Impact of Ocean Warming on Tropical Cyclone Track over the Western North Pacific: A Numerical Investigation
【摘要】：The impact of ocean warming on tropical cyclone(TC) track over the western North Pacific is an open issue. Relatively little is known about possible change of TC tracks under ocean warming conditions, let alone the involved mechanisms, due to the lack of long and successive observations and the large natural variability in a relatively short observational period. A suite of semi-idealized numerical experiments on two TC cases are conducted to investigate the response of the TC track to increases in sea surface temperature(SST). It is found that, the simulated TC track is highly sensitive to the underlying SST. Specifically, through its influence on the radial distribution of sea surface enthalpy, ocean warming can lead to the change of tangential wind profile and thus the increase of TC size in terms of the radius of gale force wind which is contributed by the increase of maximum wind speed, the expansion of radius of maximum wind, and the additional increase of outer wind. The increased TC size, as suggested by previous studies, further leads to the eastward withdrawal of western Pacific subtropical high(WPSH) and thus the northwardturning of TC. Results of our climate simulations provide the further evidence for the aforementioned impact of ocean warming on TC size, and thus the WPSH and TC track. Our results also implies that, the threat of storm to the countries in the East Asian may reduce due to the change of TC track if ocean warming happens in future.