Dataset: ScanFish OPC
Deployment: PE04-NGOMEX

Multi year ScanFish OPC data

Principal Investigator:

Michael R. Roman (University of Maryland Center for Environmental Science, UMCES/HPL)

Co-Principal Investigator:

William C. Boicourt (University of Maryland Center for Environmental Science, UMCES/HPL)

Klaus B. Huebert (University of Maryland Center for Environmental Science, UMCES/HPL)

James J. Pierson (University of Maryland Center for Environmental Science, UMCES/HPL)

Contact:

Klaus B. Huebert (University of Maryland Center for Environmental Science, UMCES/HPL)

BCO-DMO Data Manager:

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

Project:

NGOMEX - Living Marine Resources of the Northern Gulf of Mexico (GoMX - NGOMEX)

Deployment Synonyms:

NGOMEX 2004, GOMEX2004, BOICOURT 2004, PE0454

Data URL:

https://www.bco-dmo.org/dataset-deployment/746098/data

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Description

Subsets of these data were published in the papers listed in the "Related Resources" section.

Related dataset:
* Pump mesozooplankton samples: https://www.bco-dmo.org/dataset/746107

Methods & Sampling

Dataset acquisition description

Methodology:
A CTD and optical plankton counter mounted to a ScanFish platform were towed and undulated behind the vessel.

Sampling and analytical procedures:
The ScanFish was towed at a mean speed of 2.7 m/s with mean vertical descent and ascent rates of 0.3 m/s.

Notes for specific data columns:

Dissolved oxygen concentration (column "oxy"): values corrected vs. CTD rosette casts and Winkler titrations when available.

Sample volume (column "vol"): estimated from OPC mouth opening and changes in lat, lon, and depth

Data column definitions for particle counts and biovolume density include the term "ESD" which stands for "equivalent spherical diameter."

Biovolume densities (data column names beginning with "v_") were calculated using the following formula:
v = sum(4/3*pi*(0.5*ESD*1e-3)^3)/vol

The light attenuance (column "light") has relative units and the OPC unit used starting Sep. 5, 2010 22:30:00 UTC was calibrated differently.

Data Processing Description

Dataset Processing Description

Data processing:
Previously processed CTD files (https://www.bco-dmo.org/dataset/3547) and MIDAS files (https://www.bco-dmo.org/dataset/3548) were synchronized and merged with simultaneously collected OPC data. Quality controlled and interpolated MIDAS data were used as the common reference system for longitude, latitude, and time. Since the OPC clock gradually and unpredictably drifted relative to MIDAS time, synchronization was accomplished by measuring and correcting for temporal lag via cross-correlations of moving windows of OPC and CTD pressure sensor time series (with the remaining error generally <0.5 s). Data were then aggregated into 1 s time bins. The standard reference for depth was OPC pressure, adjusted to compensate for non-zero readings on deck of the research vessel over the course of each cruise. The 15 arc second resolution NOAA NCEI coastal relief model for the northern Gulf of Mexico was used as a reference for bathymetry. Data were divided into distinct vertical profiles, and only those profiles were included in the final dataset that either sampled the water column from <3 m below the surface to <3 above the bottom or sampled >30 m of vertical distance, or both. Estimated OPC particle sizes from 256 to 2048 µm equivalent spherical diameter were aggregated into 12 logarithmically spaced size bins (other particle sizes were excluded). For CTD files with both raw and corrected oxygen data, the corrected version was used. All data processing was performed using the R language and environment for statistical computing.

BCO-DMO Data Manager Processing Notes:
* added a conventional header with dataset name, PI name, version date.
* modified parameter names to conform with BCO-DMO naming conventions. Periods in column names changed to underscores.
* added ISO Timestamp column
* rounded decimal places of columns. Number of decimal places provided by data contributor.
* Missing data values are shown as the BCO-DMO missing data identifier "nd" meaning "no data."

More information about this dataset deployment

Funding

Award Number	Funding Source
NA06NOS4780148	National Oceanic and Atmospheric Administration
NA09NOS4780198	National Oceanic and Atmospheric Administration
NAS-GRP-2000006418	Gulf Research Program of the National Academies of Sciences, Engineering, and Medicine
OCE-1043248	NSF Division of Ocean Sciences
OCE-1043249	NSF Division of Ocean Sciences
OCE-1043261	NSF Division of Ocean Sciences

Instruments

CTD - profiler

Supplied Name: Sea-Bird 9 CTD

Supplied Description:

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.

Optical Plankton Counter

Supplied Name: Focal Technologies Optical Plankton Counter OPC-1T

Supplied Description:

Instrument Type

Generic Name: Optical Plankton Counter

Acronym: OPC

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/352/

Generic Description:

An OPC provides quantitative measurements of abundance and sizes of mesozooplankton ranging between approximately 0.25 and 14 mm in Equivalent Spherical Diameter (ESD), and has the capability to integrate measurements from other sensors such as a CTD, fluorometer and Global Positioning System (GPS). It can be deployed on a variety of instruments such as SeaSoar, Aries, Scanfish, MOCNESS, a bongo net or simple towing frame. The data from an OPC are typically transmitted to a data acquisition computer through two conducting wires in a towing cable at real time, but it can also be modified to have an internal memory. Large amounts of data are produced. The procedures employed by OPC users vary from; i) estimating integrated biomass by integrating the OPC size distributions, ii) comparing size distributions between OPC and net samples, and iii) simply isolating a size region in the OPC size distribution which correspond solely to specific taxa, eg. Calanus spp..

