M. Sosonkin

Aerosol layer properties over Kyiv from AERONET/PHOTONS sunphotometer measurements during 2008-2009

The AErosol RObotic NETwork (AERONET) is one of the most developed ground-based networks for aerosol monitoring. Radiative measurements (solar irradiance extinction, aureole brightness and sky light polarization) are used by the AERONET inversion retrieval technique to derive a wide variety of aerosol particle properties and parameters that are important for estimations of aerosol influences on climate change. Within the framework of scientific cooperation between Université de Lille 1 and Taras Shevchenko National University (TSNU) of Kyiv (Kiev), a CIMEL CE 318-2 sunphotometer has been operating at Kyiv since March 2008. This article presents a preliminary analysis of the columnar aerosol properties retrieved from Kyiv sunphotometer measurements and one case study with unusual behaviour of the aerosol parameters. Version 2 of the AERONET inversion products (spectral aerosol optical thickness (AOT), the Ångström parameter (α), single-scattering albedo (SSA), size distribution and refractive index, and aerosol radiative forcing estimations) is considered in the analysis, demonstrating variability of aerosol properties and radiative forcing at the Kyiv observational site during a 1-year period.

Remote Sensing of Aerosol in the Terrestrial Atmosphere from Space: New Missions

The distribution and properties of atmospheric aerosols on a global scale are not well known in terms of determination of their effects on climate. This mostly is due to extreme variability of aerosol concentrations, properties, sources, and types. Aerosol climate impact is comparable to the effect of greenhouse gases, but its influence is more difficult to measure, especially with respect to aerosol microphysical properties and the evaluation of anthropogenic aerosol effect. There are many satellite missions studying aerosol distribution in the terrestrial atmosphere, such as MISR/Terra, OMI/Aura, AVHHR, MODIS/Terra and Aqua, CALIOP/CALIPSO. To improve the quality of data and climate models, and to reduce aerosol climate forcing uncertainties, several new missions are planned. The gap in orbital instruments for studying aerosol microphysics has arisen after the Glory mission failed during launch in 2011. In this review paper, we describe several planned aerosol space missions, including the Ukrainian project Aerosol-UA that obtains data using a multi-channel scanning polarimeter and wide-angle polarimetric camera. The project is designed for remote sensing of the aerosol microphysics and cloud properties on a global scale.

Astrospectropolarimeters for weak objects

This article proposes layouts of increased-efficiency astronomical spectropolarimeters constructed using the same concept: a UV spectropolarimeter for the range 0.23-0.40 µm and a spectropolarimeter for the visible range 0.4-0.87 µm. It is shown that a limited number of elements can serve the function of optical reducer, dispersive unit, and aberration corrector. Such an approach is especially suitable in the UV region, in which the numerous elements of classical spectropolarimeters result in large losses. The dispersive system of each of the polarimeters levels off the dispersion, and this also increases the efficiency of the device in the short-wavelength region.

The use of IR sources for remote sensing of the surface layer of the atmosphere

IR radiation sources are used in a remote path analyzer of the surface atmosphere on the basis of a Fourier spectrometer. The idea is introduced of minimum operating paths on which it is possible to measure the concentrations of the main contaminants at a level of maximum permissible concentrations. The theoretical estimate of such paths is provided. The formulas for estimating the expected signal-to-noise ratio and formulating the requirements for an IR source are presented. A method for manufacturing simple and efficient IR sources based on the ΠЭ-type wire-wound resistors is described. The performance characteristics of different radiation sources are compared.