Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4
This study investigates the changes in West African monsoon features during warm years using the Regional Climate Model version 4.5 (RegCM4.5). The analysis uses 30 years of datasets of rainfall, surface temperature and wind parameters (from 1980 to 2009). We performed a simulation at a spatial reso...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-01-01
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| Series: | Atmosphere |
| Subjects: | |
| Online Access: | http://www.mdpi.com/2073-4433/10/1/23 |
| _version_ | 1811223556278714368 |
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| author | Ibrahima Diba Moctar Camara Arona Diedhiou |
| author_facet | Ibrahima Diba Moctar Camara Arona Diedhiou |
| author_sort | Ibrahima Diba |
| collection | DOAJ |
| description | This study investigates the changes in West African monsoon features during warm years using the Regional Climate Model version 4.5 (RegCM4.5). The analysis uses 30 years of datasets of rainfall, surface temperature and wind parameters (from 1980 to 2009). We performed a simulation at a spatial resolution of 50 km with the RegCM4.5 model driven by ERA-Interim reanalysis. The rainfall amount is weaker over the Sahel (western and central) and the Guinea region for the warmest years compared to the coldest ones. The analysis of heat fluxes show that the sensible (latent) heat flux is stronger (weaker) during the warmest (coldest) years. When considering the rainfall events, there is a decrease of the number of rainy days over the Guinea Coast (in the South of Cote d’Ivoire, of Ghana and of Benin) and the western and eastern Sahel during warm years. The maximum length of consecutive wet days decreases over the western and eastern Sahel, while the consecutive dry days increase mainly over the Sahel band during the warm years. The percentage of very warm days and warm nights increase mainly over the Sahel domain and the Guinea region. The model also simulates an increase of the warm spell duration index in the whole Sahel domain and over the Guinea Coast in warm years. The analysis of the wind dynamic exhibits during warm years a weakening of the monsoon flow in the lower levels, a strengthening in the magnitude of the African Easterly Jet (AEJ) in the mid-troposphere and a slight increase of the Tropical Easterly Jet (TEJ) in the upper levels of the atmosphere during warm years. |
| first_indexed | 2024-04-12T08:34:47Z |
| format | Article |
| id | doaj.art-01f444da5e4a443f9b6473b88531e5fa |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-04-12T08:34:47Z |
| publishDate | 2019-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-01f444da5e4a443f9b6473b88531e5fa2022-12-22T03:40:03ZengMDPI AGAtmosphere2073-44332019-01-011012310.3390/atmos10010023atmos10010023Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4Ibrahima Diba0Moctar Camara1Arona Diedhiou2Laboratoire d’Océanographie, des Sciences de l’Environnement et du Climat (LOSEC), UFR Sciences et Technologies, Université Assane SECK de Ziguinchor, Ziguinchor 270000, SenegalLaboratoire d’Océanographie, des Sciences de l’Environnement et du Climat (LOSEC), UFR Sciences et Technologies, Université Assane SECK de Ziguinchor, Ziguinchor 270000, SenegalUniversité Grenoble Alpes, IRD, CNRS, Grenoble INP, IGE, F-38000 Grenoble, FranceThis study investigates the changes in West African monsoon features during warm years using the Regional Climate Model version 4.5 (RegCM4.5). The analysis uses 30 years of datasets of rainfall, surface temperature and wind parameters (from 1980 to 2009). We performed a simulation at a spatial resolution of 50 km with the RegCM4.5 model driven by ERA-Interim reanalysis. The rainfall amount is weaker over the Sahel (western and central) and the Guinea region for the warmest years compared to the coldest ones. The analysis of heat fluxes show that the sensible (latent) heat flux is stronger (weaker) during the warmest (coldest) years. When considering the rainfall events, there is a decrease of the number of rainy days over the Guinea Coast (in the South of Cote d’Ivoire, of Ghana and of Benin) and the western and eastern Sahel during warm years. The maximum length of consecutive wet days decreases over the western and eastern Sahel, while the consecutive dry days increase mainly over the Sahel band during the warm years. The percentage of very warm days and warm nights increase mainly over the Sahel domain and the Guinea region. The model also simulates an increase of the warm spell duration index in the whole Sahel domain and over the Guinea Coast in warm years. The analysis of the wind dynamic exhibits during warm years a weakening of the monsoon flow in the lower levels, a strengthening in the magnitude of the African Easterly Jet (AEJ) in the mid-troposphere and a slight increase of the Tropical Easterly Jet (TEJ) in the upper levels of the atmosphere during warm years.http://www.mdpi.com/2073-4433/10/1/23RegCM4warm yearsWest Africa |
| spellingShingle | Ibrahima Diba Moctar Camara Arona Diedhiou Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4 Atmosphere RegCM4 warm years West Africa |
| title | Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4 |
| title_full | Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4 |
| title_fullStr | Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4 |
| title_full_unstemmed | Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4 |
| title_short | Investigating West African Monsoon Features in Warm Years Using the Regional Climate Model RegCM4 |
| title_sort | investigating west african monsoon features in warm years using the regional climate model regcm4 |
| topic | RegCM4 warm years West Africa |
| url | http://www.mdpi.com/2073-4433/10/1/23 |
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