Dataset: Winter to spring transition in a fjord in the northern Gulf of Alaska dataset - CTD data

Name: Winter to spring transition in a fjord in the northern Gulf of Alaska dataset - CTD data
Published: 2025-02-21
Keywords: CTD, Gulf of Alaska, winter, oceans

View Data: Data not available yet

Cite This Dataset

Spatial Extent: N:60.025 E:-149.3583 S:60.025 W:-149.3583

Resurrection Bay, Gulf of Alaska, sub-arctic Pacific

Temporal Extent: 2023-01-05 - 2023-03-24

Project:

Collaborative Research: Zooplankton restarts in a high-latitude marine ecosystem: species-specific recruitment and development in early spring (Zooplankton recruitment)

Principal Investigator:

Petra H. Lenz (University of Hawaiʻi at Mānoa)

Scientist:

Lauren N Block (University of Hawaiʻi at Mānoa)

Student:

Lauren N Block (University of Hawaiʻi at Mānoa)

BCO-DMO Data Manager:

Amber D. York (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2025-02-21

Restricted:

Yes

Release Date:

2025-03-31

Validated:

Current State:

Data not available

CTD (temperature, salinity and fluorescence) from bi-weekly vertical profiles in Resurrection Bay, AK from January to March of 2023

Abstract:

The Gulf of Alaska is a highly seasonal environment that is characterized by an order-of-magnitude increase in copepod biomass in the photic zone between winter and spring. The study focused on copepod recruitment to characterize species-specific naupliar production. Concurrent environmental monitoring included approximately bi-weekly vertical profiles of temperature, salinity and fluorescence were recorded at an established station (RES2.5) in Resurrection Bay, AK. Day-trips aboard the R/V Nanuq were conducted approximately bi-weekly in Resurrection Bay, AK during January to March, 2023.

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Methods & Sampling

Samples were collected in Resurrection Bay within the inner basin at RES2.5 (60° 1.5’ N, 149° 21.5’ W; 298 m deep) at approximately biweekly intervals aboard the R/V Nanuq between January 5th and March 24th, 2023. Collection and sample processing are described in detail in Block (2024). Vertical profiles of water temperature, salinity, and fluorescence were measured from 280 m to the surface using a CTD (SBE25 SeaLogger) and WetLabs chlorophyll α fluorometer mounted on an SBE55 rosette with six 4-L Niskin Bottles. Water was collected at discrete depths (surface, 10, 20, 30, 40, 50, 150, and 280 m) for characterization of the phytoplankton and microzooplankton community. Two casts were required to collect all water samples.

Problems/Issues

No known problems associated with the CTD dataset

Data Processing Description

CTD data were processed using the SBEDataProcessing-Win32 program. Data processing included filtering, alignment, thermal mass correction, loop edits, and derivation of depth, salinity, and density variables. Data were then averaged at 1 dbar intervals. Data processing was completed according to the SBE Advanced Data Processing Module.

BCO-DMO Processing

* Sheet 1 of submitted file "NaupProj2023_combinedCTDs_BCODMO.csv" was imported into the BCO-DMO data system for this dataset. Table will appear as Data File: 954156_v1_ctd.csv (along with other download format options).
* Several columns were undescribed in the data submission's "Parameters" section, so those appear as "undocumented" in the column descriptions. The units were listed in the original data file so those appear in the Parameter description section.

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Office of Polar Programs (formerly NSF PLR)	OCE-2222376
NSF Office of Polar Programs (formerly NSF PLR)	OCE-2222592
NSF Office of Polar Programs (formerly NSF PLR)	OCE-2222558

Deployments

None available yet

Instruments

Fluorometer

Supplied Name: WetLabs chlorophyll α fluorometer

Supplied Description:

Instrument Type

Generic Name: Fluorometer

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

Generic Description:

A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. The instrument is designed to measure the amount of stimulated electromagnetic radiation produced by pulses of electromagnetic radiation emitted into a water sample or in situ.

