Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979
Here, we examine the dynamic properties associated with the recent increase in the Sahel rainfall using an ensemble of five global reanalysis datasets (1979–2010). The rainfall that has been observed to be increasing over the Sahel is accounted for by enhancements in both the tropical easterly jet a...
Published in: | International Journal of Geophysics |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2011
|
Subjects: | |
Online Access: | https://doi.org/10.1155/2011/259529 https://doaj.org/article/adb56865677e427b9b2592e5992cce86 |
id |
ftdoajarticles:oai:doaj.org/article:adb56865677e427b9b2592e5992cce86 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:adb56865677e427b9b2592e5992cce86 2024-09-09T19:55:52+00:00 Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979 Shih-Yu Wang Robert R. Gillies 2011-01-01T00:00:00Z https://doi.org/10.1155/2011/259529 https://doaj.org/article/adb56865677e427b9b2592e5992cce86 EN eng Wiley http://dx.doi.org/10.1155/2011/259529 https://doaj.org/toc/1687-885X https://doaj.org/toc/1687-8868 1687-885X 1687-8868 doi:10.1155/2011/259529 https://doaj.org/article/adb56865677e427b9b2592e5992cce86 International Journal of Geophysics, Vol 2011 (2011) Geophysics. Cosmic physics QC801-809 article 2011 ftdoajarticles https://doi.org/10.1155/2011/259529 2024-08-05T17:48:46Z Here, we examine the dynamic properties associated with the recent increase in the Sahel rainfall using an ensemble of five global reanalysis datasets (1979–2010). The rainfall that has been observed to be increasing over the Sahel is accounted for by enhancements in both the tropical easterly jet and the African easterly jet, both of which are known to induce wet anomalies. Moreover, positional shifts in the African easterly jet and African easterly waves (AEWs) accompanied the northward migration of the Sahel rainband. Change in the African easterly jet and AEWs are coupled to a northward shift and amplification of convective activity; this signals an increased potential for the occurrence of flash floods along the northern Sahel. In addition, the result from a wave tracking analysis suggests that the change in AEWs is closely linked to increased activity of intense hurricanes in the North Atlantic. The synoptic concurrence of AEWs in driving the dynamics of the Sahel greening and the increase in tropical cyclogeneses over the North Atlantic is an important aspect in the evaluation of climate model projections. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles International Journal of Geophysics 2011 1 14 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Geophysics. Cosmic physics QC801-809 Shih-Yu Wang Robert R. Gillies Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979 |
topic_facet |
Geophysics. Cosmic physics QC801-809 |
description |
Here, we examine the dynamic properties associated with the recent increase in the Sahel rainfall using an ensemble of five global reanalysis datasets (1979–2010). The rainfall that has been observed to be increasing over the Sahel is accounted for by enhancements in both the tropical easterly jet and the African easterly jet, both of which are known to induce wet anomalies. Moreover, positional shifts in the African easterly jet and African easterly waves (AEWs) accompanied the northward migration of the Sahel rainband. Change in the African easterly jet and AEWs are coupled to a northward shift and amplification of convective activity; this signals an increased potential for the occurrence of flash floods along the northern Sahel. In addition, the result from a wave tracking analysis suggests that the change in AEWs is closely linked to increased activity of intense hurricanes in the North Atlantic. The synoptic concurrence of AEWs in driving the dynamics of the Sahel greening and the increase in tropical cyclogeneses over the North Atlantic is an important aspect in the evaluation of climate model projections. |
format |
Article in Journal/Newspaper |
author |
Shih-Yu Wang Robert R. Gillies |
author_facet |
Shih-Yu Wang Robert R. Gillies |
author_sort |
Shih-Yu Wang |
title |
Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979 |
title_short |
Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979 |
title_full |
Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979 |
title_fullStr |
Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979 |
title_full_unstemmed |
Observed Change in Sahel Rainfall, Circulations, African Easterly Waves, and Atlantic Hurricanes Since 1979 |
title_sort |
observed change in sahel rainfall, circulations, african easterly waves, and atlantic hurricanes since 1979 |
publisher |
Wiley |
publishDate |
2011 |
url |
https://doi.org/10.1155/2011/259529 https://doaj.org/article/adb56865677e427b9b2592e5992cce86 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
International Journal of Geophysics, Vol 2011 (2011) |
op_relation |
http://dx.doi.org/10.1155/2011/259529 https://doaj.org/toc/1687-885X https://doaj.org/toc/1687-8868 1687-885X 1687-8868 doi:10.1155/2011/259529 https://doaj.org/article/adb56865677e427b9b2592e5992cce86 |
op_doi |
https://doi.org/10.1155/2011/259529 |
container_title |
International Journal of Geophysics |
container_volume |
2011 |
container_start_page |
1 |
op_container_end_page |
14 |
_version_ |
1809926121635971072 |