Dataset: Groves Creek: fluorescent Dissolved Organic Matter (fDOM)
Deployment: Groves_Creek_2013-2015

fDOM

Principal Investigator:

William Savidge (Skidaway Institute of Oceanography, SkIO)

Co-Principal Investigator:

Jay Brandes (Skidaway Institute of Oceanography, SkIO)

Catherine Edwards (Skidaway Institute of Oceanography, SkIO)

Aron Stubbins (Skidaway Institute of Oceanography, SkIO)

BCO-DMO Data Manager:

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

Project:

Tempo and mode of salt marsh exchange (GrovesCreek)

Data URL:

https://www.bco-dmo.org/dataset-deployment/682897/data

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Description

Methods & Sampling

Dataset acquisition description

fDOM fluorometry sampling:
fDOM concentrations at S2 and S8 were evaluated using Wetlabs FLCD shuttered fluorometers sampling at 15 minute intervals. The deployment scheme for the FLCD units was identical to that for the YSIs. The YSIs, fDOM (and chlorophyll) fluorometers were swapped out on the same schedules. At S2, the fluorometers were also mounted below the “moon pool” of the floating dock and were ~ 1m from the YSIs. At S8, they were collocated on the bottom frame with the other instruments.

Data Processing Description

Dataset Processing Description

Raw fDOM fluorescence output (counts) have been manipulated three ways:

Counts were converted to fDOM ppb quinine sulfate equivalents (QSEs) using the manufacturer calibration data provided for each unit.

Data were corrected for quenching of fluorescence at higher temperatures. Lab experiments showed that fluorescence of a given source water declined linearly by ~20% between 20-40C. A pooled regression correction was applied to all units to compensate for the lowered fluorescence response at higher temperatures. All fluorescence data are normalized to fluorescence at 20C.

Fluorescence offsets (as QSEs) between units during successive deployments were corrected using a multi-step procedure

Obvious bad data were excised from the records
Each individual deployment output was smoothed using a weighted 8 point local regression routine (Matlab ‘rloess’) to suppress spiky outliers.
Each fluorometer output was then adjusted up or down based on their mean intercalibration and deployment overlap offsets to bring them all in rough alignment.
The mean of the residual overlap gaps for each successive deployment was determined, and a Matlab pchip spline was applied to connect those points.
Each deployment record was made to conform to the spline curve fit so that the overlapping endpoints had a mean difference -> 0 and possessed a smooth transition between successive deployments.
The concatenated data file was linearly interpolated onto a 10 minute time vector to facilitate intercomparison of records.
No attempt to date has been made to correct the fluorescence data for quenching due to turbidity in the water column.

BCO-DMO Processing notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- added station, lat, lon, date, time, ISO_DateTIme columns
- ISO Date format generated from date and time values
- reduced decimal places of fDOM and temperature to 3 places

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1234704	NSF Division of Ocean Sciences

Instruments

Fluorometer

Supplied Name: Wetlabs FLCD shuttered fluorometers

Supplied Description:

Instrument Type

Generic Name: Fluorometer

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

Generic Description:

A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. The instrument is designed to measure the amount of stimulated electromagnetic radiation produced by pulses of electromagnetic radiation emitted into a water sample or in situ.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
station	station identifier	unitless	sta
lat	latitude; north is positive	decimal degrees	lat
lon	longitude; east is positive	decimal degrees	lon
date	UTC date formatted as yyyy-mm-dd	unitless	date
time	UTC time; formatted as hh:mm	unitless	time
ISO_DateTime_UTC	Date/Time (UTC) ISO formatted based on ISO 8601:2004(E) with format YYYY-mm-ddTHH:MM:SS[.xx]Z	unitless	ISO_DateTime_UTC
datenum_matlab	MATLAB formatted datenum	unitless	date
fDOM	Fluorescent Dissolved Organic Matter (fDOM); the optically active component of the dissolved organic matter in water. Excitation wavelength 370nm. Emission wavelength 460nm.	QSE (quinine sulfate equivalents) ppb	fDOM
fDOM_temp_corrected	Temperature corrected Fluorescent Dissolved Organic Matter (fDOM) concentration	QSE (quinine sulfate equivalents) ppb	fDOM

Database

Contribute Data

Dataset: Groves Creek: fluorescent Dissolved Organic Matter (fDOM)
Deployment: Groves_Creek_2013-2015

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Groves Creek: fluorescent Dissolved Organic Matter (fDOM)Deployment: Groves_Creek_2013-2015

Dataset acquisition description

Dataset Processing Description

Dataset: Groves Creek: fluorescent Dissolved Organic Matter (fDOM)
Deployment: Groves_Creek_2013-2015