Online coupled regional meteorology-chemistry models in Europe: current status and prospects

Abstract

The simulation of the coupled evolution of atmospheric dynamics, pollutant transport, chemical reactions and atmospheric composition is one of the most challenging tasks in environmental modelling, climate change studies, and weather forecasting for the next decades as they all involve strongly integrated processes. Weather strongly influences air quality (AQ) and atmospheric transport of hazardous materials, while atmospheric composition can influence both weather and climate by directly modifying the atmospheric radiation budget or indirectly affecting cloud formation. Until recently, however, due to the scientific complexities and lack of computational power, atmospheric chemistry and weather forecasting have developed as separate disciplines, leading to the development of separate modelling systems that are only loosely coupled. <br></br> The continuous increase in computer power has now reached a stage that enables us to perform online coupling of regional meteorological models with atmospheric chemical transport models. The focus on integrated systems is timely, since recent research has shown that meteorology and chemistry feedbacks are important in the context of many research areas and applications, including numerical weather prediction (NWP), AQ forecasting as well as climate and Earth system modelling. However, the relative importance of online integration and its priorities, requirements and levels of detail necessary for representing different processes and feedbacks can greatly vary for these related communities: (i) NWP, (ii) AQ forecasting and assessments, (iii) climate and earth system modelling. Additional applications are likely to benefit from online modelling, e.g.: simulation of volcanic ash or forest fire plumes, pollen warnings, dust storms, oil/gas fires, geo-engineering tests involving changes in the radiation balance. <br></br> The COST Action ES1004 – European framework for online integrated air quality and meteorology modelling (EuMetChem) – aims at paving the way towards a new generation of online integrated atmospheric chemical transport and meteorology modelling with two-way interactions between different atmospheric processes including dynamics, chemistry, clouds, radiation, boundary layer and emissions. As its first task, we summarise the current status of European modelling practices and experience with online coupled modelling of meteorology with atmospheric chemistry including feedback mechanisms and attempt reviewing the various issues connected to the different modules of such online coupled models but also providing recommendations for coping with them for the benefit of the modelling community at large

Comparative analysis of meteorological performance of coupled chemistry-meteorology models in the context of AQMEII phase 2

“…A number of groups shared the same model system but operated the model in different configurations to test the sensitivity to different settings. Overall, eight different model systems were used out of which five were fully integrated online coupled chemistry and meteorology models (WRF-Chem, COSMO-ART, MetUM UKCA-RAQ, NMMB-BSC, GEM-MACH), and three were online access models (COSMO-MUSCAT, RACMO LOTOS-EUROS, WRF-CMAQ) following the model classification scheme of Baklanov et al (2014). In terms of meteorological core, only six different models were applied: The U.S.…”

“…In the last approximately ten years, supported both by the increased interest of weather centers in air quality issues and by the rapid increase in computer power, a new generation of models has been developed in which the chemical evolution is online coupled to the meteorological simulation. Comprehensive reviews of these coupled model systems developed in North America and Europe have been presented by Zhang (2008) and Baklanov et al (2014). Online coupled models can account for interactions between chemistry and meteorology, notably for direct effects of aerosols on radiation and for indirect effects of aerosols on clouds (e.g., Bangert et al, 2011;Giorgi et al, 2003;Helmert et al, 2007).…”

WRF-Chem model sensitivity to chemical mechanisms choice in reconstructing aerosol optical properties

“…Online coupled meteorology and chemistry models are becoming more and more popular in air quality modeling applications as they enable to achieve a significant reduction of inconsistency between meteorological and chemical processes as well as taking into account the influence of feedback effects, mainly related to aerosol load (Baklanov et al, 2014;Grell and Baklanov, 2011;Zhang et al, 2010). In order to increase knowledge on them the second phase of the Air Quality Model Evaluation International Initiative (AQMEII http://aqmeii.jrc.ec.europa.eu/) was focused on online coupled meteorology-chemistry models.…”

Aerosols in the convective boundary layer: Shortwave radiation effects on the coupled land‐atmosphere system

“…Therefore, these processes have been normally investigated separately or by means of simplified CBL numerical models [Venkatram and Viskanta, 1977;Tunved et al, 2010], regional models (see Baklanov et al [2013] for a complete review), mesoscale models [Zhang et al, 2010;Wong et al, 2012], and BARBARO ET AL. ©2014.…”