JP3.9
Interdecadal variability of the typhoon activity in Autumn
Chih-Hua Tsou, Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan; and C. J. Lee
The interannual and interdecadal variability of the typhoon activity over the western North Pacific Ocean in summer has received considerable attention, recently. This study found that the activity of categories 4-5 typhoon (TY45) in autumn also exhibits significant interdecadal variability. The super typhoon activity over the western North Pacific Ocean in autumn is strongly influenced by the environment change over the central Pacific Ocean. Both the SST and cloud top temperature increase (decrease) during the super typhoon active (inactive) period. During active period the warm sea surface temperature (SST) and high moisture content occur over the central-eastern Pacific Ocean. These conditions lead the formation of strong typhoon to extend south-eastward to the Date Line. Thus, the strong typhoons have longer (shorter) journey and life span on the warm ocean during active (inactive) period. This implies that the variation of the moisture content associated with the variation of the SST in the central Pacific play important roles on the interdecadal variability of the super typhoon in fall, despite of the increase (decrease) of stability (efficiency) during active (inactive) period. The gross characteristic of this phenomenon can be simulated by the IPCC AR4 air-sea coupled model. This study will further infer the trend of super typhoon activity after global warming from the IPCC AR4 air-sea coupled model simulation.
Joint Poster Session 3, Tropical Cyclones and Climate Change Poster Session
Monday, 21 January 2008, 2:30 PM-4:00 PM, Exhibit Hall B
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