Global Reactive Gases Modeling in GEMS and MACC: Towards an operational assimilation and forecasting system for tropospheric reactive gases

Principal Investigator

Dr. V. Huijnen
Royal Netherlands Meteorological Institute (KNMI)
Postbus 201
3730 AE De Bilt
The Netherlands

huijnen@knmi.nl

Other researchers: Dr. H. Eskes, Dr. M. van Weele

Project description

In the EU GEMS subproject on Global Reactive Gases a system is developed where Chemical Transport Models (CTM's) are coupled to the ECMWF Integrated Forecasting System (IFS). This system will perform forecasts of atmospheric chemistry and dynamics on an operational basis. Within this project the atmospheric chemistry tracer model TM5 (Krol et al., 2005) that is partly developed at KNMI, serves as one of the independent chemical transport models. Also in the follow-up project MACC, a large fraction of the activities in the G-RG subproject is devoted to the consolidation and improvement of existing semi-operational GEMS services to globally monitor stratospheric ozone and key tropospheric trace gases. For this project, satellite data from various sensors is being used and a variety of modelling tools are combined.

In both GEMS and MACC any model validation and improvement will be assisted by specific case studies. This includes retrospective analyses of extreme events, similar as the investigation of the heat wave period in 2003 with the stand-alone and coupled system. Also new modeling efforts are planned in MACC, to overcome the inherent limitations of the CTM coupling approach that are presently encountered in the GEMS system. This will include the development of modules from the three current partners, KNMI, Research Center Jülich (FZJ) and METEO-France/CERFACS, which will be integrated in the IFS model code.

In recent years a coupling strategy between the IFS and the CTM's has been developed based on the OASIS formalism. This has resulted in a coupled IFS-Mozart forecast system which is running on a daily basis. At the same time the coupling of IFS with TM5 has been established and first tests are performed. In the coming year more detailed tests are planned which are expected to lead to improvements of the coupled model. Also an optimization of the current assimilation strategy is foreseen.

The aim of this special project is to facilitate the planned validation work within the final year of GEMS (the first half of 2009), and consecutively use the computational resources in the framework of the MACC G-RG project, for the development, testing and validation of the reanalysis runs that are foreseen. This special project will contribute to an improved coupling of the CTM's with the IFS system. Also new developments of an IFS version with integrated trace gas models can benefit from the knowledge developed at KNMI, in TM5. This project is also closely linked to the KNMI project on the climate model EC-Earth, (www.ecearth.knmi.nl), where a similar coupling between TM5 and an adapted version of IFS for climate research is under development.

Timetable

2009: Perform short reanalysis simulations and sensitivity runs.

2010: Perform test runs with coupled IFS-TM5 system and additional sensitivity studies

2011: Reanalysis runs with an integrated CTM-IFS system, compared to stand-alone runs.

Explanation of the requested budget

A 1-year run of TM5 in standalone mode costs about 20.000 billing units, on the current resolution of 3x2 degree, with 60 layers. On average about two full year-runs are foreseen in every project year. Additionally 3-5 shorter sensitivity runs (5000 billing units each) and a similar number of coupled/integrated runs will be performed. These coupled runs are estimated to cost a double number of billing units. This adds up to a total of about 100 kunits per year.

References

Krol, M., S. H ouweling, B. Bregman, M. van den Broek, A. Segers, P. van Velthoven, W. Peters, F. Dentener, and P. Bergamaschi (2005), The two-way nested global chemistry-transport zoom model TM5: algorithm and applications, Atmos. Chem. Phys., 5, 417-432.

Additional information

New Project for 2009

Would accept support for 1 year only, if necessary.