Yu. S. Turchinovich

Information system for network solar photometers

The paper presents an information system designed for processing and systematized storage of network solar photometer data. The system is developed in the Builder C++ environment and integrates individual program modules that perform the following operations: calculation of instrument functions of the photometer spectral channels and band functions of atmospheric gases transmission, calculation of aerosol optical depth parameters and total moisture content of the atmosphere, filtration of the data distorted by cloudiness, and determination, by spectral data of the atmosphere aerosol transparency, of the aerosol microstructure parameters.

Characteristics of the annual behavior of the spectral aerosol optical depth of the atmosphere under conditions of Siberia

Based on multiyear observations in Tomsk (since 1995, in the wavelength range 0.37–4 μm) and other regions of the Asian part of Russia (2003–2008), we determined the specific features of the annual behavior of the characteristics of the spectral aerosol optical depth (AOD) of the atmosphere. It is shown that AOD peaks are observed in April (0.19 in the region of 0.5 μm) and July, a local minimum in June (less than 0.16), and minimum values in the fall (0.12). The seasonal variations of the Angström selectivity exponent are characterized by elevated values in the warm period (maximum in July) and low values in winter. The closeness of the seasonal variations of aerosol turbidity in three Siberian regions is noted, and the Siberia mean annual behavior of atmospheric AOD characteristics is suggested. The average values of the aerosol optical and microphysical characteristics of the atmospheric depth for characteristic periods of intraannual AOD variations are presented.

Results of spectral measurements of atmospheric aerosol optical depth with sun photometers in the 58th Russian Antarctic Expedition

We discuss the specific features of the spatiotemporal variations in the atmospheric aerosol optical depth (AOD) measured during the 58th Russian Antarctic Expedition on board RVs “Akademik Fedorov” and “Akademik Tryoshnikov” and at the Mirny station. It is shown that the main feature of the spatiotemporal AOD distribution over ocean in the Southern Hemisphere is the linear latitudinal decrease of AOD from 0.15 at the equator to 0.025 near Antarctica. We indicate that the low AOD level in Antarctica (0.022 ± 0.005) has persisted for the last 17 years.

On results of studies of atmospheric aerosol optical depth in arctic regions

We discuss the characteristics of the spectral aerosol optical depth (AOD) of the atmosphere measured using sun photometers in high-latitude regions (Spitsbergen, Tiksi, Yakutsk). The seasonal variations are characterized by a decrease in AOD from spring to fall by approximately a factor of 2 in Yakutia and by a factor of 1.5 in the region of Spitsbergen. It is shown that the high selectivity of the spectral AOD dependence in warm period (with Angström parameters varying from 1.3 to 1.8) was caused by low content of coarsely dispersed aerosol. Multiyear data of MODIS satellite observations are used to estimate the spatial distribution of turbidity; it is shown that satellite observations systematically overestimate AOD over Arctic seas.

Results of an integrated aerosol experiment in the continent-ocean transition zone (Primorye and the Sea of Japan); Part 1: Variations of atmospheric aerosol optical depth and vertical profiles

We discuss the results of an integrated aerosol experiment, performed in spring 2009 simultaneously in two regions: near Ussuriysk and in the Sea of Japan onboard the Nadezhda training boat. For the measurements of aerosol optical depth (AOD) and moisture content of the atmosphere, we used multiwavelength sun photometers operating in the wavelength range 0.34–2.14 μm. The measurements of the vertical profiles of aerosol characteristics were made using two types of lidars: a lidar based on a three-frequency (1.064, 0.532, and 0.355 μm) Big Sky Laser CFR 200 in Primorye and a one-frequency laser based on the second harmonic of the Nd:YAG (0.532 μm) laser onboard the sailing vessel. It was shown that the springtime atmosphere in the Far East region has two times larger aerosol turbidity in comparison with other (maritime and continental) midlatitude regions. Average values of the atmospheric AOD in the region of 0.5 μm were 0.46 in Primorye and 0.35 in the Sea of Japan. The elevated atmospheric turbidity is caused by continental aerosol of different types (smoke, anthropogenic, and dust) blown off the neighboring regions. We present the characteristic vertical profiles of aerosol-molecular scattering for the cases of advection of air masses from arid regions of Southeastern Asia and the boreal zone of Siberia. A relation is demonstrated between the dust activity in the Taklamakan Desert and light scattering characteristics of aerosol layers in tropopause region.

Spatiotemporal variations in aerosol characteristics along the route of the Indian-Atlantic expedition onboard the research vessel Akademik Nikolaj Strakhov

We discuss the results of studying the physical-chemical composition of the atmospheric aerosol during expedition onboard the RV Akademik Nikolaj Strakhov carried out during winter of 2015–2016 on the route from Colombo to Kaliningrad (via Suez Canal). As compared to the Mediterranean Sea and Atlantic (near Europe), the atmosphere of the Arabian and Red Seas was characterized by higher values of most aerosol characteristics: 3–5 times larger aerosol optical depth (AOD), 4 times larger aerosol number concentration, 1.5 times larger concentrations of continent- and sea-derived ions, as well as more abundant gas admixtures (SO2, HCl, HNO3, NH3). At the same time, two seas of the Indian basin substantially differ in aerosol composition, primarily due to outflows of aerosols of different types from the continents. The largest concentrations of black carbon (2.14 μg m–3, on average), sea-derived ions (Na+, Cl–, Mg2+), and NH3 are observed over the Arabian Sea; larger values of the fine component of the AOD and concentrations of “continental” ions (SO42-, Ca2+, NO3-, NH4+) and gas admixtures SO2, HCl, HNO3 are found over the Red Sea. With respect to ion composition of aerosol, most stable concentrations are noted for Ca2+ ions (less than 15% difference among the seas), and maximal spatial variations are found for NH4+ ions (the difference of up to a factor of 40).

