Impact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West Africa
Empirical studies have shown that warm El Nino/Southern Oscillation (ENSO) episodes are associated during northern summer with, first, a southward location of the intertropical convergence zone (ITCZ) over the tropical Atlantic, and, second, a weakened convection over West Africa where the ITCZ...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
1997-04-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/15/471/1997/angeo-15-471-1997.pdf |
| _version_ | 1811238986894540800 |
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| author | S. Janicot |
| author_facet | S. Janicot |
| author_sort | S. Janicot |
| collection | DOAJ |
| description | Empirical studies have shown that warm El
Nino/Southern Oscillation (ENSO) episodes are associated during northern summer
with, first, a southward location of the intertropical convergence zone (ITCZ)
over the tropical Atlantic, and, second, a weakened convection over West Africa
where the ITCZ is near its mean latitude. A modelling experiment presented here
is used to help explain this apparent contradiction. In simulated ENSO
conditions, the ITCZ is located southwards over the tropical Atlantic. Over West
Africa the intertropical front is also displaced southwards, but more slightly;
the ITCZ is located at its climatological latitude and the vertical development
of convective clouds over West and Central Africa is reduced due to dynamical
subsidence in the upper levels. |
| first_indexed | 2024-04-12T12:51:58Z |
| format | Article |
| id | doaj.art-b2552bec90184728b118b963a601354a |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-12T12:51:58Z |
| publishDate | 1997-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-b2552bec90184728b118b963a601354a2022-12-22T03:32:27ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05761997-04-011547147510.1007/s00585-997-0471-xImpact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West AfricaS. Janicot0Météo-France, Laboratoire de Météorologie Dynamique du CNRS, Palaiseau, FranceEmpirical studies have shown that warm El Nino/Southern Oscillation (ENSO) episodes are associated during northern summer with, first, a southward location of the intertropical convergence zone (ITCZ) over the tropical Atlantic, and, second, a weakened convection over West Africa where the ITCZ is near its mean latitude. A modelling experiment presented here is used to help explain this apparent contradiction. In simulated ENSO conditions, the ITCZ is located southwards over the tropical Atlantic. Over West Africa the intertropical front is also displaced southwards, but more slightly; the ITCZ is located at its climatological latitude and the vertical development of convective clouds over West and Central Africa is reduced due to dynamical subsidence in the upper levels.https://www.ann-geophys.net/15/471/1997/angeo-15-471-1997.pdf |
| spellingShingle | S. Janicot Impact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West Africa Annales Geophysicae |
| title | Impact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West Africa |
| title_full | Impact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West Africa |
| title_fullStr | Impact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West Africa |
| title_full_unstemmed | Impact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West Africa |
| title_short | Impact of warm ENSO events on atmospheric circulation and convection over the tropical Atlantic and West Africa |
| title_sort | impact of warm enso events on atmospheric circulation and convection over the tropical atlantic and west africa |
| url | https://www.ann-geophys.net/15/471/1997/angeo-15-471-1997.pdf |
| work_keys_str_mv | AT sjanicot impactofwarmensoeventsonatmosphericcirculationandconvectionoverthetropicalatlanticandwestafrica |