Wolfram Schröder

The parallel model system LM-MUSCAT for chemistry-transport simulations: Coupling scheme, parallelization and applications

Publisher Summary This chapter discusses the parallel model system LM-MultiScale chemistry aerosol transport (MUSCAT) for chemistry-transport simulations: coupling scheme, parallelization, and applications. The physical and chemical processes in the atmosphere are very complex. They occur simultaneously, coupled and in a wide range of scales. These facts have to be taken into account in the numerical methods for the solution of the model equations. The numerical techniques allow the use of different resolutions in space and also in time. Air quality models base on mass balances described by systems of time-dependent, three-dimensional advection-diffusion reaction equations. A parallel version of the multiscale chemistry-transport code MUSCAT is presented, which is based on multiblock grid techniques and implicit-explicit (IMEX) time integration schemes. The meteorological fields are generated simultaneously by the non-hydrostatic meteorological model LM. Both codes run in parallel mode on a predefined number of processors and exchange information by an implemented coupler interface. The ability and performance of the model system are discussed for a “Berlioz” ozone episode.

The Chemistry-Transport Modeling System lm-Muscat : Description and citydelta Applications

Air quality models base on mass balances described by systems of time-dependent, three-dimensional advection-diffusion-reaction equations. The solution of such systems is numerically expensive in terms of computing time. This requires the use of fast parallel computers. Multiblock grid techniques and implicit-explicit (IMEX) time integration schemes are suited to take benefit from the parallel architecture. A parallel version of the multiscale chemistry-transport code MUSCAT (MUiltiScale Chemistry Aerosol Transport) is presented which is based on these techniques (Wolke and Knoth, 2000).

A Multi-model Case Study on Aerosol Feedbacks in Online Coupled Chemistry-Meteorology Models Within the COST Action ES1004 EuMetChem

The importance of different processes and feedbacks in online coupled chemistry-meteorology models for air quality simulations and weather prediction was investigated in COST Action ES1004 (EuMetChem). Case studies for Europe were performed with different models as a coordinated exercise for two episodes in 2010 in order to analyse the aerosol direct and indirect radiative effect and the response of different models to aerosol-radiation interactions.