Analysis of approaches to modeling the annual and spectral behaviors of atmospheric aerosol optical depth in Siberia and Primorye

Data of multiyear sun photometer measurements in the Asian part of Russia are used to analyze the issues regarding the modeling of annual and spectral behaviors of the atmospheric aerosol optical depth (AOD) based on separation of the contributions of fine and coarse aerosols. The specific features of the spatial distribution and seasonal variations in AOD characteristics in different regions are discussed; and a three-parameter model of annual behavior of spectral AOD in the range 0.34–4 μm for Western Siberia (Tomsk) is suggested.

The results of two-point experiments on the estimation of the urban anthropogenic effect on the characteristics of atmospheric transparency

To estimate the anthropogenic effect of the city of Tomsk on the measurements of the aerosol optical thickness (AOT) and the columnar water vapor of the atmosphere in the eastern suburb of Tomsk (Akademgorodok), two issues are discussed: (1) the comparative analysis of the data of simultaneous measurements in the suburban zone and at the background region (∼60-km distance), and (2) the dependence of the aerosol turbidity in the suburb on the air mass transfer direction. In addition to the spectral atmospheric AOT, we also considered two AOT components: fine and coarse aerosol. It is noted that variations of the atmospheric turbidity characteristics are mainly caused by synoptic-scale processes and manifest themselves similarly in urban and background regions. During the summertime, the AOT and columnar water vapor of the atmosphere in the two abovementioned regions are statistically indistinguishable, indicating the absence of the anthropogenic urban effect. During the cold period, the suburban zone may be characterized by higher atmospheric turbidity, seemingly due to the inversion accumulation of aerosol. The dependence of the AOT on the wind direction has the following features: (1) overall, the largest aerosol turbidity is observed during winds blowing from the southern sector; (2) during the cold period, the fine AOT component is, on average, 14% higher in cases of air mass transfer from the direction of the city (from the west and northwest directions); and (3) the coarse AOT component is slightly higher during westward air transfer than during an eastward one.

Generalization of Results of Atmospheric Aerosol Optical Depth Measurements on Spitsbergen Archipelago in 2011–2016

We discuss the results of spectral measurements of aerosol optical depth (AOD) of the atmosphere, carried out in warm periods of 2011–2016 in the Arctic settlement Barentsburg (Spitsbergen Archipelago). The statistical characteristics of seasonal and interannual variations in atmospheric AOD in the wavelength range of 0.34–2.14 μm are presented. The average AOD (0.5 μm) over the six-year period of observations had been 0.086, and, in particular, the fine mode AOD component had been 0.062 and the coarse mode AOD component had been 0.024. It is shown that the seasonal variations were best manifested in the decrease of modal (most probable) values of fine mode AOD component from 0.055 in spring to 0.025 in autumn. As compared to the preceding (pre-2011) period, we noted a closer convergence in the average AOD values between spring and summer, primarily due to a decrease in the content of fine mode aerosol in spring and its increase in summer. The summertime AOD growth is most likely due to episodic outflows of smoke aerosol from boreal zones of Eurasia and North America.

Complex experiment on the study of microphysical, chemical, and optical properties of aerosol particles and estimation of atmospheric aerosol contribution in the Earth radiation budget

The main aim of the work was complex experimental measurements of microphysical, chemical, and optical parameters of aerosol particles in the surface air layer and free atmosphere. From the measurement data, the entire set of aerosol optical parameters was retrieved, required for radiation calculations. Three measurement runs were carried out in 2013 within the experiment: in spring, when the aerosol generation maximum is observed, in summer (July), when the altitude of the atmospheric boundary layer is the highest, and in the late summer – early autumn, when the second nucleation period is recorded. The following instruments were used in the experiment: diffusion aerosol spectrometers (DAS), GRIMM photoelectric counters, angle-scattering nephelometers, aethalometer, SP-9/6 sun photometer, СЕ 318 Sun-Sky radiometer (AERONET), MS-53 pyrheliometer, MS-802 pyranometer, ASP aureole photometer, SSP scanning photometer, TU-134 Optik flying laboratory, Siberian lidar station, stationary multiwave lidar complex LOZA-M, spectrophotometric complex for measuring total ozone and NO2, multivariable instrument for measuring atmospheric parameters, METEO-2 USM, 2.4 AEHP-2.4m station for satellite data receive. Results of numerical calculations of solar down-fluxes on the Earth’s surface were compared with the values measured in clear air in the summer periods in 2010—2012 in a background region of Siberian boreal zone. It was shown that the relative differences between model and experimental values of direct and total radiation do not exceed 1% and 3%, respectively, with accounting for instrumental errors and measurement error of atmospheric parameters. Thus, independent data on optical, meteorological, and microphysical atmospheric parameters allow mutual intercalibration and supplement and, hence, provide for qualitatively new data, which can explain physical nature of processes that form the vertical structure of the aerosol filed.