Arctic haze is a seasonal phenomenon with high concentrations of accumulation-mode aerosols occurring in the Arctic in winter and early spring. Chemistry transport models and climate chemistry models ...struggle to reproduce this phenomenon, and this has recently prompted changes in aerosol removal schemes to remedy the modeling problems. In this paper, we show that shortcomings in current emission data sets are at least as important. We perform a 3 yr model simulation of black carbon (BC) with the Lagrangian particle dispersion model FLEXPART. The model is driven with a new emission data set ("ECLIPSE emissions") which includes emissions from gas flaring. While gas flaring is estimated to contribute less than 3% of global BC emissions in this data set, flaring dominates the estimated BC emissions in the Arctic (north of 66° N). Putting these emissions into our model, we find that flaring contributes 42% to the annual mean BC surface concentrations in the Arctic. In March, flaring even accounts for 52% of all Arctic BC near the surface. Most of the flaring BC remains close to the surface in the Arctic, so that the flaring contribution to BC in the middle and upper troposphere is small. Another important factor determining simulated BC concentrations is the seasonal variation of BC emissions from residential combustion (often also called domestic combustion, which is used synonymously in this paper). We have calculated daily residential combustion emissions using the heating degree day (HDD) concept based on ambient air temperature and compare results from model simulations using emissions with daily, monthly and annual time resolution. In January, the Arctic-mean surface concentrations of BC due to residential combustion emissions are 150% higher when using daily emissions than when using annually constant emissions. While there are concentration reductions in summer, they are smaller than the winter increases, leading to a systematic increase of annual mean Arctic BC surface concentrations due to residential combustion by 68% when using daily emissions. A large part (93%) of this systematic increase can be captured also when using monthly emissions; the increase is compensated by a decreased BC burden at lower latitudes. In a comparison with BC measurements at six Arctic stations, we find that using daily-varying residential combustion emissions and introducing gas flaring emissions leads to large improvements of the simulated Arctic BC, both in terms of mean concentration levels and simulated seasonality. Case studies based on BC and carbon monoxide (CO) measurements from the Zeppelin observatory appear to confirm flaring as an important BC source that can produce pollution plumes in the Arctic with a high BC / CO enhancement ratio, as expected for this source type. BC measurements taken during a research ship cruise in the White, Barents and Kara seas north of the region with strong flaring emissions reveal very high concentrations of the order of 200–400 ng m−3. The model underestimates these concentrations substantially, which indicates that the flaring emissions (and probably also other emissions in northern Siberia) are rather under- than overestimated in our emission data set. Our results suggest that it may not be "vertical transport that is too strong or scavenging rates that are too low" and "opposite biases in these processes" in the Arctic and elsewhere in current aerosol models, as suggested in a recent review article (Bond et al., Bounding the role of black carbon in the climate system: a scientific assessment, J. Geophys. Res., 2013), but missing emission sources and lacking time resolution of the emission data that are causing opposite model biases in simulated BC concentrations in the Arctic and in the mid-latitudes.
The characteristics of acoustic-gravity waves (waveforms, time durations, amplitudes, azimuths and horizontal phase speeds) from the eruption of the Hunga-Tonga-Hunga-Hapai volcano detected at ...different infrasound stations of the Infrasound Monitoring System and at a network of low-frequency microbarographs in the Moscow region are studied. Using the correlation analysis of the signals at different locations, six arrivals of signals from the volcano, which made up to two revolutions around the Earth, were detected. The Lamb mode of acoustic gravity waves from the volcano eruption is identified and the effect of this mode on generation of tsunami waves and variation of aerosol concentration is studied. The energy released from an underwater volcano into the atmosphere is estimated from the parameters of the Lamb wave and compared with the energy released from the most powerful nuclear bomb of 58 Mt TNT.
Using the measurement data in a wind–sand flux on the desertified areas of Astrakhan oblast and Kalmykia, it has been established that the time variability of saltating and dust aerosol particle ...concentrations, the electric characteristics of the wind–sand flux, including electric currents of saltation, the volume charge of dust aerosol particles, and the electric field intensity in the near-surface layer of the atmosphere within a range of ~30 s to 30 min are determined by the low-frequency variations in the horizontal component of the wind velocity. According to the data of measurements, over the desertified area, the electric charge surface density reaches +25 nC/m
2
. The empirical probability distribution of a specific charge for sand grains under the condition of quasi-continuous saltation is obtained. A saltation initiation mechanism by electric discharges on the underlayer surface is proposed. An analytical model of particle liftoff to the near-surface layer of the atmosphere by electric discharges on the underlayer surface is presented. It is shown that, during the electric (corona) discharge, the saltating particle launch velocity can exceed 1 m/s.
