New Evidence for Improving Omega Estimation by Explicitly Considering Horizontal Divergence

作     者：YUAN Zhuojian QI Jindian GAO Shouting FENG Yerong XU Pengcheng WU Naigeng 

作者机构：Center for Monsoon and Regional Environment/Department of Atmospheric Science Sun Yat-sen University Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of Sciences Guangdong Meteorological Observatory Institute of Applied Mathematics Academy of Mathematics and Systems SciencesChinese Academy of Sciences 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2014年第31卷第2期

页      面：449-456页

核心收录：

学科分类：07[理学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学] 

基　　金：supported by the National Key Basic Research Project of China (Grant No. 2009CB 421404) the Chinese NSF key project (Grant Nos. 40930950 and 40730951) the Chinese NSF (Grant Nos. 40775031 and 40575021) 

主　　题：omega estimation weather forecast horizontal divergence vertical motion 

摘      要：It is well known that the quasi-geostrophic （QG） omega equation with only two contributors respectively associated with vorticity advection （VA） and temperature advection is derived for midlatitude synoptic-scale systems *** on reliable reanalysis data,new evidence revealed by cyclonic and anticyclonic cases indicates that forecasters might sometimes experience problems by paying too much attention to the 500-hPa VA when estimating vertical motions not only in subtropical systems but also in systems meeting all the assumptions of the QG omega *** investigations also showed that explicitly considering the vertical profiles of horizontal divergence could allow for better interpretation of vertical motions and weather in these real cases,suggesting that this equation might not be sufficient due to the presence of only two horizontaldivergence-related （HDR） mechanisms and the absence of other HDR mechanisms,e.g.,frictional force,mountain barriers,diabatic/adiabatic processes,and acceleration/deceleration of air flows.