24 25 Tropical intraseasonal variability is examined in version 3 of the Geophysical Fluid Dynamics 26 Laboratory Atmosphere Model (AM3). Compared to its predecessor AM2, AM3 uses a new treatment 27 of deep and shallow cumulus convection and mesoscale clouds. The AM3 cumulus parameterization is 28 a mass flux-based scheme but also, unlike that in AM2, incorporates subgrid-scale vertical velocit...

This paper prototypes a method for calibrating a cumulus parameterization against a cumulus ensemble model. The key to this technique is to run the cumulus model and the parameterization in identical test cells which provide forcing typical of that seen over tropical oceans. In particular, the mean temperature pro le is relaxed to a reference pro le which is assumed to be characteristic of the ...

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...

[1] This study investigates the ability of a droplet activation parameterization (which considers the effects of entrainment and mixing) to reproduce observed cloud droplet number concentration (CDNC) in ambient clouds. Predictions of the parameterization are compared against cloud averages of CDNC from ambient cumulus and stratocumulus clouds sampled during CRYSTAL‐FACE (Key West, Florida, Jul...

cumulus convection, as a meso-scale phenomenon, results in the release of latent heat and vertical drift of energy that by part could affect the large scale field of energy, humidity, and momentum of the atmosphere. since the current numerical models are unable to resolve the singular cumulus convective clouds that are important from a meteorological point of view, it is used to apply some sort...

A method is described for parameterizing thermodynamic forcing by the mesoscale updrafts and downdrafts of mesoscale convective systems (MCSs) in models with resolution too coarse to resolve these drafts. The parameterization contains improvements over previous schemes, including a more sophisticated convective driver and inclusion of the vertical distribution of various physical processes obta...

A newly developed spectral cumulus parameterization (spectral scheme) was implemented in the Scale Interaction Experiment-Frontier version 2 (SINTEX-F2) seasonal prediction system to improve intraseasonal variability initialization. simple sea surface temperature (SST) nudging scheme using different SST data and restoring times used initialize system, initialized atmosphere obtained from both o...

mixed layer is a part of the atmospheric boundary layer in which pollutants are uniformly distributed. it is sensitive to the earth’s surface, controls the flow of heat and momentum between the surface and the free atmosphere, thus playing a key role in atmospheric circulation. most of atmospheric pollution models require the height of the mixed layer as an input to determine the depth of atmos...

Accurate prediction of monsoon heavy rainfall events in the equatorial region has always been a challenge to weather forecasters. In this paper, forecast of a severe precipitation event that occurred over the eastern central coast of Peninsular Malaysia was attempted using the state-of-the-art Florida State University (FSU) Global and Regional Spectral Models. The sensitivity of parameterized c...