FUNDING SOURCE AND GRANT NUMBER: U.S. National Science Foundation Arctic System Science Program grant number OPP-9818066

DATASET OVERVIEW: The Ivotuk study area is located on the North Slope of Alaska on the central southern coastal plains north of the Brooks Range (Lat.68 29 N, Lon. 155 44 W). The area became part of the Arctic Transitions in Land- Atmosphere System (ATLAS) in 1998. Thaw depth is measured over a one kilometer square grid. Data collection required approximately five hours on 9-22-2001. Additional site information is available at the ATLAS/Ivotuk website: http://www.uaf.edu/water/projects/atlas/atlas.html

INSTRUMENT DESCRIPTION: Steel rod with length incremented in centimeters.

DATA COLLECTION AND PROCESSING: Data was collected by walking the grid and measuring the maximum depth to which the probe could be inserted, in accordance with the CALM protocol.

DATA FORMAT: Excel file;Data was gathered at grid points only (100 meter increments); Thaw depth is recorded in centimeters.

REFERENCE: CALM (Circumpolar Active Layer Monitoring) website: http://www.geography.uc.edu/~kenhinkel/CALM/