Extended Abstract (112K)9B.4
The African Easterly jet-wave system
Rosalind J. Cornforth, Univ. of Reading, Reading, Berks., United Kingdom
African Easterly waves are grown on an Easterly jet forced in an intermediate general circulation model (IGCM) with simple dry parameterizations. A linear instability analysis and lifecycle study show that the dry waves are characterised by low-level structure polewards of the jet and baroclinic energetics. The relationship of the waves, the jet and the dry convection is shown to be sensitive to the land-surface properties. This has implications for how the boundary layers are incorporated into GCMs for an African climate to be well-represented. In addition, an idealised analysis of CAPE, supports the existence of a coherent relationship between wave structure and convection. Results bear most relevance to the early, pre-monsoon period in north west Africa and to dry periods within the full monsoon season.The work differs from previous authors in that the jet is allowed to evolve realistically rather than being prescribed.
Session 9B, Large-Scale Dynamics and Convection IV (Parallel with Sessions 9A, 9C, and 9D)
Wednesday, 1 May 2002, 11:00 AM-12:30 PM
Previous paper Next paper