Effects of the Vertical Aerosol Structure on Short-range Air Temperature Forecasting and Clear-sky Shortwave Radiation Calculations in the ICON Model

The paper examines the influence of the vertical aerosol distribution on the forecast of the lower troposphere shortwave radiation and air temperature from the Tegen and CAMS aerosol climatologies. The differences in the vertical aerosol structure are shown, and the annual variations in aerosol properties in these climatologies are compared with the AERONET observational data from the Lomonosov Moscow State University Meteorological Observatory. Numerical experiments with the mesoscale ICON model were held for clear-sky days in the Moscow region with a lead time to four days. An error in calculating total solar radiation at the Earth surface has been found to be  \(-16.9 \pm 4.1\)  W/m² when using the Tegen aerosol climatology as compared to measured data, while with using the CAMS, the error is  \(2.0 \pm 3.8\)  W/m². At the same time, the error in calculating the temperature in the lower troposphere decreases as compared to the radiosonde data from the Dolgoprudny station. On some days, an improvement in the air temperature forecast was registered up to the level of 850 hPa and was about 0.3°C. In addition, it has been revealed that the sensitivity of air temperature calculations to a decrease in the net shortwave radiation is reduced with increasing altitude from 0.9°C per 100 W/m² at 1000 hPa to 0.1°C per 100 W/m² at 850 hPa.