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Description

This dataset contains the latest reprocessed version 3.1 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 3.1 processing begins with the same L1B (time-ordered backscatter) data as used in the previous Version 3.0 processing. Version 3.1 improves upon the previous Version 3.0 processing by incorporating enhanced coastal processing using a Land Contamination Ratio (LCR) method with a fixed threshold. The 12.5 km binning resolution combined with the LCR processing enables this dataset to provide wind vector retrievals with approximately half the coastal gap as compared to the Version 3.0 12.5 km L2B dataset. The geophysical model function used to produce the wind vector cell retrievals remains unchanged between Version 3.0 and 3.1. 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 NASA QuikSCAT Project through the SeaWinds Processing and Analysis Center (SeaPAC). More details to the processing changes and improvements are to be published in the near future, but for now can be referenced by the following presentation: https://mdc.coaps.fsu.edu/scatterometry/meeting/docs/2016/Thu_AM/coastal-poster.pdf .

Product Summary

Platforms
QUIKSCAT
Instruments
SEAWINDS
Spatial Extent

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

Spatial Resolution
12500 Meters x 12500 Meters
Geographic Region
GLOBAL OCEAN
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) ,
QUIKSCAT, JET PROPULSION LABORATORY, NASA (NASA/JPL/QUIKSCAT)
Concept ID
C2036882492-POCLOUD
Data State
COMPLETE
Number of Files/Granules
51900
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. (2016). QuikSCAT Level 2B Ocean Wind Vectors in 12.5km Slice Composites Version 3.1 [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/QSX12-L2B31 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
ambiguity_direction wind direction ambiguity degree float -9999 0 to 360 1
ambiguity_obj wind objective function values 1 float -9999 -199 0 1
ambiguity_speed wind speed ambiguity m s-1 float -9999 0 to 100 1
atmospheric_speed_bias atmospheric speed bias m s-1 float -9999 -100 to 100 1
cross_track_wind_speed_bias relative wind speed bias with respect to sweet spot m s-1 float -9999 -100 to 100 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 degree float -9999 0 to 360 1
nudge_wind_speed model wind speed m s-1 float -9999 0 to 100 1
number_in_aft number of inner aft looks in wind vector cell 1 byte 0 1 to 127 1
number_in_fore number of inner forward looks in wind vector cell 1 byte 0 1 to 127 1
number_out_aft number of outer aft looks in wind vector cell 1 byte 0 1 to 127 1
number_out_fore number of outer forward looks in wind vector cell 1 byte 0 1 to 127 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 degree 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 1999-1-1 0:0:0 double N/A N/A 1
wind_obj retrieved wind objective function value 1 float -9999 -199 0 1
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