从资料搜集、同化系统、数值模式、检验评估四个方面介绍了东亚区域大气再分析技术研究及资料建设取得的进展。就观测资料而言,搜集了常规地面和探空、飞机观测、GPS、雷达、风廓线、卫星导风、野外试验等观测资料。其中未参加国际交换...从资料搜集、同化系统、数值模式、检验评估四个方面介绍了东亚区域大气再分析技术研究及资料建设取得的进展。就观测资料而言,搜集了常规地面和探空、飞机观测、GPS、雷达、风廓线、卫星导风、野外试验等观测资料。其中未参加国际交换的地面、探空资料、雷达等观测资料是本再分析资料构建的特色之一。针对Gridpoint Statistical Interpolation(GSI)同化系统,开展了该系统的本地化移植,并改进了GSI雷达径向风同化算子。对于Weather Research and Forecasting Model(WRF-ARW)模式,采用多组物理过程参数化方案组合,开展了批量个例和长时间模拟试验,并基于试验结果优化了模式的配置。检验评估系统采用NCAR模式评估系统MET。目前,再分析系统搭建及优化已完成,试验结果表明再分析系统初步具有在全球再分析的基础上提高区域再分析资料性能的能力,可将本再分析系统用于今后再分析数据的研制。展开更多
The spatial distribution of clouds and their seasonal variations, and the three-dimensional(3D) cloud structures over East Asia have been analyzed with the CALIPSO-GOCCP data during the period from 2007 to 2012. The r...The spatial distribution of clouds and their seasonal variations, and the three-dimensional(3D) cloud structures over East Asia have been analyzed with the CALIPSO-GOCCP data during the period from 2007 to 2012. The results show that there is a large cloud fraction greater than 0.7 over southern China, and the largest cloud fraction appears in southwest China. Besides, a large cloud fraction occurs over the southeast of the Tibetan Plateau. The total and high cloud fractions show notable variations with seasons, while the middle and low cloud fractions vary a little. As for cloud vertical structure, significant differences of the cloud vertical distributions are observed between over land and ocean. Cloud fractions and the height of the maximum cloud fractions decline gradually with the increasing latitude, except for the vertical-latitude profiles over the Tibetan Plateau regions. The longitude-vertical cross sections show similar patterns from the longitude 70° E to 140° E, except the profiles with large cloud fractions over the Tibetan Plateau. From the horizontal distribution patterns and vertical structures of the clouds over East Asia, it is concluded that the huge terrain of the Tibetan Plateau has significant impacts on the cloud formation over the Tibetan Plateau region and the areas to the east. At last, the clouds from the CALIPSO-GOCCP observations are compared to those from the ERA-Interim reanalysis data. The results indicate that the ERA-Interim reanalysis data provide reasonable spatial distribution patterns and the vertical structures in terms of the total cloud fraction over East Asia. However, the total cloud fraction was underestimated about 20% by the ERA-Interim reanalysis data over most parts of East Asia, especially over the neighboring areas east of the Tibetan Plateau. Additionally, the ERA-interim reanalysis data overestimate the cloud fractions at each level in the vertical direction.展开更多
文摘从资料搜集、同化系统、数值模式、检验评估四个方面介绍了东亚区域大气再分析技术研究及资料建设取得的进展。就观测资料而言,搜集了常规地面和探空、飞机观测、GPS、雷达、风廓线、卫星导风、野外试验等观测资料。其中未参加国际交换的地面、探空资料、雷达等观测资料是本再分析资料构建的特色之一。针对Gridpoint Statistical Interpolation(GSI)同化系统,开展了该系统的本地化移植,并改进了GSI雷达径向风同化算子。对于Weather Research and Forecasting Model(WRF-ARW)模式,采用多组物理过程参数化方案组合,开展了批量个例和长时间模拟试验,并基于试验结果优化了模式的配置。检验评估系统采用NCAR模式评估系统MET。目前,再分析系统搭建及优化已完成,试验结果表明再分析系统初步具有在全球再分析的基础上提高区域再分析资料性能的能力,可将本再分析系统用于今后再分析数据的研制。
基金supported by the National Natural Science Foundation of China(Grant No.41405006)the China Special Fund for Meteorological Research in the Public Interest(Grant Nos.GYHY201406003+3 种基金GYHY-201406001)the National Basic Research Program of China(Grant No.2012CB417204)the Basic Research Fund of the Chinese Academy of Meteorological Sciences(Grant Nos.2014R0162015Z003)
文摘The spatial distribution of clouds and their seasonal variations, and the three-dimensional(3D) cloud structures over East Asia have been analyzed with the CALIPSO-GOCCP data during the period from 2007 to 2012. The results show that there is a large cloud fraction greater than 0.7 over southern China, and the largest cloud fraction appears in southwest China. Besides, a large cloud fraction occurs over the southeast of the Tibetan Plateau. The total and high cloud fractions show notable variations with seasons, while the middle and low cloud fractions vary a little. As for cloud vertical structure, significant differences of the cloud vertical distributions are observed between over land and ocean. Cloud fractions and the height of the maximum cloud fractions decline gradually with the increasing latitude, except for the vertical-latitude profiles over the Tibetan Plateau regions. The longitude-vertical cross sections show similar patterns from the longitude 70° E to 140° E, except the profiles with large cloud fractions over the Tibetan Plateau. From the horizontal distribution patterns and vertical structures of the clouds over East Asia, it is concluded that the huge terrain of the Tibetan Plateau has significant impacts on the cloud formation over the Tibetan Plateau region and the areas to the east. At last, the clouds from the CALIPSO-GOCCP observations are compared to those from the ERA-Interim reanalysis data. The results indicate that the ERA-Interim reanalysis data provide reasonable spatial distribution patterns and the vertical structures in terms of the total cloud fraction over East Asia. However, the total cloud fraction was underestimated about 20% by the ERA-Interim reanalysis data over most parts of East Asia, especially over the neighboring areas east of the Tibetan Plateau. Additionally, the ERA-interim reanalysis data overestimate the cloud fractions at each level in the vertical direction.
