Validation report of the MACC near-real time global atmospheric composition service. System evolution and performance statistics until November 2011

The MACC II (Modelling Atmospheric Composition and Climate, www.gmes-atmosphere.eu) project is establishing the core global and regional atmospheric environmental service delivered as a component of Europe's GMES (Global Monitoring for Environment and Security) initiative. The global MACC near-real time (NRT) service provides daily analyses and forecasts of trace gas and aerosol concentrations. This document presents the validation statistics and system evolution of the MACC NRT service for the period until the end of November 2011.

Below the validation results are summarised. This summary is split according to areas of interest to users: tropospheric reactive gases, aerosols, stratospheric composition, and boundary conditions for regional air quality models. Specific attention is given to the ability of the MACC system to capture recent events. We consider three available MACC model configurations: the coupled IFS-Mozart modelling system with assimilation (IFS-MOZ AN), the coupled IFS-Mozart modelling system without assimilation (IFS-MOZ FC) and the coupled IFS-TM5 modelling system with assimilation (IFS-TM5 AN), referring to the two chemistry models, MOZART and TM5, and the ECMWF IFS model. Aerosol analyses and forecasts based on the MACC prognostic aerosol module in IFS are included in the IFS-MOZ AN model experiment. No major upgrades of the system have taken place during the period December 2010 to November 2011. Minor changes include a couple of bug fixes and variations in data-usage in the assimilation system.