The Randolph Bromery Spring 2019 Seminar Series: Charles Ichoku

Description

Dr. Charles Ichoku, a professor in the Atmospheric Science graduate program at Howard University, will give a talk entitled "Climatic and Human influences on Water-Cycle Dynamics in Tropical Sub-Saharan Africa" for the Department of Earth & Planetary Sciences. Dr. Ichoku is also a research physical scientist with the Climate and Radiation Laboratory at NASA Goddard Space Flight Center.

Abstract:

Various parts of tropical sub-Saharan Africa north of the equator have experienced multiple episodes of devastating droughts, but occasionally also intense flooding, in recent decades. Scientists have investigated different possible indicators of the regional and remote drivers, which may be responsible for changes in the precipitation patterns that result in these climatic extremes. Some of the phenomena to which this situation has been attributed in various studies include: teleconnections with large scale natural variability such as the El-Nino southern oscillation (ENSO), remote industrial sulfur emissions, northern hemisphere volcanic eruptions, as well as regional grazing and biomass-burning activities. In this talk, we will examine the relationships between precipitation patterns and some of the associated large-scale natural phenomena such as ENSO and the Atlantic Multidecadal Oscillation (AMO) over the last century, and how these may have contributed to severe regional droughts during the 1970s and 1980s, as symbolized by the dramatic drying of Lake Chad, which is located in the center of the region. Secondly, we will examine changes in some of the regional hydrological cycle indicators, which are associated with satellite-observed land-use activities that are dependent on the use of wildland fires and other types of biomass burning over the last couple of decades. Thirdly, we will examine the intrinsic precipitation patterns observed from satellite and ground-based measurements over the last few years. Finally, we will assess the current knowledge gaps and provide some perspectives on future research that can help unravel some of the ambiguities related to the highly variable water-cycle dynamics in tropical sub-Saharan Africa.