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

Published by DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce | National Oceanic and Atmospheric Administration, Department of Commerce | Catalog Last Checked: August 03, 2026 at 06:54 AM | Dataset Last Updated: January 01, 2019 at 12:00 AM
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.

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Earth Science > Cryosphere Oceanic - Surface - Sea Ice Atmospheric - Upper-air - Cloud Properties Terrestrial - Albedo Atmospheric - Surface - Surface Radiation Budget (including Solar Irradiance) Atmospheric - Surface - Air Temperature Oceanic - Surface - Sea-surface Temperature Geographic Region > Arctic

Complete Metadata
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accessLevel non-public
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describedByType application/octet-steam
description 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.
distribution 
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identifier https://data.noaa.gov/waf/NOAA/NESDIS/ncei/aim/iso/xml/C01580.xml
issued 1975-01-01T00:00:00.000+00:00
keyword 
[
  "Earth Science > Cryosphere",
  "Oceanic - Surface - Sea Ice",
  "Atmospheric - Upper-air - Cloud Properties",
  "Terrestrial - Albedo",
  "Atmospheric - Surface - Surface Radiation Budget (including Solar Irradiance)",
  "Atmospheric - Surface - Air Temperature",
  "Oceanic - Surface - Sea-surface Temperature",
  "Geographic Region > Arctic",
  "Continent > Antarctica",
  "Vertical Location > Land Surface",
  "Vertical Location > Sea Surface",
  "NOAA Climate Data Record (CDR) Program",
  "NOAA OneStop Project",
  "AVHRR > Advanced Very High Resolution Radiometer",
  "NOAA POES > NOAA Polar Orbiting Environmental Satellites",
  "10 km - < 50 km or approximately .09 degree - < .5 degree",
  "Satellite",
  "DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce",
  "DOC/NOAA/NESDIS/STAR > Center for Satellite Applications and Research, NESDIS, NOAA, U.S. Department of Commerce"
]
landingPage https://www.ncei.noaa.gov/contact
language 
[]
license https://creativecommons.org/publicdomain/zero/1.0/
modified 2019-01-01T00:00:00.000+00:00
publisher 
{
  "name": "DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce",
  "@type": "org:Organization"
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rights otherRestrictions
spatial -64.8,18.6,-77.8,25.4
temporal 1959-05-27T00:00:00+00:00/1959-06-22T00:00:00+00:00
theme 
[
  "geospatial"
]
title NOAA Climate Data Record (CDR) of AVHRR Polar Pathfinder Extended (APP-X) Cryosphere, Version 2

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