Data on black carbon (BC) concentration C
BC
in the air basin of Moscow, and 5-day back trajectories of air mass motion, obtained in the period of 2003–2014, were used to determine the dependence of ...variations in black carbon concentration in the air basin of Moscow on the direction of air mass transport, and to determine the black carbon source regions. The 12-year measurements of black carbon concentration in Moscow air are used to show that the С
BC
variations are determined by the character of the air mass circulation in the troposphere. Measurements of black carbon content in the Moscow air basin in June–September 2019 and 10-day back trajectories of air mass transport were used to study the effect of the latter on the air pollution level in Moscow.
The saltating particle aleurite mode has been discovered in the wind–sand flux over a desertified area. The approximation of the measured saltating particle distribution was found using two lognormal ...distribution functions. In the wind–sand flux, the countable concentrations of aleurite and sand particles depend differently on the wind velocity in the atmospheric surface layer.
In Russian Arctic seas, observations of surface methane concentrations (CH
4
), ozone, nitrogen and carbon oxides, as well as the content of
isotope and black carbon (BC, soot aerosol), were carried ...out from onboard of the R/V
Academician Mstislav Keldysh
. The areas of local methane releasing from bottom sediments were investigated. It was shown that the studied methane releasing on the Arctic shelf are of a local nature and, on the whole, insignificantly affect the composition of the atmosphere in the region. The average concentration of methane in the surface air in the Arctic seas is mainly determined by large-scale processes of air mass transfer. An analysis of the distribution of black carbon along the route of the vessel was carried out. It was found that the excess in the concentration of black carbon over the background values is observed occasionally during advection of air masses from the mainland and from the areas of associated gases burning and forest fires. The effect of emissions from a ship’s chimney on the data obtained was analyzed.
According to the monitoring data of the optical and microphysical characteristics of smoke aerosol at AERONET stations during forest fires in the summer of 2019 in Alaska, the anomalous selective ...absorption of smoke aerosol has been detected in the visible and near-infrared spectral range from 440 to 1020 nm. With anomalous selective absorption, the imaginary part of the refractive index of smoke aerosol reached 0.315 at a wavelength of 1020 nm. A power-law approximation of the spectral dependence of the imaginary part of the refractive index with an exponent from 0.26 to 2.35 is proposed. It is shown that, for anomalous selective absorption, power-law approximations of the spectral dependences of the aerosol optical extinction and absorption depths are applicable with an Ångström exponent from 0.96 to 1.65 for the aerosol optical extinction depth and from 0.97 to –0.89 for the aerosol optical absorption depth, which reached 0.72. Single scattering albedo varied from 0.62 to 0.96. In the size distribution of smoke aerosol particles with anomalous selective absorption, the fine fraction of particles of condensation origin dominated. The similarity of the fraction of particles distinguished by anomalous selective absorption with the fraction of tar balls (TBs) detected by electron microscopy in smoke aerosol, which, apparently, arise during the condensation of terpenes and their oxygen-containing derivatives, is noted.
The article presents the results of a study of black carbon concentrations in the atmospheric boundary layer over the Baltic and North seas, the North Atlantic, and Norwegian, Barents, Kara, and ...Laptev seas from June 30 to September 29, 2017, on cruises 68 and 69 of the R/V
Akademik Mstislav Keldysh
. Black carbon has a significant impact on climate change and pollution in the Arctic. It forms as a result of incomplete combustion of fossil fuels (primarily coal and oil) and biomass or biofuels. It consists of submicron particles and their aggregates and can be transported long distances from their source. Samples were taken by pumping air for 4–6 h through Hahnemule quartz filters at a height of 10 m above sea level in a headwind to prevent exhaust from the smokestack from entering the filters. The black carbon content was subsequently determined in a laboratory with an aethalometer. The backward trajectories of air mass transfer and the transported black carbon particles to the sampling points were calculated by the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model on the NOAA website at
http://www.arl.noaa.gov/ready.html
. Studies show low black carbon concentrations (<50 ng/m
3
) along the expedition’s route when the air masses came from background regions of the North Atlantic and Arctic. High black carbon concentrations (100–200 ng/m
3
or more) are characteristic of active shipping areas (southwestern Baltic, North Sea) and near ports (e.g., Reykjavik), as well as the arrival of air masses from industrialized areas of Europe in the southeastern Baltic and from oil and gas field areas where gas flaring is carried out (North, Norwegian, and Kara seas).
Measurements of electric currents of saltation in the wind-sand flux and currents caused by the wind transport of dust aerosol particles have been carried out in the desertified territories of ...Astrakhan oblast and Kalmykia. Empirical distribution functions of the specific charge of saltating particles in a wind-sand flux are presented for the conditions of quasi-continuous and intermittent saltation. It is established that the electric charge surface density reaches +25 nC/m
2
. It is shown that the local electric field on the surface of the saltating particles can exceed 450 kV/m. An abnormal high electrization mechanism of the wind-sand flux is proposed, including the initiation of high-speed saltation: electric (corona) discharges on the underlying surface, which makes it possible to consider the wind-sand flux a dusty plasma. An analytical model has been developed for the escape of saltating particles from the underlying surface during a corona discharge. It is shown that, when saltation is initiated by a corona discharge, the escape velocity of charged particles can exceed 1 m/s.
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