Contents: 1.

The procedures and results of a study undertaken to evaluate and assess the impacts of three new parameterization schemes for the GL global spectral model as a 3-4 day range forecast model are described. The tree parameterization schemes are one each for the boundary-layer physics, moist convection and heating due to solar and terrestrial radiations. These schemes are incorporated either singly or jointly into a rhomboidal-30, 12-layer global spectral model for four-day simulations using FGGE III- a data as input. Evaluation and assessment are made on the basis of two kinds of global statistics: mean and root-mean-square errors, and on their magnitudes and distributions. The statistics are generated for both the primary, that is, prognostic, variables, and supplementary variables such as zonal-mean and zonal-eddies energy densities. The new moist convection scheme has been found to increase convective activity significantly and maintain it throughout the four-day period. It also warms and dries the middle troposphere, but produces rainfall far in excess of the climatology. The radiation parameterization has been found to cool the atmosphere and reduce its specific humidity. It counterbalances enhanced heating and moistening brought about by the new boundary-layer and moist convection schemes and eliminates the systematic warming of the old model.

This book presents descriptions of numerical models for testing cumulus in cloud fields. It is divided into six parts. Part I provides an overview of the problem, including descriptions of cumulus clouds and the effects of ensembles of cumulus clouds on mass, momentum, and vorticity distributions. A review of closure assumptions is also provided. A review of "classical" convection schemes in widespread use is provided in Part II. The special problems associated with the representation of convection in mesoscale models are discussed in Part III, along with descriptions of some of the commonly used mesoscale schemes. Part IV covers some of the problems associated with the representation of convection in climate models, while the parameterization of slantwise convection is the subject of Part V.

Numerical weather prediction models play an increasingly important role in meteorology, both in short- and medium-range forecasting and global climate change studies. The most important components of any numerical weather prediction model are the subgrid-scale parameterization schemes, and the analysis and understanding of these schemes is a key aspect of numerical weather prediction. This book provides in-depth explorations of the most commonly used types of parameterization schemes that influence both short-range weather forecasts and global climate models. Several parameterizations are summarised and compared, followed by a discussion of their limitations. Review questions at the end of each chapter enable readers to monitor their understanding of the topics covered, and solutions are available to instructors at www.cambridge.org/9780521865401. This will be an essential reference for academic researchers, meteorologists, weather forecasters, and graduate students interested in numerical weather prediction and its use in weather forecasting.

General circulation model (GCM) experiments in the late 1970's indicated that the climate is sensitive to variations in evaporation at the land surface. Thus, in the context of climate modeling, it became important to develop techniques which would realistically estimate the evaporation flux on land. Land Surface Evaporation: Measurement and Parameterization discusses strategies for the use of experimental data in developing and testing parameterization schemes of the evaporation flux in GCM's. The book reviews state-of-the-art techniques, such as remote sensing, which measure evaporation fluxes over continental surfaces. It evaluates their relevance with respect to the various spatial and temporal scales of interest. This book will provide researchers in climatology, meteorology, hydrology and water management, and remote sensing with a thorough overview of current research in land surface evaporation. It will also give young scientists insight into surface processes.