Атмосферная циркуляция в индоокеанском секторе Восточной Антарктиды за последние 200 лет по данным изучения химического состава снежно‑фирнового покрова

Spatial and temporal variability of a sea‑salt aerosol (Na+) concentration was investigated in snow‑firn cores and snow pits taken at four sites of the Indian Ocean sector of the East Antarctica (along a profile between stations Progress and Vostok: PV‑10, NVFL‑1, SW‑42, and the Vostok point). In long annually resolved Na+ records, we had revealed the following periodicities: 17 to 95‑year (Vostok) and 29 to 52‑year (NVFL‑1), while the shorter records are characterized by 8‑year periodicity. The Na+ concentrations decrease as the snow accu‑ mulation increases (especially, at the Vostok station), and this is evidence for a presence of «dilution effect» in the sites with the great part of «dry precipitation». The closest relationship was revealed between changes in flows of Na+ at points SW‑42, and PV‑10. Variability of the Na+ fluxes had been linked to the circulation indices (AAO, PDO, SOI, MEI, SPO) and the sea level pressure in the Southern Hemisphere, as well as to occurrence of Elementary Circulation Mechanisms (ECM). The revealed irregularity of the Na+ precipitation over the area under investigation is caused by different atmospheric circulation patterns as well as by influ‑ ence of basic Action Centers of the Atmosphere (ACA) in the Southern Hemisphere. The closest relationship is found to take place with South Pacific ACA (Vostok, 1976–2009) and with the South Indian ACA (SW‑42 and PV‑10). A presence of distant atmospheric relations (including one with El Nino) had been revealed for the inland areas. Changes in features of the atmospheric circulation in the South Indian Ocean over the last 200‑year period have been reconstructed on the basis of summarized Na+ records from the Vostok station area. Distinctive feature of the atmospheric circulation is the 40‑year periodicity with its increasing intensity during the following periods: 1805–1820, 1830–1860, 1890–1900, 1940–1950, and 1980–2000. In addition, we had revealed that changes in the atmospheric circulation in the Indian Ocean (Southern Hemisphere) were synchronous with similar variability of the circulation in the Siberian (Northern Hemisphere) sector.По данным изучения химического состава снежно-фирнового покрова в индоокеанском секторе Восточной Антарктиды установлены пространственно-временные изменения аккумуляции морского аэрозоля (Na+). Исследованы корреляционные связи аккумуляции Na+ с индексами циркуляции и полем давления Южного полушария, а также элементарными циркуляционными механизмами. Впервые выполнена реконструкция интенсивности региональной циркуляции за последние 200 лет

Химический состав приземного атмосферного аэрозоля в Баренцбурге (архипелаг Шпицберген) по результатам многолетних исследований

The chemical composition (ions, elements, polycyclic aromatic hydrocarbons) of aerosol and gaseous impurities (SO2, HNO3, HCl, NH3) in the surface layer of the atmosphere in Barentsburg, located on the Western Svalbard island (Svalbard archipelago), is analyzed. Atmospheric aerosol and gaseous impurities brought to the Arctic from middle latitudes and deposited on snow and ice not only interact with various natural objects, but also spread to long distances with melting dirty snow and ice. Air sampling was carried out following to methodology adopted by the international networks of the atmospheric monitoring programs in South-East Asia (EANET) and Europe (EMEP). In 2011-2015, the observations of the chemical composition of the atmospheric ground layer were performed daily during the light season (April–September), and monthly from April 2016 to 2018. The largest total ion concentrations were observed in 2011–2012. Seasonal variability of ion concentrations in the aerosol was characterized by high values in the cold period (October–February) and low values in the warm one (May–June). High values of the coefficient of correlation between ions Na+ and Cl− (r = 0,93) as well as between Mg2+ and Cl−  (r = 0,81) throughout the year show that the main source of the aerosol is the sea surface. The significant correlation between ions K+, NO3-, NH4+, SO42−, K+, SO42− in the polar night point to the influence of local sources: coal mining at the mine and its3 combustion at thermal power plants. Emission of polycyclic aromatic hydrocarbons and the gaseous impurities (SO2, HNO3) into the atmosphere, especially during the polar night, is also influenced by local sources. Among the elements the maximum enrichment of the aerosol was revealed for As, Cr, Zn, Mo, Cd, Sn, Sb, W, and Pb with a low content of Cd, Sn, Sb, W, and Pb in the coal, sludge and on the underlying surface. On the basis of the elemental composition of the aerosol and the back-trajectory analysis, it was shown that the air masses enriched in heavy metals come to the area of the Barentsburg settlement from middle latitudes.Прослежена межгодовая (2011–2017 гг.) и сезонная (2016–2018 гг.) изменчивость компонентов химического состава (ионы, элементы, полициклические ароматические углеводороды) атмосферного аэрозоля и газообразных примесей (SO2, HNO3, HCl, NH3) в приземной атмосфере западной части Российской Арктики (пос. Баренцбург на Шпицбергене)

Atmospheric circulation in the Indian Ocean sector of East Antarctica over the last 200 years according to chemical studies of snow‑firn cover

