Circulation Pattern Controls of Summer Temperature Anomalies in Southern Africa  

作　　者：Chibuike Chiedozie IBEBUCHI Cameron C.LEE 

机构地区：[1]Department of Geography,Kent State University,Kent,Ohio 44242,USA [2]ClimRISE Lab,Kent State University,Kent,Ohio 44242,USA

出　　处：《Advances in Atmospheric Sciences》2024年第2期341-354,共14页大气科学进展（英文版）

摘　　要：This study investigates the relationship between circulation patterns and austral summer temperature anomalies in southern Africa. The results show that the formation of continental lows tends to increase the thickness of the lower atmosphere. Further, the distinct variabilities of high and low pressure under the circulation types, influence air mass advection from the adjacent oceans, as well as atmospheric stability over land. Stronger anticyclonic circulation at the western branch of the Mascarene high-pressure system enhances the low-level cold air advection by southeast winds,decreases the thickness, and lowers the temperature over a majority of the land in southern Africa. Conversely, a weaker Mascarene High, coupled with enhanced cyclonic activity in the southwest Indian Ocean increases low-level warm air advection and increases temperature anomalies over vast regions in southern Africa. The ridging of a closed South Atlantic anticyclone at the southern coast of southern Africa results in colder temperatures near the tip of southern Africa due to enhanced low-level cold air advection by southeast winds. However, when the ridge is weak and westerly winds dominate the southern coast of southern Africa, these areas experience temperature increases. The northward track of the Southern Hemisphere mid-latitude cyclone, which can be linked to the negative Southern Annular Mode, reduces the temperature in the southwestern part of southern Africa. Also, during the analysis period, El Ni?o was associated with temperature increases over the central parts of southern Africa;while the positive Indian Ocean dipole was linked to a temperature increase over the northeastern, northwestern, and southwestern parts of southern Africa.

关 键 词：TEMPERATURE circulation types Subtropical Indian Ocean dipole Southern Annular Mode El Ni?o Indian Ocean dipole Mascarene High South Atlantic anticyclone 

分 类 号：P434[天文地球—大气科学及气象学]