Papers by Leonid Maksimenkov
Long-Term Variability of the Composition of Near-Surface Aerosol over Desertified and Arid Zones in Southern Russia
Atmospheric and Oceanic Optics
On the effect of changes in wind direction on dust aerosol concentrations in the near-surface layer
Aerosol pollution in the arid and semi-arid regions of southern Russia
EGU General Assembly Conference Abstracts, May 1, 2014
О прогностическом значении одного критерия оценки спиральности скорости атмосферных движений
Образование аэрозольных слоев в атмосферном пограничном слое с мезомасштабной циркуляцией
Experimental studies of aerosol in South-East Crimea
26th International Symposium on Atmospheric and Ocean Optics, Atmospheric Physics, 2020
The results of experimental studies of the microphysical parameters of aerosol particles in the s... more The results of experimental studies of the microphysical parameters of aerosol particles in the surface layer of the atmosphere of southeastern Crimea, performed in September 2018 - June 2019 at the background environmental monitoring station (BEMS) of the T.I. Vyazemsky Karadag Scientific Station. The dispersed composition and counting concentration of aerosol particles in the range of 0.15 -5 µm are determined. The mass concentration of aerosol PM5 particles ranged from 5 to 80 mg /m3 . An elemental composition analysis of aerosols taken on filters during primary measurements was performed.
Computational Continuum Mechanics, 2017
On the relationship of aeolian relief, microrelief and wind direction with the concentration of dust aerosol in the near-surface layer
<p>Saltations, secondary knock-out of particles, and their rolling over the surface in the ... more <p>Saltations, secondary knock-out of particles, and their rolling over the surface in the abrasion process are the main source of micron- and submicron-sized particles near the surface [1]. Zones with different aerosol generation rates and wiping dynamics emerge around growing aeolian structures [3,4]. On the leeward slope, larger particles remain in the embedding zone and abrasion is less active. On the windward slope, fractions of smaller size accumulate in the zone of cascade capture of layers by wind [2], and abrasion is predominant.</p><p>&#160;</p><p>The occurrence of aeolian forms varies in time depending on their height. Three areas are considered: 1-3 m, 1-3 cm, <1 cm. The effect of changes in wind direction at intervals of a few hours changes the length of zones near aeolian structures. Thus, the cascade trapping zone expands and the accumulation zone narrows. Aeolian microstructures on the surface of the windward slope decrease the length of the cascade capture zone, leaving structures with a height > 1 cm almost unchanged.</p><p>&#160;</p><p>We consider a sample of data from summer field measurements obtained in the evening with close values of air temperature (30-32&#176;C) and wind speeds (6.1-6.5 m/s). Observations were made on a perennial patch of unfixed sands about 1.5 km long and 200-300 m wide at 5 km to the west of Naryn Khuduk settlement (Kalmykia, 2010-2020). The lines of dune ridges for this area extend approximately in the latitudinal direction.</p><p>&#160;</p><p>Based on the empirical functions of aerosol size and mass distribution, the classification related to the wind direction in relation to the line of windward and leeward slopes connection was obtained. When the wind direction changes from frontal to tangential along the slopes, mass concentrations of coarse aerosol fraction increase. This can be related to the processes of chipping for newly involved large particles from the layers of the leeward slope setting zone. The phenomenon is also illustrated by the observed emergence on the surface of a ripple with a ridge spacing of 10-30 cm during the next day of a micro-ridge with a period of 1-2 cm. For the windward slope line change model [5], it was obtained that the fraction of detached particles decreases with the growth of new structures. The presence of aeolian ripples [6] and larger particles generally reduces the fraction of particles moving in the wind flow.&#160; There is weakening of wiping intensity at collision and reduction of concentration of submicron particles as a result, as compared to the case of absence of developed microrelief. The type of aerosol distribution function is influenced by the size of the embedding and cascade trapping zones and the composition of the layer of particles involved in collisions and displacements near the surface.</p><p>The study was supported by the Russian Science Foundation project 20-17-00214.</p><p>&#160;</p><p>1.Houser C.A., Nickling W.G. Sedimentology. 48(2). 255,. (2001)</p><p>2.Chepil W.S. Soil Science &#160;60(4) 305.(1945)</p><p>3.Anderson R. Sedimentology 34, 943 (1987).</p><p>4.Hoyle R., Woods A. Phys. Rev. E 56, 6861 (1997).</p><p>5.Malinovskaya E.A. Izvestiya. Atmospheric and Oceanic Physics 55(2) 218 (2019)</p><p>6. Malinovskaya E. et al. EGU2019-3693-1 (2019)</p><p>&#160;</p>
