Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation

This study analyzes changes in the long-term (1901-2015) monthly values of potential evapotranspiration (PET), precipitation, and minimum (Tmin) and maximum (Tmax) temperatures across Africa to quantify trends and assess covariability between these climatic variables. Both warming and drying trends...

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Detalles Bibliográficos
Autor: Onyutha, Charles
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:México
Institución:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repositorio:Atmósfera
Idioma:inglés
OAI Identifier:oai:ojs.pkp.sfu.ca:article/52788
Acceso en línea:https://www.revistascca.unam.mx/atm/index.php/atm/article/view/52788
Access Level:acceso abierto
Palabra clave:climate variability
temperature trends
precipitation trends
evapotranspiration trends
seasonal CSD trend
hydroclimate of Africa
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spelling Trends and variability of temperature and evaporation over the African continent: Relationships with precipitationOnyutha, Charlesclimate variabilitytemperature trendsprecipitation trendsevapotranspiration trendsseasonal CSD trendhydroclimate of AfricaThis study analyzes changes in the long-term (1901-2015) monthly values of potential evapotranspiration (PET), precipitation, and minimum (Tmin) and maximum (Tmax) temperatures across Africa to quantify trends and assess covariability between these climatic variables. Both warming and drying trends were observed across the continent. The 1979-2015 warming was stronger than that from 1901 to 1940. Some cooling occurred from 1941 to the mid-1970s. The 1901-2015 annual Tmax, Tmin, and PET averaged over Africa exhibited increasing or drying trends across the continent at rates of 0.18 ºC, 0.22 ºC, and 3.5 mm per decade, respectively. The 1961-1990 annual precipitation averaged over the whole continent showed that Africa experienced drying at a rate of about –28 mm per decade. When considering the period 1961-2015, the rate of precipitation decrease was about –8 mm per decade. From 1901 to 1915, areas around Lake Victoria in East Africa and along the western coastline south of the equator experienced wetting rates of up to 36 mm per decade. Significant (p < 0.01) warming trends occurred in Sudan, Southern and Northern Africa. Positive PET trends were significant (p < 0.01) in the warm Mediterranean climate, and the western part of South Africa. Long-term temperature increase and precipitation decrease across northern Africa possibly indicated the Sahara Desert expansion over time. Except in the warm desert climate, the continent exhibited high precipitation variability. Equatorial climate experienced low temperature and PET variability. The strongest coherence between precipitation and temperature existed at multiple scales (6-8 years). Correlations between precipitation and PET (or temperature) were mostly negative and weak (p > 0.01). Because the sensitivity of Tmin to local influences is higher than that of Tmax, areas with strong negative correlation were larger in coverage for Tmax than those of Tmin. These results call for planned measures to tackle food insecurity in sub-Saharan Africa.Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México2021-06-30info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdftext/htmlhttps://www.revistascca.unam.mx/atm/index.php/atm/article/view/5278810.20937/ATM.52788Atmósfera; Vol. 34 Núm. 3 (2021); 267-287Atmósfera; Vol. 34 No. 3 (2021); 267-2872395-88120187-6236reponame:Atmósferainstname:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICOinstacron:UNAMenghttps://www.revistascca.unam.mx/atm/index.php/atm/article/view/52788/46727https://www.revistascca.unam.mx/atm/index.php/atm/article/view/52788/46838Copyright (c) 2020 Atmósferahttp://creativecommons.org/licenses/by-nc/4.0info:eu-repo/semantics/openAccessoai:ojs.pkp.sfu.ca:article/527882024-08-16T16:52:41Z
dc.title.none.fl_str_mv Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
title Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
spellingShingle Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
Onyutha, Charles
climate variability
temperature trends
precipitation trends
evapotranspiration trends
seasonal CSD trend
hydroclimate of Africa
title_short Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
title_full Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
title_fullStr Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
title_full_unstemmed Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
title_sort Trends and variability of temperature and evaporation over the African continent: Relationships with precipitation
dc.creator.none.fl_str_mv Onyutha, Charles
author Onyutha, Charles
author_facet Onyutha, Charles
author_role author
dc.subject.none.fl_str_mv climate variability
temperature trends
precipitation trends
evapotranspiration trends
seasonal CSD trend
hydroclimate of Africa
topic climate variability
temperature trends
precipitation trends
evapotranspiration trends
seasonal CSD trend
hydroclimate of Africa
description This study analyzes changes in the long-term (1901-2015) monthly values of potential evapotranspiration (PET), precipitation, and minimum (Tmin) and maximum (Tmax) temperatures across Africa to quantify trends and assess covariability between these climatic variables. Both warming and drying trends were observed across the continent. The 1979-2015 warming was stronger than that from 1901 to 1940. Some cooling occurred from 1941 to the mid-1970s. The 1901-2015 annual Tmax, Tmin, and PET averaged over Africa exhibited increasing or drying trends across the continent at rates of 0.18 ºC, 0.22 ºC, and 3.5 mm per decade, respectively. The 1961-1990 annual precipitation averaged over the whole continent showed that Africa experienced drying at a rate of about –28 mm per decade. When considering the period 1961-2015, the rate of precipitation decrease was about –8 mm per decade. From 1901 to 1915, areas around Lake Victoria in East Africa and along the western coastline south of the equator experienced wetting rates of up to 36 mm per decade. Significant (p < 0.01) warming trends occurred in Sudan, Southern and Northern Africa. Positive PET trends were significant (p < 0.01) in the warm Mediterranean climate, and the western part of South Africa. Long-term temperature increase and precipitation decrease across northern Africa possibly indicated the Sahara Desert expansion over time. Except in the warm desert climate, the continent exhibited high precipitation variability. Equatorial climate experienced low temperature and PET variability. The strongest coherence between precipitation and temperature existed at multiple scales (6-8 years). Correlations between precipitation and PET (or temperature) were mostly negative and weak (p > 0.01). Because the sensitivity of Tmin to local influences is higher than that of Tmax, areas with strong negative correlation were larger in coverage for Tmax than those of Tmin. These results call for planned measures to tackle food insecurity in sub-Saharan Africa.
publishDate 2021
dc.date.none.fl_str_mv 2021-06-30
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://www.revistascca.unam.mx/atm/index.php/atm/article/view/52788
10.20937/ATM.52788
url https://www.revistascca.unam.mx/atm/index.php/atm/article/view/52788
identifier_str_mv 10.20937/ATM.52788
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv https://www.revistascca.unam.mx/atm/index.php/atm/article/view/52788/46727
https://www.revistascca.unam.mx/atm/index.php/atm/article/view/52788/46838
dc.rights.none.fl_str_mv Copyright (c) 2020 Atmósfera
http://creativecommons.org/licenses/by-nc/4.0
info:eu-repo/semantics/openAccess
rights_invalid_str_mv Copyright (c) 2020 Atmósfera
http://creativecommons.org/licenses/by-nc/4.0
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
text/html
dc.publisher.none.fl_str_mv Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México
publisher.none.fl_str_mv Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México
dc.source.none.fl_str_mv Atmósfera; Vol. 34 Núm. 3 (2021); 267-287
Atmósfera; Vol. 34 No. 3 (2021); 267-287
2395-8812
0187-6236
reponame:Atmósfera
instname:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
instacron:UNAM
instname_str UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
instacron_str UNAM
institution UNAM
reponame_str Atmósfera
collection Atmósfera
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812455

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