Could Land-Falling Typhoons Be Controlled by the Meridional Oscillation of the Kuroshio Extension?

Low-frequency variations of typhoon paths are often attributed to changes in the North Pacific subtropical high and monsoon through influences on the steering wind. Our preliminary study shows evidence indicating that there may exist a strong imprint of the Kuroshio on the atmosphere, which may modify the steering wind and therefore typhoon paths. We propose to use observations and numerical models, including idealized model and WRF AGCM to study whether the meridional oscillation of Kuroshio and sea surface temperature (SST) gradient will change the westerly tropospheric wind, allowing more typhoons to veer toward (away from) the East Asian continent (included: Taiwan, East China, Japan, south Korea). These model analyses will be accompanied with observational data analyses. Typhoons that veer into northern Taiwan and East China Sea are of considerable importance for obvious reasons. This proposal seeks funding to investigate this problem. In the past 3 years (2015-2017), we have made good progress in completing the proposed goals. The research has resulted in 6 SCI papers, 1 on winter monsoon and air-sea coupling and 5 about typhoon issues: Oey et al. [2015 Clim Dyn], Sun and Oey [2015 MWR], Sun and Oey et al. [2015 Ocean Dyn], Oey and Simon [2016 JGR-Ocean], Liang et al. [2017 JGR-Atmos], Sun et al. [2017 Nature Scientific Reports]. The results obtained from the proposed research are expected to be of interest to the society as well because they may be used to provide long-term and annual typhoon seasonal projections of anticipated changes in the East Asia typhoons in response to the shift of the Kuroshio Extension.