CYGNSS Level 3 MRG Science Data Record Version 3.2.1

This dataset contains the version 3.2.1 CYGNSS level 3 science data record merged storm (MRG) wind speed which combines CYGNSS storm-centric gridded (SCG) wind speeds, which are derived from the L2 Young Seas Limited Fetch (YSLF) winds for a region surrounding a given tropical cyclone (TC), with L3 Fully Developed Seas (FDS) winds away from the TC center on a 0.2x0.2 degree latitude by longitude equirectangular grid obtained from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation.

L3 MRG combines the L2 FDS and Young Seas Limited Fetch (YSLF) winds and eliminates the need to choose between them depending on sea state development and the proximity to storms. The data are provided in netCDF-4 format and extend from 1 August 2018 to the present with an approximate 6 day latency. A tapered weighted averaging scheme is used centered on the 25 m/s wind radius of the storm. The 34 knot wind radius (R34) algorithm has been updated for v3.2.1 release to center around the National Hurricane Center or the Joint Typhoon Warning Center (NHC/JTWC) reported storm center instead of the CYGNSS Vmax location. The algorithm produces global (+/- 40 deg latitude) wind speeds reported on a 0.1x0.1 deg grid every 6 hours for each tropical cyclone, although some 6-hourly increments may be missing if there are an insufficient number of satellite overpasses of the storm during that time interval. The netCDF files are output on a storm-by-storm basis.

The CYGNSS is a NASA Earth System Science Pathfinder Mission that is intended to collect the first frequent space‐based measurements of surface wind speeds in the inner core of tropical cyclones. Made up of a constellation of eight micro-satellites, the observatories provide nearly gap-free Earth coverage using an orbital inclination of approximately 35° from the equator, with a mean (i.e., average) revisit time of seven hours and a median revisit time of three hours. This inclination allows CYGNSS to measure ocean surface winds between approximately 38° N and 38° S latitude. This range includes the critical latitude band for tropical cyclone formation and movement.

Data and Resources

Additional Info

Field	Value
Maintainer	Earthdata Forum
Last Updated	September 8, 2026, 06:23 (UTC)
Created	April 1, 2025, 15:19 (UTC)
accessLevel	public
bureauCode	{026:00}
catalog_conformsTo	https://project-open-data.cio.gov/v1.1/schema
harvest_object_id	684bf345-51d5-46a9-aea9-d329652840a8
harvest_source_id	b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title	Science Discovery Engine
identifier	10.5067/CYGNS-3M321
license	https://www.usa.gov/government-works
modified	2026-08-31T22:16:04Z
programCode	{026:000}
publisher	NASA/ESSP/UMICH/CYGNSS;NASA/JPL/PODAAC
resource-type	Dataset
source_datajson_identifier	true
source_hash	704ed2f1e0926806c25627f770b7f07136f8bdbe5b917e7f53bdff7d7b141bb1
source_schema_version	1.1
spatial	["CARTESIAN", [{"NorthBoundingCoordinate": 40, "WestBoundingCoordinate": -180, "EastBoundingCoordinate": 180, "SouthBoundingCoordinate": -40}]]
theme	{"Earth Science"}