Dataset: Nutrients and chlorophyll
Deployment: Tokyo_4

Nutrient and chlorophyll analyses from surface samples collected by container ships in the North Pacific

View Data: For data, See Dataset Metadata Page: https://osprey.bco-dmo.org/dataset/829141

Principal Investigator:

Paul Quay (University of Washington, UW)

Co-Principal Investigator:

Hilary I. Palevsky (University of Washington, UW)

Contact:

Hilary I. Palevsky

BCO-DMO Data Manager:

Dana Stuart Gerlach (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

North Pacific Surface Carbon, Oxygen and Isotope Measurements from Container Ships (2008-) (NPac Cont Ship)

Version:

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Description

Methods & Sampling

Dataset acquisition description

Samples were collected from shipboard seawater intake (10 m depth) on basin-wide transects of the North Pacific between Hong Kong and Long Beach, California onboard the M/V OOCL Tianjin and the M/V OOCL Tokyo (each individual transect has a unique Cruise ID). Sea surface temperature and salinity at the time of sample collection were determined using a Sea-Bird Electronics SBE45 thermosalinograph installed in the ship’s seawater intake. To prevent biofouling that could cause respiration in the ship’s seawater lines [Juranek et al., 2010], intake lines between the anticorrosive sea chest and the sampling port were purged with bleach and freshwater between every cruise. Since the samples were collected underway on a vessel moving ~24 knots and samples for all parameters were collected by a single shiprider, ship transit from the time that the location coordinates were recorded to the time of actual sampling could reflect a transit distance offset from the recorded location of up to 40 kilometers.

Details of collection event issues (dataset Notes field):

Missing info on duplicate: A number of data entries are missing timestamp and location information for duplicates because separate times were not recorded at the time of collection. Since the ship moves at ~24 knots, differences between the duplicate samples may represent real spatial variations between the times the duplicate samples were collected.
Intake temp issue: The intake temperature was not working until 2010-02-17 on the TJ9 cruise, so 23 of the reported temperatures are derived from TSG -0.3 (approximate correction for inline warming)
Missing TSG data and/or GPS signal: On the Tokyo_0 cruise, 7 entries are missing TSG data and 2 additional are missing GPS information as well as TSG data.
No GPS data: On the Tianjin_1 cruise, six entries did not have GPS available.

Data Processing Description

Dataset Processing Description

Methods are described in detail in Clayton et al. (in preparation for JGR: Oceans). Discrete samples were collected from the underway seawater system (10 m depth). Chlorophyll samples were filtered onto Whatman GF/F. Both chlorophyll and nutrient samples were frozen for later analysis in a shore-based laboratory. Samples were measured in the Marine Chemistry Laboratory at the University of Washington. For nutrients, analyses and calibration follow the protocols of the WOCE Hydrographic Program using a Seal Analytical AA3. For chlorophyll, analysis is acetone extraction and fluorometric detection on a Turner Designs TD-700 fluorometer.

BCO-DMO Processing:

Converted datetimes to ISO Date UTC format
Converted Longitudes to 0 to 180 scale
Rounded fields to 4 decimal places
Shortened Notes column (for better display) and listed details above in Acquisition description
Adjusted parameter names to comply with database requirements.
Removed units from field names and added to Parameter Description metadata section.
Added a conventional header with dataset name, PI names, version date.
Missing data identifier of 'nd' used ('nd' is BCO-DMO system default missing data identifier).

More information about this dataset deployment

Funding

Award Number	Funding Source
A10OAR4310088	NOAA Oceanic and Atmospheric Research (OAR) Climate Program Office
OCE-0628663	NSF Division of Ocean Sciences
OCE-1259055	NSF Division of Ocean Sciences

Instruments

Sea-Bird SBE 45 MicroTSG Thermosalinograph

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: Sea-Bird SBE 45 MicroTSG Thermosalinograph

Acronym: SBE 45 MicroTSG

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0190/

Generic Description:

A small externally powered, high-accuracy instrument, designed for shipboard determination of sea surface (pumped-water) conductivity and temperature. It is constructed of plastic and titanium to ensure long life with minimum maintenance. It may optionally be interfaced to an external SBE 38 hull temperature sensor.

Sea Bird SBE 45 MicroTSG (Thermosalinograph)

Seal Analytical AutoAnalyser 3HR

Supplied Name: Seal Analytical AA3

Supplied Description:

Instrument Type

Generic Name: Seal Analytical AutoAnalyser 3HR

Generic Description:

A fully automated Segmented Flow Analysis (SFA) system, ideal for water and seawater analysis. It comprises a modular system which integrates an autosampler, peristaltic pump, chemistry manifold and detector. The sample and reagents are pumped continuously through the chemistry manifold, and air bubbles are introduced at regular intervals forming reaction segments which are mixed using glass coils. The AA3 uses segmented flow analysis principles to reduce inter-sample dispersion, and can analyse up to 100 samples per hour using stable LED light sources.

Turner Designs 700 Laboratory Fluorometer

Supplied Name: Turner Designs TD-700 fluorometer

Supplied Description:

Instrument Type

Generic Name: Turner Designs 700 Laboratory Fluorometer

Acronym: TD-700

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0510/

Generic Description:

The TD-700 Laboratory Fluorometer is a benchtop fluorometer designed to detect fluorescence over the UV to red range. The instrument can measure concentrations of a variety of compounds, including chlorophyll-a and fluorescent dyes, and is thus suitable for a range of applications, including chlorophyll, water quality monitoring and fluorescent tracer studies. Data can be output as concentrations or raw fluorescence measurements.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
ISO_DateTime_UTC	Timestamp (mean GMT time for each time interval) in ISO format (yyyy-mm-dd hh:mm) with UTC time zone	unitless	ISO_DateTime_UTC
Cruise	Cruise ID	unitless	cruise_id
Station	Station number	unitless	station
Salinity	Sea surface Salinity as measured by shipboard thermosalinograph	psu	sal_ss
Temperature	Sea surface Temperature as measured by shipboard thermosalinograph	degrees Celsius	SST
Latitude	Latitude of sample collection, South is negative	decimal degrees	lat
Longitude	Longitude of sample collection, West is negative	decimal degrees	lon
Lon360	Longitude on 360 degree scale with 180 at the Date Line	decimal degrees	lon_360
PO4	Phosphate concentration	micromoles (umols)	PO4
SiO4	Silicate concentration	micromoles (umols)	SiO4
NO3	Nitrate concentration	micromoles (umols)	NO3
NO2	Nitrite concentration	micromoles (umols)	NO2
NH4	Ammonium concentration	micromoles (umols)	NH4
Chlorophyll	Chlorophyll	micrograms per Liter (ug/L)	chl_a
Phaeopigment	Phaeopigment	micrograms per Liter (ug/L)	phaeo
Fo_to_Fa	Fo/Fa, ratio of unacidified to acidified chlorophyll a	unitless	Fo_to_Fa
Notes	Comments about collection events	unitless	comment

Database

Contribute Data

Dataset: Nutrients and chlorophyll
Deployment: Tokyo_4

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Nutrients and chlorophyllDeployment: Tokyo_4

Dataset acquisition description

Dataset Processing Description

Dataset: Nutrients and chlorophyll
Deployment: Tokyo_4