Long-term variability in Northern Hemisphere snow cover and associations with warmer winters

• Published in: Climatic change Vol. 99; no. 1-2; pp. 141 - 153
• Main Authors: McCabe, Gregory J, Wolock, David M
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01-03-2010; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: 20th century; Atmospheric models; Atmospheric Sciences; Climate change; Climate Change/Climate Change Impacts; Climatology. Bioclimatology. Climate change; Datasets; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Exact sciences and technology; External geophysics; Hydrologic data; Latitude; Melts; Meteorology; Northern Hemisphere; Precipitation; Snow; Snow accumulation; Snow cover; Snow. Ice. Glaciers; Snowmelt; Temperature; Time series; Winter; Storm Track; Northern Hemisphere; Snow Cover; Arctic Oscillation; Northern Hemisphere Temperature; time series analysis; Century 20th; Atmospheric temperature; Winter; Atmosphere cryosphere interaction; Observation data; Climate models; digital simulation; Snow cover; statistical analysis
• ISSN: 0165-0009; 1573-1480
• DOI: 10.1007/s10584-009-9675-2

A monthly snow accumulation and melt model is used with gridded monthly temperature and precipitation data for the Northern Hemisphere to generate time series of March snow-covered area (SCA) for the period 1905 through 2002. The time series of estimated SCA for March is verified by comparison with previously published time series of SCA for the Northern Hemisphere. The time series of estimated Northern Hemisphere March SCA shows a substantial decrease since about 1970, and this decrease corresponds to an increase in mean winter Northern Hemisphere temperature. The increase in winter temperature has caused a decrease in the fraction of precipitation that occurs as snow and an increase in snowmelt for some parts of the Northern Hemisphere, particularly the mid-latitudes, thus reducing snow packs and March SCA. In addition, the increase in winter temperature and the decreases in SCA appear to be associated with a contraction of the circumpolar vortex and a poleward movement of storm tracks, resulting in decreased precipitation (and snow) in the low- to mid-latitudes and an increase in precipitation (and snow) in high latitudes. If Northern Hemisphere winter temperatures continue to warm as they have since the 1970s, then March SCA will likely continue to decrease.