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This data set consists of active layer thickness (ALT) measurements based on soil temperatures in the Russian Arctic. The active layer is the top layer of ground that freezes in the winter and thaws in the summer over permafrost. Changes in ALT over northern high-latitude permafrost regions have important impacts on the surface energy balance, hydrologic cycle, carbon exchange between the atmosphere and the land surface, plant growth, and ecosystem as a whole. Warming may thicken the active layer and induce permafrost thaw.
Investigators collected data from 31 ground-based stations. Derived from monthly averages, the record includes annual maximum active layer depths from 1930 to 1990. Data are in tab-delimited ASCII text format and are available via FTP.
Zhang, T., O. W. Frauenfeld, and R. G. Barry. 2006. Time series of active layer thickness in the Russian Arctic, 1930-1990. Boulder, CO: National Snow and Ice Data Center. Digital media.
To broaden awareness of our services, NSIDC requests that you acknowledge the use of data sets distributed by NSIDC. Please refer to the citation below for the suggested form, or contact NSIDC User Services for further information. We also request that you send us one reprint of any publication that cites the use of data received from our Center. This helps us to determine the level of use of the data we distribute. Thank you.
| Category | Description |
|---|---|
| Data format | Data are in tab-delimited ASCII text files. A station list is provided in tab-delimited ASCII text format or Microsoft Excel format, and an image showing station locations is provided in graphics interchange format (GIF). |
| Spatial coverage and resolution | Southernmost Latitude: 60.90° N Northernmost Latitude: 70.75° N Westernmost Longitude: 88.30° E Easternmost Longitude: 178.90° E Minumum Altitude: 22 m Maximum Altitude: 802 m |
| Temporal coverage and resolution | The data record includes annual maximum active layer depths taken from monthly averages collected from 1930 to 1990. |
| Tools for accessing data | Data can be viewed with a text editor. |
| File naming convention | Data files are named following the convention TMD2.sss.max where sss is the three-digit station identification number. |
| File size | File sizes range from 1 KB to 35 KB. Data are distributed as a 48.52 KB compressed (.zip) file. |
| Parameter(s) | Active layer thickness (ALT) is the only variable included in this data set |
| Procedures for obtaining data | Data are available via FTP. |
1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information
Tingjun Zhang
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449
Roger G. Barry
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449
Oliver W. Frauenfeld
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449
NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449 USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org
This research was supported by the National Science Foundation (NSF) Office of Polar Programs (OPP) Arctic System Science (ARCSS) Program grant number OPP-0229766.
Data are in tab-delimited ASCII text files. A station list is also provided in tab-delimited ASCII text format or Excel format, and an image showing station locations is provided in graphics interchange format (GIF).
Data files are named following the convention TMD2.sss.max where sss is the three-digit station identification number. The supplementary composite file including the average active layer thickness of all 31 sites for each year is titled Composite_1930-1990_ALT.txt. The following files are also included in the directory:
File sizes range from 1 KB to 35 KB. Data are distributed as a 48.52 KB compressed (.zip) file.
 |
Click on the thumbnail to view locations of the 31 stations where data was collected. |
Southernmost Latitude: 60.90° N
Northernmost Latitude: 70.75° N
Westernmost Longitude: 88.30° E
Easternmost Longitude: 178.90° E
Minumum Altitude: 22 m
Maximum Altitude: 802 m
The data record includes annual maximum active layer depths taken from monthly averages collected from 1930 to 1990.
Permafrost is broadly defined as perennially frozen ground, soil, or rock with a temperature at or below 0 °C for at least two years. The active layer is the top layer that freezes in winter and thaws in summer over permafrost. ALT is controlled by many factors including air temperature, vegetation, snow cover, soil moisture, etc. In general the most important factor influencing ALT is summer air temperature. ALT is determined by linearly interpolating between measurement levels to find the position of the 0 °C isotherm at its maximum depth of the year.
Annual maximum active layer depths range from 0.20 m to 3.17 m.
These sample data are from the file TMD2.239.max, collected at the Isit' station (239).
1954 |
-999 |
1955 |
-999 |
1956 |
0.6 |
1957 |
1.16667 |
1958 |
1.2 |
1959 |
1.12727 |
1960 |
1.16923 |
1961 |
1.12727 |
1962 |
1.09474 |
1963 |
1.12 |
1964 |
1.08 |
1965 |
1.16522 |
1966 |
1.13333 |
1967 |
1.1 |
1968 |
1.18 |
Data are available via FTP.
The entire data set uncompressed is 107 KB.
Soil temperature was measured in the former Soviet Union with some records beginning in the 1980s and many others beginning in the 1930s or 1950s. Data collection procedures are summarized by Gilichinsky et al. [1998], Zhang et al. [2001], and the instruction manuals of the State Committee of the U.S.S.R. for Hydrometeorology and Environmental Control [1985]. The data are available primarily as monthly means formed from the daily and sub-daily measurements. Soil temperatures were generally measured at depths of 0, 0.05, 0.10, 0.15, 0.20, 0.40, 0.60, 0.80, 1.20, 1.60, 2.00, 2.40, and 3.20 m. Temperatures at depths from 0.0 m - 0.60 m were measured at least three times per day. Measurements at depths of 80 cm and deeper were made once daily near midday.
Frauenfeld, O. W., T. Zhang, R. G. Barry, and D. Gilichinsky. 2004. Interdecadal changes in seasonal freeze and thaw depths in Russia. Journal of Geophysical Research 109, D05101. doi:10.1029/2003JD004245.
Gilichinsky, D. A., R. G. Barry, S. S. Bykhovets, et. al. 1998. A century of temperature observations of soil climate: Methods of analysis and long-term trends, in Proceedings of 7th International Conference on Permafrost, edited by A. Lewkowicz and M. Allard, pp. 313-317, Cent. d'Etudes Nordiques, Univ. Laval, Ste-Foy, Canada.
State Committee of the U.S.S.R. for Hydrometeorology and Environmental Control. 1985. Instructions for meteorological stations and posts, in Meteorological Observations at Stations, vol. 3, part 1, Gidrometeoizdat, Leningrad.
Zhang, T., O. W. Frauenfeld, M. C. Serreze, et. al. 2005. Spatial and temporal variability in active layer thickness over the Russian Arctic Drainage Basin. Journal of Geophysical Research 100, D16101. doi:10.1029/2004JD005642.
Zhang, T., R. G. Barry, D. Gilichinsky, et. al. 2001. An amplified signal of climatic change in soil temperatures during the last century at Irkutsk, Russia. Climate Change 49, 41-76.
The following acronyms are used in this document:
ALT: Active Layer Thickness
ARCSS: Arctic System Sciences
GIF: Graphics Interchange Format
NSF: National Science Foundation
NSIDC: National Snow and Ice Data Center
OPP: Office of Polar Programs
URL: Uniform Resource Locator
March 3, 2006
May 22, 2006
http://nsidc.org/data/docs/arcss/arcss160/index.html
