Based on the NCEP reanalysis and conventional observation information,the circulation background and physical quantity field of the rare continuous intensive precipitation process occurred in autumn(from October 24 to...Based on the NCEP reanalysis and conventional observation information,the circulation background and physical quantity field of the rare continuous intensive precipitation process occurred in autumn(from October 24 to November 5) of 2008 in central section of Yunnan Province were analyzed and diagnosed.The results showed that the low-level cold front shear and mid-high level convergence zone maintenance constituted the main synoptic situation background of the rare continuous heavy rainfall in autumn in the middle regions of Yunnan Province.The two water vapor which came from the Bay of Bengal and the south of Indo-China Peninsula converged in the central and southern Yunnan,forming a deep moisture convergence zone.The warm and humid air climbed upward along the low-level cold air with the formation of a long period of upward motion,playing an important part in the maintenance of heavy precipitation weather process.The continuous heavy rainfall center and the weak high values of convective available potential energy(CAPE) had good corresponding indexicality.During the heavy precipitation,there were five mesoscale clouds which generated in the cold wind shear cloud belt.In this favorable context of large-scale circulation,frequent movement of the mesoscale system was the direct cause of this continuous intensive precipitation process.展开更多
基金Supported by Regional Fund Program of Natural Science Foundation of China(NSFC)(40965002)Natural Science Foundation of Yun-nan Province(2005D0078M2)
文摘Based on the NCEP reanalysis and conventional observation information,the circulation background and physical quantity field of the rare continuous intensive precipitation process occurred in autumn(from October 24 to November 5) of 2008 in central section of Yunnan Province were analyzed and diagnosed.The results showed that the low-level cold front shear and mid-high level convergence zone maintenance constituted the main synoptic situation background of the rare continuous heavy rainfall in autumn in the middle regions of Yunnan Province.The two water vapor which came from the Bay of Bengal and the south of Indo-China Peninsula converged in the central and southern Yunnan,forming a deep moisture convergence zone.The warm and humid air climbed upward along the low-level cold air with the formation of a long period of upward motion,playing an important part in the maintenance of heavy precipitation weather process.The continuous heavy rainfall center and the weak high values of convective available potential energy(CAPE) had good corresponding indexicality.During the heavy precipitation,there were five mesoscale clouds which generated in the cold wind shear cloud belt.In this favorable context of large-scale circulation,frequent movement of the mesoscale system was the direct cause of this continuous intensive precipitation process.
