Dataset: Oregon Shelf Eddy Covariance Data
Deployment: OC1802B

View Data: For data, See Dataset Metadata Page: https://osprey.bco-dmo.org/dataset/827116

Principal Investigator:

Clare E. Reimers (Oregon State University, OSU)

BCO-DMO Data Manager:

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

Project:

Benthic Biogeochemical Exchange Dynamics on the Oregon Shelf (BBEDOS)

Version:

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Description

This dataset is comprised of individual files of eddy covariance time series data identified by the cruise id and an event number corresponding to the lander deployment. Eddy covariance fluxes and other parameters derived from these data are presented in a manuscript submitted to JGR-Oceans (Reimers and Fogaren).

This dataset will be updated in the future to include additional processed eddy covariance measurements from additional cruises. The future version of this dataset will combine data from ten repeat R/V Oceanus cruises on the central Oregon shelf that spanned December 2017 through July 2019.

Methods & Sampling

Dataset acquisition description

All data acquired with sensors mounted on a bottom lander ~30 cm above the seafloor unless noted otherwise.

Problems/Issues:
The temperature data were collected at lower frequencies and in the OC1901 Ev51 case processed with a 15 min moving average to interpolate to 8 Hz.

Instrument summary:

Nortek Vector ADV (yielded u, v, w, P, BSI).

Pyroscience fiber-optic oxygen sensors (OXB430) (yielded O2). The fiber-optic sensors were activated through PyroScience FireStingO2-Subport modules enclosed in Delrin housings with 12V to 5V power converter circuits produced and integrated by Rockland Scientific (Victoria, BC, Canada).

A new fiber-optic sensor was installed for each EC experiment, and it was calibrated in seawater solutions at 0 and 100% air saturation using FirestingO2 software, before and after each deployment. When processing EC data records the specific Firesting “pre” and “post” calibration parameters were applied with time-series inputs of temperature, salinity and pressure to convert the sensor measurements to two parallel O2 time-series in units of mmol L-1. Because it was observed that the fiber-optic sensor calibrations shifted gradually over time, independent reference measurements (from OOI data products or ship-based casts) were used to derive corrected fiber-optic time-series based on the fractions of pre- and post-calibration series needed to align with the reference measurements. For each deployment, four reference points were assigned, with calibration proportions extrapolated in between each reference point. Not surprisingly, these fractions shifted from mostly dependent on the “pre” calibration to dominantly the “post” calibration over the course of each deployment. Adjustments in mean concentration were generally about 10%.

Temperature records were extracted from the neighboring OOI Benthic Experimental Package CTD when at the 80 m station. Temperature records were measured with a recording CTD (SBE 37) during deployments at 30 m.

Data Processing Description

Dataset Processing Description

In most cases temperature data were collected at lower frequencies and processed with a moving average to interpolate to 8 Hz.

Velocity and oxygen time-series were filtered to remove spikes (extreme data outliers) using a phase-space method adapted from Goring and Nikora [2002] whereby spikes are replaced with points based on a spline fit to adjacent data. These “cleaned” time series, together with coincident pressure measurements (P) made by the ADV were then reduced from 64 to 8 Hz by computing sequential eight-point averages.

BCO-DMO Data Manager Processing Notes (Data version 1):
* Combined submitted files into one data table adding columns for cruise_id and event from information in the file names.
* added site latitude and longitude for each event in the dataset(information submitted by email).
* Added ISO_DateTime_PT and ISO_DateTime_UTC in ISO 8601 format using the matlab DateNumber provided. Verified by checking the conversion in MATLAB using datestr().
* rounded decimals to five decimal places after confirming the precision with the data submitter.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1634319	NSF Division of Ocean Sciences

Instruments

Acoustic Doppler Velocimeter

Supplied Name: Nortek Vector ADV

Supplied Description:

Nortek Vector ADV (yielded u, v, w, P, BSI).

