POSSIBLE CONTRIBUTION OF A TROPICAL CYCLONE TO SHORT-TERM CLIMATE ANOMALIES IN EAST ASIA VIA SNOW COVER ON THE TIBETAN PLATEAU     

符巧  梁旭东  张庆红  王子谦  段安民 《热带气象学报(英文版)》2017,23(4):462-470

Snow cover on the Tibetan Plateau (TP) has been shown to be essential for the East Asian summer monsoon. In this paper, we demonstrate that tropical cyclone (TC) 04B (1999) in the northern Indian Ocean, which made landfall during the autumn of 1999, may have contributed to climate anomalies over East Asia during the following spring and summer by increasing snow cover on the TP. Observations indicate that snow cover on the TP increased markedly after TC 04B (1999) made landfall in October of 1999. Sensitivity experiments, in which the TC was removed from a numerical model simulation of the initial field, verified that TC 04B (1999) affected the distribution as well as increased the amount of snow on the TP. In addition, the short-term numerical modeling of the climate over the region showed that the positive snow cover anomaly induced negative surface temperature, negative sensible heat flux, positive latent heat flux, and positive soil temperature anomalies over the central and southern TP during the following spring and summer. These climate anomalies over the TP were associated with positive (negative) summer precipitation anomalies over the Yangtze River valley (along the southeastern coast of China).  相似文献   

GRAPES_3Dvar中雷达径向风同化改进观测算子的应用   总被引：1，自引：1，他引：0  

马昊  梁旭东  罗义  符巧 《气象》2016,42(1):34-43

在GRAPES_3Dvar系统中添加雷达径向风预处理模块以及雷达径向风同化模块(包含传统观测算子与改进算子)。对GRAPES_3Dvar系统中雷达同化算子进行正确性检验后,利用该系统对2014年6月6日03时(UTC)北京南郊多普勒雷达径向风资料进行同化试验,分析不同观测算子对于初始场以及降水模拟的影响。研究结果表明,同化雷达径向风资料加强了对流系统低层中小尺度辐合辐散信息,同时综合分析风场的径向分量与切向分量,改进算子对于初始场的调整效果优于传统观测算子。对比分析累计降水模拟,采用改进算子的结果在能够准确模拟出降水雨带的位置和量级的同时极大程度地抑制了虚假降水的范围,降水评分也较好地验证了改进观测算子的优越性。  相似文献