European snow cover extent variability and associations with atmospheric forcings

Abstract

Snow cover in Europe represents an important component of the region's climatic system. Variability in snow cover extent can have major implications on factors such as low-level atmospheric temperatures, soil temperatures, soil moisture, stream discharge, and energy allocation involved in the warming and melting of the snowpack. The majority of studies investigating Northern Hemisphere snow cover identify European snow cover extent as a portion of the Eurasian record, possibly masking complexities of this subset. This study explores the variability of European snow cover extent from 1967-2007, with the region in question including the area of Europe extending eastward to the Ural Mountains (60°E). Using the 89 × 89 gridded National Oceanic and Atmospheric Administration (NOAA) Northern Hemisphere weekly satellite snow cover product, area estimates of seasonal snow cover were calculated, and their relationship to gridded temperature, precipitation, and sea-level pressure data analysed. The spatial variability of snow cover extent was also explored using geographical information systems (GIS). The combined results from both surface temperature and precipitation analyses point towards snow cover extent in Europe being primarily temperature dependent. Atmospheric variables associated with extremes in snow cover extent were investigated. Large (small) European snow extent is associated with negative (positive) 850 hPa zonal wind anomalies, negative (positive) European 1000-500 hPa thickness anomalies, and generally positive (negative) Northern European precipitation anomalies. Sea-level pressure and 500 hPa results indicate strong associations between large (small) snow cover seasons and the negative (positive) phase of the North Atlantic Oscillation.

Seasonal stability of snow cover in Poland in relation to the atmospheric circulation

“…Henderson and Leathers (2010) confirm the strong associations between large (small) snow cover seasons and the negative (positive) phase of the North Atlantic Oscillation.…”

Regional Evidence of Global Warming

“…Large-scale atmospheric circulation-and the NAO in particular-have been shown to be a strong determining factor of changing snow conditions in the Baltic Sea region. The large-scale circulation affects the extent of European snow cover (Henderson and Leathers 2010), snow amounts (Kohler et al 2006;Falarz 2007;Popova 2007;Bednorz and Wibig 2008), the occurrence of heavy snowfall (Bednorz and Wibig 2008) and snow cover duration (Klavins et al 2009). However, formal assessments of the ultimate causes, such as increasing atmospheric greenhouse gas concentrations, for changes in snow conditions are still rare.…”

Recent Change—Terrestrial Cryosphere

“…A modelling study that eliminated snow cover from the climate system found that this resulted in higher mean annual surface air temperature; decreased soil temperature and increased permafrost extent; drying of upper-layer soils and changes in the annual cycle of run-off; and the disappearance of extreme cold air outbreaks (Vavrus 2007). Variability in SCE in Europe affects low-level atmospheric temperature, soil temperature, soil moisture, stream discharge and energy flow in the warming and melting of the snowpack (Henderson and Leathers 2010).…”