Instrument Type

Generic Name: Acoustic Doppler Velocimeter

Acronym: ADV

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/384/

Generic Description:

ADV is the acronym for acoustic doppler velocimeter. The ADV is a remote-sensing, three-dimensional velocity sensor. Its operation is based on the Doppler shift effect. The sensor can be deployed either as a moored instrument or attached to a still structure near the seabed.

Reference:
G. Voulgaris and J. H. Trowbridge, 1998. Evaluation of the Acoustic Doppler Velocimeter (ADV) for Turbulence Measurements. J. Atmos. Oceanic Technol., 15, 272–289. doi: http://dx.doi.org/10.1175/1520-0426(1998)015<0272:EOTADV>2.0.CO;2

Oxygen Sensor

Supplied Name: Pyroscience fiber-optic oxygen sensors (OXB430)

Supplied Description:

Pyroscience fiber-optic oxygen sensors (OXB430) (yielded O2).The fiber-optic sensors were activated through PyroScience FireStingO2-Subport modules enclosed in Delrin housings with 12V to 5V power converter circuits produced and integrated by Rockland Scientific (Victoria, BC, Canada).

Instrument Type

Generic Name: Oxygen Sensor

Acronym: Dissolved Oxygen Sensor

Generic Description:

An electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed

Supplied Description:

A new fiber-optic sensor was installed for each EC experiment, and it was calibrated in seawater solutions at 0 and 100% air saturation using FirestingO2 software, before and after each deployment. When processing EC data records the specific Firesting “pre” and “post” calibration parameters were applied with time-series inputs of temperature, salinity and pressure to convert the sensor measurements to two parallel O2 time-series in units of mmol L-1. Because it was observed that the fiber-optic sensor calibrations shifted gradually over time, independent reference measurements (from OOI data products or ship-based casts) were used to derive corrected fiber-optic time-series based on the fractions of pre- and post- calibration series needed to align with the reference measurements. For each deployment, four reference points were assigned, with calibration proportions extrapolated in between each reference point. Not surprisingly, these fractions shifted from mostly dependent on the “pre” calibration to dominantly the “post” calibration over the course of each deployment. Adjustments in mean concentration were generally about 10%.

Instrument Type

no generic instrument available

Water Temperature Sensor

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: Water Temperature Sensor

Acronym: Water Temp Sensor

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/134/

Generic Description:

General term for an instrument that measures the temperature of the water with which it is in contact (thermometer).

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
matlab_DateNumber	Date/Time of measurement in local time (U.S. Pacific); resolution 8 Hz. Matlab DateNumber. Numerical number representing calendar days (e.g., January 1, 2019 12:00PM = 737426.500000000)	unitless	DateTime
u	Horizontal velocity in direction of the X probe of ADV	cm s-1	hzvel
v	Horizontal velocity in Y direction	cm s-1	hzvel
w	Vertical velocity in Z direction	cm s-1	vtvel
O2	Oxygen concentration	micromoles per L (umol L-1)	O2
P	Pressure	m	press
temp	Temperature	degrees Celsius (C)	temp
BSI	Backscatter Intensity	unitless	Acc_bksctr
cruise_id	Cruise identifier	unitless	cruise_id
event	Event name	unitless	event
lat	Site latitude	decimal degrees	lat
lon	Site longitude	decimal degrees	lon
ISO_DateTime_PT	Date and time (local Pacific Time) in ISO 8601 format YYYY-MM-DDThh:mm:ss.SSS.	unitless	ISO_DateTime_Local
ISO_DateTime_UTC	Date and time (UTC) in ISO 8601 format YYYY-MM-DDThh:mm:ss.SSSZ.	unitless	ISO_DateTime_UTC

Database

Contribute Data

Dataset: Oregon Shelf Eddy Covariance Data
Deployment: OC1802B

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Oregon Shelf Eddy Covariance DataDeployment: OC1802B

Dataset acquisition description

Dataset Processing Description

Dataset: Oregon Shelf Eddy Covariance Data
Deployment: OC1802B