Studies of the Dispersed Composition of Atmospheric Aerosol and Its Relationship with Small Gas Impurities in the Near-Water Layer of Lake Baikal Based on the Results of Ship Measurements in the Summer of 2020

The atmosphere over Lake Baikal covers a vast area (31,500 square meters) and has more significant differences in the composition and variability of gaseous and aerosol components in atmospheric air than in coastal continental areas and is still a poorly studied object. In recent years, the anthropogenic impact on the ecosystem of Lake Baikal has been increasing due to the development of industry in the region, the expansion of tourist infrastructure and recreational areas of the coastal zone of the lake. In addition, one of the significant sources of atmospheric pollution in the Baikal region is the emissions of smoke aerosol and trace gases from forest fires, the number of which is increasing in the region. This article presents the results of experimental studies of the dispersed composition of aerosols and gas impurities, such as ozone, sulfur dioxide, and nitrogen oxides during route ship measurements in the water area of Lake Baikal in the summer of 2020.

Simulation of the impact of the atmospheric weather state on the efficiency of functioning of solar thermal and power plants

THE PURPOSE. Determine the impact of the meteorological state of the atmosphere on the efficiency of the functioning of solar thermal and power plants. Modeling the molecular absorption of solar radiation by the atmosphere. Modeling the optical characteristics of the gaseous components of the atmosphere, atmospheric aerosol and clouds.METHODS. A method for numerical modeling of incoming solar radiation fluxes their functioning to determine the efficiency of solar thermal and power plants. The solar fluxes are calculated by stacking layers in a multi-stream approximation, taking into account the multi-tiered cloud cover and the probability of overlapping the sky with clouds. The absorption of radiation by the gaseous phase of the atmosphere is taken into account by the method of equivalent mass in an inhomogeneous atmosphere. The optical characteristics of the dispersed phase of the atmosphere are calculated using the Mie theory.RESULTS. An electronic database has been created on the optical characteristics of the gaseous components of the atmosphere, the optical characteristics of atmospheric aerosol and clouds. The effect of anthropogenic impact on the flux of solar radiation falling on the underlying surface is taken into account. The developed modeling takes into account the effect of humidity on the optical characteristics of atmospheric aerosol and its multicomponent composition, depending on the location of the power plant.CONCLUSION. The information necessary for numerical modeling of meteorological effects on the functioning of solar thermal and power plants is generalized. When calculating solar radiation fluxes, direct illumination of the light-receiving surface by solar radiation, scattered radiation by atmospheric aerosol and clouds are taken into account.

A universal deep learning-based framework towards fully ab initio simulation of atmospheric aerosol nucleation

Atmospheric aerosol nucleation contributes to around half of cloud condensation nuclei globally. Despite the importance for climate, detailed nucleation mechanisms are still poorly understood. Understanding aerosol nucleation dynamics is hindered by non-reactivity of force fields and high computational costs due to rare event nature of aerosol nucleation. Developing reactive force fields for nucleation systems are even more challenging than covalently bonded materials because of wide size range and high dimensional characteristics of non-covalent hydrogen bonding bridging clusters. Here we proposes a system transferable framework to train an accurate reactive force field (FF) based on deep neural network (DNN) and further bridges the DNN-FF based molecular dynamics (MD) with cluster kinetics model based on Poisson distributions of reactive events to overcome high computational costs from direct MD. We found that previously reported acid-base formation rates tend to be underestimated several times, emphasizing acid-base nucleation observed in multiple environments should be revisited.

Transport and transformation of atmospheric aerosol across Central Europe with emphasis on anthropogenic sources

<p>The trend in PM<sub>10</sub> concentrations in Europe has stagnated over the last two decades, showing only limited annual changes even though there are continued reductions in PM emissions. Possible reasons could be linked to both the aging processes of the particles in the atmosphere and their long-range transport. Therefore, better understanding the multiple origins of the atmospheric aerosol, their sources apportionment at different places are necessary for the development of efficient mitigation strategies. The ultimate objective of the project TRACE is to assess the transport and transformation of atmospheric aerosol across Central Europe with emphasis on anthropogenic sources (including coal and wood combustion) using synergic measurement methods (offline and online) and state-of-the art modelling tools including receptor-oriented models and Chemical transport models. Measurements were performed during winter and summer periods in 2021 simultaneously at three sampling places (Melpitz, DE, Kosetice, CZ, and Frydland, CZ) using state-of-the-art online and offline comprehensive chemical characterization of the atmospheric aerosol. Preliminary results from Scanning Mobility Particle Sizer (SMPS) showed peaks as high as 50 µg/m³ mass concentration during a dust event. Moreover, results from Aerosol Mass Spectrometer (AMS) and receptor modeling (RF) via Positive Matrix Factorization (PMF) from the winter campaign will be presented. </p>

