ESRL/PSD Seminar Series

On the dynamics of African Easterly Waves: Their origin, growth and interaction with the environment

Stephanie Leroux
NRC Postdoc, NOAA ESRL PSD

Abstract


This seminar will present some results from my PhD thesis as part of the international research program AMMA (African Monsoon Multidisciplinary Analyses). This work focused on one specific type of tropical wave: African Easterly Waves (AEWs), which are the dominant mode of atmospheric variability over West Africa on synoptic scales.

These waves are baroclinic westward propagating disturbances with a wavelength of about 3000 km and a period of 3-5 days. They are intermittent on intraseasonal timescales, and in different studies they have been associated with the modulation and spatial organization of convection in West Africa. They have also been studied as the precursors of tropical Atlantic disturbances that later become hurricanes.

My thesis work aimed to investigate the question of the origin, growth and intermittence of AEWs through a combination of idealized modelling and analysis of observations. I will examine and discuss factors such as the relationship of the waves with the background environment - in particular the African Easterly Jet (AEJ) - and with convection.


NOAA Skaggs 1D-403
Wednesday, 27 January
2:00pm

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