Abstract
Abstract. The climate effect of atmospheric aerosols is associated with their influence on the radiative budget of the Earth due to the direct aerosol–radiation interactions (ARIs) and indirect effects, resulting from aerosol–cloud–radiation interactions (ACIs). Online coupled meteorology–chemistry models permit the description of these effects on the basis of simulated atmospheric aerosol concentrations, although there is still some uncertainty associated with the use of these models. Thus, the objective of this work is to assess whether the inclusion of atmospheric aerosol radiative feedbacks of an ensemble of online coupled models improves the simulation results for maximum, mean and minimum temperature at 2 m over Europe. The evaluated models outputs originate from EuMetChem COST Action ES1004 simulations for Europe, differing in the inclusion (or omission) of ARI and ACI in the various models. The cases studies cover two important atmospheric aerosol episodes over Europe in the year 2010: (i) a heat wave event and a forest fire episode (July–August 2010) and (ii) a more humid episode including a Saharan desert dust outbreak in October 2010. The simulation results are evaluated against observational data from the E-OBS gridded database. The results indicate that, although there is only a slight improvement in the bias of the simulation results when including the radiative feedbacks, the spatiotemporal variability and correlation coefficients are improved for the cases under study when atmospheric aerosol radiative effects are included.
Highlights
Atmospheric aerosol particles are known to have an impact on Earth’s radiative budget due to their interaction with radiation and clouds properties, which is dependent on their optical, microphysical and chemical properties, and they are considered to be the most uncertain forcing agent
For aerosol–radiation interactions (ARIs) and ARI+aerosol–cloud interactions (ACIs) simulations, slightly lower MBE values than NRF are found in all the experiments
The MBE for the ensemble (NRF −1.3; ARI −1.23; aerosol–radiation– cloud interactions are considered (ARI+ACI) −1.40) does not show this improvement, but this analysis should be treated with caution because the ARI+ACI ensemble does not include DE3 simulations
Summary
Atmospheric aerosol particles are known to have an impact on Earth’s radiative budget due to their interaction with radiation and clouds properties, which is dependent on their optical, microphysical and chemical properties, and they are considered to be the most uncertain forcing agent. Aerosol absorption may decrease low-cloud cover by heating the air and reducing relative humidity. This leads to a positive radiative forcing, termed the semi-direct effect, which amplifies the warming influence of absorbing aerosols (Hansen et al, 1997). The Fifth Report of the Intergovernmental Panel on Climate Change (IPCC AR5) (Boucher et al, 2013; Myhre et al, 2013) distinguishes between aerosol–radiation interactions (ARIs), which encompass the aerosol direct and semidirect effect, and the aerosol–cloud interactions (ACIs), which encompass the indirect effects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