Adaptation of the COSMO-CLM model to the IAP RAS computational capabilities for assessing the impact of energy consumption on the urban climate
Earth and Space Science, 2021
Results of field measurements taken in the near‐Caspian (2002, 2003, 2007, 2009, 2010, 2011, 2013... more Results of field measurements taken in the near‐Caspian (2002, 2003, 2007, 2009, 2010, 2011, 2013, 2014, 2016 years) and near‐Aral sea (1998) deserts under the conditions of weak winds (almost in the absence of saltation processes) and strong heating of the land surface are given. These results show that the fine mineral dust aerosol (0.1–1 m) considerably contributes to the total aerosol content of the atmospheric surface layer under such conditions. The scaling of daytime mean size distribution at a height of 2 m is approximated by dependence , where changes from 4 to 6 for different years of measurements, in contrary to the law for fraction m. Different compositions of aerosol particles at m and m, including multicomponent fractions (less than m) may result in different probabilities of their integration and disintegration. It is hypothesized that the equilibrium distribution of submicron aerosol is a result of sequential disintegration of aerosol particles with a possibility for...
Atmosphere, 2021
In-situ knowledge on characteristics of mineral aerosols is important for weather and climate pre... more In-situ knowledge on characteristics of mineral aerosols is important for weather and climate prediction models, particularly for modeling such processes as the entrainment, transport and deposition of aerosols. However, field measurements of the dust emission flux, dust size distribution and its chemical composition under realistic wind conditions remain rare. In this study, we present experimental data over annual expeditions in the arid and semi-arid zones of the Caspian Lowland Desert (Kalmykia, south of Russia); we evaluate characteristics of mineral aerosol concentration and fluxes, estimate its chemical composition and calculate its long-distance transport characteristics. The mass concentration in different years ranges from several tens to several hundred of μg m−3. The significant influence of wind velocity on the value of mass and counting concentration and on the proposed entrainment mechanisms is confirmed. An increased content of anthropogenic elements (S, Sn, Pb, Bi, ...
Influence of Wind Direction on the Size Distribution of Aeolian Microparticles
Izvestiya, Atmospheric and Oceanic Physics, 2021
In this paper, microparticle size distributions due to the wind direction - frontal and tangentia... more In this paper, microparticle size distributions due to the wind direction - frontal and tangential in respect to the prevailing orientation of the dune crests are analyzed using field measurement data obtained during the 2010–2020 summer seasons in the arid conditions of the Near Caspian Lowland (Kalmykia, Russia). A smaller number of coarse-fraction microparticles (2–5 μm) and a larger number of fine-fraction microparticles (0.2–2 μm) are observed for the frontal wind direction in comparison with data for the tangential direction under similar conditions. The concentration of microparticles decreases for the frontal wind direction and increases for the tangential wind direction with the increase in friction dynamic velocity. Dust aerosol generation is associated with the movement of large particles near the surface by means of saltation or rolling (movement near the surface). The sizes of the generated microparticles are related to the momentum transferred to the particles in the layer. Concentrations of the fine fraction microparticles are associated with the presence of secondary aeolian structures on the surface of the windward slope and the relative change in the slope angle of inclination under the wind of different directions. This fraction generation due to shaking is more likely to occur when large particles move near the surface. The coarse-fraction concentrations are determined by the chipping processes that occur when a saltating particle blown from the top of the dune falls to the surface. When the wind direction is tangential and large irregularly shaped particles from the accumulation zone on the leeward slope are involved, the air circulation over the leeward slope weakens and the chipping processes intensify. The analytical derivation of the microparticle size distribution function and the comparison with field measurement data makes it possible to assess these effects in relation to the variation of angles of the aeolian-structure surface inclination and of particle velocities, which occur when the wind veers.
