Snow Precipitation and Snow Cover Climatic Variability for the Period 1971–2009 in the Southwestern Italian Alps: The 2008–2009 Snow Season Case Study

Silvia Terzago,Roberto Cremonini,Claudio Cassardo,Simona Fratianni

doi:10.3390/w2040773

Silvia Terzago, Roberto Cremonini + Show 2 more

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https://doi.org/10.3390/w2040773

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Abstract

Snow cover greatly influences the climate in the Alpine region and is one of the most relevant parameters for the climate change analysis. Nevertheless, snow precipitation variability is a relatively underexplored field of research because of the lack of long-term, continuous and homogeneous time series. After a historical research aiming to recover continuous records, three high quality time series of snow precipitation and snow depth recorded in the southwestern Italian Alps were analyzed. The comparison between the climatological indices over the 30 years reference period 1971–2000 and the decade 2000–2009 outlined a general decrease in the amount of snow precipitation, and a shift in the seasonal distribution of the snow precipitation in the most recent period. In the analysis of the last decade snow seasons characteristics, the attention was focused on the heavy snowfalls that occurred in Piedmont during the 2008–2009 snow season: MODerate resolution Imager Spectroradiometer (MODIS) snow cover products were used to evaluate snow cover extension at different times during the snow season, and the results were set in relation to the temperatures.

Highlights

Snow cover and duration are among the major controlling factors for a range of environmental and socio-economic systems in mountainous regions
In this work the attention is focused on snow depth and snow precipitation: the measurements were performed over a flat field where a vertical graduated scale was fixed at the ground and a small tablet, usually made of wood, was available
Total and fresh snow depth measurements performed at the three meteorological observation sites during the period of January 1971 to December 2009 were analyzed in order to evaluate the following snow indices:

Summary

Introduction

Snow cover and duration are among the major controlling factors for a range of environmental and socio-economic systems in mountainous regions. Snow abundance depends on both temperature and precipitation: snow depth, snow cover extension and duration are related to the diurnal values of temperature and precipitation, but they are based on the history of these variables over a period preceding the observation itself. For this reason, snow records, averaged over monthly or yearly periods, provide a useful insight into inter-annual or longer time scale climatic fluctuations [3]. Snow can be considered as a main parameter, both as indicator and controlling factor, for studying the climate change in the Alpine area

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