DOI: 10.1175/JCLI-D-13-00175.1
Scopus记录号: 2-s2.0-84893834990
论文题名: How do tropical temperate troughs form and develop over Southern Africa?
作者: Macron C. ; Pohl B. ; Richard Y. ; Bessafi M.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 4 起始页码: 1633
结束页码: 1647
语种: 英语
英文摘要: This paper aims at separating the respective influences of tropical and midlatitude variability on the development and life cycle of tropical temperate troughs (TTTs) over southern Africa in austral summer (November-February). Cluster analysis is applied to 1971-2000 40-yr ECMWF Re-Analysis (ERA-40) daily outgoing longwave radiation (OLR) anomalies to identify TTTs and monitor tropical convection. The same analysis applied to the zonal wind stretching deformation at 200 hPa (ZDEF) characterizes midlatitude transient perturbations. Results based on the comparison between these two classifications first confirm that midlatitude baroclinic waves are a necessary condition for TTT development, but they are not sufficient. Roughly 40% of those occurring in austral summer are associated with a TTT. They tend to be stronger than the baroclinic waves not associated with TTT development. In the tropics, additional conditions needed to form a TTT consist of an excess of latent energy over the Mozambique Channel, mostly because of moisture advections and convergence from the Atlantic and Indian Oceans. Taken together, these conditions are highly favorable for deep atmospheric convection over and near southern Africa and seem to explain a large fraction of TTT variability. © 2014 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50980
Appears in Collections: 气候变化事实与影响
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作者单位: Centre de Recherches de Climatologie, CNRS/Université de Bourgogne, Dijon, France; Laboratoire d' Energétique, d' Electronique et Procédés, Université de la Réunion, Réunion, France
Recommended Citation:
Macron C.,Pohl B.,Richard Y.,et al. How do tropical temperate troughs form and develop over Southern Africa?[J]. Journal of Climate,2014-01-01,27(4)