Dataset: Biofloat_48 LI-COR sensor PAR profiles
Deployment: Biofloat_48

Photosynthetically available radiation (PAR) profiles from LI-COR 192-SA sensor

Principal Investigator:

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

Contact:

Eric Rehm (University of Washington, UW APL)

BCO-DMO Data Manager:

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

Project:

North Atlantic Bloom Experiment 2008 (NAB 2008)

Version:

08 March 2011

Deployment Synonyms:

B4-2008_Lagrangian_Float 48

Coordinated Deployments:

KN193-03, B4-2008, B10-2008, B9-2008, SG140, SG141, SG142, SG143

Version Date:

2011-03-08

Data URL:

https://www.bco-dmo.org/dataset-deployment/454421/data

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Description

Calibrated PAR (photosynthetically available radiation) profiles acquire by LI-COR 192-SA downwelling Plane Irradiance sensor

Methods & Sampling

Dataset acquisition description

Data Processing Description

Dataset Processing Description

In situ photosynthetically active radiation (PAR; parameter name PAR): Using factory-supplied calibration factors, the LI-COR 192SA PAR sensor has a stated NIST-traceable accuracy of +/- 5% in air, stability of less than +/- 2%. Reported values for in situ PAR from the float 48 LI-COR 192-SA sensor do not match those computed by spectral integration from the TriOS hyperspectral downwelling irradiance (ACC) sensor (parameter name acc.par); a systematic bias exists between the two PAR values. Further, using matchups when the float was at the surface, neither LI-COR PAR or TriOS PAR match PAR values computed from various R/V Knorr 193-03 PAR sensors. Shading of the LI-COR sensor is possible by the top-mounted CTD, GPS/Argos antennas, and float ring supports; effects of this shading has not been quantified. The effects of self-shading due to the 1 m square drogue deployed during drift mode have not yet been quantified. For more details, see Radiometry_and_PAR_Calibration-NAB08.pdf.

More information about this dataset deployment

Funding

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

Instruments

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.

LI-COR Biospherical PAR Sensor

Supplied Description:

Instrument Type

Generic Name: LI-COR Biospherical PAR Sensor

Acronym: LI-COR Biospherical PAR

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0074/

Generic Description:

The LI-COR Biospherical PAR Sensor is used to measure Photosynthetically Available Radiation (PAR) in the water column. This instrument designation is used when specific make and model are not known.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Cruise_ID	Cruise identifier	dimensionless	cruise_id
float_cycle	index counting float cycles	dimensionless	float_cycle
mode	0 = down profile 1 = settle 2 = up profile 3 = drift_iso 5 = drift_ml	dimensionless	float_operational_mode
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
PAR	Calibrated photosynthetically available radiation (PAR)	micromol photons per meter squared per second	PAR
yrday	Yearday 2008. Yearday 1 is 2008-01-01:00:00:00Z	dimensionless	yrday

Database

Contribute Data

Dataset: Biofloat_48 LI-COR sensor PAR profiles
Deployment: Biofloat_48

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Biofloat_48 LI-COR sensor PAR profilesDeployment: Biofloat_48

Dataset acquisition description

Dataset Processing Description

Dataset: Biofloat_48 LI-COR sensor PAR profiles
Deployment: Biofloat_48