Dataset: Summary CTD data
Deployment: Tobin_2015_2016

CTD summary data from phytoplankton monitoring sites in Juneau, AK.

Principal Investigator:

Dr Elizabeth D. Tobin (University of Alaska Fairbanks, UAF-Juneau)

BCO-DMO Data Manager:

Hannah Ake (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Mathew Biddle (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Enhancing Sustainability of Shellfish Harvest in Alaska: Addressing the Ecology of Alexandrium Blooms and their Sociocultural Impacts (SEAK-AHAB)

Current State:

Final no updates expected

Version:

Final

Version Date:

2016-09-30

Data URL:

https://www.bco-dmo.org/dataset-deployment/660318/data

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Description

Summary CTD data collected approximately weekly from two phytoplankton monitoring sites in Juneau, AK from 2015-2016.

Methods & Sampling

Dataset acquisition description

Dock-based CTD casts were completed at approximately weekly intervals at two phytoplankton sampling stations, Auke Bay and Amalga Harbor, in Juneau, AK using a SBE-25 Sealogger CTD equipped with a SBE-3 temperature sensor, SBE-4C conductivity sensor, SBE-29 external pressure sensor, and a WETLabs Fluorometer. The CTD was deployed down to ~1 meter above the seafloor. Local date and time were recorded at the start of each sampling event.

The CTD instrument package was last serviced and calibrated by Sea-Bird Electronics, Inc. in June 2015.

Data Processing Description

Dataset Processing Description

CTD casts were uploaded as .hex files and converted to .cnv files using the Seasoft V2 software. The .cnv files were processed in batch (R programming) to calculate summary water column parameters: cast depth (m), sea surface temperature (degrees celsius), surface salinity (psu), bottom salinity (psu), surface density (kg/m3), bottom density (kg/m3) and maximum fluorescence (mg/m3). Sea Surface temperature, surface salinity and surface density were averaged over 0.5 – 2 meters of the water column. Bottom salinity and density are data values recorded at the maximum cast depth. Maximum fluorescence is the peak of the fluorescence signal.

All summary data was referenced with water column profiles plotting using the SeaSoft V2 software.

BCO-DMO Data Processing Notes:

-Reformatted column names to comply with BCO-DMO standards
-Removed spaces from data values and replaced with underscores
-Filled in blank cells with "nd"
-2017-07-25: Updated with data from 2016.

More information about this dataset deployment

Funding

Award Number	Funding Source
ICER-1415195	NSF Divsion of Integrative and Collaborative Education and Research

Instruments

CTD - profiler

Supplied Name: SBE-25 Sealogger CTD

Supplied Description:

Dock based CTD casts were used in this survey

Instrument Type

Generic Name: CTD - profiler

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

Generic Description:

The Conductivity, Temperature, Depth (CTD) unit is an integrated instrument package designed to measure the conductivity, temperature, and pressure (depth) of the water column. The instrument is lowered via cable through the water column. It permits scientists to observe the physical properties in real-time via a conducting cable, which is typically connected to a CTD to a deck unit and computer on a ship. The CTD is often configured with additional optional sensors including fluorometers, transmissometers and/or radiometers. It is often combined with a Rosette of water sampling bottles (e.g. Niskin, GO-FLO) for collecting discrete water samples during the cast.

This term applies to profiling CTDs. For fixed CTDs, see https://www.bco-dmo.org/instrument/869934.

CTD-fluorometer

Supplied Name: WETLabs fluorometer

Supplied Description:

Equipped on CTD

Instrument Type

Generic Name: CTD-fluorometer

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

Generic Description:

A CTD-fluorometer is an instrument package designed to measure hydrographic information (pressure, temperature and conductivity) and chlorophyll fluorescence.

Pressure Sensor

Supplied Name: SBE-29 external pressure sensor

Supplied Description:

Equipped on CTD

Instrument Type

Generic Name: Pressure Sensor

Generic Description:

A pressure sensor is a device used to measure absolute, differential, or gauge pressures. It is used only when detailed instrument documentation is not available.

Sea-Bird SBE-4 Conductivity Sensor

Supplied Name: SBE-4C conductivity sensor

Supplied Description:

Equipped on CTD

Instrument Type

Generic Name: Sea-Bird SBE-4 Conductivity Sensor

Acronym: SBE-4 Conductivity

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0417/

Generic Description:

The Sea-Bird SBE-4 conductivity sensor is a modular, self-contained instrument that measures conductivity from 0 to 7 Siemens/meter. The sensors (Version 2; S/N 2000 and higher) have electrically isolated power circuits and optically coupled outputs to eliminate any possibility of noise and corrosion caused by ground loops. The sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Because the outer electrodes are connected together, electric fields are confined inside the cell, making the measured resistance (and instrument calibration) independent of calibration bath size or proximity to protective cages or other objects.

Water Temperature Sensor

Supplied Name: SBE-3 temperature sensor

Supplied Description:

Equipped on CTD

Instrument Type

Generic Name: Water Temperature Sensor

Acronym: Water Temp Sensor

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/134/

Generic Description:

General term for an instrument that measures the temperature of the water with which it is in contact (thermometer).

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
sampling_event	Sampling event ID	unitless	event
date	Date sample was taken; YYYYmmdd	unitless	date
time_zone	Time zone where sample was taken	unitless	time_zone
time_local	Local time when sampling occurred; HH:MM	unitless	time_local
station	Station where sample was taken	unitless	station
lon	Longitude	decimal degrees	lon
lat	Latitude	decimal degrees	lat
instrument	Instrument used to collect sample	unitless	instrument
investigator	Investigator responsible for collecting sample	unitless	investigator
cast_depth	Bottom depth of cast	meters	depth_cast
surface_temp	Sea surface temperature	celsius	SST
s_salinity	Surface salinity	practical salinity units (PSU)	sal_ss
b_salinity	Bottom salinity	practical salinity units (PSU)	sal
s_density	Surface density	kilogram per meter cubed (kg/m3)	density
b_density	Botton density	kilogram per meter cubed (kg/m3)	density
max_fluor	Maximum fluorescence	milligram per meter cubed (mg/m3)	fluor
data_quality	Codes providing information about missing or flagged data	unitless	comment
ISO_DateTime_Local	DateTime local; YYYY-mm-dd HH:MM	unitless	ISO_DateTime_Local
year	Four digit year sample was taken; YYYY	unitless	year

Database

Contribute Data

Dataset: Summary CTD data
Deployment: Tobin_2015_2016

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Summary CTD dataDeployment: Tobin_2015_2016

Dataset acquisition description

Dataset Processing Description

Dataset: Summary CTD data
Deployment: Tobin_2015_2016