Aquarius CAP Level 3 Sea Surface Salinity Rain Corrected Standard Mapped Image 7-Day Data V4.0

Aquarius CAP Level 3 Sea Surface Salinity Rain Corrected Standard Mapped Image 7-Day Data V4.0
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DescriptionVersion 4.0 Aquarius CAP Level 3 products are the third release of the AQUARIUS/SAC-D mapped salinity and wind speed data based on the Combined Active Passive (CAP) algorithm. CAP Level 3 standard mapped image products contain gridded 1 degree spatial resolution salinity and wind speed data averaged over 7 day and monthly time scales. This particular data set is the 7-Day running mean sea surface salinity (SSS) rain corrected V4.0 Aquarius CAP product. CAP is a P.I. produced data set developed and provided by the JPL Climate Oceans and Solid Earth group (S. Yueh). The CAP algorithm utilizes data from both the onboard radiometer and scatterometer to simultaneously retrieve salinity, wind speed and direction by minimizing the sum of squared differences between model and observations. The main improvement in CAP V4.0 is calibration of the rain roughness correction geophysical model function to HYCOM SSS adjusted by the Rain Impact Model (RIM) to account for the rain induced near surface stratification. Rain corrected salinity retrieval at L2 is based on collocation with ancillary rain rate from NOAA CMORPH at 0.25 degree and 30 minute resolution, replacing the SSMI/S and WindSAT data previously used previously for this in CAP V3.0. The Aquarius instrument is onboard the AQUARIUS/SAC-D satellite, a collaborative effort between NASA and the Argentinian Space Agency Comision Nacional de Actividades Espaciales (CONAE). The instrument consists of three radiometers in push broom alignment at incidence angles of 29, 38, and 46 degrees incidence angles relative to the shadow side of the orbit. Footprints for the beams are: 76 km (along-track) x 94 km (cross-track), 84 km x 120 km and 96km x 156 km, yielding a total cross-track swath of 370 km. The radiometers measure brightness temperature at 1.413 GHz in their respective horizontal and vertical polarizations (TH and TV). A scatterometer operating at 1.26 GHz measures ocean backscatter in each footprint that is used for surface roughness corrections in the estimation of salinity. The scatterometer has an approximate 390km swath.
Dataset TypeOPEN
MeasurementOceans > Salinity/Density > Salinity
Processing Level3
CoverageRegion: Global
Northernmost Latitude: 90 degrees
Southernmost Latitude: -90 degrees
Westernmost Longitude: -180 degrees
Easternmost Longitude: 180 degrees
Time Span: 2011-Aug-25 to 2015-Jun-07
ResolutionSpatial Resolution: 1 degrees (Latitude) x 1 degrees (Longitude)
Temporal Resolution: 7 Day
ProjectionType: Gridded
Ellipsoid: WGS 84
Latency720 hours
Name: Aquarius SAC-D (AQUARIUS_SAC-D)
Orbit Period: 98 minutes
Inclination Angle: 98 degrees
Ascending Node: 1970-Jan-01 00:00:00
Name: Aquarius Radiometer (AQUARIUS_RADIOMETER)
Swath Width: 390 km
Description: Launched in 2011 the 3 Aquarius radiometers meet very exacting requirements for low noise and calibration stability. This makes them about an order of magnitude more accurate than any radiometer ever used before for remote sensing of the earth. Aquarius measures in the microwave range at 1.413 GHz (+/- 25MHz).

Name: Aquarius SAC-D (AQUARIUS_SAC-D)
Orbit Period: 98 minutes
Inclination Angle: 98 degrees
Ascending Node: 1970-Jan-01 00:00:00
Name: Aquarius Scatterometer (AQUARIUS_SCATTEROMETER)
Swath Width: 390 km
Description: The Aquarius scatterometer is a total-power L-band (1.26 GHz)radar system for estimating ocean surface roughness. Itsmeasurements will enable the removal of wind effects from theAquarius radiometer ocean-surface brightness temperaturemeasurements being used to retrieve ocean salinity. TheAquarius scatterometer is a relatively simple, low-spatialresolution power-detecting radar, without ranging capability.But to meet its science requirement, it must be very stable, withrepeatability on the order of 0.1 dB over several days, andcalibrated accuracy to this level over several months. Datafrom this instrument over land as well as ocean areas will beavailable for a variety of geophysical applications.

Data ProviderCreator: Simon Yueh
Release Place: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA91109, USA
Release Date: 2015-Oct-07
Keyword(s)Aquarius, CAP, salinity, polar, sun-synchronous, sss, psu, CONAE, argentina, JPL
Persistent IDPODAAC-AQR40-3Q7CS
Questions related to this dataset? Contact
User's Guide
Aquarius-CAP Users Guide and ATBD
Aquarius CAP V4.0 Algorithm and Data Users Guide
Project Materials
Aquarius-CAP V4.0 Documentation Package
ATBD, Validation & Uncertainty Analyses, Publications, etc
Additional Sites
Aquarius/SAC-D Mission Website
NASA Aquarius/SAC-D mission website
PO.DAAC Aquarius/SAC-D Mission page
Mission and Instrument Overview
Known Issues
Aquarius/SAC-D Event Log
Information on observatory maneuvers, anomalies and other events
Citation Simon Yueh. 2015. Aquarius CAP Level 3 Sea Surface Salinity Rain Corrected Standard Mapped Image 7-Day Data V4.0. Ver. 4.0. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at

For more information see Data Citations and Acknowledgments.

Journal Reference Yueh,S.H., W.Tang,A.K.Hayashi,G.S.E.Lagerloef (2014).L-Band Passive and Active Microwave Geophysical Model Functions of Ocean Surface Winds and Applications to Aquarius Retrieval. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING,51(9), 4619-4632