Spatial and temporal variability of a sea‑salt aerosol (Na+) concentration was investigated in snow‑firn cores and snow pits taken at four sites of the Indian Ocean sector of the East Antarctica (along a profile between stations Progress and Vostok: PV‑10, NVFL‑1, SW‑42, and the Vostok point). In long annually resolved Na+ records, we had revealed the following periodicities: 17 to 95‑year (Vostok) and 29 to 52‑year (NVFL‑1), while the shorter records are characterized by 8‑year periodicity. The Na+ concentrations decrease as the snow accu‑ mulation increases (especially, at the Vostok station), and this is evidence for a presence of «dilution effect» in the sites with the great part of «dry precipitation». The closest relationship was revealed between changes in flows of Na+ at points SW‑42, and PV‑10. Variability of the Na+ fluxes had been linked to the circulation indices (AAO, PDO, SOI, MEI, SPO) and the sea level pressure in the Southern Hemisphere, as well as to occurrence of Elementary Circulation Mechanisms (ECM). The revealed irregularity of the Na+ precipitation over the area under investigation is caused by different atmospheric circulation patterns as well as by influ‑ ence of basic Action Centers of the Atmosphere (ACA) in the Southern Hemisphere. The closest relationship is found to take place with South Pacific ACA (Vostok, 1976–2009) and with the South Indian ACA (SW‑42 and PV‑10). A presence of distant atmospheric relations (including one with El Nino) had been revealed for the inland areas. Changes in features of the atmospheric circulation in the South Indian Ocean over the last 200‑year period have been reconstructed on the basis of summarized Na+ records from the Vostok station area. Distinctive feature of the atmospheric circulation is the 40‑year periodicity with its increasing intensity during the following periods: 1805–1820, 1830–1860, 1890–1900, 1940–1950, and 1980–2000. In addition, we had revealed that changes in the atmospheric circulation in the Indian Ocean (Southern Hemisphere) were synchronous with similar variability of the circulation in the Siberian (Northern Hemisphere) sector

Ozenka vozmoznosti ispol’zovanija profilja ozona vysokogo razresenija po dannym pribora GOME-2 dlja ozenki [On the possibility of using the GOME-2 high resolution ozone profiles for assessment of near-surface ozone concentrations]

Near-surface concentrations of ozone over the Baikal region were assessed using ozone observations from GOME-2 instrument onboard the MetOp-A satellite. High resolution ozone profiles were provided by EUMETSAT. In order to verify near surface ozone concentrations obtained from satellite data, a comparison was performed with observations at ground stations. It was shown that the two measurements were consistent, that is the time series of satellite data describe well seasonal changes and are also appropriate for regional air pollution assessment. However, there are limitations on using satellite data for predicting instant ozone concentrations and urban pollution. Spatial distributions of mean annual and seasonal ozone concentrations were derived for the Baikal region. These evidence distinct seasonality in surface ozone concentrations with maxima and minima falling on spring and autumn months, respectively, throughout the entire region. According to the satellite data, ozone concentrations in remote mountainous areas are higher in comparison with those from industrial regions of Angara and Selenga river valleys

Molecular characterization of water-soluble aerosol particle extracts by ultrahigh-resolution mass spectrometry: Observation of industrial emissions and an atmospherically aged wildfire plume at Lake Baikal.

Air pollution over Lake Baikal originating from anthropogenic emissions as well as wildfire events and secondary organic aerosol (SOA) formation poses a threat to this world heritage ecosystem. During a ship expedition in 2018, ambient aerosol particles were sampled on filters at different locations of Lake Baikal and extracted to obtain the fraction of water-soluble organic aerosol (WSOA). Subsequent analysis by Fourier transform ion cyclotron resonance (FTICR) mass spectrometry with direct-infusion electrospray ionization (ESI) in both ionization modes provides insights into the molecular composition of polar and high-molecular-weight species in WSOA. Light absorption spectral dependence determined by absorption Ångstrom exponent (AAE) is correlated to summed compound class abundancies to identify light-absorbing compounds. Most detected species are heavily oxidized, associated with intense atmospheric aging, and contain significant amounts of nitrogen or sulfur, with the most abundant compound classes being CHO, CHON, and CHOS. Nitrogen-containing species are more frequently found in positive ESI and correlate well with AAE. Oxygen-to-nitrogen ratios (O/N) larger than 3 indicate organic nitrates, and also less oxidized nitrogen species can be linked to brown carbon (BrC). ESI in both ionization modes provides complementary molecular information with, on the one hand, more sensitive detection of high average carbon oxidation state (OSC) and low-volatility oxidized organic aerosol species in negative mode, and on the other hand, lower OSC (OSC < 0) species as well as oligomers and potential biomass burning organic aerosol in positive mode. Additionally, a great overlap of sum formulae was found at all sampling sites along the expedition route, regardless of the potential primary emission sources, indicating strong atmospheric aging and mixing, leading to a similar oxidized organic aerosol (OOA) from different primary sources

Sea level fluctuations and their signature in the composition and structure of polygonal wedge ice in the Yenisei River lower reaches

Late Pleistocene and Holocene polygonal-wedge ice is studied in the lower course of the Yenisei River. Ice distribution, features of the formation, chemical and microbiological composition were determined. It was established that ice wedges were formed on the slopes of the depression, in coastal-marine lagoons and in thermokarst during Holocene. The evidence of thermoabrasion and thermokarst in sediments as well as the marine signal in composition of polygonal-wedge ice allowed clarifying the southern limit of the Holocene transgression