Klaus-Dirk Gottschaldt

Methane Modeling: From Process Modeling to Global Climate Models

Methane is a long-lived greenhouse gas playing an important role in global climate change. Since preindustrial times atmospheric CH4 concentrations have more than doubled. The global CH4 budget is determined by the balance between surface emissions and different sink processes. Model projections of future atmospheric CH4 concentrations are complicated by uncertainties not only in the strength of individual CH4 sources, but also by uncertainties in other trace species affecting the major CH4 loss reaction.

Dynamics and composition of the Asian summer monsoon anticyclone

This paper is dedicated to the better characterization of the different processes (STE, convective uplift, dynamics, photochemistry...) that control the composition and specifically the O3 distribution in the Asian Summer Monsoon Anticyclone (ASMA). It is based on (i) in-situ observations taken on board the HALO research aircraft during the ESMVal field experiment in September 2012 to document one particular case (ii) multiannual simulations from the EMAC global chemistry climate model to document intra seasonal variabilities. The ASMA is a major feature of the Northern Hemispheric atmosphere during the monsoon season and its composition controls large parts of the tropospheric composition (such as over the Pacific and Middle East) during the mon-

Global chemistry-climate modelling with EMAC

The Institute of Atmospheric Physics of the German Aerospace Center (DLR) uses the numerical model system ECHAM/MESSy Atmospheric Chemistry (EMAC). The model has a flexible modular structure and allows for coupled chemistry-climate simulations. Typical fields of application are related to questions regarding Earth’s climate, atmospheric chemical composition, and aerosol characteristics. In its current setup, the performance of EMAC on LRZ/ALTIX allows for multi-decadal simulations with climatologically significant results. The good performance demonstrates the multi-purpose capabilities of LRZ/ALTIX because EMAC involves various different numerical concepts and implementations of parallel decomposition. Our EMAC activities on LRZ/ALTIX are devoted to both model development and production simulations. The former comprise a new upper-boundary representation, a chemistry-transport mode, the inclusion of a mixed-layer ocean, and full-Lagrangian transport and dynamics. The latter tackle, for instance, questions related to the environmental impact of anthropogenic aerosol and gaseous substances.