantic Ocean;

PLATFORMS:

R/V Sarmiento de Gamboa (ID: 29AH);

RESEARCH PROJECT(S):

Observatoire de la variabilite interannuelle et decennale (OVIDE);

VARIABLES / PARAMETERS:

Total alkalinity
Abbreviation:	ALKALI
Unit:	UMOL/KG
Observation type:	discrete
In-situ / Manipulation / Response variable:	In-situ observation
Measured or calculated:	Measured
Type of titration:	potentiometric titration
Curve fitting method:	Total alkalinity was measured by potentiometric titrations to final pH of 4.40 following Pérez and Fraga 1987. Seawater samples for alkalinity were collected after pH samples, in 600 ml glass bottles. Samples were filled to overflowing and immediately stopped. Total alkalinity was measured using an automatic potentiometric titrator "TITRANDO Metrohm", with a combination glass electrode and a Pt-1000 probe (Metrohm 6.0257.000). The potentiometric titrations were carried out with hydrochloric acid ([HCl] = 0.1 M, Riedel-deHaën, Fixanal 38285).
Uncertainty:	The precision of the AT measurements (± 0.34 μmol·kg-1) was calculated analysing 14 samples for reproducibility taken from different Niskin bottles closed at the same level (4815 dbar) at station 0. Besides, the 1011 AT duplicates analyses showed a reproducibility of 0.23 ± 0.44 μmol·kg-1 along the cruise.
Method reference:	Pérez, F.F. and F. Fraga. 1987. A precise and rapid analytical procedure for alkalinity determination. Mar. Chem.,21, 169-182

pH
Abbreviation:	pH
pH scale:	SWS@25C
Observation type:	discrete
In-situ / Manipulation / Response variable:	In-situ observation
Measured or calculated:	Measured
Temperature of pH measurement:	25C
Detailed sampling and analyzing information:	pH was measured spectrophotometrically following Clayton and Byrne (1993). This method consists on adding a dye solution to the seawater sample, so that the ratio between two absorbencies at two different wavelengths is proportional to the sample pH. Seawater samples for pH were collected at 95 stations after oxygen samples from depth using cylindrical optical glass 10-cm path length cells, which were filled to overflowing and immediately stopped. The indicator was a solution of m-cresol purple prepared in seawater. After sampling all the samples were stabilised at 25ºC. All the absorbance measurements were obtained in the thermostated (25±0.2 oC) cell compartment of a SHIMADZU UV-2401PC spectrophotometer. Seawater pH was measured using a double-wavelength spectrophotometric procedure (Byrne, 1987). The absorbance was measured at three different fixed wavelengths (434, 578 and 730 nm) and 75 μl of the dye solution were added to each sample using an adjustable repeater pipette. pH, on the total hydrogen ion concentration scale, is calculated using the following formula (Clayton and Byrne, 1993):

CTDTMP
Abbreviation:	CTDTMP
Unit:	DEG_C
Controlled vocabulary name:	WATER TEMPERATURE
In-situ / Manipulation / Response variable:	in-situ

CTDSAL
Abbreviation:	CTDSAL
Controlled vocabulary name:	SALINITY
In-situ / Manipulation / Response variable:	in-situ

SALNTY
Abbreviation:	SALNTY
Controlled vocabulary name:	SALINITY
In-situ / Manipulation / Response variable:	in-situ

OXYGEN
Abbreviation:	OXYGEN
Unit:	UMOL/KG
Controlled vocabulary name:	DISSOLVED OXYGEN
In-situ / Manipulation / Response variable:	in-situ

SILCAT
Abbreviation:	SILCAT
Unit:	UMOL/KG
Controlled vocabulary name:	silicate
In-situ / Manipulation / Response variable:	in-situ

NITRAT
Abbreviation:	NITRAT
Unit:	UMOL/KG
Controlled vocabulary name:	NITRATE
In-situ / Manipulation / Response variable:	in-situ

Phosphate
Abbreviation:	PHSPHT
Unit:	UMOL/KG
Controlled vocabulary name:	PHSPHT
In-situ / Manipulation / Response variable:	in-situ

PH_TMP
Abbreviation:	PH_TMP
Unit:	DEG_C
Controlled vocabulary name:	pH
In-situ / Manipulation / Response variable:	in-situ

Chlorofluorocarbons (CFC-11, CFC-12)
Abbreviation:	CFCs
Unit:	PMOL/KG
Controlled vocabulary name:	Potential temperature (theta)
In-situ / Manipulation / Response variable:	in-situ

PUBLICATIONS DESCRIBING THIS DATASET:

Clayton, T. D., R. H. Byrne, 1993. Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale concentration scale calibration of m-cresol purple and at-sea results. Deep-sea Research I, 40(10), 2115-2129, https://doi.org/10.1016/0967-0637(93)90048-8

ADDITIONAL INFORMATION:

none;

FUNDING AGENCY:

SUBMITTED BY: Robert M. Key (key@princeton.edu)

SUBMISSION DATE: 2018-05-21

Follow us

Contact us