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    • NOAA Climate Data Record (CDR) of AVHRR Polar Pathfinder Extended (APP-X) Cryosphere, Version 2

    Metadata Updated: November 2, 2023

    NOAA Climate Data Record (CDR) of the eXtended AVHRR Polar Pathfinder (APP-X) cryosphere contains 19 geophysical variables over the Arctic and Antarctic for the period 1982 - present. All of them have undergone various degrees of validation, though not all are considered CDR quality. The variables are (those considered by the developers to be CDR-quality are identified with an asterisk): Surface temperature, all-sky, snow, ice, and land Surface albedo, all-sky Sea ice thickness Surface type Cloud mask Cloud particle thermodynamic phase Cloud optical depth Cloud particle effective radius Cloud temperature Cloud pressure Cloud type Downwelling shortwave radiation at the surface Downwelling longwave radiation at the surface Upwelling shortwave radiation at the surface Upwelling longwave radiation at the surface Upwelling shortwave radiation at the TOA Upwelling longwave radiation at the TOA Shortwave cloud radiative forcing at the surface Longwave cloud radiative forcing at the surface APP-x data products are mapped to a 25 km EASE grid at two local solar times: 04:00 and 14:00 for the Arctic, and 02:00 and 14:00 for the Antarctica. Using local solar time rather than standard UTC times provides better information on diurnal differences at all locations. The latest update to version 2 includes folding in the APP FCDR updates (updated calibration coefficients for AVHRR GAC visible channels) along with improved algorithms for the land mask, cloud mask, and ice thickness.

    Access & Use Information

    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.

    Downloads & Resources

    Dates

    Metadata Date September 19, 2023
    Metadata Created Date October 28, 2022
    Metadata Updated Date November 2, 2023
    Reference Date(s) 2019 (publication)
    Frequency Of Update daily

    Metadata Source

    Harvested from ncdc

    Other Data Resources

    Graphic Preview

    APP-x broadband surface albedo

    Additional Metadata

    Resource Type Dataset
    Metadata Date September 19, 2023
    Metadata Created Date October 28, 2022
    Metadata Updated Date November 2, 2023
    Reference Date(s) 2019 (publication)
    Responsible Party DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce (Point of Contact)
    Contact Email
    Guid gov.noaa.ncdc:C01580
    Access Constraints Cite as: Key, Jeffrey; Wang, Xuanji; Liu, Yinghui; and NOAA CDR Program (2019). NOAA Climate Data Record of AVHRR Polar Pathfinder Extended (APP-X), Version 2. [indicate subset used]. NOAA National Centers for Environmental Information. doi:10.25921/AE96-0E57 [access date]., See the Use Agreement for this CDR available on the CDR page., Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives., Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
    Bbox East Long 180.0
    Bbox North Lat 90.0
    Bbox South Lat -90.0
    Bbox West Long -180.0
    Coupled Resource
    Frequency Of Update daily
    Graphic Preview Description APP-x broadband surface albedo
    Graphic Preview File https://www.ncei.noaa.gov/pub/data/metadata/images/C00941_appx_surface_albedo.jpg
    Graphic Preview Type JPEG
    Harvest Object Id 008f36cb-b340-4e18-b03a-64d546723019
    Harvest Source Id 2cb3ef77-1683-4c2a-9119-dc65e50917c6
    Harvest Source Title ncdc
    Licence Uncertainties in most of the retrieve parameters (e.g., surface temperature, cloud optical depth, etc.) are smallest in the presence of sunlight ("polar day") and largest during the polar winter. Cloud detection in the polar regions at night is notoriously difficult. All other retrieved parameters are in one way or another dependent upon cloud detection., See the Algorithm Theoretical Basis Document for a description of use limitations.
    Lineage This Climate Data Record (CDR) were produced by NOAA Center for Satellite Applications and Research (STAR) and University of Wisconsin and are archived at the NOAA National Climatic Data Center (NCDC).
    Metadata Language eng; USA
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-180.0, -90.0], [180.0, -90.0], [180.0, 90.0], [-180.0, 90.0], [-180.0, -90.0]]]}
    Progress onGoing
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 1982-01-01

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