基于CERES数据的青海省上空云特性时空规律研究

Time-space regularity of cloud properties over Qinghai Province based on CERES data

为了对青海省上空云特性在时空上的分布情况及变化规律进行研究,采用美国NASA地球观测系统2003年1月至2016年12月的CERES SSF Aqua MODIS Edition 4A云资料,根据青海省的地形地貌特征及原始CERES数据云分层的有效气压与海拔高度的对应关系,按距地表高度对原始CERES数据重新分层,云层距地高度0~3 000 m为低云,3 000~5 500 m为中低云,5 500~9 000 m为中高云,9 000 m以上为高云进行分析。结果表明:(1)青海省上空总云量取值范围在38.2%~71.3%,多年均值为59.5%,云量分布形势呈南高北低。(2)各季节(春夏秋冬)总云量平均值为66.2%,67.3%,52.5%,52.0%。(3)云中液态水路径和冰水路径取值范围为143.6~221.3 g/m^2,202.2~380.3 g/m^2。(4)青海省上空中高云、中低云、低云云量占各层云量总和的28.6%,43.7%,27.7%。(5)设定低云有效的临界条件为云量大于30%,低云有效天数多年均值为276.6 d。该结果为青海省人工影响天气作业的实施提供了数据支撑。

In order to study the distribution of cloud characteristics over time and space over Qinghai Province,CERES SSF Aqua MODIS Edition 4 A cloud data from the Earth’s Radiant Energy System（ CERES） of NASA’ s EOS from January 2003 to December 2016,cloud properties over Qinghai province were analyzed. According to landform characteristics of Qinghai province and the relationship between the effective pressure and altitude in the original CERES data cloud classification,the original CERES data were restratified according to the height from the earth’s surface. The low cloud height is 0 ~ 3 000 m and the mid-low cloud height is 3 000 ~ 5 500 m. The mid-high cloud is5 500 ~ 9 000 m and the high cloud is over 9 000 m. Statistical analysis results show that：（ 1） The data of total cloud amount over Qinghai province range between 38. 2% and 71. 3%,and the average annual mean is 59. 5%. The trend of cloud distribution is low in the north.（ 2） The total cloud amount of each quarter（ spring,summer,autumn,winter） are 66. 2%,67. 3%,52. 5% and 52. 0%,respectively.（ 3） The range of each month of liquid water path and ice water path is 143. 6 ~221. 3 g/m^2,202. 2 ~ 380. 3 g/m^2.（ 4） The total cloud amount of mid-high cloud,mid-low cloud and low cloud over Qinghai province accounts for 28. 5%,43. 7%,27. 7% of the total cloud.（ 5） The effective critical condition of low cloud coverage setting is more than 30%. Low clouds effective number of days is 276. 6 d. The above conclusions provide data support for the implementation of artificial weather operations in Qinghai province.