V. V. Pol’kin

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.

Estimation of Aerosol Radiation Effects under Background and Smoke-haze Atmospheric Conditions over Siberia from Empirical Data

The results of numerical simulation of downward solar radiation fluxes for background and smoke-contaminated atmospheric conditions are discussed. Vertical profiles of aerosol characteristics are obtained from the empirical model based on the data of aircraft sounding of profiles of angular scattering coefficients and content of absorbing particles in the lower troposphere. The background model was created using the results of measurements obtained under cloudless and mostly cloudless atmospheric conditions in 1999–2011. Optical parameters of smoke aerosol are determined from the data of aircraft measurements in the period of long-term wildfires in Siberia in the summer 2012. It is demonstrated that deficiency in diurnal values of total solar radiation at the surface level caused by the formation of the optically dense smoke layer as compared to background conditions, is more than 13 MJ/m2.

Multiyear variations in aerosol condensation activity in Tomsk

We consider the results of 13 years (1998–2010) of studies of the aerosol condensation activity in Tomsk. The long-term behavior of the condensation activity parameter exhibits, in addition to the annual cycle and its second harmonic, a tendency toward slower, ∼6–7-year oscillations. The values were maximum in 1998–1999 and 2005–2007. The annual average values were minimum in 2003 and 2008, i.e., in years when intrusions of subtropical air masses from arid regions of Kazakhstan and Central Asia were the most frequent.

Optical and microphysical parameters of aerosol in the near-water atmosphere of the White Sea as assessed from the data of simultaneous ship-borne and coast-based measurements in August 2006

Simultaneous measurements of the optical and microphysical parameters of near-water aerosol were performed over the White Sea in August 2006 during the 80th cruise of the research vessel Professor Shtockman rom onboard the vessel and in the coastal zone (on the territory of the Unskii beacon, the southern coast of Dvina Bay). The spatial-temporal variability of the concentrations of aerosol and soot in the marine atmosphere are studied, and the geophysical factors determining this variability are analyzed. The conditions of extremely low aerosol content in the atmosphere with concentrations of aerosol and soot of 1.2–1.7 µg/m3 and 0.01 µg/m3, respectively, were observed both in ship-borne and coast-based measurements on August 20–23 in anticyclonic conditions in the Arctic air mass. Such values are comparable with the values observed in open ocean areas. The regions of the central area of the White Sea, Kandalaksha Bay, and the Unskii beacon can be considered as background during the period of the experiment, according to the contents of aerosol and soot. The results of the comparison of simultaneous ship-borne and coast-based measurements of the concentrations of aerosol and soot revealed a similarity of their interday variability, which is evidence of the fact that the peculiarities of temporal variations, at least during the experiment, have a regional scale and are principally determined by the dynamics of synoptic processes of the change of the air masses.

Comparative studies of optical and microphysical characteristics and chemical composition of aerosol over water basin of Caspian Sea in the 29th and 41st cruises of RV Rift

We perform a comparative analysis of the atmospheric aerosol characteristics obtained in the Caspian Sea onboard the RV Rift in November 2008 and in October 2012 in the near-water atmospheric layer and in the entire atmospheric depth. We studied the aerosol optical depth in the wavelength range of 0.3–2.14 μm and the columnar water vapor of the atmosphere; the particle number density and the particle size distribution in the diameter range of 0.3–20 μm; the mass concentration of fine aerosol and the mass concentration of absorbing aerosol, i.e., black carbon; and the chemical ion composition of the soluble part of aerosol and gas admixtures, namely, Cl−, SO42−, NO3−, PO43−, F−, HCO3−, Na+, NH4+, K+, Mg2+, Ca2+, H+, HCl, HNO3, SO2, and NH3.

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.