from: Zhou, M., Tande, K., 2002. Optical Plankton Counter Workshop. GLOBEC Report 17, University of Tromso, Tromso

towed undulating vehicle

Supplied Name: GMI ScanFish

Supplied Description:

Instrument Type

Generic Name: towed undulating vehicle

Acronym: TUV

Generic Description:

A towed undulating vehicle is a generic class of instruments. See the data set specific information for a detailed description. These are often prototype instrument packages designed to make very specific measurements.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
profile	ScanFish profile ID which includes profile start time in UTC	unitless	cast
lon	MIDAS longitude	decimal degrees	lon
lat	MIDAS latitude	decimal degrees	lat
ISO_DateTime_UTC	Timestamp (UTC) in standard ISO 8601:2004(E) format YYYY-mm-ddTHH:MM:SSZ	unitless	ISO_DateTime_UTC
depth	OPC depth	dbar	depth
temp	CTD temperature	degrees Celsius (C)	temp
sal	CTD salinity	unitless	sal
oxy	CTD dissolved oxygen concentration	milligrams per liter (mg/l)	O2
chl	CTD chlorophyll a fluorescence	milligrams per cubic meter (mg/m^3)	chl_a
CDOM	CTD colored dissolved organic matter fluorescence	milligrams per cubic meter (mg/m^3)	CDOM
light	OPC light attenuance. The units are relative. The OPC unit used starting Sep. 5, 2010 22:30:00 UTC was calibrated differently.	relative	no_bcodmo_term
n_0256_0279	OPC particle count (0256 to 0279 um ESD)	unitless	count
n_0279_0304	OPC particle count (0279 to 0304 um ESD)	unitless	count
n_0304_0332	OPC particle count (0304 to 0332 um ESD)	unitless	count
n_0332_0362	OPC particle count (0332 to 0362 um ESD)	unitless	count
n_0362_0395	OPC particle count (0362 to 0395 um ESD)	unitless	count
n_0395_0431	OPC particle count (0395 to 0431 um ESD)	unitless	count
n_0431_0470	OPC particle count (0431 to 0470 um ESD)	unitless	count
n_0470_0512	OPC particle count (0470 to 0512 um ESD)	unitless	count
n_0512_0558	OPC particle count (0512 to 0558 um ESD)	unitless	count
n_0558_0609	OPC particle count (0558 to 0609 um ESD)	unitless	count
n_0609_0664	OPC particle count (0609 to 0664 um ESD)	unitless	count
n_0664_0724	OPC particle count (0664 to 0724 um ESD)	unitless	count
n_0724_0790	OPC particle count (0724 to 0790 um ESD)	unitless	count
n_0790_0861	OPC particle count (0790 to 0861 um ESD)	unitless	count
n_0861_0939	OPC particle count (0861 to 0939 um ESD)	unitless	count
n_0939_1024	OPC particle count (0939 to 1024 um ESD)	unitless	count
n_1024_1117	OPC particle count (1024 to 1117 um ESD)	unitless	count
n_1117_1218	OPC particle count (1117 to 1218 um ESD)	unitless	count
n_1218_1328	OPC particle count (1218 to 1328 um ESD)	unitless	count
n_1328_1448	OPC particle count (1328 to 1448 um ESD)	unitless	count
n_1448_1579	OPC particle count (1448 to 1579 um ESD)	unitless	count
n_1579_1722	OPC particle count (1579 to 1722 um ESD)	unitless	count
n_1722_1878	OPC particle count (1722 to 1878 um ESD)	unitless	count
n_1878_2048	OPC particle count (1878 to 2048 um ESD)	unitless	count
vol	OPC sample volume	cubic meters (m^3)	volume
v_0256_0279	OPC biovolume density (0256 to 0279 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0279_0304	OPC biovolume density (0279 to 0304 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0304_0332	OPC biovolume density (0304 to 0332 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0332_0362	OPC biovolume density (0332 to 0362 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0362_0395	OPC biovolume density (0362 to 0395 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0395_0431	OPC biovolume density (0395 to 0431 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0431_0470	OPC biovolume density (0431 to 0470 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0470_0512	OPC biovolume density (0470 to 0512 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0512_0558	OPC biovolume density (0512 to 0558 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0558_0609	OPC biovolume density (0558 to 0609 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0609_0664	OPC biovolume density (0609 to 0664 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0664_0724	OPC biovolume density (0664 to 0724 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0724_0790	OPC biovolume density (0724 to 0790 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0790_0861	OPC biovolume density (0790 to 0861 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0861_0939	OPC biovolume density (0861 to 0939 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_0939_1024	OPC biovolume density (0939 to 1024 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1024_1117	OPC biovolume density (1024 to 1117 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1117_1218	OPC biovolume density (1117 to 1218 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1218_1328	OPC biovolume density (1218 to 1328 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1328_1448	OPC biovolume density (1328 to 1448 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1448_1579	OPC biovolume density (1448 to 1579 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1579_1722	OPC biovolume density (1579 to 1722 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1722_1878	OPC biovolume density (1722 to 1878 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
v_1878_2048	OPC biovolume density (1878 to 2048 um ESD)	cubic millimeters per cubic meter (mm^3/m^3)	biovolume
bathy	NOAA NCEI coastal relief model bottom depth	meters (m)	depth_bottom

Database

Contribute Data

Dataset: ScanFish OPC
Deployment: PE04-NGOMEX

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: ScanFish OPCDeployment: PE04-NGOMEX

Dataset acquisition description

Dataset Processing Description

Dataset: ScanFish OPC
Deployment: PE04-NGOMEX