Dataset: LB_2012_Glider_DO_L2

Name: Time series of dissolved oxygen measured on an undulating glider collected from the South Atlantic Bight (SAB) cruises along the continental shelf off Long Bay from January to April in 2012 (Long Bay Wintertime Bloom project)
Published: 2016-01-26
Keywords: oceans

Cite This Dataset

Spatial Extent: N:33.38228 E:-77.39313 S:32.33788 W:-78.75069

Project:

Mechanisms of nutrient input at the shelf margin supporting persistent winter phytoplankton blooms downstream of the Charleston Bump (Long Bay Wintertime Bloom)

Principal Investigator:

Dr James Nelson (Skidaway Institute of Oceanography, SkIO)

Co-Principal Investigator:

Catherine Edwards (Skidaway Institute of Oceanography, SkIO)

Dr Harvey E. Seim (University of North Carolina at Chapel Hill, UNC-Chapel Hill)

Contact:

Sara Haines (University of North Carolina at Chapel Hill, UNC-Chapel Hill)

BCO-DMO Data Manager:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

2016-01-26

Version Date:

2016-01-26

Validated:

Current State:

Preliminary and in progress

Data URL:

https://www.bco-dmo.org/dataset/636636/data

Time series of dissolved oxygen measured on an undulating glider collected from the South Atlantic Bight (SAB) cruises along the continental shelf off Long Bay from January to April in 2012 (Long Bay Wintertime Bloom project)

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Description

Two Webb Slocum gliders were used to measure salinity, temperature, and depth. Glider 'Pelagia' was deployed in Long Bay, S. Carolina, South Atlantic Bight and glider 'Ramses' was deployed along the upper slope of S. Carolina. in 2012. Data were collected in a time series from January to April, 2012.

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Acquisition Description

Time series of dissolved oxygen were measured from an undulating Webb Slocum Electric glider (serial #44, named Pelagia and serial #32, named Ramses) every few seconds by an Aandera Oxygen Optode. The glider Pelagia nominally occupied a cross-shelf transect but deviated from its prescribed course due to currents and other issues. The glider Ramses occupied a profiling station on the upper slope.

Processing Description

Data were read from glider stored memory after recovery. The following table documents the specific steps applied to arrive at the Level 2 (L2) dataset. The details of the corrections and calibrations that were applied can be found in the supporting document (Glider_L2_DissolvedOxygen_Corrections_20150817.pdf). Glider CTD dataset is described separately.

Regular sample interval	The CTD variables (temperature, salinity, and depth) are resampled at a 3 second sample interval.
Filter the CTD’s temperature and salinity	Filter the temperature and salinity (from the CTD), using cut-off frequency fc = 1/30 per second i.e. Tc = 30 seconds. Matlab filtfilt was used with a 4th order butterworth filter i.e. 4th order forward- and 4th order reverse-filtered.
Delay the CTD variables	Delay the CTD variables by 27 seconds.
Interpolate CTD data to the DO time base	The delayed CTD variables (filtered temperature, filtered salinity, and depth) are interpolated to the DO sensor’s time base, which has an irregular sample interval (median approximately 3.3 seconds).
Recalculate DO output variables	The TSP-corrected oxygen concentration (o2_tspcorr) is calculated using the modified CTD data: • Temperature filtered, delayed, and interpolated • Salinity filtered, delayed, and interpolated • Depth delayed and interpolated.
Apply Calibration Curve	The calibration curve (i.e. the slope and intercept described above in the “Calibration Fix” section) is applied. So, the calibrated TSP-corrected oxygen concentration (o2_sat) is: slope*o2_tspcorr + intercept.

BCO-DMO Processing:

-extracted data from MatLab .mat files
- added conventional header with dataset name, PI name, version date, reference information
- renamed parameters to BCO-DMO standard
- added yrday_utc and ISO_DateTime_UTC to served view
- reduced number of significant digits
- change NaN's to nd's

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1032276
NSF Division of Ocean Sciences	OCE-1032285

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
LB_2012_Pelagia-3		2012-03-16	AUV Slocum Glider Pelagia	Catherine Edwards (Chief Scientist) Dr James Nelson (Co-Chief Scientist)	data info
LB_2012_Ramses-1		2012-01-26	AUV Slocum Glider Ramses	Catherine Edwards (Co-Chief Scientist) Dr James Nelson (Co-Chief Scientist)	data info
LB_2012_Ramses-2		2012-02-15	AUV Slocum Glider Ramses	Catherine Edwards (Co-Chief Scientist) Dr James Nelson (Co-Chief Scientist)	data info
SAV-12-03	LB 2012 Leg 1 Cruise	2012-01-24	R/V Savannah	Dr James Nelson (Chief Scientist) Catherine Edwards (Co-Chief Scientist)	data info
SAV-12-05	LB 2012 Leg 2 Cruise	2012-02-13	R/V Savannah	Dr James Nelson (Chief Scientist) Catherine Edwards (Co-Chief Scientist)	data info
SAV-12-11	LB 2012 Leg 3 Cruise	2012-03-13	R/V Savannah	Dr James Nelson (Chief Scientist) Catherine Edwards (Co-Chief Scientist)	data info
SAV-12-14	LB 2012 Recovery Cruise	2012-04-02	R/V Savannah	Dr James Nelson (Chief Scientist) Catherine Edwards (Co-Chief Scientist)	data info

Instruments

CTD Sea-Bird

Supplied Description:

The CTD is a component of the Slocum glider used for this dataset.

Instrument Type

Generic Name: CTD Sea-Bird

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

Generic Description:

Conductivity, Temperature, Depth (CTD) sensor package from SeaBird Electronics, no specific unit identified. This instrument designation is used when specific make and model are not known. See also other SeaBird instruments listed under CTD. More information from Sea-Bird Electronics.

Global Positioning System Receiver

Supplied Name: GPS

Supplied Description:

GPS is a component of the Slocum glider used for this dataset.

Instrument Type

Generic Name: Global Positioning System Receiver

Acronym: GPS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/POS03/

Generic Description:

The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis. The U.S. Air Force develops, maintains, and operates the space and control segments of the NAVSTAR GPS transmitter system. Ships use a variety of receivers (e.g. Trimble and Ashtech) to interpret the GPS signal and determine accurate latitude and longitude.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
glider_id	glider identification	unitless	Glider_ID
lat_start	starting latitude; north is positive	decimal degrees	lat_start
lon_start	starting longitude; east is positive	decimal degrees	lon_start
day	day of month	1-31	day
month	month	1-12	month
year	year	yyyy	year
yrday_utc	year day: UTC day and decimal time; as 326.5 for the 326th day of the year or November 22 at 1200 hours (noon).	day.part of day	yrday_utc
ISO_DateTime_UTC	Date/Time (UTC) ISO formatted standard is based on ISO 8601:2004(E) and takes on any of the following forms: 2009-08-30T14:05:00Z (UTC time)	yyyy-mm-ddTHH:MM:SSZ	ISO_DateTime_UTC
hour	hour	HH	hour_gmt
min	minute	MM	minute_gmt
sec	seconds	SS	seconds_gmt
lat	interpolated latitude; north is positive	decimal degrees	lat
lon	interpolated longitude; east is positive	decimal degrees	lon
depth	interpolated CTD depth	meters	depth
O2_sat	corrected oxygen saturation	percent	O2sat
O2_corr	temperature salinity and pressure corrected dissolved oxygen	10e-6 mol/dm3	O2

Database

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Dataset: LB_2012_Glider_DO_L2