Regional climate feedback of anthropogenic aerosols over Europe using RegCM3

Climate Research

I. Pytharoulis¹  P. Zanis¹  T. Karacostas¹  A. Zakey¹  C. Ntogras¹ 

关键词: Aerosols;    Climate feedback;    Direct effect;    Regional climate models;    Simulations;    Europe;   

DOI  :  10.3354/cr01070

来源: Inter-Research Science Publishing

【 摘 要 】

ABSTRACT: The regional climate model RegCM3 coupled with aerosols is used in this study to investigate the direct shortwave effect of anthropogenic aerosols on the regional European climate over a 12 yr period (1996–2007). Aerosol feedback induced small changes in the yearly averaged near-surface temperature over Europe during this period and the greatest negative temperature difference of −0.2°C was observed over the Balkan Peninsula. The field of aerosol-induced near-surface temperature anomalies is not spatially collocated with the field of aerosol radiative forcing as the spatial correlation coefficient is only 0.24. A characteristic of the aerosol-induced changes on near-surface temperature is a dipole pattern in which cooling occurs south of the latitudinal zone from 50 to 55° N and warming occurs northwards. This characteristic dipole pattern of changes in temperature is also seen at higher atmospheric levels but the signal weakens at higher altitudes. A characteristic in the aerosol-induced changes in atmospheric circulation is a negative anomaly of the zonal westerly wind of 500 hPa in the latitudinal belt between 45 and 55°N, which is consistent with a dipole pattern in geopotential heights that consists of an anticyclonic anomaly north of approx. 55°N and cyclonic anomaly south of approx. 45°N. The greatest aerosol-induced negative lower troposphere temperature anomaly over the Balkan Peninsula is associated with the collocated greatest cyclonic anomaly. This reveals the important role of the aerosol-induced circulation changes for the pattern of the temperature anomalies and explains the poor correlation between the patterns of aerosol-induced temperature changes and aerosol radiative forcing. Because the aerosol-induced changes in temperature and atmospheric circulation are at the limits of statistical significance, the present regional climate modelling study indicates there is a limited feedback on the European climate related to the direct shortwave effect of European anthropogenic aerosols.

【 授权许可】

Unknown