Early development of African Easterly Waves in the Eastern Atlantic

Tropical storms that develop in the Eastern Atlantic from African Easterly waves (AEW) are likely to be most affected by the characteristics of the parent wave and its structure as it left the West African coast. Hopsch et al (2010) showed that by comparing developing and non-developing wave composites, there were significant differences, with developing waves having stronger vorticity at mid-levels, a broader region of high relative humidity and stronger vertical velocity in the trough.

Thorncroft & Hodges (2001) showed that the Guinea Highlands at the West African coast was an area of significant genesis activity in easterly wave filtered (2-6 day) vorticity and also an area of increased growth rate. Using the composite developing wave as motivation and looking at individual waves, this research attempts to assess the impact of the West African coast on early developing waves from the 2010 & 2011 hurricane seasons. Are these waves conducive to development before reaching the coast, or did the West African coast influence the early development of these waves. Using CFSR data and TRMM PR data, AEW waves will be objectively identified, analysed and compared to the Hopsch et al (2010) developing wave. Analysis of the vertical structure of the AEW and the transition from land to ocean and from wave to tropical storm will allow us to evaluate the impact the West African coast has on these systems.