Dataset: Kelp tracking drifter data

Name: Data from freely drifting kelp plants tagged with drifters in the Santa Barbara Channel between November of 2015 and December of 2017
Published: 2018-08-03
Keywords: oceans

Cite This Dataset

DOI:10.1575/1912/bco-dmo.739111.1

Spatial Extent: N:34.472431 E:-119.500015 S:34.162992 W:-120.449764

Temporal Extent: 2015-11-30 - 2017-10-13

Project:

Linking nearshore kelp forest dynamics to sandy beach ecosystems (Linking Kelp to Beaches)

Principal Investigator:

Carter Ohlmann (University of California-Santa Barbara, UCSB-ERI)

BCO-DMO Data Manager:

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

Version:

Version Date:

2018-08-03

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Data from freely drifting kelp plants tagged with drifters in the Santa Barbara Channel between November of 2015 and December of 2017

Abstract:

Kelp plants were tagged monthly with drifters in the Santa Barbara Channel between November of 2015 and December of 2017. This dataset contains GPS positions of freely drifting kelp plants (nominally) every 10 minutes. Tagged kelp plants begin at one of three kelp forests (Mohawk, Hope Ranch, or Isla Vista) off the Santa Barbara coast.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2018-08-03	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.1575/1912/bco-dmo.739111.1	2019-06-07

Description

Various tabular formats of these data are available by clicking the "Get Data" button on this page and then selecting "Downloads & Other Options."

These data are also available as a Matlab struct data type containing data for each drift deployment.
Download: kelp_drifter_data.mat (865 KB)

Methods & Sampling

GPS positions were sampled every 10 minutes. Velocities were computed as centered differences in position (first differences at endpoints).

The instruments were deployed by finding kelp plants near the edges of the three study forests that had been detached from the bottom and were freely drifting, and then attaching gps buoys to the plants with 1/4” polypropylene line. The line was generally attached to part of the kelp plant nearest the surface. The instruments were then left to record their position every 10 minutes. The buoys were retrieved when they reached the shoreline or when it appeared they were leaving the Santa Barbara Channel and would thus become unrecoverable.

More information about Microstar drifters (manufactured by Pacific Gyre Corp.) can be found in Ohlmann et al., 2005.

Data Processing Description

Velocities were computed as centered differences in position (first differences at endpoints). Matlab serial time (UTC) is computed from the recorded GPS time.

BCO-DMO Data Manager Processing Notes:
* added a conventional header with dataset name, PI name, version date
* modified parameter names to conform with BCO-DMO naming conventions
* Originally submitted data as matlab structs "day" and "readme" combined into one .mat file and made available for download as "kelp_drifter_data.mat"
* the "day" matlab struct converted to a tabular format (matlab Table). Date in format yyyy-mm-dd, time (HH:MM) and ISO timestamp in format yyyy-mm-ddTHH:MMZ were added as columns. Column "vel" was removed as it contained only NaN values. The .csv was imported into the BCO-DMO data system. Blank values are displayed as the default "nd" value for "no data" in the BCO-DMO system.

Data Files

File
kelp_drifter_data.csv (Comma Separated Values (.csv), 2.60 MB) MD5:0c6eb80a051db1c510e2762cec2dce64 Primary data file for dataset ID 739111

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1458845

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
Dugan_UCSB_2015-2017		2015-07-02	lab_UCSB	Jenifer E. Dugan (Principal Investigator)	data info

Instruments

Drifter Buoy

Supplied Name: Microstar drifter

Supplied Description:

More information about Microstar drifters (manufactured by Pacific Gyre Corp.) can be found in Ohlmann et al., 2005.

Instrument Type

Generic Name: Drifter Buoy

Generic Description:

Drifting buoys are free drifting platforms with a float or buoy that keep the drifter at the surface and underwater sails or socks that catch the current. These instruments sit at the surface of the ocean and are transported via near-surface ocean currents. They are not fixed to the ocean bottom, therefore they "drift" with the currents. For this reason, these instruments are referred to as drifters, or drifting buoys.

The surface float contains sensors that measure different parameters, such as sea surface temperature, barometric pressure, salinity, wave height, etc. Data collected from these sensors are transmitted to satellites passing overhead, which are then relayed to land-based data centers.

definition sources: https://mmisw.org/ont/ioos/platform/drifting_buoy and https://www.aoml.noaa.gov/phod/gdp/faq.php#drifter1

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
id	drifter id	unitless	Sensor_Id
lat	Latitude	decimal degrees	lat
lon	Longitude	decimal degrees	lon
matime	Matlab datenum data type	unitless	DateTime
u	u velocity	centimeters per second (cm/s)	u
v	v velocity	centimeters per second (cm/s)	v
z	water depth interpolated from bathymetry data to each drifter position (negative values are beneath the sea surface)	meters (m)	depth
date	date in format yyyy-mm-dd	unitlesss	date
time	time in format HH:MM	unitless	time
ISO_DateTime_UTC	timestamp (UTC) in standard ISO 8601:2004(E) format YYYY-mm-ddTHH:MMZ	unitless	ISO_DateTime_UTC