Authors: Ali S. Alghamdi*, King saud University, John A. Harrington, Independent Scholar
Topics: Climatology and Meteorology
Keywords: Arabian Subtropical Anticyclone, Arabian High, Arabian Peninsula, maximum geopotential height
Session Type: Virtual Paper
Start / End Time: 8:00 AM / 9:15 AM
Room: Virtual 7
Presentation File: No File Uploaded
The Arabian High or Arabian subtropical Anticyclone (ASA) has been shown to have an essential role in regulating weather systems including precipitation, atmospheric river events, the build up and transport of regional tropospheric ozone, and dust storms over the Arabian Peninsula (Arabia) and adjacent countries. However, most of the studies related to subtropical anticyclones within the region are either case studies for a short timescale or focused on the South Asian High. Specifics related to spatial and temporal characteristics and variability/change of the ASA within the troposphere at seasonal and interannual time scales have not been documented completely. Such knowledge is critical for weather forecasts, climate prediction, and indications of climate change. This research developed a spatiotemporal climatology for the ASA and its links to surface conditions over Arabia. Specifically, the research (1) addressed the seasonal and interannual structural characteristics of the ASA and variability/change at different levels of the troposphere; and (2) examined the regional surface weather characteristics of precipitation, temperature, and wind on the basis of the structural characteristics of ASA.
To identify the monthly ASA position/center, locating the maximum geopotential height (gph) approach was applied at 850, 500, and 300 gph. Overall, results show that the ASA over Arabia is a dominant synoptic feature year around, but at different levels in different seasons. Distinct geographical and temporal patterns were observed, with the ASA better defined in the lower troposphere in winter and in the mid- to upper-troposphere in summer.