Future changes of the extreme high‐temperature events influenced by foehn winds in Niigata, Japan

Abstract

AbstractThis study quantifies the future changes in extreme high‐temperature events (ETE) influenced by foehn winds in Niigata, Japan, using numerical and sensitivity experiments based on regional climate modelling. Numerical simulations suggest that the contribution of foehn winds to ETEs is approximately 3.5°C in both the baseline (past) and future climate, and hence it remains unaffected by future climate change; however, the frequency of ETEs is influenced by foehn winds may increase by a factor of 1.5. This is due to the fact that the pressure gradient between land and sea (i.e., the pressure gradient driving the sea breezes) is expected to decrease during the daytime in the future, making it easier for foehn winds to reach Niigata; it also suggests that foehn winds, due to their high‐pressure pattern, which is easily affected by the weakening of the sea breezes, may increase in the future. Overall, to evaluate the regional effects of climate change, it is necessary to understand how future changes in local circulation will impact future changes in the regional climate.