Dataset Available Remotely Hosted

Surface ocean velocities obtained by High Frequency (HF) radar stations located in Straits of Florida from 2019-12-28 to 2022-06-03

Authors: Merz, Clifford and Michael Smith
Published On: Oct 14 2022 19:02 UTC
DOI: https://doi.org/10.7266/ZR437PFW
UDI: U1.x843.000:0002
Files

No. of Downloads: 0

File Format(s):
CTF, ruv

Project Information

Funded By:
National Academies of Sciences Gulf Research Program

Funding Cycle:
Understanding Gulf Ocean Systems Grants 1

Research Group:
Dry Tortugas and Lower Keys High Frequency Radars

Point of Contact

Clifford Merz
University of South Florida / College of Marine Science
cmerz@usf.edu

Data Collection Period
2019-12-28
to
2022-06-03
Theme keywords

sea surface currents, current speed, ocean circulation, ocean currents, Loop Current, HFR, High Frequency Radar, radial currents, meridional current speed, zonal current speed, current speed

ISO 19115-2 Metadata
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Abstract:

High Frequency (HF) Radar is a real-time ocean surface current mapping instrument with the intended purpose of observing surface currents over the horizon out to a range of about 200 km. The radial velocity components, eastward surface current (u) and northward surface current (v) may be used for model assimilation and validation, and to better understand the evolution of the Loop Current System (LCS) in the Gulf of Mexico. The Center for Ocean Observing Leadership at Rutgers University assembles raw HF radar data from UGOS HF radar operators. This data is post-processed from the radar cross spectra into radial ocean current data. Radial velocity files are presented in the Columnar Table Format (CTF) format which presents keyword descriptors as metadata preceded by percent signs (%) while the measured velocities and diagnostic data are reported in a tab-delimited format in separate tables. The data currently span the dates 2019-12-28 - 2022-06-03.

Suggested Citation:

Merz, Clifford and Michael Smith. 2022. Surface ocean velocities obtained by High Frequency (HF) radar stations located in Straits of Florida from 2019-12-28 to 2022-06-03. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/ZR437PFW

Purpose:

The real-time data from this site is used for oceanographic model data assimilation and validation to better understand the evolution of the Loop Current System.

Data Parameters and Units:

Longitude [decimal deg], latitude [decimal deg], u [cm/s], v [cm/s], X distance [km], Y distance [km], range [km], bearing [degrees true], max velocity [cm/s], minimum velocity [cm/s]; date [month day], time (UTC, [hours, minutes, seconds]) of spectral estimates.

Methods:

Data was recorded in real time at the Marathon, Florida, HFR site (MARA). An HF signal is propagated at the ocean water surface and travels beyond the horizon. The radar signal reflects off of ocean waves and return to source. The returning signal exhibits a Doppler-frequency shift. This signal is saved in the form of observed ocean spectrum maps which are produced approximately every 20 minutes. These spectra are filtered, averaged, and processed into hourly radial current maps.

Instruments:

Codar SeaSonde High Frequency radar

Error Analysis:

Radial currents were tested based on Version 1.0 of the Quality Assurance / Quality Control of Real Time Oceanographic Data (QARTOD) Manual for Real-Time Quality Control of High Frequency Radar Surface Current Data by U.S. Integrated Ocean Observing System (2016). New columns containing QARTOD flags are appended to the data tables. QARTOD QC radial files are then submitted on a semi-annual basis to NCEI. The QARTOD radial tests that have been applied are Syntax (Test 6), Max Threshold (Test 7), Valid Location (Test 8), Radial Count (Test 9), Spatial Median Filter (Test 10), and the Temporal Gradient (Test 12). A flag, PRIM, is included which is the highest flag value of executed QARTOD QC tests for each radial current velocity.

Provenance and Historical References:

The QARTOD manual is available at https://cdn.ioos.noaa.gov/media/2017/12/HFR_QARTOD_Manual_05_26_16.pdf.