Item: Climate Change in Italian Alps: Analysis of Snow Precipitation, Snow Durations and Avalanche Activity
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Title: Climate Change in Italian Alps: Analysis of Snow Precipitation, Snow Durations and Avalanche Activity
Proceedings: International Snow Science Workshop Grenoble – Chamonix Mont-Blanc - October 07-11, 2013
Authors:
- Mauro Valt [ ARPAV DRST SNV Centro Valanghe di Arabba, BL, Italy ]
- Cianfarra Paola [ Università degli Studi Roma Tre, Dipartimento di Scienze Geologiche, Roma, Italy ]
Date: 2013-10-07
Abstract: The historical record (1961-2010), of snowfall, snow duration and of temperatures collected in the Italian Alps are presented and analysed. A reduction of the snow cover duration and of the snowfall stronger in springtime was detected during the last 40 years with the greatest decreasing rate during the 1990s. The last decade is characterised by a recovery from the documented decreasing trend mainly evident between 800 m and 1500 m. Principal component trend analysis of the snow duration and of the snowfall showed a long term decreasing trend. The change point test showed the existence of breakpoints between 1984 and 1994 that characterise the snow duration and snowfall time series analysed by elevation range and by seasons. These breakpoints mark a drastic trend variability in the time series: a positive trend characterises the time series before the breakpoint and a decreasing trend characterises the historical record after the breakpoint. The described negative trends result from the documented decrease in winter and spring precipitation. This in turn may either relate to a change in fraction of liquid to solid precipitation, and/or be associated to an increase of the temperatures. Northern Hemisphere and Italian Alps snow cover trends strongly correlate in the frequency domain. Among the dominant frequencies the 11.2 period was detected that may relate to the 11-year solar activity cycle. Analysis of the temperature record showed similar trend. Comparison of snow duration and temperatures during springtime (March-April) showed a strong linear correlation (significance level 0.001). This study will contribute to better understand the avalanche activity in the investigated region. Activity data avalanche have a very limited range time compared to time series of temperature and snow. Good coverage of data is available since 1980 for a limited number of stations the Italian Alps. The data processed in the number of days with avalanches show an increase of days with avalanches from 1980 to 2013. The trend of days with avalanches seems to follow the same trends in the accumulation of snow (SAI Index) processed for the same time interval (1980 - 2013).
Language of Article: English
Presenters: Unknown
Keywords: snow cover, avalanche activity, climate change
Page Number(s): 1247-1250
Subjects: avalanche activity snow precipitation climate change
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Digital Abstract Not Available
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