中国西北地区夏季降水及其东部降尺度预测模型  

Characteristics and East Downscaling Forecast Model of Summer Precipitation in Northwest China

作　　者：朱姜韬 杨庆怡 李旭[1] 李艳[1] ZHU Jiangtao;YANG Qingyi;LI Xu;LI Yan(College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,Gansu,China;College of Meteorology,Lanzhou Resources&Environment Voc-Tech University,Lanzhou 730000,Gansu,China)

机构地区：[1]兰州大学大气科学学院,甘肃兰州730000 [2]兰州资源环境职业技术大学气象学院,甘肃兰州730000

出　　处：《高原气象》2023年第3期646-656,共11页Plateau Meteorology

基　　金：甘肃省自然科学基金项目(21JR7RA497,21JR7RA495)。

摘　　要：利用中国气象局提供的降水数据和NCEP/NCAR再分析资料,分析了1961-2018年中国西北地区降水的气候特征,并构建了西北地区东部降水短期预测的统计降尺度模型。结果表明,1961-2018年西北地区降水整体呈现增加趋势,尤其是2000年以后降水明显偏多;西北地区降水呈西少东多的特征,但西部降水增加明显,而东部降水无明显趋势变化。针对西北地区东部夏季降水进行归因分析,找到了影响西北地区东部降水的4个同期关键影响因子——中亚地区200 hPa位势高度、北太平洋850 hPa V风、北大西洋850 hPa U风、南印度洋海平面气压,这4个因子分别反映了西风急流的特征、北太平洋海平面气压的“-+”结构、北大西洋涛动(North Atlantic Oscillation,NAO)的特征及马斯克林高压的强度;当西风急流偏北偏强、北太平洋海平面气压“-+”结构减弱、NAO偏强或马斯克林高压偏弱时,有利于西北地区东部降水。在降尺度模型建立阶段,模型结果与西北地区东部夏季降水量平均偏差为17.5 mm,平均偏差率为10.3%;在模型检验阶段,模型结果与西北地区东部夏季降水量平均偏差为26.2 mm,平均偏差率为16.4%,统计降尺度模型总体能够较好预测西北地区东部的降水,可为西北地区降水的短期气候预测提供新的思路。Based on the precipitation data provided by China Meteorological Administration and NCEP/NCAR reanalysis data(data comes from a joint project between the National Centers for Environmental Prediction(NCEP)and the National Center for Atmospheric Research(NCAR)),this paper analyzed the climatic characteristics of precipitation in northwest China from 1961 to 2018,and constructed a statistical downscaling forecast model for short-term prediction of precipitation in eastern northwest China.The results demonstrate that the precipitation in northwest China showed an increasing trend from 1961 to 2018,especially after 2000.The precipitation in northwest China is characterized by less in the west and more in the east,while the precipitation in the western part of northwest China increases obviously,while there is no obvious trend change in the eastern part of northwest China.According to the attribution analysis of summer precipitation in the eastern part of Northwest China,four key factors were found,that is affecting the precipitation in the eastern part of Northwest China in the same period:geopotential height field of 200 hPa isobaric surface in Central Asia,meridional wind field of 850 hPa isobaric surface in North Pacific,zonal wind field of 850 hPa isobaric surface in North Atlantic and sea level pressure in South Indian Ocean.These four factors respectively reflect the characteristics of westerly jet,the"minus and plus"structure of sea level pressure in North Pacific,the characteristics of the North Atlantic Oscillation and the intensity of Mascarene High.When the intensity of westerly jet is stronger and the position of westerly jet is further north,the"minus and plus"structure of sea level pressure in the North Pacific Ocean is weaker,the North Atlantic Oscillation is stronger or the Mascarene High is weaker,it is beneficial to the precipitation in the eastern part of Northwest China.In the establishment stage of downscaling model,the average deviation between the downscaling model results and the summer precip

关 键 词：中国西北地区 夏季降水 统计降尺度 降水预测 

分 类 号：P461[天文地球—大气科学及气象学]