Data Set ID: 

MEaSUREs Polar EASE-Grid 2.0 Daily 6 km Land Freeze/Thaw Status from AMSR-E and AMSR2, Version 2

This data set, part of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Program, consists of a Northern Hemisphere daily landscape Freeze/Thaw status at 6 km resolution. The data are derived from observations acquired by the Japan Aerospace Exploration Agency's (JAXA) Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) and the Advanced Microwave Scanning Radiometer 2 (AMSR2).

This is the most recent version of these data.

Version Summary: 

This version includes the following updates:
• Extended temporal coverage to 2020;
• Title changed to reflect addition of data for the Southern Hemisphere;
• Addition of Annual Accuracy data;
• The PER FT-ESDR now includes both Northern Hemisphere (NH) and Southern Hemisphere (SH) polar grid domains to facilitate high latitude studies of the changing cryosphere in both polar hemispheres;
• A modified seasonal threshold algorithm (MSTA) is used for the FT classification where MSTA Tb reference FT conditions are calibrated annually for each pixel using 6-km resolution daily surface air temperature (SAT) records downscaled from coarser resolution (0.25°) ERA5 reanalysis data (Hersbach et al., 2018) using temperature lapse rates defined from an Aqua MODIS LST climatology and digital elevation map;
• Over NH permanent snow/ice regions, an Adaptive Threshold algorithm (ADT) is used by adaptively determining the FT threshold from analyzing Tb time series of a given year and grid cell (Kimball et al., 2021). For areas where seasonal melting events occur, a Breaks For Additive Seasonal and Trend (BFAST) approach (Verbesselt et al., 2012) is applied to detect the abrupt change point connecting the adjacent frozen and thawed periods to determine FT reference Tb values. For areas where there is no persistent snow/ice melting, diurnal change signals from AMSR ascending and descending orbit Tb retrievals are used to confirm diurnal thaw and refreeze events and determine FT reference Tb values;
• Updated annual data quality assurance (QA) maps are included indicating product performance and reliability.


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Data: Data integrity verified

Documentation: Key metadata and links to supporting documentation available

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Data Format(s):
  • Binary
  • GeoTIFF
Spatial Coverage:
N: 90, 
S: -90, 
E: 180, 
W: -180
Platform(s):Aqua, GCOM-W1
Spatial Resolution:
  • 6 km x 6 km
Sensor(s):AMSR-E, AMSR2
Temporal Coverage:
  • 2 June 2002 to 31 December 2020
Temporal Resolution1 dayMetadata XML:View Metadata Record
Data Contributor(s):Youngwook Kim, John Kimball, Jinyang Du, Joe Glassy, Kyle McDonald

Geographic Coverage

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As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Kim, Y., J. S. Kimball, J. Du, and J. Glassy. 2021. MEaSUREs Polar EASE-Grid 2.0 Daily 6 km Land Freeze/Thaw Status from AMSR-E and AMSR2, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].

Literature Citation

As a condition of using these data, we request that you acknowledge the author(s) of this data set by referencing the following peer-reviewed publication.

  • Kim, Y., J. S. Kimball, J. Glassy, and J. Du. 2017. An Extended Global Earth System Data Record on Daily Landscape Freeeze-Thaw Determined from Satellite Passive Microwave Remote Sensing, Earth System Science Data. 9. 133–147.

A user guide is not available for this data set.

How To

V0 Programmatic Data Access Guide
Data from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) can be accessed directly from our HTTPS file system. We provide basic command line Wget and curl instructions for HTTPS file system downloads below. For questions about programmatic access to NSIDC... read more
How do I convert a GeoTIFF into a NetCDF file?
We recommend using the Geospatial Data Abstraction Library (GDAL) to convert GeoTIFF files into a different format. If you want to reproject to lat/lon as well, then we recommend reprojecting before converting to NetCDF (see the FAQ "How do I reproject a GeoTIFF to from polar steroegraphic to... read more