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Global Annual Freezing and Thawing Indices, Version 1

Metadata Updated: September 22, 2025

The total annual freezing and thawing indices are defined as thecumulative number of degree-days when air temperatures are below andabove zero degrees Celsius. The total annual freezing index has beenwidely used to predict permafrost distribution; estimate themaximum thickness of sea, lake, and river ice, and the maximum depth ofground-frost penetration; and classify snow types. The annual totalthawing index has been used to predict permafrost distribution and toestimate the maximum depth of thaw in frozen ground. Both totalfreezing and thawing indices are important parameters for engineeringdesign 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 degreeslatitude by 0.5 degrees longitude. Two data files are available, forthe freeze and thaw indices respectively, in flat binary format. Eachfile is approximately 1 MB in size. The total annual freezing andthawing indexes were calculated based upon the monthly mean airtemperature by Legates and Willmott (1990).

Access & Use Information

Public: This dataset is intended for public access and use. 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 Created Date April 11, 2025
Metadata Updated Date September 22, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date September 22, 2025
Publisher NASA NSIDC DAAC
Maintainer
Identifier 10.5067/TT6J3BH5YSSR
Data Last Modified 2025-09-11
Category Earth Science
Category Tag 16E15F51 D96E 4051 9124 75665Abdc6Ff "Energy Infrastructure"
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 607bf990-1a8d-400b-9cbd-391925d28172
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://daacdata.apps.nsidc.org/pub/DATASETS/FREEZE-THAW-INDICES/
Old Spatial
Program Code 026:000
Source Datajson Identifier True
Source Hash e4d13ec92a1a9363c706e7ee86572432fff420bb1436cfb3e4f45f36309b85cb
Source Schema Version 1.1
Spatial
Temporal 1920-01-01/1920-01-01

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