Recent Northern Hemisphere snow cover extent trends and implications for the snow-albedo feedback
Abstract
Monotonic trend analysis of Northern Hemisphere snow cover extent (SCE) over the period 1972-2006 with the Mann-Kendall test reveals significant declines in SCE during spring over North America and Eurasia, with lesser declines during winter and some increases in fall SCE. The weekly mean trend attains -1.28, -0.78, and -0.48 × 106 km2 (35 years)-1 over the Northern Hemisphere, North America, and Eurasia, respectively. The standardized SCE time series vary and trend coherently over Eurasia and North America, with evidence of a poleward amplification of decreasing SCE trends during spring. Multiple linear regression analyses reveal a significant dependence of the retreat of the spring continental SCE on latitude and elevation. The poleward amplification is consistent with an enhanced snow-albedo feedback over northern latitudes that acts to reinforce an initial anomaly in the cryospheric system.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- November 2007
- DOI:
- 10.1029/2007GL031474
- Bibcode:
- 2007GeoRL..3422504D
- Keywords:
-
- Cryosphere: Snow (1827;
- 1863);
- Cryosphere: Distribution;
- Global Change: Cryospheric change (0776);
- Atmospheric Processes: Polar meteorology;
- Global Change: Land cover change