On measurements of aerosol-gas composition of the atmosphere during two expeditions in 2013 along the Northern Sea Route

Abstract

Abstract. We presented the results of expedition measurements of the set of physical-chemical characteristics of atmospheric aerosol in areas of the Arctic and Far East seas, performed onboard RV Akademik Fedorov (17 August-22 September 2013) and RV Professor Khljustin (24 July-7 September 2013). The specific features of spatial distribution and time variations of aerosol optical depth (AOD) of the atmosphere in the wavelength range of 0.34-2.14 µm and boundary layer height, aerosol and black carbon mass concentrations, and disperse and chemical composition of aerosol are discussed. Over the Arctic Ocean (on the route of RV Akademik Fedorov) there is a decrease in aerosol and black carbon concentrations in a northeastern direction: higher values were observed in the region of Spitsbergen and near the Kola Peninsula; and minimum values were observed at northern margins of the Laptev Sea. Average AOD (0.5 µm) values in this remote region were 0.03; the aerosol and black carbon mass concentrations were 875 and 22 ng m −3 , respectively. The spatial distributions of most aerosol characteristics over Far East seas show their latitudinal decrease in the northern direction. On transit of RV Professor Khljustin from the Japan Sea to the Chukchi Sea, the aerosol number concentration decreased on average from 23.7 to 2.5 cm −3 , the black carbon mass concentration decreased from 150 to 50 ng m −3 , and AOD decreased from 0.19 to 0.03. We analyzed the variations in the boundary layer height, measured by ship-based lidar: the average value was 520 m, and the maximal value was 1200 m. In latitudinal distribution of the boundary layer height, there is a characteristic minimum at a latitude of ∼ 55 • N. For water basins of eight seas, we present the chemical compositions of the water-soluble aerosol fraction (ions, elements) and small gasphase species, as well as estimates of their vertical fluxes. It is shown that substances are mainly (75-89 %) supplied from the atmosphere to the sea surface together with gas-phase species. The deposited ions account for from 11 to 24.5 %, and trace elements account for 0.2-0.4 % of the total sum of water-soluble components. The average vertical fluxes of aerosol substance are a factor of 4-7 larger in the Japan Sea than in the water basins of Arctic seas.

Spatial Distribution of Atmospheric Aerosol Physicochemical Characteristics in the Russian Sector of the Arctic Ocean

“…4". As in the previous expeditions [13,19,29], the measurements were performed using the same set of instruments, comprising particle counter AZ-10 [30], aethalometer MDA [31], and portable sun photometer SPM [32]. Based on data from these instruments, for every hour of measurements we determined the following characteristics: Volumes of particles in the fine and coarse fractions of aerosol (Vf and Vc), which were calculated from the formula V = 4/3•π•ri 3 •dNi for the radius ranges 0.15-0.5 and 0.5-5 µm, respectively; • AOD of the atmosphere τ a (λ) in the wavelength range of 0.34-2.14 µm and parameters of the Ångström formula α, β; •…”

“…It is well known that the particles in fine and coarse aerosol fractions differ in the natures of their origin, processes of transformation in the atmosphere, propagation distances, and lifetimes. Therefore, in studying aerosol variations, the behavior of each fraction is expedient to consider separately, both in the As in the previous expeditions [13,19,29], the measurements were performed using the same set of instruments, comprising particle counter AZ-10 [30], aethalometer MDA [31], and portable sun photometer SPM [32]. Based on data from these instruments, for every hour of measurements we determined the following characteristics: • AOD of the atmosphere τ a (λ) in the wavelength range of 0.34-2.14 µm and parameters of the Ångström formula α, β;…”

“…The results obtained serve as a basis for determining seasonal variations in aerosol characteristics, sources of aerosol emissions and long-range transport pathways, absorbing properties, and radiation effects [11][12][13][14][15][16][17]. In addition to observations at polar stations, expedition measurements of aerosol characteristics are carried out every year in different regions of the Arctic Ocean and North Atlantic [17][18][19][20][21][22][23].…”

“…Therefore, in studying aerosol variations, the behavior of each fraction is expedient to consider separately, both in the near-surface layer and in the atmospheric depth. In the previous works (e.g., [19,23]) we analyzed the individual variations of number concentrations in two particle fractions (N f and N c ), while in the current case the particle volumes V f and V c will be analyzed. This change is explained by two circumstances.…”

Aerosol carbonaceous, elemental and ionic composition variability and origin at the Siberian High Arctic, Cape Baranova

“…In the Siberian high Arctic, the knowledge of the aerosol chemical composition has poor spatiotemporal coverage, due to the small number of monitoring sites and logistical difficulties associated with these sites. Recently, a few BC measurements were performed in the Siberian Arctic, mostly from field campaigns over the Arctic (Popovicheva et al, 2017a;Sakerin et al, 2015;Stohl et al, 2013), and from the drifting station "North Pole" (Stock et al, 2012). Model validation has been benefited from observations performed in the proximity of the major industrial sources (Popovicheva et al, 2017a).…”