Note: This data set was first published on the 1998 CAPS CD.
The text for this document was taken unchanged from that CD.

See also Description of Data Files.

The data files in this directory (\SOILTEMP) contain soil temperatures collected from 1963-66 and 1993 at Barrow, Alaska. Active layer temperature observations of the seasonal thaw layer and upper meter of permafrost at Barrow, Alaska, were conducted starting in 1963 by the U.S. Army's Cold Regions Research and Engineering Laboratory (CRREL) and continued intermittently until 1966. Soil temperature measurements were resumed in 1993 as part of an NSF funded project under the new U.S. Global Change Program's Arctic System Science (ARCSS) Land-Atmosphere-Ice Interactions (LAII) program. Frederick Nelson, Department of Geography and Planning, State University of New York at Albany, and LAII investigator, compiled the 1993 data.

The files 1963.DAT, 1964.DAT, 1965.DAT, and 1966.DAT contain soil temperature measurement data collected in those years. All of the data files are in tabular ASCII format. Each data file for each measurement site contains header information (1 record) that you may want to remove before using the data. The reported 1960's data include periodic measurements, either weekly or seasonally, from seven cores located within several hundered meters of each other on several plots along the 2-km long transect characteristic of the ice-wedge dominated Arctic Coastal Plain. Temperatures were measured in degrees Celsius. The files are 138 characters wide.

Soil temperatures were measured by thermocouples at closely spaced intervals in the upper 50 cm and to depths ranging between 100 cm and 165 cm (Brown et.al., 1965). The observational interval varied from year to year. Consecutive daily readings are available for selected periods of freeze-up and thaw, otherwise, readings are weekly. There were three cables in Plot 37 (37-1,37-2,37-3) and two cables each in Plot 40 (40-1,40-2), Plot 44 (44-1,44-2) and Plot 1 (1-1,1-2). The cables BR and CM were located on the beach ridge (BR) and in Central Marsh (CM). Measurements were made with thermocouples embedded in undisturbed, frozen cores to the depth of one meter. During the first several years, temperatures were recorded throughout the year on strip charts and results tabulated; in later years temperatures were measured manually with a Wheatstone bridge. The original charts are no longer available. The number of data set intervals in this file include for 1963 (42); 1964 (93); 1965 (15); and 1966 (1).

In early July 1965, after several years of freeze-thaw, it was noted that the upper portion of most cables had been displaced upwards. The amount of displacement is noted below. Originally the reference point was at the ground surface with thermocouple no.1 buried 5 cm. below the surface. The data are not corrected for the displacement described below.

Cable Number	Reference Point	Location above surface	Comments
37-1		12cm	No 1 and 2 on surface
37-2		15cm	No 1 and 2 on surface
37-3		8cm	No 1 on surface
40-1	(polygon top)	10cm	No 1 on surface
40-2	(polygon trough)	1cm	--"-- --"--
44-1	(hummock top)	3cm	--"-- --"--
44-2	(hummock base)	4cm	--"-- --"--
1-1	(west)	3cm	--"-- --"--
1-2	(east)	7cm	No 1 on surface
BR		4cm	--"-- --"--
CM		11cm	--"-- --"--

The file 1993.DAT contains temperatures observations from Barrow made during summer 1993 using the rigid thermistor probe and Campbell data logger, by Frederick Nelson, Department of Geography and Planning, State University of New York at Albany. Temperature values are given in degrees Celsius.

Starting in June 1993, a Campbell recorder was installed in close proximity to the original CRREL sites using a commercially fabricated, rigid thermistor probe anchored in permafrost to the depth of 1.2 m. Data values in column 1 in the file 1993.DAT give the Julian day and hour (AST) of observation (the hour is represented by the decimal portion of the value). Temperatures were read at hourly intervals. Each successive pair of readings was averaged and written to a storage module as a single value. Data values thus reflect the time of the second reading in each pair, which is also the time at which two-hour averages were written to the storage module. Data in column 2 represents temperatures measured by a thermistor placed at the soil/vegetation interface ("ground surface"). The lead connecting this thermistor to the rigid probe was severed, apparently by animal activity, at or about observation time 227.17. Temperature values in column 2 appearing after this time are invalid. Data in columns 3-14 represent below ground temperatures in degrees Celsius at thermistor spacings at the following levels below the surface: 0, 5, 10, 15, 20, 25, 30, 35, 45, 70, 95, and 120 cm. The file is 140 characters wide.

ANALYSIS:

This incomplete time series of active-layer temperature measurements should provide valuable insight into the response of permafrost terrain to climate fluctuations; to date warmer ummers have not produced increased depth of the active layer at Barrow. A more shallow active layer has been observed in the 1990's thaw data. In addition to these data sets, numerous other soil temperature data have been collected for the Barrow area starting in the 1950's. Another substantial data set was obtained during the IBP (1970-1974) years by CRREL and results reported in several papers by Nakano, Brown and McGaw (references listed in the file README.DOC in the directory \PERMA). However, those data are no longer available other than in reduced published form.

CONTACT INFORMATION:

Further questions and requests for information about this data set may be forwarded to Frederick Nelson, Department of Geography and Planning, State University of New York at Albany, Albany, NY 12222. Phone: (518) 442-4770. FAX: (518) 442-4867. Internet: fnelson@uacsc1.albany.edu.

REFERENCES:

Brown, Jerry and Johnson, P.L. 1965. Pedo-ecological Investigations, Barrow, Alaska. Cold Regions Research and Engineering Laboratory Technical Report 159, Hanover, NH, 32 pages plus appendices.

Brown, Jerry 1969. Soil properties developed on the complex tundra relief of northern Alaska. Biuletyn Peryglacjalny, vol. 18, pp. 153-167.

Mc Gaw, R. W., Outcalt, S.I., and Ng, E. 1978. Thermal properties and regime of wet tundra soils at Barrow, Alaska. In Proceedings, Third International Conference on Permafrost, National Research Council of Canada, Ottawa, Canada, vol. 1, 47-53.

Nakano,Y.,and Brown,J. 1972. Mathematical modelling and validation of the thermal regimes in tundra soils, Barrow, Alaska. Arctic and Alpine Research, 4: 19-38.

National Science Foundation Grant OPP 9214897; Active Layer/Landscape Interactions: A Retrospective and Contemporary Regional Approach in Arctic Alaska. Ohio State University.