Localized climate change scenarios of mean temperature and precipitation over Switzerland

Abstract

There is a growing need of the climate change impact modeling and adaptation community to have more localized climate change scenario information available over complex topography such as in Switzerland. A gridded dataset of expected future climate change signals for seasonal averages of daily mean temperature and precipitation in Switzerland is presented. The basic scenarios are taken from the CH2011 initiative. In CH2011, a Bayesian framework was applied to obtain probabilistic scenarios for three regions within Switzerland. Here, the results for two additional Alpine sub-regions are presented. The regional estimates have then been downscaled onto a regular latitudelongitude grid with a resolution of 0.02°or roughly 2 km. The downscaling procedure is based on the spatial structure of the climate change signals as simulated by the underlying regional climate models and relies on a Kriging with external drift using height as auxiliary predictor. The considered emission scenarios are A1B, A2 and the mitigation scenario RCP3PD. The new dataset shows an expected warming of about 1 to 6°C until the end of the 21st century, strongly depending on the scenario and the lead time. Owing to a large vertical gradient, the warming is about 1°C stronger in the Alps than in the Swiss lowlands. In case of precipitation, the projection uncertainty is large and in most seasons precipitation can increase or decrease. In summer a distinct decrease of precipitation can be found, again strongly depending on the emission scenario.

Projected changes in precipitation intensity and frequency in Switzerland: a multi‐model perspective

“…This study aims at decomposing and interpreting the seasonal and regional mean changes of the recent CH2011 scenario initiative (CH2011, 2011Fischer et al, 2011;Zubler et al, 2014). We therefore begin this section by firstly recapitulating the results of these projections first.…”

“…We used five distinct regions of similar grid-point size (upper panel in Figure 1): northeastern Switzerland (CHNE), western Switzerland (CHW), southern Switzerland (CHS), Eastern Swiss Alps (CHAE) and Western Swiss Alps (CHAW). For more details on the depiction of these regions, we refer to Fischer et al (2011) andZubler et al (2014). The changes as presented in Section 3 represent the regional average of a quantity (e.g.…”

“…In a study with the RegCM3 model at different resolutions (including the run from ENSEMBLES), Im et al (2010) related this response feature to local soil-atmosphere feedbacks associated with reduced snow cover and soil moisture at the onset of summer. Given that model-projected seasonal temperatures are subject to rise stronger at higher altitudes (Im et al, 2010;Zubler et al, 2014) and given the relatively invariant ranking of CFs across models in the reference period from one season to the next (Figure 3), seasonal mean temperature rises are suggested to be a further explanatory factor for the elevation-dependent convective changes.…”

Swiss alpine summer farming: current status and future development under climate change

“…Recent predictions for climate change in the Alpine Arc indicate that, by 2050, average temperature will rise by up to 28C and precipitation will decrease, particularly during the summer months (CH2011 2011; Zubler et al 2014 Table 2. It is evident that the results of such qualitative interviews have to be interpreted with caution.…”

Objective climate classification of Slovenia

“…In recent years there has been a growing demand for georeferenced climate regionalization, based on climate variables alone. The demand came from climate experts, to use the climate classification for climate scenarios development (Zubler et al , ) and for determination of representative climate stations (Begert, ). In the present study, our aim was to utilize the recently constructed gridded climatology of Slovenia (Dolinar, ).…”