Data Set ID:
NSIDC-0063

Global Annual Freezing and Thawing Indices, Version 1

The total annual freezing and thawing indices are defined as the
cumulative number of degree-days when air temperatures are below and
above zero degrees Celsius. The total annual freezing index has been
widely used to predict permafrost distribution; estimate the
maximum thickness of sea, lake, and river ice, and the maximum depth of
ground-frost penetration; and classify snow types. The annual total
thawing index has been used to predict permafrost distribution and to
estimate the maximum depth of thaw in frozen ground. Both total
freezing and thawing indices are important parameters for engineering
design in cold regions.

Data coverage is global. The data set contains the total annual freezing and thawing indices with a spatial resolution of 0.5 degrees
latitude by 0.5 degrees longitude. Two data files are available, for
the freeze and thaw indices respectively, in flat binary format. Each
file is approximately 1 MB in size. The total annual freezing and
thawing indexes were calculated based upon the monthly mean air
temperature by Legates and Willmott (1990).

This is the most recent version of these data.

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Parameter(s):
  • ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > AIR TEMPERATURE
  • SNOW/ICE > FREEZE/THAW
  • TERRESTRIAL HYDROSPHERE INDICATORS > PERMAFROST MELT > PERMAFROST
Data Format(s):Not specified
Spatial Coverage:
N: 90, 
S: -90, 
E: 180, 
W: -180
Platform(s):GROUND STATIONS
Spatial Resolution:Not SpecifiedSensor(s):THERMOMETERS
Temporal Coverage:
  • 1 January 1920 to 31 December 1980
Version(s):V1
Temporal Resolution1 yearMetadata XML:View Metadata Record
Data Contributor(s):Tingjun Zhang

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.

Zhang, T. Z. 1998. Global Annual Freezing and Thawing Indices, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/TT6J3BH5YSSR. [Date Accessed].

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No technical references available for this data set.

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