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Aqua AIRS Level 2 JoSFRA Retrieval Standard: Atmosphere cloud and surface geophysical state per footprint V2 at GES DISC

Metadata Updated: August 22, 2025

The Joint Single Footprint Retrieval Algorithm (JoSFRA) Level-2 geophysical parameters include estimates of atmospheric temperature and water vapor profiles, cloud properties, and surface temperature. These are retrieved from infrared spectra observed by the Atmospheric Infrared Sounder (AIRS) instrument on the Aqua satellite. AIRS is a grating spectrometer aboard Aqua, the second Earth Observing System (EOS) polar-orbiting platform. AIRS is co-boresited with the Advanced Microwave Sounding Unit (AMSU) also on Aqua. Horizontal resolutions are 50 km for AMSU and 13.5 km for AIRS. The JoSFRA algorithm uses an optimal-estimation scheme and retrieves geophysical quantities from AIRS thermal infrared spectra at their native horizontal resolution. Cloud observations from MODIS are used in the forward model without recourse to a cloud-cleared state. JOSFRA retrievals provide improved spatial resolution (13.5 km vs 50 km for cloud-cleared retrievals) and information content quantification, making them well-suited for process studies. JoSFRA retrievals are particularly useful in cases where high resolution (finer than 45 km) is needed or is beneficial, such as regions of strong horizontal gradients in water vapor. Use of JoSFRA retrievals is recommended under medium to low cloud cover. AIRS observations provide near-global coverage twice daily (around 1:30 am and pm local time) since August 30, 2002. An AIRS granule includes 6 minutes of data, 90 AIRS (30 AMSU) footprints across the orbit track by 135 AIRS (45 AMSU) footprints along track. Each day includes 240 granules, with an orbit repeat cycle of approximately 16 days. For the initial release of Version 2 JoSFRA, a limited test data set is provided. Future releases will expand the dataset. The initial dataset includes full global coverage data for two 5-day periods: January 13-17, 2011 and July 13-17, 2011, the Marine ARM GPCI Investigation of Clouds (MAGIC) (Lewis and Teixeira, EOS, 2015) test campaign in the Pacific Ocean with all 6-minute granules that overlap the box bounded by 20-35 degrees North latitude and 120-160 West longitude, June 1, 2012 – September 30, 2013, select granules from the years 2002-2007 where correlative data were available. The locations include Dept. of Energy (DOE) Atmospheric Radiation Measurement (ARM) sites at the North Slope of Alaska (NSA), Southern Great Plains (SGP), and Tropical Western Pacific (TWP), as well as scientific field campaigns.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date April 11, 2025
Metadata Updated Date August 22, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date August 22, 2025
Publisher NASA/GSFC/SED/ESD/TISL/GESDISC
Maintainer
Identifier 10.5067/0K06YE0Y8IDS
Data Last Modified 2025-08-06
Category Earth Science
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 8925019f-ba75-4e75-8621-e64811e7b755
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Old Spatial "GEODETIC",{"WestBoundingCoordinate":-180,"NorthBoundingCoordinate":90,"EastBoundingCoordinate":180,"SouthBoundingCoordinate":-90}
Program Code 026:000
Source Datajson Identifier True
Source Hash 5743e8555aaf81afa74e3d0840a5e1d6d4b372bab86f1b283d84ec7c9a6dc33e
Source Schema Version 1.1
Spatial

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