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MODIS的多波段及高时空分辨率特征有利于对大面积干旱区域的动态监测。2008年10月下旬至2009年2月中旬我国中东部和北方地区十多个省市遭遇了严重干旱。论文选取2009年初干旱较严重的辽宁省作为研究区域,使用热惯量法提取MODIS数据的干旱信息,识别出干旱区域和干旱程度。为了深入分析导致此次干旱的大气结构特征和机理,从天气形势、斜温图(Skew-T)两方面揭示了干旱发生期间影响旱区的大气风向风速、温度、湿度及大气能量的结构特征。研究表明东北冷涡强大稳定而导致的干冷空气路径维持,整层大气的温度-露点差较大,西北风使来源地水汽稀少,稳定的大气层结及干下沉气流等大气结构特征是引起辽宁省严重干旱的重要原因。
The multi-band and high spatio-temporal resolution characteristics of MODIS are conducive to the dynamic monitoring of a large area of arid areas. From late October 2008 to mid-February 2009, more than 10 provinces and cities in the central-east and northern regions of China suffered a serious drought. In this paper, Liaoning Province, whose drought was more severe in early 2009, was selected as the research area. The thermal information of MODIS data was extracted by thermal inertia method, and the degree of drought and drought were identified. In order to further analyze the characteristics and mechanism of the atmospheric structure that led to this drought, the structural characteristics of the wind speed, temperature, humidity and atmospheric energy in the arid region affected by the drought are revealed from the weather and Skew-T . The results show that the strong and stable northeastern cold eddy maintains the dry and cool air path, and the temperature-dew point difference of the whole atmosphere is relatively large. The northwest wind makes the source water scarce, and the atmospheric structure such as stable atmosphere subsidence, Severe drought is an important reason.