Interannual Variability of Winter N-Factors in the Kuparuk River Basin, Alaska

• Main Authors: Anna E. Klene, Frederick E. Nelson, Nikolay I. Shiklomanov, Dmitry A. Streletskiy
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: air temperature; Alaska; n-factor; permafrost; snow cover; soil-surface temperature
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.520.4617; http://www.cas.umt.edu/geography/documents/Klene_et_al_NICOP_2008.pdf

Hourly air and soil temperatures were monitored using arrays of miniature data loggers within eight 1-ha plots representing natural land cover types in northern Alaska’s Kuparuk River watershed between 1995 and 2006. For each plot, mean daily air and soil temperatures were used to calculate mean winter n-factors, the ratio of seasonal freezing degree-day sums at the ground surface to those in the air. Mean 12 year n-factors ranged from 0.32 to 0.58 within the various plots, with ranges of 0.18 to 0.28 over the period of record. A distinct latitudinal gradient of n-factor values exists along this continentality gradient. Although direct measurements of snow cover are not available at the sites, temperature patterns indicate that snow cover is a major determinant of winter n-factor values.