Vertical helicity flux as an index of interannual atmospheric variability
IOP Conference Series: Earth and Environmental Science, 2020
As an index of interannual climatic variability of the atmosphere, it is proposed to calculate th... more As an index of interannual climatic variability of the atmosphere, it is proposed to calculate the weighted average over the hemisphere area (to the pole from latitude 20°) of the vertical helicity flux across the upper boundary of the planetary boundary layer, which is determined by the product of the Coriolis parameter and the square of the wind speed at this boundary. In practical calculations, the data of reanalyses ERA-Interim and ERA-20C on the wind speed at the isobaric level of 850 hPa were used. The statistical distribution of the Earth’s surface area on the helicity flux values, as well as the informational entropy of this distribution, are calculated. It is shown that the introduced index usefully characterizes the interannual climate variability of the atmosphere in both hemispheres.
Helicity in atmosphere as a prognostic criterion
IOP Conference Series: Earth and Environmental Science, 2020
It is shown theoretically that the tendency of the height of the isobaric surface of 1000 hPa is ... more It is shown theoretically that the tendency of the height of the isobaric surface of 1000 hPa is proportional to the integral helicity of the geostrophic flow. This result is confirmed by calculations.
To the prognostic meaning for the one of criteria for helicity estimation in atmosphere
IOP Conference Series: Earth and Environmental Science, 2019
Izvestiya, Atmospheric and Oceanic Physics, 2019
Проводится исследование мезомасштабной валиковой циркуляции и ее транспортных свойств в атмосферн... more Проводится исследование мезомасштабной валиковой циркуляции и ее транспортных свойств в атмосферном пограничном слое (аПС). С использованием модели WRF-aRW рассматривается характерный эпизод 28 июля 2007 г. в Калмыкии, охваченный наблюдениями экспедиции ИФа им. а.М. Обухова Ран. Отмечается развитие циркуляции, с существенной асимметрией по положительным и отрицательным компонентам поля скорости и спиральности. Квазидвумерные валиковые структуры отмечаются интенсификацией захвата и аккумуляции пыли, поднимающейся с подстилающей поверхности, и, наряду с интенсивными вихрями с вертикальной осью, являются существенным источником примесей в атмосфере. захваченный мелкодисперсный аэро золь способен переноситься на большие расстояния и образовывать аэрозольные слои. ключевые слова: атмосферный пограничный слой, мезомасштабная циркуляция, асимметрия, численное моделирование, спиральность, транспорт аэрозоля, аэрозольные слои.
Doklady Earth Sciences, 2018
As an index of the general atmospheric circulation over the hemisphere, it is proposed to calcula... more As an index of the general atmospheric circulation over the hemisphere, it is proposed to calculate the hemisphere-area-averaged (poleward of the latitude 20°) product of the Coriolis parameter by the wind velocity squared at the upper boundary of the planetary boundary layer. In practical calculations, data on the wind velocity at an isobaric level of 850 hPa were used. Control calculations for the 900 hPa level gave similar results. It is shown that the index introduced adequately characterizes the seasonal and interannual variability of the general atmospheric circulation over both hemispheres.
Izvestiya, Atmospheric and Oceanic Physics, 2016
The parameters of atmospheric aerosol (mass concentration, both dispersed and elemental compositi... more The parameters of atmospheric aerosol (mass concentration, both dispersed and elemental compositions) and meteorological parameters were measured in Tsimlaynsk raion (Rostov oblast). The chemical composition of aerosol particles in the atmospheric surface layer has been determined, and the coefficients of enrichment of elements with respect to clarkes in the Earth's crust have been calculated. It is shown that, in summer, arid aerosols are transported from both alkaline and sandy soils of Kalmykia to the air basin over the observation zone. Aerosol particles in the surface air layer over this region have been found to contain the products of combustion of oil, coal, and ethylized fuel. These combustion products make a small contribution to the total mass concentration of atmospheric aerosol; however, they are most hazardous to the health of people because of their sizes and heavy-metal contents. A high concentration of submicron sulfur-containing aerosol particles of chemocondensation nature has been recorded. Sources of aerosol of both natural and anthropogenic origins in southern Russia are discussed.
Changes in the atmospheric circulation and environmental pollution in Siberia from the industrial regions of Norilsk and the Urals in the early 21st century
Atmospheric and Oceanic Optics, 2009
ABSTRACT
Dust emission under weak wind conditions: Direct observations and model
ABSTRACT
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Papers by Leonid Maksimenkov