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.
运用Quickbird、Landsat TM/ETM+、Modis、房地产图、卫星过境时气象资料等数据,研究了昆明市主城区建筑区热环境特征。采用Modis数据进行Landsat band 6数据有效性验证,采用ENVI的FE模块进行基于Quickbird的城中村提取,分析连片建筑区、城中村和住宅小区的地表温度(LST)的空间分布特征。结果表明:城内、城郊地表热环境差异很明显;建筑区地表温度高温区逐渐从一、二环间向二、三环间移动;城中村和住宅小区的LST均温都存在相同特征:一环内>一、二环线间>二、三环线间>南三环外区域;2000-04-24住宅小区LST均值比城中村高0.5℃,2008-04-06城中村LST均值比住宅小区高1℃,2个时期住宅小区温度范围波动均比城中村大。
