Temperature regime and air pollution analysis for winter 2020-2021 has been carried out. Average urban heat island effect in December 2020, January 2021 and February 2021 reached 1.5, 2.0. and 2.5°С. During the cold weather maximum heat island effect was equal 6.0, 7.5 and 9.5°С, respectively. It is shown than during cold weather temperature inversions in the boundary lager of the atmosphere influence markedly on the urban air pollution.
Automated instruments for measuring of (1) the dust aerosol particle concentrations and the dust aerosol particle size distribution function, (2) the vertical turbulent fluxes of the dust aerosol and (3) the electric characteristics of the windsand flux. The dust aerosol particle concentrations in the range from 0.5 to 5.0 mcm at heights 2 m and 20 cm were measured. The vertical turbulent fluxes and the uplift rate (reached 5 cm/s) of the dust aerosol were determined. Influence of the convective structures on the emission and turbulent fluxes of the dust aerosol was found. It was established that the average volume electric charge of the dust aerosol reached – 70 nC/m3 and the electric charge density at the surface did not exceed + 25 nC/m2 .
Aleurite particle saltation trajectories have been calculated using the saltation dynamics model. Variability of the saltation trajectory parameters including of the height, range and particle flight time was analyzed. Saltation parameter dependencies from particle diameter and the friction velocity are approximated. Influence the lift-off velocity and the lift-off angle on the aleurite particle saltation trajectories was considered. Sliding coefficient dependencies from time during aleurite saltating particle transport were received for the various values of the particle diameter, friction velocity, lift-off velocity and lift-off angle.
An analysis of smoke haze over Europe in July 2016 caused by the wildfires in Siberia has been carried out. Surface air pollution by aerosols in Moscow region during the smoke event was also investigated. It was found that optical and microphysical characteristics of the smoke aerosol in Europe were typical for the boreal forest fires. The aerosol radiative forcing (ARF) variations at the top of the atmosphere (TOA) and the bottom of the atmosphere (BOA) during the smoke haze period were analyzed. The regional mean direct radiative forcing of aerosols at the TOA and BOA on 26 July 2016 were estimated to be -25 and -45 W/m2 respectively. Probability distribution function of ARF values at the TOA was presented.
The kinetics equation is considered for the differential concentration of a single atmospheric aerosol component particles. For the size distribution function, the kinetics equation is obtained under assumption that the function describing an elementary size interval change due to gas-to- particle process doesn't depend on time. The terms in the right side of the equation are due to gas-to-particle conversion and presents the product of the particle growth rate and the particle size derivative of the differential concentration. Under mist the particles' growth rate is determined as the product of three factors: the supersaturation of condensing substance, the function describing particles' volume dependence on air relative humidity and the function of particles size, which is analogically to the growth law in the dry atmosphere. In case of multicomponent aerosol we use the kinetics equations system. The equations of system are related with each other due to coagulation process and redistribution of condensing gas impurities on al aerosol components. It is shown that polymodal approximation is the effective instrument to solve different tasks of multicomponent aerosol kinetics. The possibility to control and aerosol structure and physical- chemical composition is illustrated by help the simple kinetics model of water-soluble and soot aerosol at the stationary approximation. Coagulation process is considered by analogy with gas-to-particle conversion processes. Therefore, the growth rate of particle volume and size is presented as the sum of two terms. The second term allows to take into account coagulation process approximately for a wide range of particle size change. For soot, water-soluble particles, the particular cases of growth law are considered. To determine soot volume part in aerosol mixed particles the analytical method is suggested.
Conference Committee Involvement (1)
Fifteenth International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics
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