National Weather Center Colloquium

Representation of African Easterly Waves in Historical and Future CMIP5 Simulations

Dr. Elinor Martin

OU School of Meteorology

26 January 2016, 4:00 PM

National Weather Center, Room 1313
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK

African easterly waves (AEWs) can act as seed disturbances for tropical cyclones (TCs) in the Atlantic. Changes in future AEW activity may thus have important consequences for development of TCs. Simulated AEWs were investigated using output from the Coupled Model Intercomparison Project 5 (CMIP5) suite of experiments including coupled historical and future, and atmosphere only (AMIP) simulations. Large biases exist in the simulation of low- and mid-level eddy kinetic energy (EKE, a proxy for AEW activity) in AMIP and historical simulations. CMIP5 models predict excessive EKE and deficient rainfall south of 17N. The same biases exist in historical and AMIP models, and those are not a consequence of errors in sea surface temperatures. The models also struggle to accurately couple AEWs and rainfall. CMIP5 models are unable to propagate AEWs across the coast and into the Atlantic which is shown to be related to the resolution of the Guinea Highlands. Future projections of the annual cycle of AEW activity show a reduction in late spring and early summer, and a large increase between July and October. The simulation of AEWs is challenging for CMIP5 models and must be further diagnosed in order to accurately predict future TC activity and rainfall in the Sahel.

Dr. Martin earned her B.Sc. (Hons) in Meteorology from the University of Reading. She was part of the first group of Reading students to attend OU within the ongoing exchange program. After receiving M.S. from Colorado State University, where she worked on understanding atmospheric bores, she gained a Ph.D. in Atmospheric Science from Texas A&M University, where her work was focused on weather-climate interactions in the Caribbean. Prior to joining the School of Meteorology in 2014 she held a postdoctoral position at SUNY Albany. Her research interests include tropical and sub-tropical climate variability and change, with focus on precipitation processes, and weather-climate interactions

National Weather Center Colloquium Seminar Series website