Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions
We present a study of upper tropospheric westward transport of air masses coming from the Indian monsoon zone over the period 1998–2008. The objective is to characterize upper tropospheric transport of water vapor from the Indian to Sahelian regions, and to improve the understanding of the...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2018-10-01
|
| Series: | Atmosphere |
| Subjects: | |
| Online Access: | http://www.mdpi.com/2073-4433/9/10/403 |
| _version_ | 1819212623092121600 |
|---|---|
| author | Abdoulaye Sy Bouya Diop Joël Van Baelen Christophe Duroure Yahya Gour Jean-Luc Baray |
| author_facet | Abdoulaye Sy Bouya Diop Joël Van Baelen Christophe Duroure Yahya Gour Jean-Luc Baray |
| author_sort | Abdoulaye Sy |
| collection | DOAJ |
| description | We present a study of upper tropospheric westward transport of air masses coming from the Indian monsoon zone over the period 1998–2008. The objective is to characterize upper tropospheric transport of water vapor from the Indian to Sahelian regions, and to improve the understanding of the dynamical mechanisms that govern water vapor variations in West Africa and the interconnections between India and the Sahel, focusing on the direct role of the Indian monsoon region on Sahel tropospheric water vapor and precipitation. The calculations of forward trajectories with LACYTRAJ (LACY TRAJectory code) and humidity fluxes show that a substantial part (40 to 70% at 300 hPa) of trajectories coming from the upper troposphere of the monsoon region crossed the Sahelian region in a few days (3–14 days), and water vapor fluxes connecting these two regions are established when the Indian monsoon begins at latitudes higher than 15° N in its south–north migration. The intensity and orientation of water vapor fluxes are related to the tropical easterly jet, but they are from the east above the high convection zones. Between 1998 and 2008, these fluxes between the 500–300 hPa pressure levels are associated with precipitation in Sahel only if they are from the east and with an intensity exceeding 8 kg·(m·s)−1. |
| first_indexed | 2024-12-23T06:45:54Z |
| format | Article |
| id | doaj.art-1f3df43bd0534971b99b7a31427d9c01 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-12-23T06:45:54Z |
| publishDate | 2018-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-1f3df43bd0534971b99b7a31427d9c012022-12-21T17:56:35ZengMDPI AGAtmosphere2073-44332018-10-0191040310.3390/atmos9100403atmos9100403Upper Tropospheric Water Vapor Transport from Indian to Sahelian RegionsAbdoulaye Sy0Bouya Diop1Joël Van Baelen2Christophe Duroure3Yahya Gour4Jean-Luc Baray5Laboratoire des Sciences de l’Atmosphère et des Océans (LSAO), Saint-Louis 234, SénégalLaboratoire des Sciences de l’Atmosphère et des Océans (LSAO), Saint-Louis 234, SénégalCNRS, Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne, UMR6016, F-63000 Clermont-Ferrand, FranceCNRS, Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne, UMR6016, F-63000 Clermont-Ferrand, FranceCNRS, Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne, UMR6016, F-63000 Clermont-Ferrand, FranceCNRS, Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne, UMR6016, F-63000 Clermont-Ferrand, FranceWe present a study of upper tropospheric westward transport of air masses coming from the Indian monsoon zone over the period 1998–2008. The objective is to characterize upper tropospheric transport of water vapor from the Indian to Sahelian regions, and to improve the understanding of the dynamical mechanisms that govern water vapor variations in West Africa and the interconnections between India and the Sahel, focusing on the direct role of the Indian monsoon region on Sahel tropospheric water vapor and precipitation. The calculations of forward trajectories with LACYTRAJ (LACY TRAJectory code) and humidity fluxes show that a substantial part (40 to 70% at 300 hPa) of trajectories coming from the upper troposphere of the monsoon region crossed the Sahelian region in a few days (3–14 days), and water vapor fluxes connecting these two regions are established when the Indian monsoon begins at latitudes higher than 15° N in its south–north migration. The intensity and orientation of water vapor fluxes are related to the tropical easterly jet, but they are from the east above the high convection zones. Between 1998 and 2008, these fluxes between the 500–300 hPa pressure levels are associated with precipitation in Sahel only if they are from the east and with an intensity exceeding 8 kg·(m·s)−1.http://www.mdpi.com/2073-4433/9/10/403water vaporteleconnectiontropical easterly jetmonsoon fluxesSahelIndia |
| spellingShingle | Abdoulaye Sy Bouya Diop Joël Van Baelen Christophe Duroure Yahya Gour Jean-Luc Baray Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions Atmosphere water vapor teleconnection tropical easterly jet monsoon fluxes Sahel India |
| title | Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions |
| title_full | Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions |
| title_fullStr | Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions |
| title_full_unstemmed | Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions |
| title_short | Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions |
| title_sort | upper tropospheric water vapor transport from indian to sahelian regions |
| topic | water vapor teleconnection tropical easterly jet monsoon fluxes Sahel India |
| url | http://www.mdpi.com/2073-4433/9/10/403 |
| work_keys_str_mv | AT abdoulayesy uppertroposphericwatervaportransportfromindiantosahelianregions AT bouyadiop uppertroposphericwatervaportransportfromindiantosahelianregions AT joelvanbaelen uppertroposphericwatervaportransportfromindiantosahelianregions AT christopheduroure uppertroposphericwatervaportransportfromindiantosahelianregions AT yahyagour uppertroposphericwatervaportransportfromindiantosahelianregions AT jeanlucbaray uppertroposphericwatervaportransportfromindiantosahelianregions |