Contrasting seasonal changes in total and intense precipitation in the European Alps from 1903 to 2010

Abstract

<jats:p>Abstract. Changes of precipitation over the European Alps are investigated with the regional climate model MAR applied with a 7-km resolution over the period 1903–2010 using the reanalysis ERA-20C as forcing. A comparison with several observational datasets demonstrates that the model is able to reproduce the climatology as well as both the inter-annual variability and the seasonal cycle of precipitation over the European Alps. The relatively high resolution allows to estimate precipitation at high elevations. The vertical gradient of precipitation simulated by MAR over the European Alps reaches 33 % km−1 (1.21 mm.day−1.km−1) in summer and 38 % km−1 (1.15 mm.day−1.km−1) in winter, on average over 1971–2008 and shows a large spatial variability. A significant (p-value </jats:p>

Potential and limitations of convection‐permitting CNRM‐AROME climate modelling in the French Alps

“…On the other hand, the seasonal accumulations values produced by AROME (see Figures 4b-f), showing a strong altitudinal increase, and maxima in winter and spring, are very different from those in S2M in past climate or ADA-MONT in future climate for which the altitudinal gradient is lower, with maxima in autumn. These results were also found with MAR simulations compared to S2M reanalyses and other observation datasets Ménégoz et al (2020), as well as similar geographical seasonal variations of accumulated precipitations. Similarly to the results of Vionnet et al (2016), we find that total snowfall values are larger for AROME above 1800 m, with a difference increasing with elevation, despite a strong spatial variability relative to the orography.…”

“…These results were also found with MAR simulations compared to S2M reanalyses and other observation datasets Ménégoz et al . (2020), as well as similar geographical seasonal variations of accumulated precipitations. Similarly to the results of Vionnet et al .…”

“…Investigations were conducted by Ménégoz et al . (2020) addressing 20th century changes in the French Alps using the MAR model driven by a reanalysis, where wetter trends were explained by more intense wet days and longer albeit less‐frequent wet spells, and drying trends with less frequent wet days. Further extensive research at finer spatiotemporal scale would provide further information on these changes.…”

“…A stronger warming signal than AROME are also found in ADAMONT for the summer and spring seasons at all elevations and the autumn below 1800 m. Similar geographical variations of the 21 st century change in the amount of seasonal precipitation in the French Alps can be seen in all three datasets : general increase in winter and autumn in the northern part at all elevations, and a decrease in the southern part at all elevation, whereas a general drying dominates in spring and summer in the entire domain. Investigations were conducted by Ménégoz et al (2020) addressing 20 t h century changes in the French Alps using the MAR model driven by a reanalysis, where wetter trends were explained by more intense wet days and longer albeit less-frequent wet spells, and drying trends with less frequent wet days. Further extensive research at finer spatio-temporal scale would provide further information on these changes.…”

Past Evolution and Recent Changes in Western Europe Large-scale Circulation

“…The latter is not necessarily in contradiction with our results sinceBloomfield et al (2018) study sea-level pressure while we study the 500 hPa geopotential height. At higher levels, this increase in meridional pressure gradient is consistent withMénégoz et al (2020) who show an increase in the westerly component of moisture flux over the Northern half of Europe using a regional climate model forced by ERA20C from 1902 to 2010 (Fig.5therein). It is also in line withRohrer et al (2019) showing an increasing storm track activity in ERA20C along the 20th century over the North Atlantic/European domain.…”