DATE2019-01-08 12:44:22
IDABSTRACT2014/201
CONTACTmagdywahab1949@gmail.com
PRESENTATIONORAL
INVITED0
IDSESSION2
TITLETHE CHANGES IN THE RAINFALL INTENSITY OVER AFRICA DUE TO THE ROLE OF ATMOSPHERIC AEROSOLS
AUTHORSMohamed Magdy Abdel Wahab (2)|Ashraf Saber Zakey (2)|Zeinab Mohamed Ahmed (2)
AFFILIATIONS
  1. Cairo university, Cairo, Egypt
  2. Meteorological Authority, Cairo, Egypt
  3. Meteorological Authority, Cairo, Egypt
ABSTRACTThe Online integrated climate-chemistry model (RegCM4-CHEM) is used in this study to identify the change in the rainfall over Africa due to the role of atmospheric aerosols. In this study, we investigated the large-scale connection between African aerosol and precipitation over Africa during the period (2011–2013). The model simulations of RegCM4-CHEM included both of the direct and indirect effects of atmospheric aerosols. The monthly and daily Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products (aerosol optical depth, fine mode fraction) and Tropical Rainfall Measuring Mission (TRMM) precipitation and rain type is used to validate our results. The results indicated that the climate of Africa north of the equator is characterized by pronounced seasonal contrasts, regulated by the inter-tropical convergence zone (ITCZ). The ITCZ is made manifest at the surface by the transition zone between the dry harmattan air and the moist air from the equatorial regions. This transition is marked by discontinuities in wind, dew point, and temperature. This study suggests that African aerosol outbreaks in the West African Monsoon (WAM) region can influence precipitation in the local monsoon system that has direct societal impact on the local community. Based on the seasonal cycle of dust and smoke and their geographical distribution, our results suggest that both dust (coarse mode aerosol) and smoke (fine mode aerosol) contribute to the precipitation suppression. However, the dust effect is evident over the Gulf of Guinea while the smoke effect is evident over both land and ocean.
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