Analysis and prognosis of tropical cyclone genesis over the western North Pacific on the background of global warming

As revealed by the observational study, there are more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-1970s to the present.The decadal change of tropical cyclones activities are closely related to the decadal changes of atmospheric general circulation in the troposphere, which provide favorable or unfavorable conditions for the formation of tropical cyclone.Furthermore, based on the simulation of corresponding atmospheric general circulation from a coupled climate model under the schemes of Intergovernmental Panel on Climate Change (IPCC) special report on emission scenarios (SRES) A2 and B2 emissions scenarios an outlook on the tropical cyclone frequency generated over the western North Pacific in the coming half century is presented.It is indicated that in response to the global climate change the general circulation of atmosphere would become unfavorable for the formation of tropical cyclone as a whole and the frequency of tropical cyclones formation would likely decrease by 5% within the next half century, although more tropical cyclones would appear during a short period in it.