Niskin bottle

Supplied Name:

Supplied Description:

SBE55 rosette with 6 4-L Niskin Bottles

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.

Sea-Bird SBE 25 Sealogger CTD

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: Sea-Bird SBE 25 Sealogger CTD

Acronym: CTD SBE 25

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0040/

Generic Description:

The Sea-Bird SBE 25 SEALOGGER CTD is battery powered and is typically used to record data in memory, eliminating the need for a large vessel, electrical sea cable, and on-board computer. All SBE 25s can also operate in real-time, transmitting data via an opto-isolated RS-232 serial port. Temperature and conductivity are measured by the SBE 3F Temperature sensor and SBE 4 Conductivity sensor (same as those used on the premium SBE 9plus CTD). The SBE 25 also includes the SBE 5P (plastic) or 5T (titanium) Submersible Pump and TC Duct. The pump-controlled, TC-ducted flow configuration significantly reduces salinity spiking caused by ship heave, and in calm waters allows slower descent rates for improved resolution of water column features. Pressure is measured by the modular SBE 29 Temperature Compensated Strain-Gauge Pressure sensor (available in eight depth ranges to suit the operating depth requirement). The SBE 25's modular design makes it easy to configure in the field for a wide range of auxiliary sensors, including optional dissolved oxygen (SBE 43), pH (SBE 18 or SBE 27), fluorescence, transmissivity, PAR, and optical backscatter sensors. More information from Sea-Bird Electronics: http:www.seabird.com.

Turbidity Meter

Supplied Name: Sea-Bird ECO-NTU Turbidity Sensor

Supplied Description:

Instrument Type

Generic Name: Turbidity Meter

Generic Description:

A turbidity meter measures the clarity of a water sample. A beam of light is shown through a water sample. The turbidity, or its converse clarity, is read on a numerical scale. Turbidity determined by this technique is referred to as the nephelometric method from the root meaning "cloudiness". This word is used to form the name of the unit of turbidity, the NTU (Nephelometric Turbidity Unit). The meter reading cannot be used to compare the turbidity of different water samples unless the instrument is calibrated. Description from: http://www.gvsu.edu/wri/education/instructor-s-manual-turbidity-10.htm

(One example is the Orion AQ4500 Turbidimeter)

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
binned_pressure	Pressure (dbar) binned at 1 dbar intervals	Decibars (dbar)	press
temperature	Water column temperature	Celsius (C)	temp
conductivity	Water column conductivity	Siemens per meter (S/m)	cond
turbidity	Water column turbidity	Nephelometric Turbidity Unit (NTU)	turbidity
fluorescence	Water column chlorophyll-a fluorescence	Milligrams per cubic meter (mg/m^3)	fluor
time_elapsed	undocumented.	Seconds (s)	time_elapsed
scan	undocumented. Units described as "integer" in provided metadata	unitless	scan
depth	Depth of CTD in water column.	Meters (m)	depth
salinity	Water column salinity	Practical Salinity Units (PSU)	sal
sigmaT	Water column density	Kilograms per cubic meter (kg/m^3 )	sigma_t
descent_rate	undocumented. Assumed to be descent rate of an instrument package.	Meters per second (m/s)	descent_rate
nbin	undocumented. Assumed to be the commonly preported CTD nbin term referring to the number of data cycles used to compile an average value for a given depth/BIN interval	unitless	nbin
date	Date (Local time, Alaska Time Zone) in ISO 8601 format yyyy-mm-dd Format: %Y-%m-%d	unitless	date_local
julianday	Intiger Day of Year (1=Jan 1st)	days	yrday
cruise	Cruise ID	Unitless	cruise_id
station	Station ID	Unitless	station
lat	Station latitude, north is positive	Decimal Degrees	lat
lon	Station latitude, west is negative	Decimal Degrees	lon

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Dataset: Winter to spring transition in a fjord in the northern Gulf of Alaska dataset - CTD data