基于Himawari-8气象卫星的东亚夏季冰云云顶特征分布

利用Advanced Himawari Imager (AHI)/Himawari-8(HW8)云产品分析2017年夏季东亚地区不同下垫面条件对冰云云顶特征的影响,针对不同下垫面条件选择了9个研究区域。结果表明,冰云最常出现在青藏高原和南亚季风区。冰云的发生频率存在南北递减的趋势,并在日本附近有高值中心。冰云云顶的垂直分布高度依赖于纬度,此外还有地形和海陆热力差异的作用。青藏高原和南亚季风区冰云最常发生在6~9 km和6~15 km;冰云云顶温度在南北之间存在明显差异,不同高度的冰云形成方式也存在不同;青藏高原和南亚季风区的冰云光学厚度较高,且冰云光学厚度与发生频率呈正相关。在冰云云顶属性垂直分布中,中国东部冰云发生频率相对于其他区域较低,冰云粒子半径表现出随高度增加先增大后减小的趋势,海洋上的平均冰云粒子半径相对于其他研究区域最大;在中国西部地区,冰云光学厚度存在双峰结构,而其他相对平坦的区域只有一个单峰。

The ice cloud top characteristic distributions over East Asia in summer based on Himawari-8 meteorological satellites

The vertical distributions of ice clouds top properties in summer of 2017 were analyzed by using the Advanced Himawari Imager(AHI)/Himawari-8 (HW8) cloud products. Nine research areas were selected based on different terrain and land-sea aspects. Results show that ice clouds occur most frequently in the Tibetan Plateau and the South Asian monsoon region. There is a steep gradient of ice clouds occurrence frequency extending from southern to northern China. The vertical distributions of ice clouds top are highly dependent on latitude, in addition to the important roles of terrain, land-sea thermal contrast,and monsoons. In the Tibetan Plateau, the frequency of ice clouds top is maximum at 6 to 9 km,and in the monsoon region, ice clouds are widely distributed from 6 to 15 km. There is a significant difference of temperature of the ice clouds top between the north and the south. The Tibet Plateau and the monsoon region are consistent with the above studies, and the eastern part of China is lower than other research areas. The radius of ice cloud particles shows a trend of increasing first and then decreasing with height. The radius of ice cloud particles is the largest relative to other research areas over the ocean area. The double-peak structure of ice cloud optical thickness exists in western China, in other relatively flat areas, there is only one single peak.