摘要
利用NCEP/NCAR再分析春季逐月平均位势高度、风、温度、垂直速度等物理量的格点资料,通过图形分析技术进行天气系统识别,建立3类宁夏春季干旱多层次环流概念模型,并对各类型主要影响因子进行特征量对比计算,得出了宁夏春季干旱监测预测定量化指标。在如下条件下,宁夏易发生春季干旱:(1)500hPa东亚大槽位于120°—140°E,其中位于120°—130°E间时发生的干旱强度最大,偏东或偏西则强度减弱;(2)500hPa中亚脊强盛、完整且位于60°—100°E,位于80°E附近干旱强度最大,弱脊分裂或偏西则干旱强度较弱;(3)副热带高压呈带状,脊线位于20°N以南且西脊点位于110°E以西时;(4)850hPa偏南气流强度较弱,北界位于27°N以南时;(5)700hPa判定区域(30°—50°N、90°—110°E)内干区控制范围比率达45%时;(6)500hPa判定区域(30°—50°N、90°—110°E)内下沉气流区占区域面积的比率≥75%,700hPa下沉气流区占区域面积的比率≥60%,且宁夏北部受下沉气流区控制。利用图形分析法对宁夏春季干旱进行监测预测,对2010年和2011年春季气候趋势进行拟合检验,效果良好。
Three kinds multi-level atmospheric circulation conceptual model of spring drought in Ningxia were established, and monitoring and predicting quantitative indices were studied based on the NCEP/NCAR reanalysis monthly data sets, through technology of weather system identification and other graphic analysis methods. And the monitoring and forecasting quantitative indices of Ningxia spring drought were given here. Spring drought in Ningxia occurs under following conditions： （1） East Asia Trough at 500 hPa is over 120--140 °E , and the drought is the most serious when the trough is over 120°- 130°E; （2） The whole Central Asia Ridge at 500 hPa is over 60°- 100°E, especially when it is near 80°E; （3）The Subtropical High Pressure is in ribbon shape and the west ridge point extends to 110 °E; （4） Southern Air Stream at 850 hPa is weak, and its north side stretches to 27 °N; （5） Dry area occupies more than 45% of the key area （90°-110°E, 30°N to 50°N） at 700 hPa; （6）Downdraft at 500 hPa （700 hPa） occupies more than 75% （60%） of the key area （90°- 110°E, 30°- 50°N）, and the northern Ningxia is controlled by downdraft. Meteorological data analysis showed that spring droughts in Ningxia in 2010 and 2011 were well predicted by weather system identification technology.
出处
《中国沙漠》
CSCD
北大核心
2013年第3期874-881,共8页
Journal of Desert Research
基金
国家公益性行业(气象)科研专项项目(GYHY201206005)
中国气象局科研项目(CCSF2011-26
CMATG2010Y21)
干旱气象科学研究基金项目
宁夏自然科学基金项目(NZ08161)
宁夏科技攻关项目(KGX-12-09-02)共同资助
关键词
干旱
图形分析
影响因子自动判别
监测预测方法
宁夏
drought
graph recognition, auto-discrimination
monitoring and predicting method
Ningxia
