Long-term variability in Northern Hemisphere snow cover and associations with warmer winters
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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.
KeywordsNorthern Hemisphere Snow Cover Storm Track Arctic Oscillation Northern Hemisphere Temperature
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- Brown R (2002) Reconstructed North American, Eurasian, and Northern Hemisphere snow cover extent, 1915–1997. National Snow and Ice Data Center, Boulder, Digital mediaGoogle Scholar
- McCabe GJ, Ayers MA (1989) Hydrologic effects of climate change in the Delaware River Basin. Water Resour Bull 25:1231–1242Google Scholar
- Nijssen B, O’Donnell GM, Hamlet A, Lettenmaier DP (2000) Hydrologic sensitivity of global rivers to climate change. Clim Change 50:515–517Google Scholar
- Rango A, Martinec J (1995) Revisiting the degree-day method for snowmelt computations. Water Resour Bull 31:657–669Google Scholar
- Tarboton DG, Al-Adhami MJ, Bowles DS (1991) A preliminary comparison of snowmelt models for erosion prediction. In: Proceedings of the 59th annual western snow conference, Juneau, Alaska, pp 79–90Google Scholar
- Tasker G, Ayers M, Wolock D, McCabe G (1991) Sensitivity of drought risks in the Delaware River Basin to climate change. In: Proceedings of the technical and business exhibition and symposium, Huntsville Association of Technical Societies, Huntsville, Alabama, pp 153–158Google Scholar
- van Hylckama TEA (1956) The water balance of the earth. Publ Climatol 9:1–117Google Scholar