GAW Report No. 205 - IGAC Project

CHAPTER 7 – OVERVIEW OF INTERNATIONAL COLLABORATIVE RESEARCH ACTIVITIESThe work was organized in four work packages, as illustrated in Figure 4. WP1 focused onanalyzing past trends and present distributions, using both models and observations. WP2 dealtwith climate-chemistry interactions, while WP3 looked at mitigation options. Both WP2 and WP3included subtasks for providing emissions inventories. In WP4 we integrated the work of the firstthree work packages, ensured dissemination and contact with policy workers and otherpolicy-oriented frameworks.Figure 4 - The organisation of the work in CityZen in work packagesThe CityZen consortium combines expertise in the fields of observations, modelling and theprovision of emission scenarios. The flow of information is intended to proceed from the datasources (observations, emissions, meteorology, chemical transformation and sink mechanisms)towards the "Core research activities" where all available information and model calculations areblended together into 4-dimensional datasets of a spatial and temporal resolution that aredetermined by the problem under study. On the basis of these "Core research activities" research isundertaken in work packages 1-3 by a goal-oriented and specialized analysis of the data fields(observed, calculated, assimilated). Figure 5 illustrates the coordinated action of different scientifictools.Figure 5 - Model systems bridge processes occurring on different spatial scales spanning from the urban to the global. Airpollution flows between megacities/hotspots, the surrounding regions and globally. The analysis and forecasting of airpollution in hotspots require observations and modelling efforts that take into account the interactions of transportprocesses and air pollution loads on this range of spatial scales and cover the range of temporal scales determined by theatmospheric life times of the essential pollutants involved254