ABSTRACT

The Arabian Subtropical Anticyclone (ASA) plays an essential role in regulating weather systems over the Arabian Peninsula (Arabia) and adjacent areas. A need exists to document specific details of the spatial and temporal climatology of the ASA. In order to identify the monthly ASA position/center, the local maximum geopotential height (gph) should be located at different vertical levels. The common automated method did not work for the ASA in the warm season and an approach involving wind flow patterns was needed. The ASA was better defined in the lower troposphere in the cool season and in the mid- to upper-troposphere during the warm season. The near surface ASA begins in Aug over northern Arabia and migrates southeast until it reaches the Arabian Sea in Feb. Apr is the onset of the middle-troposphere ASA. From May to Aug, this anticyclone moves to the north with increasing height. The upper-level ASA is located over northeast Arabia in May and goes north in Jun and Jul. Seasonal changes in energy fluxes and atmospheric circulation patterns linked with the Asian Monsoon are identified as possible drivers of the temporal changes in the ASA.

摘要

阿拉伯副热带反气旋（ASA）在调节阿拉伯半岛（阿拉伯）及邻近地区的天气系统方面发挥着重要作用。需要记录 ASA 的空间和时间气候学的具体细节。为了确定每月的 ASA 位置/中心，当地最大位势高度 (gph) 应位于不同的垂直高度。常见的自动化方法在温暖季节不适用于 ASA，需要一种涉及风流模式的方法。ASA 在凉爽季节的对流层低层和温暖季节的对流层中高层有更好的定义。近地表 ASA 于 8 月开始在阿拉伯北部上空并向东南迁移，直到 2 月到达阿拉伯海。4 月是对流层中层 ASA 的开始。从五月到八月，这个反气旋随着高度的增加向北移动。上层 ASA 于 5 月位于阿拉伯东北部，并于 6 月和 7 月向北移动。与亚洲季风相关的能量通量和大气环流模式的季节性变化被确定为 ASA 时间变化的可能驱动因素。