Local trends of snow water equivalents in the Alps

The spatial and temporal snow mass variation is clearly indicated as knowledge gap by the “IPCC Special Report on the Ocean and Cryosphere in a Changing Climate”, thus impeding current efforts to quantify historic and future trends. This is especially true for the Alps, which are very rich in snow depth (HS) records (both in number and length), but notoriously lack the same for snow water equivalent (SWE) observations.

The ∆SNOW model - freely available as part of the R-package “nixmass” - improved by temporally varying density parameters (cf. EGU22-2326), is used to estimate SWE at more than 2000 stations with continuous, daily HS records in and around the Alps from flatlands to very high Alpine regions with 130 stations above 2000 m.

In this contribution first results of a trend analysis of historical SWE observations of this very large number of stations is presented. The very high station density and large elevation range covered opens the opportunity for a climatologically detailed and elevation dependent analysis of historic trends of seasonal mean and peak SWE at an unprecedented local scale.