July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs
July-September rainfall is a key component of Ethiopia’s annual rainfall and is a source of rainfall variability throughout inland Greater Horn of Africa. In this study we investigate the relative influences of the Mascarene (MH) and South Atlantic (AH) highs on July-September rainfall in a covaryin...
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Online Access: | https://centaur.reading.ac.uk/104865/ https://centaur.reading.ac.uk/104865/9/Dyer2022_Article_JulySeptemberRainfallInTheGrea.pdf https://centaur.reading.ac.uk/104865/1/gha_mh_ah_2022.pdf |
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ftunivreading:oai:centaur.reading.ac.uk:104865 2024-06-23T07:56:56+00:00 July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs Dyer, Ellen Hirons, Linda Teferi Taye, Meron 2022-04-28 text https://centaur.reading.ac.uk/104865/ https://centaur.reading.ac.uk/104865/9/Dyer2022_Article_JulySeptemberRainfallInTheGrea.pdf https://centaur.reading.ac.uk/104865/1/gha_mh_ah_2022.pdf en eng Springer https://centaur.reading.ac.uk/104865/9/Dyer2022_Article_JulySeptemberRainfallInTheGrea.pdf https://centaur.reading.ac.uk/104865/1/gha_mh_ah_2022.pdf Dyer, E., Hirons, L. <https://centaur.reading.ac.uk/view/creators/90004922.html> orcid:0000-0002-1189-7576 and Teferi Taye, M. (2022) July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs. Climate Dynamics. ISSN 0930-7575 doi: https://doi.org/10.1007/s00382-022-06287-0 <https://doi.org/10.1007/s00382-022-06287-0> cc_by_4 Article PeerReviewed 2022 ftunivreading https://doi.org/10.1007/s00382-022-06287-0 2024-06-11T15:11:42Z July-September rainfall is a key component of Ethiopia’s annual rainfall and is a source of rainfall variability throughout inland Greater Horn of Africa. In this study we investigate the relative influences of the Mascarene (MH) and South Atlantic (AH) highs on July-September rainfall in a covarying region of the Greater Horn of Africa using CHIRPS observed rainfall and the ERA5 reanalysis. We show that a mixed metric using the circulation at 850 hPa of these two subtropical anticyclones (AH-MH), is better correlated with rainfall than individual high circulations. Variations in remote circulation are translated by changes in Central African westerlies and Turkana Jet wind speeds. We apply the AH-MH mixed metric to the CMIP5 and CMIP6 ensembles and show that it is a good indicator of mean July-September rainfall across both ensembles. Biases in circulation are shown to be related to the Hadley circulation in CMIP5 atmosphere-only simulations, while causes of biases in CMIP6 are more varied. Coupled model biases are related to southern ocean warm biases in CMIP5 and western Indian Ocean warm biases in CMIP6. CMIP6 shows an improved relationship between rainfall and Turkana Jet and Central African westerlies across the ensemble. Article in Journal/Newspaper Southern Ocean CentAUR: Central Archive at the University of Reading Southern Ocean Indian Climate Dynamics |
institution |
Open Polar |
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CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
July-September rainfall is a key component of Ethiopia’s annual rainfall and is a source of rainfall variability throughout inland Greater Horn of Africa. In this study we investigate the relative influences of the Mascarene (MH) and South Atlantic (AH) highs on July-September rainfall in a covarying region of the Greater Horn of Africa using CHIRPS observed rainfall and the ERA5 reanalysis. We show that a mixed metric using the circulation at 850 hPa of these two subtropical anticyclones (AH-MH), is better correlated with rainfall than individual high circulations. Variations in remote circulation are translated by changes in Central African westerlies and Turkana Jet wind speeds. We apply the AH-MH mixed metric to the CMIP5 and CMIP6 ensembles and show that it is a good indicator of mean July-September rainfall across both ensembles. Biases in circulation are shown to be related to the Hadley circulation in CMIP5 atmosphere-only simulations, while causes of biases in CMIP6 are more varied. Coupled model biases are related to southern ocean warm biases in CMIP5 and western Indian Ocean warm biases in CMIP6. CMIP6 shows an improved relationship between rainfall and Turkana Jet and Central African westerlies across the ensemble. |
format |
Article in Journal/Newspaper |
author |
Dyer, Ellen Hirons, Linda Teferi Taye, Meron |
spellingShingle |
Dyer, Ellen Hirons, Linda Teferi Taye, Meron July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs |
author_facet |
Dyer, Ellen Hirons, Linda Teferi Taye, Meron |
author_sort |
Dyer, Ellen |
title |
July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs |
title_short |
July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs |
title_full |
July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs |
title_fullStr |
July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs |
title_full_unstemmed |
July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs |
title_sort |
july-september rainfall in the greater horn of africa: the combined influence of the mascarene and south atlantic highs |
publisher |
Springer |
publishDate |
2022 |
url |
https://centaur.reading.ac.uk/104865/ https://centaur.reading.ac.uk/104865/9/Dyer2022_Article_JulySeptemberRainfallInTheGrea.pdf https://centaur.reading.ac.uk/104865/1/gha_mh_ah_2022.pdf |
geographic |
Southern Ocean Indian |
geographic_facet |
Southern Ocean Indian |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://centaur.reading.ac.uk/104865/9/Dyer2022_Article_JulySeptemberRainfallInTheGrea.pdf https://centaur.reading.ac.uk/104865/1/gha_mh_ah_2022.pdf Dyer, E., Hirons, L. <https://centaur.reading.ac.uk/view/creators/90004922.html> orcid:0000-0002-1189-7576 and Teferi Taye, M. (2022) July-September rainfall in the Greater Horn of Africa: the combined influence of the Mascarene and South Atlantic highs. Climate Dynamics. ISSN 0930-7575 doi: https://doi.org/10.1007/s00382-022-06287-0 <https://doi.org/10.1007/s00382-022-06287-0> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1007/s00382-022-06287-0 |
container_title |
Climate Dynamics |
_version_ |
1802650329587646464 |