Results of the investigations of aerosol characteristics over the caspian sea during the 29th cruise of the research vessel Rift

The results are presented of the investigations of the characteristics of near-water aerosol during the 29th cruise of the research vessel Rift in the fall of 2008 along the Astrakhan-Derbent-Aktau route. The following parameters were determined: the aerosol optical depth (AOD in the wavelength range of 0.30–2.14 µm) and the columnar water vapor of the atmosphere; the number concentration of particles Na (cm−3) and the aerosol particle size distribution in the diameter range of 0.4–10 µm; the mass concentration of submicron aerosol Ma (µg m−3) and the mass concentration of black carbon (soot) Mc (µg m−3); and the ion composition of the soluble aerosol fraction and gas admixtures Na+, K+, Ca2+, Mg2+, NH4+, Cl−, NO3−, HCO3−, SO42−, SO2, NO2, HNO3, and NH3.

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).

Variations in aerosol microphysical parameters of the surface air layer in the “ocean-continent” transitional zone

This article provides the study results of variations in microphysical parameters of atmospheric aerosol in the surface layer of the “ocean-continent” transitional zone. The analyzed data were obtained during the period from August 1, 2010, to December 31, 2012, at the lidar station of the Institute of Automation and Control Processes, Far Eastern Branch, Russian Academy of Sciences (IACP FEB RAS), Vladivostok. Mass concentrations of fine aerosol and black carbon and particle size distribution functions typical for the region under study were obtained. In winter, with strong north winds and low relative humidity (50 ± 20)%, dry continental aerosol predominates, and values of the aerosol number density Na are increased, with maxima in the range from 100 and 120 cm−3. In summer, when south winds prevail and the relative humidity attains 98%, sea aerosol predominates and Na took values from (5 ± 5) cm−3 in June, 2011, to (44 ± 20) cm−3 in July, 2011. Periodicity of diurnal variations in the mass and number density of atmospheric aerosol and black carbon are pronounced the best in winter. The modal radius of fine aerosol particles is from 0.275 μm in summer to 0.375 μm in winter, and of coarse aerosol particles, from 1.05 to 2.5 μm, respectively. Seasonal and diurnal variations in the mass concentration of black carbon MBC are the most stable; its values vary from (0.5 ± 0.5) μg/m3 in the early summer to (3.0 ± 2.0) μg/m3 in January–February. It has been ascertained that diurnal variations in MBC in Siberia (Tomsk) and in the “ocean-continent” transitional zone (Vladivostok) are similar in shape, but the amplitude of variations is higher in the latter case and is maximal in winter.

Results of integrated aerosol experiment in the continent-ocean transition zone (primorye and the Japan Sea). Part 3. Microphysical characteristics and ion composition of aerosol in the near-ground and near-water layers

The paper discusses the results of simultaneous aerosol measurements performed in the spring 2009 in two regions: near Ussuriysk (43.7° N, 132.2° E) and in the Japan Sea onboard the Nadezhda sailing training vessel. The mass concentrations of aerosol and black carbon and the particle size distribution were measured using PhaN-type nephelometers, aethalometers, and AZ-5 and GRIMM photoelectric particle counters. Simultaneously, air samples were collected on filters to determine the ion chemical composition of aerosol. The spatiotemporal variations in chemical and microphysical composition of aerosol were studied. It is shown that the atmosphere of the Far East region in spring of 2009 was characterized by high contents of aerosol and black carbon, comparable with that over the Caspian Sea and three times larger than the level of concentrations over the White Sea. The average mass concentrations of aerosol and black carbon and the number concentration of particles were (17.5 ± 8.70) μg/m3, (0.99 ± 0.72) μg/m3, and (22.0 ± 13.6) cm−3, respectively. The high concentrations of aerosol and black carbon were due to emissions of continental aerosol of different origins (dust, anthropogenic, and smoke) and marine aerosol from regions neighboring the measurement regions. Close values of the concentrations in Primorye and the Japan Sea argue for the existence of a mean regional aerosolbackground. About 80% of the aerosol chemical composition in the region is accounted for by continental particle sources. Submicron aerosol prevailed in dust emissions, which formed the ion composition in most cases. The content of large particles (about 2 μm in radius) in the size spectrum may serve as an indicator of dust emissions. It follows from comparison with other regions that the maximum concentrations of “continentally derived” SO42−, NO3−, and NH4+ ions are observed over the Japan Sea, those of “sea-derived” Cl−, Na+, and Mg2+ ions are observed over the White Sea, and the minimum concentrations of most ions are observed near Antarctica.