Elevation-dependent trends in extreme snowfall in the French Alps from 1959 to 2019

• Published in: The Cryosphere
• Main Authors: E. Le Roux, G. Evin, N. Eckert, J. Blanchet, S. Morin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-15-4335-2021; https://doaj.org/article/308a29fab2f845959b5849980d062dff

Climate change projections indicate that extreme snowfall is expected to increase in cold areas, i.e., at high latitudes and/or high elevation, and to decrease in warmer areas, i.e., at mid-latitudes and low elevation. However, the magnitude of these contrasting patterns of change and their precise relations to elevation at the scale of a given mountain range remain poorly known. This study analyzes annual maxima of daily snowfall based on the SAFRAN reanalysis spanning the time period 1959–2019 and provided within 23 massifs in the French Alps every 300 m of elevation. We estimate temporal trends in 100- year return levels with non-stationary extreme value models that depend on both elevation and time. Specifically, for each massif and four elevation ranges (below 1000, 1000–2000, 2000–3000, and above 3000 m ), temporal trends are estimated with the best extreme value models selected on the basis of the Akaike information criterion. Our results show that a majority of trends are decreasing below 2000 m and increasing above 2000 m . Quantitatively, we find an increase in 100- year return levels between 1959 and 2019 equal to +23 % ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">32</mn><mspace width="0.125em" linebreak="nobreak"/><msup><mrow class="unit"><mi mathvariant="normal">kg</mi><mspace width="0.125em" linebreak="nobreak"/><mi mathvariant="normal">m</mi></mrow><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="55pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="031292d0c0966987e722c7e1fb0272ca"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-4335-2021-ie00001.svg" width="55pt" height="15pt" ...