2026-10-28T21:40:53Zhttp://nsidc.org/api/dataset/metadata/oai

oai:nsidc.org/ATL09.0062026-03-03T04:17:04Zcumulusretirednasa_nsidc_daac

ATL09.006ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer CharacteristicsPalm, S. P., Yang, Y., Herzfeld, U. C., Hancock, D., Barbieri, K. A., Wimert, J. & the ICESat-2 Science TeamATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics2023-05-18Boulder, Colorado USANASA NSIDC DAAC: NASA National Snow and Ice Data Center Distributed Active Archive Center6false10.5067/ATLAS/ATL09.006https://nsidc.org/sites/default/files/documents/user-guide/atl09-v006-userguide.pdfATL09Technical ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468

CIRES, 449 UCB

University of Colorado

BoulderCO80309-0449USAEARTH SCIENCESPECTRAL/ENGINEERINGLIDARLIDAR BACKSCATTER Climatology/Meteorology/Atmosphereicesat2-projectATLASAdvanced Topographic Laser Altimeter SystemICESat-2Ice, Cloud, and land Elevation Satellite-22018-10-132025-03-02deprecated-9090-180180GEOGRAPHIC REGIONGLOBAL280 m30 m91 dayThese data have been retired and are no longer accessible, though a more recent version of these data may be available.These data have been retired and are no longer available for use, though a more recent version of these data may be available. Cite any prior or planned use of these data according to the recommended citation at https://nsidc.org/about/data-use-and-copyright. For more information on the NASA ESDIS Data Use Guidance, see https://www.earthdata.nasa.gov/engage/open-data-services-software-policies/data-use-guidance.EnglishNASA/GSFC/SED/ESD/I2-SIPSNASA NSIDC DAACNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daacData Center ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-6199

National Snow and Ice Data Center

CIRES, 449 UCB

University of Colorado

BoulderCO80309-0449USAHTTPSHDF5

This data set (ATL09) contains calibrated, attenuated backscatter profiles, layer integrated attenuated backscatter, and other parameters including cloud layer height and atmospheric characteristics obtained from the data. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory.

VIEW RELATED INFORMATIONhttps://nsidc.org/sites/default/files/documents/user-guide/atl09-v006-userguide.pdfATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics, Version 6 User GuideCEOS IDN DIFVERSION 9.92023-05-182026-03-03NSIDCVersion SummaryModified blowing snow detection algorithm to reduce false positive detections often seen in daylight; Added and modified the blowing snow confidence values (bsnow_con) to include new descriptions and changed the parameter from a one-byte to a two-byte integer value; Added four values to the layer attribute parameter (layer_attr); Added a new parameter called clear air precipitation top height (cap_h) that denotes the top height of clear air precipitation that reached the ground; Replaced the ANC32 surface reflectance map (now based on three years of ICESat-2 surface reflectance measurements instead of two) to fill in gaps; Changed bs_quartile to bs_quantile in ATL09 and related code; Modified code to use density matrix 1 instead of density matrix 2 when computing layer densities; Implemented a third pass of the density dimension algorithm to reduce the effect of noise in creating false layers; Updated the ANC45 cloud/aerosol discrimination table to increase the accuracy of detected layers.NSIDCMinor Version1

Data were reprocessed using ITRF2014 (replacing ITRF2020) for consistency across the entire data set.

2022-11-132023-10-260NSIDCSpatial Reference SystemsEPSG:4326WGS 84NSIDCLevel of ServiceNo Data AccessNSIDCFull Dataset CitationPalm, S. P., Yang, Y., Herzfeld, U. C., Hancock, D., Barbieri, K. A., Wimert, J. & the ICESat-2 Science Team. (2023). <i>ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics</i>. (ATL09, Version 6). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. <a href="https://doi.org/10.5067/ATLAS/ATL09.006">https://doi.org/10.5067/ATLAS/ATL09.006</a>. [<i><describe subset used if applicable></i>].NSIDCRetiredtrue