IMPACT OF WARMER OCEAN SURFACE TEMPERATURE ON THE TROPICAL CYCLONE DESTRUCTIVE POTENTIAL OVER WESTERN NORTH PACIFIC:ANALYSIS OF HIGH-RESOLUTION CASE SIMULATIONS
YI Lan
SUN Yuan
ZHONG Shi
HU Yi-jia
Abstract：To reveal the impact of increased sea surface temperature (SST) on TC destructive potential over the western North Pacific (WNP),a series of SST sensitivity experiments with the Weather Research and Forecasting (WRF) model is conducted for three tropical cyclone (TC) cases in the WNP.The results show that,the SST increases over different radial extents play different roles in determining TC intensity,size,and potential destructiveness.The inner SST increase within approximately 100 km of TC center promotes TC intensification,but reduces TC inner-core size.In contrast,the outer SST beyond 100 krn of the TC center contributes greatly to the growth of TC inner-core size,but reduces TC intensity.Further analysis indicates that,as the inflow air moves towards the eyewall,warmer outer SST can gradually increase the underlying surface air temperature and moisture,reduce the inward-directed pressure gradient near the eyewall,and thus decrease the air-sea temperature and moisture differences,which will lead to less sensible and latent heat fluxes entering the eyewall and then decrease the TC intensity,but with an outward centrifugal displacement of eyewall and thus an increase in the TC inner-core size.The opposite happens as the inner SST increases.Therefore,when a TC moves across a warm/cold pool,the changes of TC intensity and size are determined by not only the conditions of local SST,but also the SST difference between the inner and outer TC regions.Due to the different effects of inner-SST and outer-SST on TC intensity and inner-core size,the TC potential destructiveness does not monotonically increase with the expansion of the ocean warm pool.There exists a critical range of the ocean warm pool.The TC potential destructiveness may not increase and may even decrease once the size of ocean warm pool exceeds the critical range.
Keywords：tropical cyclonedestructive potentialsea surface temperature(SST)sensitivity analysisclimate change
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 313-322 )