We provide evidence that midlatitude postsunrise traveling ionospheric disturbances (TIDs) are comprised of electrified waves with an eastward propagation component. The post-sunrise gravity wave (GW) wind-induced dynamo action effectively generated periodic meridional polarization electric fields (PEFs), facilitating TID zonal in a similar fashion as GW-driven neutral perturbations. A combinat...

The aim of this study was to classify the most frequently observed atmospheric circulation anomaly patterns in eastern Africa and the adjacent Indian Ocean. As an example of the usefulness of such a classification, the second objective was to test whether these patterns account for intraseasonal rainfall anomalies in the region. A partitioning algorithm, known as dynamical cluster analysis, was...

Several scientific programs, including the Mediterranean Forecasting System Toward Environmental Predictions (MFSTEP project), request high space and time resolutions of surface wind speed and direction. The purpose of this paper is to focus on surface wind improvements over the global Mediterranean Sea, based on the blending near real time remotely sensed wind observations and ECMWF wind analy...

the baroclinic adjustment is defined as the neutralization of the mean flow by eddies. with the amplitude growth of the baroclinic waves generated by an unstable mean flow, the eddy fluxes increase and act to reduce the meridional temperature gradient or vertical wind shear of the mean flow to subcritical value. this is believed to constitute the basic mechanism of baroclinic adjustment. the co...

Several scientific programs, including the Mediterranean Forecasting System Toward Environmental Predictions (MFSTEP project), request high space and time resolutions of surface wind speed and direction. The purpose of this paper is to focus on surface wind improvements over the global Mediterranean Sea, based on the blending near 5 real time remotely sensed wind observations and ECMWF wind ana...

The variability of the zonal mean flow in the Southern Hemisphere during the period 1985–94 is studied using European Centre for Medium-Range Forecasts analyses. The dominant mode of variability has approximately equivalent barotropic variations of opposite signs centered at 408 and 608S. This structure is dominant in all seasons and has similar variance in all seasons. The temporal variance of...

Rossby Wave Chromatography (RWC) is implemented in a linearized barotropic model as a tool to understand the interaction between the mid-latitude jet and the eddy momentum fluxes (UV) in an idealized GCM. Given the background zonal-mean flow and the space-time structure of the baroclinic wave activity source, RWC calculates the space-time structure of the upper tropospheric UV. It is found that...

Equatorial long-wave theory applies where a small horizontal aspect ratio between meridional and zonal length scales is assumed. In an idealized setting, the theory suggests that (i) meridional wind is small, (ii) geostrophic balance holds in the meridional direction, and (iii) inertio-gravity waves are small in amplitude or ‘‘filtered out.’’ In this paper a spectral data analysis method is use...

Recent retrievals of zonal thermal winds obtained in a cyclostrophic regime on Venus are generally consistent with cloud tracking measurements at midlatitudes, but become unphysical in polar regions where the values obtained above the clouds are often less than or close to zero. Using a global atmospheric model, we show that the main source of errors that appear in the polar regions when retrie...

A majority of positive Indian Ocean dipole (IOD) events in the last 50 years were accompanied by enhanced summer monsoon circulation and above-normal precipitation over central-north India. Given that IODs peak during boreal autumn following the summer monsoon season, this study examines the role of the summer monsoon flow on the Indian Ocean (IO) response using a suite of ocean model experimen...