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.

Precipitating atmospheric convection is fundamental to the Earth's weather and climate. It plays a leading role in the heat, moisture and momentum budgets. Appropriate modelling of convection is thus a prerequisite for reliable numerical weather prediction and climate modelling. The current standard approach is to represent it by subgrid-scale convection parameterization.Parameterization of Atmospheric Convection provides, for the first time, a comprehensive presentation of this important topic. The two-volume set equips readers with a firm grasp of the wide range of important issues, and thorough coverage is given of both the theoretical and practical aspects. This makes the parameterization problem accessible to a wider range of scientists than before. At the same time, by providing a solid bottom-up presentation of convection parameterization, this set is the definitive reference point for atmospheric scientists and modellers working on such problems.Volume 1 of this two-volume set focuses on the basic principles: introductions to atmospheric convection and tropical dynamics, explanations and discussions of key parameterization concepts, and a thorough and critical exploration of the mass-flux parameterization framework, which underlies the methods currently used in almost all operational models and at major climate modelling centres. Volume 2 focuses on the practice, which also leads to some more advanced fundamental issues. It includes: perspectives on operational implementations and model performance, tailored verification approaches, the role and representation of cloud microphysics, alternative parameterization approaches, stochasticity, criticality, and symmetry constraints.