Summertime Temperature Extremes over Japan in the Late 21st Century Projected by a High-Resolution Regional Climate Model

摘要: Future changes in summertime temperature extremes over Japan are projected by a well-developed regional climate model (RCM) with spatial resolution of 5 km. The performance the RCM respect to tempera- ture present is evaluated first based on observations. Although dierences biases (from observations) daily temperatures between and driving atmospheric general circulation (AGCM) simulations not statistically significant, root-mean-square errors mean minimum reproduced smaller than those AGCM coarser resolution. These results indicate that higher has better simulating variability. A test whether can capture ex- tremes reveals good quantitative agreement simulated observed values appearance frequency extreme high for during July August. pattern upper tail distribution maximum also observations, although underestimated. Projected extremely relatively large lee side Hidaka Mountains, southeast Hokkaido. This finding be explained foehn phenomenon: windward Froude number conditions future more favorable intensification foehn. In terms temperature, dierence present-day climates August Tama area, west Tokyo. phenomenon solely responsible changes, explain pro- jected when westerly winds prevail located Kanto Mountains.