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The origins and variety of aerosols in Israel are strongly influenced by synoptic conditions as well as other variables. Days affected by a weak Persian trough system are characterized by coarse aerosols from North Africa, which contain mainly mineral dust aerosols, whereas days affected by the Red Sea trough with an eastern axis are characterized by fine aerosols from northern Europe. Some synoptic systems contain both groups of aerosols as well as mixed aerosols, e.g., the Red Sea trough with a central axis. This study utilizes the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra Satellite to obtain a synoptic classification of aerosols over Israel for 6 years. MODIS synoptic classification revealed a number of different aerosol types. For weak Persian trough, a high from the west and a medium Persian trough, the MODIS Terra aerosol optical thickness (AOT) fine mode fractions are 0.51, 0.54, and 0.51, respectively. While for Red Sea trough with an eastern or central axis AOT fine mode fraction (‘f’) is higher and is equal to 0.63 and 0.59, respectively. This is the first study in the region that investigates average back trajectory with regards to both synoptic systems and aerosol type. Investigation of back trajectories for the Persian trough synoptic system indicates that days with low ‘f’ at 700 hPa are associated with flows from North Africa, while days with high ‘f’ are linked to flow from Europe. Most of our findings are not unexpected, but provide the first 6 years quantified aerosol classification which is based on the synoptic systems.

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A B S T R A C TThe total real response of the atmosphere to aerosols can be predicted by examining numerical models. In this study, the moderate resolution imaging spectroradiometer (MODIS) aerosol optical thickness (AOT) is correlated to model temperature errors to estimate this response for Israel and for Italy. Significant correlations between aerosols and atmospheric numerical model temperature errors are presented. Two main results were found in this study. First, the correlation between the UK Metrological Office (UKMO) model temperature error ( T) at level 850 hPa for Tel Aviv (Israel) during the year 2002 and the MODIS AOT ≥ 0.5, was found to be −0.54. Second, the sign of the correlation between the European Center for Medium-Range Weather Forecasting (ECMWF) monthly averaged model surface temperature errors for Italy and the MODIS AOT depends on the aerosol type, as reflected by the specific area. The correlation between air surface ECMWF T and AOT was found to be +0.70 in southern Italy. Although the contribution of aerosols is ignored by most models, the findings presented here are statistically significant and provide a first reliable estimation of the realistic full atmospheric temperature response to aerosol processes.

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