The aerosol- and water vapor-related variability of precipitation in the West Africa Monsoon

• Main Authors: Jingfeng Huang, C. Zhang, J. M. Prospero
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.521.9988; http://www.rsmas.miami.edu/personal/jhuang/Huangetal_AMS28thTropical_Manuscript_15Apr08.pdf

The precipitation variability in the West Africa Monsoon (WAM) is affected by many factors. Close to the largest aerosol emission sources (mineral dust from Sahara and Sahel, and biomass burning smokes from Sahel and southern Africa), the WAM provides a natural laboratory to study the possible connections between aerosol, water vapor and precipitation. Possible aerosol and water vapor effects have, however, not been thoroughly investigated. Additionally how aerosol effect is distinguished from environmental water vapor effect is hardly visited. Using long term multi-satellite observations of aerosol, water vapor and precipitation, this study elucidates possible large-scale effects from the absorbing aerosol (primarily mineral dust and carbonaceous aerosol) and atmospheric water vapor on precipitation over the WAM region. After removing seasonal cycle, ENSO, tropical Atlantic SST and North Atlantic Oscillation (NAO) effects, precipitation difference composite between anomalously high and low aerosol (or water vapor) was made. It is found that in the WAM region both aerosol and water vapor effects on precipitation feature strong seasonality and spatial variability.