中国海洋大学学报（自然科学版）2024，Vol.54Issue(5)：10-22,13.DOI:10.16441/j.cnki.hdxb.20220479
太平洋上空"射线状"云的观测分析
Observation Analysis of "Actinoform Clouds" over the Pacific Ocean
摘要
Abstract
This paper aims to investigate the fundamental features and geographical distribution of actinoform clouds over the Pacific Oceans,which have not been included in the current cloud classifica-tion system.Total of 257 actinoform clouds over the Pacific Ocean from 2017 to 2021 were statistically analyzed by using satellite visible cloud imagery provided by MODIS sensors carried on Aqua and Terra,and satellite visible and infrared cloud imagery from NOAA-20 and Suomi NPP.The results show that the shapes of actinoform clouds are approximately circular or elliptical,with obvious centers of cloud systems and clear"banded radial cloud arm"extending from the center to outside.Most of actinoform clouds occur over the mid-and low-latitude regions of the Southeastern Pacific and the Northeastern Pacific.In the whole year,actinoform clouds occur in all months except for April.Their high occur-rence frequency months are June,July and August,middle occurrence frequency months are May,September,October and November,and low occurrence frequency months are January,March,April and December.Some actinoform clouds have rotation patterns,with counterclockwise rotation over Northern Hemisphere and clockwise rotation over Southern Hemisphere.There usually exists inversion layer in the top of actinoform clouds.Their motion characteristics are summarized as follows:in the lower-level the atmosphere mainly moves horizontally,and the lower atmosphere is convergent.In the mid-level,the upward motions are dominant,and the horizontal convergence and divergence are weak.In the top of cloud system the atmospheric motions are blocked by stable inversion layer,so that the vertical velocities are almost zero.关键词
"射线状"云/带状云臂/太平洋/统计分析/大气逆温层Key words
actinoform clouds/banded cloud arms/Pacific Ocean/statistical analysis/atmospheric in-version layer分类
天文与地球科学引用本文复制引用
王忠石,傅刚,孙维康..太平洋上空"射线状"云的观测分析[J].中国海洋大学学报（自然科学版）,2024,54(5):10-22,13.基金项目
国家重点研究发展计划项目(2022YFC3004200) （2022YFC3004200）
国家自然科学基金项目(42275001)资助 Supported by the National Key Research and Development Program Projects(2022YFC3004200) （42275001）
the National Natural Science Foun-dation of China Projects(42275001) （42275001）
