2004年冬春季中国地区云的模拟分析

Analysis of CREM Simulations of Clouds over China in Late Spring and Early Summer in 2004

文中利用卫星和地面观测资料分析了中国地区总云量和低云量的分布及华南沿海、华东地区和北方地区的云量垂直分布。利用CREM模式模拟了中国地区的云量,并初步分析了模拟误差的原因。模拟表明,模式能较好地再现中国地区云量水平和垂直分布的形势和演变趋势,但对总云量和低云量模拟系统性偏小20%,且模拟的华南沿海云量垂直分布大值中心偏低。初步分析认为这种云量大小的误差是云量诊断方案的经验系数值不适当引起的。

Based on the data from the International Satellite Cloud Climatology Project （ISCCP） and China Meteorological Administra- tion （CMA） surface station observations, the spatial pattetn of total and low cloud coverage and the vertical distributions of southeastern, eastern and northern China are examined. Meanwhile it is examined for the simulations of the clouds distribution with the CREM （ Climate version of AREM）. The CREM can reasonably reproduce the horizontal and vertical pattern of cloud amount. But it is less to 20% of total and low cloud amount than the observations. The height of the maximum of cloud amount is lower with comparison of the observations. It is suggested that the reason of the cloud amount departure is the inaccuracy of the empirical parameters of the cloudiness parameterization. It is mainly attributed to the feature of vertical distribution of the relatively humidity of the error of the height of cloud amount maximum center mainly in southeastern China, while the inaccuracy of the empirical parameters is the secondly factor.