Understanding African easterly waves: a moist singular vector approach

Ensemble-based Sensitivity Analysis applied to African Easterly Waves

An ensemble Kalman filter (EnKF) coupled to the Advanced Research version of the Weather Research and Forecasting (WRF) model is used to generate ensemble analyes and forecasts of a strong African Easterly Wave (AEW) during the African Monsoon Multidisciplinary Analysis field campaign. Ensemble sensitivity analysis is then used to evaluate the impact of initial condition errors on AEW amplitude...

Observational evidence of African desert dust intensification of easterly waves

[1] This paper presents indirect observational evidence that desert dust can modulate the amplitude of easterly waves in the Atlantic Ocean. Twenty two years of NCEP/ NCAR reanalysis and dust from a global transport model are used to characterize the evolution of enhanced easterly waves. Lag composites of analysis increments (analysis minus first–guess) of geopotential height (700–hPa) anomalie...

On African easterly waves that impacted two tropical cyclones in 2004

[1] The U. S. Navy Operational Global Atmospheric Prediction System (NOGAPS) daily analysis fields are used to study the African easterly waves to show how they impacted two tropical cyclones. Danielle and Earl (2004) formed approximately at the same time in the Atlantic. A three to eight day band-pass filter is applied to the daily global analysis fields to reveal the characteristics of the Af...

Characteristics of African Easterly Waves Depicted by ECMWF Reanalyses for 1991-2000

Tropical cyclogenesis in a tropical wave critical layer: easterly waves

The development of tropical depressions within tropical waves over the Atlantic and eastern Pacific is usually preceded by a “surface low along the wave” as if to suggest a hybrid wave-vortex structure in which flow streamlines not only undulate with the waves, but form a closed circulation in the lower troposphere surrounding the low. This structure, equatorward of the easterly jet axis, is id...