Section: New Software and Platforms

Polyphemus

Participants : Vivien Mallet, Sylvain Doré [CEREA] , Karine Sartelet [CEREA] , Yelva Roustan [CEREA] .

Polyphemus (see the web site http://cerea.enpc.fr/polyphemus/ ) is a modeling system for air quality. As such, it is designed to yield up-to-date simulations in a reliable framework: data assimilation, ensemble forecasts and daily forecasts. Its completeness makes it suitable for use in many applications: photochemistry, aerosols, radionuclides, etc. It is able to handle simulations from local to continental scales, with several physical models. It is divided into three main parts:

• libraries that gather data processing tools (SeldonData), physical parameterizations (AtmoData) and post-processing abilities (AtmoPy);

• programs for physical pre-processing and chemistry-transport models (Polair3D, Castor, two Gaussian models, a Lagrangian model);

• model drivers and observation modules for model coupling, ensemble forecasting and data assimilation.

Fig. 1 depicts a typical result produced by Polyphemus.

Clime is involved in the overall design of the system and in the development of advanced methods in model coupling, data assimilation and uncertainty quantification (through model drivers and post-processing).

In 2015, version 1.9 was released, with all previous developments on the interface between Verdandi and Polyphemus. The other improvements were developed by CEREA on aerosol modeling.