Convective Bursts Episode of the Rapidly Intensified Typhoon Mujigae(2015)  

作　　者：Shuai YANG Xiba TANG Shuixin ZHONG Bin CHEN Yushu ZHOU Shouting GAO Chengxin WANG 

机构地区：[1]Laboratory of Cloud-Precipitation Physics and Severe Storms, Institute of Atmospheric Physics,Chinese Academy of Sciences [2]Guangdong Province Key Laboratory of Regional Numerical Weather Prediction, Institute of Tropical and Marine Meteorology,China Meteorological Administration [3]State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences [4]University of Chinese Academy of Sciences

出　　处：《Advances in Atmospheric Sciences》2019年第5期541-556,共16页大气科学进展（英文版）

基　　金：supported by the National Basic Research Program of China (973 Program) (Grant No. 2015CB452804);the National Natural Science Foundation of China (Grant Nos. 41575064, 41875079, 91637102, 41475036, 91437215 and 41575047);the Basic Research Fund of CAMS (Grant No. 2017Y010)

摘　　要：Convective burst(CB) characteristics at distinct stages of a rapidly intensified Typhoon Mujigae(2015), are investigated based on a 72-h simulation. The spatial features show that almost all CB elements develop in the eyewall. The number of CBs in the inner-core region within a 100 km radius—which account for a large proportion of the total CBs, with a sharp increase about 6 h before the onset of rapid intensification(RI)—provides some indication of the RI of the typhoon. The CBs during pre-RI and RI are examined from dynamic and thermodynamic viewpoints. The combination of lower-level convergent inflow and upper-level divergent outflow pushes a relay-race-like transmission of convective activity, favorable for the development of deep convection. A double warm-core structure is induced by the centripetal outflow sinking and warming associated with CBs, which directly accelerates RI by a sudden decrease in hydrostatic pressure. By utilizing the convection activity degree(CAD) index derived from the local total energy anomaly, a correlation formula between CBs and CAD is deduced.Furthermore, an intense CAD(ICAD) signal threshold(with a value equal to 100) to predict CBs is obtained. It is verified that this ICAD threshold is effective for estimating the occurrence of a CB episode and predicting RI of a typhoon. Therefore,this threshold may be a valuable tool for identifying CB episodes and forecasting rapidly intensified typhoons.Convective burst(CB) characteristics at distinct stages of a rapidly intensified Typhoon Mujigae(2015), are investigated based on a 72-h simulation. The spatial features show that almost all CB elements develop in the eyewall. The number of CBs in the inner-core region within a 100 km radius—which account for a large proportion of the total CBs, with a sharp increase about 6 h before the onset of rapid intensification(RI)—provides some indication of the RI of the typhoon. The CBs during pre-RI and RI are examined from dynamic and thermodynamic viewpoints. The combination of lower-level convergent inflow and upper-level divergent outflow pushes a relay-race-like transmission of convective activity, favorable for the development of deep convection. A double warm-core structure is induced by the centripetal outflow sinking and warming associated with CBs, which directly accelerates RI by a sudden decrease in hydrostatic pressure. By utilizing the convection activity degree(CAD) index derived from the local total energy anomaly, a correlation formula between CBs and CAD is deduced.Furthermore, an intense CAD(ICAD) signal threshold(with a value equal to 100) to predict CBs is obtained. It is verified that this ICAD threshold is effective for estimating the occurrence of a CB episode and predicting RI of a typhoon. Therefore,this threshold may be a valuable tool for identifying CB episodes and forecasting rapidly intensified typhoons.

关 键 词：CONVECTIVE BURSTS RAPID INTENSIFICATION TYPHOON simulation 

分 类 号：O4[理学—物理]