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Description

This dataset contains the latest reprocessed version 3 of the Level 2B science-quality ocean surface wind vector retrievals from the QuikSCAT scatterometer. The retrievals are provided on a non-uniform grid within the swath at 12.5 km pixel resolution. Higher resolution is achieved through a slice composite technique in which high resolution slice measurements from L1B data are composited into a 12.5 km wind vector cell. Version 3 processing begins with the same L1B (time-ordered backscatter) data as used in the previous processing. Version 3 has several improvements over the previous JPL processing of the QuikSCAT L2B winds: 1) changes to measurement binning, which was done in order to decrease noise and reduce gaps in the 12.5 km L2B wind retrievals, 2) an improved geophysical model function (GMF) to model the effect of wind on backscatter, 3) a neural network approach to correct rain contaminated winds speeds, 4) cross-track dependent wind speed biases were estimated and removed from the wind retrievals. The 12.5 km binning resolution enables users to obtain wind vector retrievals 10 km closer to shore when compared to the 25 km L2B dataset (only available in versions 1 and 2). More details to the processing changes and improvements are noted by Fore et al. (2014): PO.DAAC Drive at https://podaac-tools.jpl.nasa.gov/drive/files/allData/quikscat/L2B12/docs/fore_et_al_ieee_2014.pdf . Each L2B file corresponds to a specific orbital revolution (rev) number, which begins at the southernmost point of the ascending orbit. This is the official dataset produced by the QuikSCAT Project through the SeaWinds Processing and Analysis Center (SeaPAC). The Version 3 User Guide document is accessible from https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/quikscat/open/L2B12/docs/qscat_l2b_v3_ug_v1_0.pdf.

Product Summary

Platforms
QUIKSCAT
Instruments
SEAWINDS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
12.5 Kilometers x 12.5 Kilometers
Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
1999-10-27 to 2009-11-22
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C2526576230-POCLOUD
Data State
COMPLETE
Number of Files/Granules
51991
Processing Level
2
Published
Updated
Science Keywords
Surface Winds

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

SeaPAC. (2013). QuikSCAT Level 2B Ocean Wind Vectors in 12.5km Slice Composites Version 3 [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/QSX12-L2B01 Date Accessed: 2025-12-14

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
atmospheric_speed_bias atmospheric speed bias m s-1 float -9999 0 to 100 1
cross_track_wind_speed_bias relative wind speed bias with respect to sweet spot m s-1 float -9999 0 to 100 1
eflags extended wind vector cell quality flags bit short 32767 0 to 15 1
flags wind vector cell quality flags bit short 32767 0 to 32643 1
lat latitude degrees_north float N/A -90 to 90 1
lon longitude degrees_east float N/A 0 to 360 1
nudge_wind_direction model wind direction degrees float -9999 0 to 360 1
nudge_wind_speed model wind speed m s-1 float -9999 0 to 100 1
num_ambiguities number of ambiguous wind directions found in point-wise wind retrieval prior to spatial filtering 1 byte 0 1 to 4 1
rain_impact impact of rain upon wind vector retrieval 1 float -9999 0 to 100 1
retrieved_wind_direction equivalent neutral wind direction at 10 m degrees float -9999 0 to 360 1
retrieved_wind_speed equivalent neutral wind speed at 10 m m s-1 float -9999 0 to 100 1
retrieved_wind_speed_uncorrected wind speed without rain correction m s-1 float -9999 0 to 100 1
time date and time seconds since 1999-01-01 0:0:0 float N/A N/A 1
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