AS1.12

Dynamics and chemistry of atmospheric convection
Convener: J.-I. Yano  | Co-Conveners: C.H. Mari , L. Donner , H. Tost 
Oral Programme
 / Wed, 22 Apr, 17:30–19:00  / Room 10
Poster Programme
 / Attendance Tue, 21 Apr, 17:30–19:00  / Halls X/Y
The goal of this session is to organize a joint forum for the wide range of communities concerned with atmospheric convection and its various aspects: both dynamics and chemistry, especially emphasizing the importance of cloud physics and radiation. It is intended to bring together observers, modelers, forecasters, and theoreticians. Moist convection is the most important weather phenomenon in the tropical atmosphere and the crucial component in large-scale processes such as monsoons, Madden-Julian Oscillation, ENSO. Its contribution to surface rainfall in the mid-latitudes during summer is significant. Forecasting intense precipitation events strongly hinges on our understanding of moist convection. Atmospheric convection is also a key process which controls the tropospheric composition above 5 km through vertical transport and wet deposition. The improvement of wet deposition and scavenging parameterizations is a key issue for large-scale models. Contributions on that topic is encouraged. A wide range of contributions will be accepted not only from those directly dealing with moist convection, but also from those studying mesoscale processes where convection plays a significant role, as well as tropical and mid-latitude cyclones, tropical meteorology, and climate dynamics.

This year's session will place particular emphases on the parameterization of convection in climate models. The IPCC report of 2007 emphasizes the uncertainties associated with cloud parameterization, which make the estimates of cloud-radiation feedbacks notably difficult. Most of the major climate centers have just begun to define their model configurations for the next IPCC assessment. The aim of this focus is to assess the state of art of convection representations in current global climate models in timely manner so that we can all well prepare for the next assesment. The issues include, but no exclusively, representations of microphysics (notably of ice), aerosoles and their coupling both with shallow and deep convection, improvements of convective parameterization, calculation of radiative transfer under a complex interaction with clouds.