Search

As the Tibetan Plateau (TP) is an important Asian water resource, future changes in precipitation over the TP are an essential part of climate change assessments for the TP and surrounding regions. Here we investigate the water budget over the TP with a global 20-km grid atmospheric general circulation model. Future simulations are performed using CMIP5 multi-model ensemble mean sea surface temperature changes at the end of the 21st century under the RCP8.5 scenario. In the present climate, an east-west contrast in the water budget is noted: over the eastern TP, both moisture flux convergence and local evaporation contribute to summertime precipitation with comparable magnitude; on the other hand, over the western TP, contribution from local evaporation dominates. Under the future climate, precipitation increases over the TP. Contribution from increasing evaporation dominates that from increasing moisture flux convergence into the TP. A prominent east-west contrast is also found in future surface water budget changes. Over the western TP, surface temperature increases are higher, an increasing rate of precipitation is greater, soil moisture becomes wetter, and runoff increases more than over the eastern TP. This suggests that the east-west contrast in surface climate over the TP could become smaller in the future. [ABSTRACT FROM AUTHOR]

Typhoon Mireille (1991) caused devastation over Japan. Assessing the impacts of such an extreme typhoon under global warming is an important task to prevent and mitigate future natural disasters. This study investigated the influences of global warming on the strong winds of Typhoon Mireille by conducting pseudo-global warming (PGW) experiments with a regional model. Since significant damages to forest areas occurred in Kyushu and Tohoku, we compared the typhoon impacts in these two regions. It was demonstrated that on average the mean wind speeds induced by Typhoon Mireille become stronger in Kyushu and weaker in Tohoku under the PGW conditions than under the September 1991 conditions. The difference between the two regions in the future is due to the simulated typhoons under PGW being stronger at lower latitudes and weakening more rapidly at higher latitudes. Thus, the impacts of Typhoon Mireille under a warmed climate are considered to be more severe at a lower latitude and weaker at a higher latitude. [ABSTRACT FROM AUTHOR]

This study numerically investigates the influences of global warming on Typhoon Vera (1959) by conducting pseudo-global warming experiments. It was found that the intensity of Typhoon Vera will be stronger in warmed climate conditions than in the actual September 1959 condition not only at the time of the typhoon's maturity but also at the time of the landfall. Sensitivity experiments indicate that this projected increase in the typhoon intensity is robust, by taking into consideration the effects of the increase in sea surface temperature and temperature lapse rate under global warming. The examination of rainfall characteristics over the Kiso River and the Yodo River basin demonstrated that the maximum accumulated rainfall and the maximum hourly rainfall at a certain location within the region are more intensified in the PGW conditions than in the 1959 condition at their worst levels. Robustness and uncertainty of the projected changes in the typhoon impacts are discussed. [ABSTRACT FROM AUTHOR]