Dataset: Biofloat_48 CTD Profiles

Name: Full-resolution profiles of pressure, salinity, and temperature plus derived variables from Biofloat_48 deployment in the subpolar North Atlantic and Iceland Basin in 2008 (NAB 2008 project)
Published: 2011-03-08
Keywords: oceans

Cite This Dataset

Spatial Extent: N:61.779 E:-19.277 S:58.693 W:-27

Project:

North Atlantic Bloom Experiment 2008 (NAB 2008)

Program:

Ocean Carbon and Biogeochemistry (OCB)

Principal Investigator:

Eric D'Asaro (University of Washington Applied Physics Laboratory, UW APL)

Contact:

Eric Rehm (University of Washington Applied Physics Laboratory, UW APL)

BCO-DMO Data Manager:

Theresa McKee (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

08 March 2011

Version Date:

2011-03-08

Validated:

Yes

Current State:

Final no updates expected

Full-resolution profiles of pressure, salinity, and temperature plus derived variables from Biofloat_48 deployment in the subpolar North Atlantic and Iceland Basin in 2008 (NAB 2008 project)

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Description

Full-resolution profiles of temperature, salinity, and derived variables from Biofloat_48 Seabird 41 CTD sensors. Two CTD sensors were mounted: one on top of the float, the other on the bottom.

Data Processing Description

The CTD sensors on float 48, the R/V Knorr process cruise 193-03, the float deployment cruise on the R/V Bjarni Saemundsson and the pre- and post-cruise float sensor calibrations were compared. Formulae were found to bring them all into agreement to within 0.001 salinity using the Knorr CTD as the absolute standard. A 3 point running median filter was applied to eliminate single spikes. An algorithm to merge data from the two float CTD’s (top and bottom) were used to reduce the effect of other errors. For more details, see CTD_float_Calibration-NAB08.pdf.

Data Files

File
Biofloat_48_CTD.csv (Comma Separated Values (.csv), 6.31 MB) MD5:172c98676dcfdba0ad6255e64fc4e1d4 Primary data file for dataset ID 3423

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-0628107
NSF Division of Ocean Sciences	OCE-0628379

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
Biofloat_48	B4-2008_Lagrangian_Float 48	2008-04-04	Biofloat 48	Eric D'Asaro (Chief Scientist) Eric Rehm (Contact)	data info

Instruments

CTD Sea-Bird 41

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird 41

Acronym: CTD SBE 41

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

Generic Description:

The Sea-Bird SBE 41 CTD module was originally developed in 1997 for integration with sub-surface oceanographic floats. It uses MicroCAT Temperature, Conductivity, and Pressure sensors.

Druck PDCR 4020 pressure sensor

Supplied Name: Druck PCDR 4020 pressure sensor

Supplied Description:

Instrument Type

Generic Name: Druck PDCR 4020 pressure sensor

Acronym: Druck PDCR 4020

Generic Description:

The PDCR 4000 Series provides a complete range of mV output pressure transducers offering advanced levels of measurement accuracy stability and flexibility from a standard production device.

Lagrangian Float

Supplied Description:

The 2008 North Atlantic Bloom Experiment (NAB08) employed a “Lagrangian float”, custom built at the University of Washington Applied Physics Laboratory. (D’Asaro, 2003, Performance of Lagrangian Floats, Journal of Atmospheric and Oceanic Technology, Vol. 20, 896-911).

Instrument Type

Generic Name: Lagrangian Float

Generic Description:

Built at the University of Washington Applied Physics Laboratory, the Lagrangian Float is not an ARGO float. It is primarily designed to accurately follow the three-dimensional motion of water parcels within the mixed layer, through a combination of neutral buoyancy and high drag provided by a one meter diameter black drogue. Typical buoyancies of a few grams result in vertical velocities relative to the water of a few mm/s, small compared to the cm/s turbulent velocities in the mixed layer. The float’s motion within the mixed layer thus closely imitates that of a planktonic organism. The float can also profile vertically. It sends data and receives commands using the Iridium satellite system. The float is designed to accommodate a wide variety of sensors.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
Cruise_ID	Cruise identifier	dimensionless	cruise_id
float_cycle	index counting float cycles	dimensionless	float_cycle
julian_day_yr0	time when sample was taken in decimal days since Jan-0-0000 (Matlab)	dimensionless	julian_day_yr0
latitude	latitude	decimal degrees	lat
longitude	longitude	decimal degrees	lon
start_date	date sampling begins	YYYYMMDD	date_begin
start_time	time sampling begins	HHMM	time_begin
end_date	date sampling ends	YYYYMMDD	date_end
end_time	time sampling ends	HHMM	time_end
press	water pressure at measurement	decibars	press
depth	depth at which sample was taken	meters	depth
temp	Temperature	degrees Celsius	temp
potemp	Potential Temperature	degrees Celsius	potemp
sal	Salinity	dimensionless	sal
sigma_0	water potential density minus 1000	kilograms/meter^3	sigma_0
yrday	Yearday 2008. Yearday 1 is 2008-01-01:00:00:00Z	dimensionless	yrday
mode	0 = down profile 1 = settle 2 = up profile 3 = drift_iso 5 = drift_ml	dimensionless	float_operational_mode

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Database

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Dataset: Biofloat_48 CTD Profiles