1979—2012年夏季黄土高原空中云水资源时空分布

Spatial-temporal Distribution of Summer Cloud Water Resources over the Loess Plateau from 1979 to 2012

利用欧洲数值预报中心(ECMWF)发布的新一代全球全分辨率ERA-Interim再分析数据,采用经验正交函数(EOF)、小波分析、回归分析等方法,分析1979—2012年夏季黄土高原空中云水资源分布特征。结果表明:(1)夏季黄土高原空中云水资源远大于该地区实际年降水量,具有较大空中云水资源开发利用潜势;(2)空间上云水资源表现为两种模态——西北部、东南部反位相振荡(EOF1)以及中部云水资源偏多西北、东南两端偏少(EOF2),且具有显著年际变化周期;(3)黄土高原的空中云水资源主要来自东海,当水汽输送反气旋环流中心偏南(北)时,影响EOF1(EOF2)空间模态;(4)云水、云冰量峰值分别出现在700hPa、400hPa左右,当700hPa存在水汽辐合及上升运动时有利于黄土高原空中云水资源开发。

Spatial and temporal distribution features of cloud water resources over the Loess Plateau in summer from1979 to 2012 were analyzed by using ERA-Interim dataset issued by European Centre for MediumRange Weather Forecasts(ECMWF).Results are the following:(1)There are much more cloud water resources than the actual amount of precipitation in summer,leaving agreat potential for cloud water resources exploitation.(2)The distribution of cloud water resources shows two main modes:firstly,anti-phase oscillation appears between the northwest and the southeast(EOF1);secondly,cloud water resources are abundant in the center of the Loess Plateau,while they are not enough in the northwest and the southeast regions(EOF2);The associated time series of EOF1 and EOF2 also show significant inter-annual cycle.(3)The cloud water resources over the Loess Plateau come from the East China Sea,and when the center location of the water vapor transports anticyclonic circulation southerly(northerly),the spatial mode EOF1(EOF2)is influenced.(4)The amount of cloud water and cloud ice reach the peak value at about 700 hPa and 400 hPa,respectively.It is benefit to exploitation of cloud water resources that the appearance of the water vapors convergence and the upward motion at 700 hPa.