西藏夏季降水特征及其预测分析  

Summer Precipitation in Tibet and Its Prediction

作　　者：米玛卓嘎 秦增良 肖卓靖 次仁德吉 次仁曲珍 Mirmah Zhuoga;QIN Zeng-liang;XIAO Zhuo-jing;Ciren Deji;Ciren Quzhen(Meteorological Service Center of Tibet Autonomous Region,Lhasa 850000,Tibet,China;Weifang Meteorological Bureau,Weifang 261011,Shandong,China;College of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044,Jiangsu,China;Meteorological Observatory of Tibet Autonomous Region,Lhasa 850000,Tibet,China)

机构地区：[1]西藏自治区气象服务中心,西藏拉萨850000 [2]山东省潍坊市气象局,山东潍坊261011 [3]南京信息工程大学大气科学学院,江苏南京210044 [4]西藏自治区气象台,西藏拉萨850000

出　　处：《干旱区研究》2019年第5期1060-1069,共10页Arid Zone Research

基　　金：国家自然科学基金项目(91637105,41475041);国家科技支撑计划项目(2015BAC03B06)资助

摘　　要：采用EOF分解、滑动交叉检验、距平相关系数(ACC)、时间相关系数(TCC)等方法,分析西藏1981-2017年夏季降水量的变化特征,并对西藏夏季降水量进行预测研究。结果表明:西藏夏季降水空间分布不均匀,整体上呈现出自东南向西北递减的分布规律。除个别站点降水量呈下降趋势外,西藏各区夏季降水量普遍呈上升趋势,但趋势不显著。西藏夏季降水的异常空间分布型有一致型、南北型和东西型。当随机选择一年样本剔除时,西藏夏季降水的前3个EOF模态具有很好的时间稳定性,首次尝试在EOF模态稳定的基础上对西藏夏季降水进行预测,寻找的关键指数对稳定模态的PC系数具有很好的指示意义。由关键指数预测的西藏夏季降水的历史回报场平均ACC为0.31,大部分地区的TCC大于0,变化趋势具有很好的一致性,且大部分地区通过了α=0.05的显著性检验。采用EOF模态时间稳定性的方法对西藏夏季降水有很好的预测效果,具有较好的业务应用前景。Study on the characteristics and prediction of summer precipitation in Tibet during 1981-2017 was carried out using the Empirical Orthogonal Functions(EOF),cross-validation,anomaly correlation coefficient(ACC),time correlation coefficient(TCC)and some other methods.The results showed that the spatial distribution of summer precipitation was very uneven,and the precipitation decreased from the southeast to the northwest.In addition to some regions,the precipitation was in an increase trend in most areas of Tibet,but the increase trend was not significant.There was not only a regional similarity in spatial distribution of summer precipitation in Tibet,but also a regional variation from the south to the north and from the east to the west.The results suggested that,when a one-year sample was randomly removed,the temporal stability of the first three EOF modes was high.It was attempted to predict summer precipitation in Tibet on the basis of the stability of EOF modes for the first time,and the key indices which were found had a good prediction capability for PCs coefficient of stable modes.The anomaly correlation coefficient between the observed and predicted values of summer precipitation could be reached 0.31.The temporal correlation coefficient was higher than zero in most areas.TCC passed the significance test ofα=0.05 in most areas.The predicted results of summer precipitation were ideal,and the application prospect was wide.

关 键 词：夏季降水 EOF模态 空间分布型 西藏 

分 类 号：R73[医药卫生—肿瘤]