Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1029/2019JD030803 |
Tropical Lows in Southern Africa: Tracks, Rainfall Contributions, and the Role of ENSO | |
Howard, Emma1; Washington, Richard1; Hodges, Kevin I.2 | |
2019-11-05 | |
发表期刊 | JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES |
ISSN | 2169-897X |
EISSN | 2169-8996 |
出版年 | 2019 |
文章类型 | Article;Early Access |
语种 | 英语 |
国家 | England |
英文摘要 | Southern African tropical lows are synoptic-scale cyclonic vortices that propagate westward across southern Africa in the Austral summer. They strongly influence local rainfall and aggregate in the climatological December, January, and February mean to form the Angola Low. In this study, tropical lows are identified and tracked using an objective feature tracking method. The statistics of tropical low tracks over southern Africa are presented and compared across three reanalysis products. Findings are compared to the literature of tropical low-pressure areas elsewhere in the world, where it is found that most tracking statistics compare well but that the tendency of tropical lows to become semistationary over Angola is unique to southern Africa. The hypothesis that tropical lows in Angola have a causal relationship with Tropical Temperate Troughs is tested, and a correlation between occurrence frequencies is found at interannual but not daily time scales. Precipitation is attributed to the tropical lows, and it is found that tropical lows are associated with 31% of rainfall across tropical southern Africa, based on gridded precipitation products. The interannual variability of the number of tropical lows that form per year (sigma=6 events/year) is linked to El Nino-Southern Oscillation (ENSO) and the tropical easterly jet. The mean latitude of tropical lows is shifted northward during El Nino and southward during La Nina. Much of the interannual precipitation variability maximum in Angola is attributed to rainfall associated with tropical lows. These results provide insights into the southern African response to ENSO and into the mechanisms of rainfall in the southern African tropical edge. |
英文关键词 | tropical lows southern Africa ENSO reanalysis objective feature tracking |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000494065400001 |
WOS关键词 | EASTERLY WAVE DISTURBANCES ; TEMPERATE TROUGHS ; EQUATORIAL WAVES ; CYCLONES ; IMPACTS ; CLIMATOLOGY ; OSCILLATION |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/188249 |
专题 | 气候变化 |
作者单位 | 1.Univ Oxford, Sch Geog & Environm, Oxford, England; 2.Univ Reading, Dept Meteorol, Reading, Berks, England |
推荐引用方式 GB/T 7714 | Howard, Emma,Washington, Richard,Hodges, Kevin I.. Tropical Lows in Southern Africa: Tracks, Rainfall Contributions, and the Role of ENSO[J]. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES,2019. |
APA | Howard, Emma,Washington, Richard,&Hodges, Kevin I..(2019).Tropical Lows in Southern Africa: Tracks, Rainfall Contributions, and the Role of ENSO.JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES. |
MLA | Howard, Emma,et al."Tropical Lows in Southern Africa: Tracks, Rainfall Contributions, and the Role of ENSO".JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES (2019). |
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