Dependence of Hurricane Intensity and Structures on Vertical Resolution and Time-Step Size
In view of the growing interests in the explicit modeling of clouds and precipitation, the effects of varyingvertical resolution and time-step sizes on the 72-h explicit simulation of Hurricane Andrew (1992) arestudied using the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR)mesoscale model (i.e., MMS) with the finest grid size of 6 km. It is shown that changing vertical resolutionand time-step size has significant effects on hurricane intensity and inner-core cloud/precipitation, butlittle impact on the hurricane track. In general, increasing vertical resolution tends to produce a deeperstorm with lower central pressure and stronger three-dimensional winds, and more precipitation. Similareffects, but to a less extent, occur when the time-step size is reduced. It is found that increasing thelow-level vertical resolution is more efficient in intensifying a hurricane, whereas changing the upper-levelvertical resolution has little impact on the hurricane intensity. Moreover, the use of a thicker surface layertends to produce higher maximum surface winds. It is concluded that the use of higher vertical resolution,a thin surface layer, and smaller time-step sizes, along with higher horizontal resolution, is desirable tomodel more realistically the intensity and inner-core structures and evolution of tropical storms as well asthe other convectively driven weather systems.
作 者： Da-Lin ZHANG Xiaoxue WANG 作者单位： Department of Meteorology, University of Maryland, College Park, Maryland, 20742 USA 刊 名： 大气科学进展(英文版) ISTIC SCI 英文刊名： ADVANCES IN ATMOSPHERIC SCIENCES 年，卷(期)： 2003 20(5) 分类号： P4 关键词： hurricane intensity vertical resolution numerical weather prediction