ИСТИНА

Aerosol has a significant impact on solar radiation, and thus may affect the meteorological conditions and the quality of the weather forecast. In Moscow, the AERONET program of aerosol monitoring has been in operation at the Meteorological Observatory of Moscow State University (MSU MO) since 2001 [1].The objective of the study was to obtain the estimates of seasonal and interannual variability of aerosol properties and their radiative effects, as well as to perform numerical experiments for assessing the influence of aerosol on the weather forecast in mesoscale model COSMO-Ru. During the 2001 - 2013 period a significant (20%) aerosol optical depth decrease was obtained, especially in UV and visible spectral range. Particular attention was paid to interannual variations of the fine-mode aerosol fraction, which was estimated by two methods. The main algorithm is the retrieval of microphysical and optical properties of aerosols according to the direct and diffuse radiation, proposed by Dubovik, King [2]. But the statistics obtained by this method is small. Another algorithm is the algorithm proposed by O'Neill [3]. This method is based on measurements of direct solar radiation that significantly (approximately by a factor of 10) increases the number of cases. The application of both methods has revealed a significant decrease of fine-mode aerosol during last years. Variability of other aerosol properties of the atmosphere over this period is also analyzed. The estimates of the aerosol radiative effect at the low and upper boundary of the atmosphere under various atmospheric parameters, including different surface albedo, were obtained for Moscow conditions. These results are compared with the measurements by CNR4 Kipp & Zonen instrument, which currently is being in operation at the MSU MO. In addition, for several cases with large and small aerosol loading the comparisons were made between the measurements of shortwave and longwave radiation by CNR4 instrument at the MSU MO and the radiative simulations [4], which has been implemented in the mesoscale COSMO-Ru2 model [5,6]. A series of numerical experiments for evaluating the effects of aerosol on the quality of weather forecast were performed. References: 1. Chubarova N., Smirnov А., Holben B.N.: Aerosol properties in Moscow according to 10 years of AERONET measurements at the Meteorological Observatory of Moscow State University // Geography, Environment, Sustainability, 4, 1, 19-32, 2011 2. Dubovik, O., A. Smirnov, B. N. Holben, M. D. King, Y.J. Kaufman, T. F. Eck, and I. Slutsker, 2000: Accuracy assessments of aerosol optical properties retrieved from AERONET sun and sky-radiance measurements, J. Geophys. Res.,v. 105, p. 9791-9806. 3. O’Neill, N. T., O. Dubovik, and T. F. Eck, 2001: A modified Angstrom coefficient for the characterization of sub-micron aerosols, App. Opt., v. 40, No.14, p. 2368 –2375. 4. Ritter B., Geleyn J.-F. 1992: A Comprehensive Radiation Scheme for Numerical Weather Prediction Model with Potential Applications in Climate Simulations, Mon.Wea. Rev., v.120, p. 303–325. 5. Vilfand R.M., Rivin G.S., Rozinkina I.A. 2010: Mesoscale weather short-range forecasting at the Hydrometcenter of Russia, on the example of COSMO-Ru. Russian Meteorology and Hydrology, v. 35, No.1, p. 1–9. 6. Vilfand R.M., Rivin G.S., Rozinkina I.A. 2010: COSMO-Ru system of nonhydrostatic mesoscale short-range weather forecast of the Hydrometcenter of Russia: the first stage of realization and development. Russian Meteorology and Hydrology, v. 35,No. 8, p. 503–514.