Synchronous detection of multiple optical characteristics of atmospheric aerosol by coupled photoacoustic cavity

Due to the influence of sampling loss, cavity difference and detecting source, the multi-optical parameter measurement of atmospheric aerosol cannot be detected simultaneously under the same reference. In order to solve this problem, a new method for simultaneous detection of aerosol optical parameters by coupling cavity ring-down spectroscopy with photoacoustic spectroscopy was proposed. Firstly, the coupled photoacoustic cavity is formed by the organic fusion of the photoacoustic cavity and the ring-down cavity. Secondly, the integrated design of the coupling spectroscopy system is carried out. Finally, the extinction coefficient and absorption coefficient of aerosol are measured simultaneously by the system, and then the aerosol scattering coefficient and single albedo are calculated indirectly. The accuracy of the system is verified by comparing with the data from the environmental quality monitoring station, which provides a new idea for the detection of multi-optical characteristics of atmospheric aerosol.

A Method to Generate Experimental Aerosol with Similar Particle Size Distribution to Atmospheric Aerosol

The SARS-CoV virus spreads in the atmosphere mainly in the form of aerosols. Particle air filters are widely used in indoor heating, ventilation, and air-conditioning (HVAC) systems and filtration equipment to reduce aerosol concentration and improve indoor air quality. Requirements arise to rate filters according to their mass-based filtration efficiency. The size distribution of test aerosol greatly affects the measurement results of mass-based filtration efficiency and dust loading of filters, as well as the calibration of optical instruments for fine-particle (PM2.5) mass concentration measurement. The main objective of this study was to find a new method to generate a chemically nontoxic aerosol with a similar particle size distribution to atmospheric aerosol. We measured the size distribution of aerosols generated by DEHS (di-ethyl-hexyl-sebacate), PSL (poly-styrene latex), olive oil, and 20% sucrose solution with a collision nebulizer in a wide range of 15 nm–20 μm. Individually, none of the solutions generated particles that share a similar size distribution to atmospheric aerosol. We found that the 20% sucrose solution + olive oil mixture solution (Vss:Voo = 1:2) could be used to generate a chemically nontoxic aerosol with similar particle number/volume size distribution to the atmospheric aerosol (t-test, p < 0.05). The differences in the mass-base filtration efficiency measured by the generated aerosol and the atmospheric aerosol were smaller than 2% for MERV 7, 10, 13, and 16 rated filters. The aerosol generated by the new method also performed well in the calibration of optical-principle-based PM2.5 concentration measurement instruments. The average relative difference measured by a tapered element oscillating microbalance (TEOM) and a Dusttrak Model 8530 (calibrated by aerosol generated by the new method) was smaller than 5.8% in the real-situation measurement.

Long term Spatiotemporal Variability of Atmospheric Aerosol Parameters over Western Indian sites by Satellite Remote Sensing Measurements

Long term satellite observations over more than one decade of several aerosols parameters, i.e., AOD550 nm, AE, COT, UV-AI and ASA have been analyzed to describe their overall monthly and seasonally climatology over least explored region of Western Indian sites. It has been found that maximum aerosols loading characteristics of coarse aerosols of dust mineral origin in May and minimum aerosols values in December month at selected arid sites and semi-arid site. Aerosol variables in noon hours seem to their two time higher values than their fore-noon magnitude at all selected places. Observed findings may be interpreted in view of mixed effect of increasing accumulation of regional and local aerosols emission activities. An significant long term trend in aerosols variable of positive values of more 47% in AE and 25% in AOD 550 nm itself would be indicated due to the extra-enhancement in human made activities of more than 10% in term of population growth, population density, transportation vehicles, industries as the enhancement in local anthropogenic aerosols production sources specially over western arid sites. Thus, the abundance of fine size of anthropogenic aerosols is found to be systematically enhanced in the last decade, which is serious concern to both climate and air pollution change aspect over western Indian region also in similar to other Indian regions.