Interaction between moisture transport and Kelvin waves events over Equatorial Africa through ERA‐interim. (3rd July 2017)

• Record Type: Journal Article
• Authors: Zebaze, Sinclaire; Lenouo, André; Tchawoua, Clément; Gaye, Amadou T.; Kamga, François M.
• Is Part Of: Atmospheric science letters. Volume 18:Number 7(2017)
• Page Start: 300
• Page End: 306
• Publication Date: 2017-07-03
• Subjects: ERA‐interim -- moisture flux -- Kelvin waves -- Central Africa; Atmospheric physics -- Periodicals; 551
• DOI: 10.1002/asl.756
• Languages: English
• ISSNs: 1530-261X

Abstract

Abstract: This study examines the moisture transport variability and its interaction between rainfall and Kelvin wave's events over Equatorial Africa using 1979–2010 ERA‐interim reanalysis data, precipitation from Global Precipitation Climatology Project and outgoing long‐wave radiation. Kelvin waves events influenced in Congo basin varies within each rainy season, as the intertropical convergence zone moves through the region. The moisture flux is calculated for the entire tropospheric column (1000–300 hPa) over Central Africa (5–10°N; 5–30°E). Analysis of mean monthly fluxes shows a progressive penetration of the flux into Gulf of Guinea (5°S–5°N; 0–15°E). Mean seasonal values of moisture components across boundaries indicate that the zonal component is the largest contributor to mean moisture over Central Africa, while the meridional component contributes the most over the Gulf of Guinea. Lag correlation between precipitation and moisture is largely dominated over land with a coefficient greater than 0.5, while moisture increases with enhanced phase of Kelvin waves. Abstract : Monthly mean moisture transport (vectors; kg m −1 s −1 ), moisture flux divergence/convergence (shading; 10 −6 s −1 g kg −1 ) vertically integrated in layers 1000–300 hPa and NOAA OLR anomalies (green contours; <−5 Wm −2, only the enhanced phase is shown for clarity) for (a) March, (b) April, (c) May, (d) June, (e) July, (f) August, (g) September and (h) October averaged from 1979 to 2010. Boxes indicate Central Africa (5°S–10°N; 5–30°E, red). Gulf of Guinea (5°S–5°N; 0–15°E, black).