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Applying orbital multi-angle photopolarimetric observations to study properties of aerosols in the Earth's atmosphere: Implications of measurements in the 1.378 μm spectral channel to retrieve microphysical characteristics and composition of stratospheric aerosols

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JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2021年 261卷 107483-107483页

作者： Dlugach, Janna M. Mishchenko, Michael, I Veles, Oleksandr A. Natl Acad Sci Ukraine Main Astron Observ 27 Zabolotny Str UA-03143 Kiev Ukraine NASA Goddard Inst Space Studies 2880 Broadway New York NY 10025 USA

We analyze the possibilities of orbital photopolarimetric measurements to study properties of aerosols in the Earth's atmosphere. As an example, we consider the case when such measurements are performed within a narrow spectral channel centered at 1.378 mu m that allows to retrieve microphysical characteristics of stratospheric aerosols separately from those of tropospheric aerosols. We consider the case of stratospheric aerosols caused by volcanic eruption, and adopt the model of the stratosphere in the form of a homogeneous plane-parallel layer composed of polydisperse spherical particles. We use numerically exact solutions of the vector radiative transfer equation to theoretically simulate measurements carried out at various numbers of scattering angles, including: (i) radiance measurements alone;(ii) polarization measurements alone;and (iii) radiance and polarization measurements together. The results of computations show that the simultaneous use of radiance and polarization measurements at a sufficiently large number of scattering angles enables one to retrieve the optical thickness, effective radius, and refractive index of aerosols with adequate accuracy. We demonstrate how the accuracy of the derived values of the optical parameters of aerosols depends on the accuracy of measurements of the intensity and polarization of the reflected light, optical thickness of aerosol layer itself, effective radius of aerosols, width of the particle size distribution, and number of viewing angles. (C) 2020 Published by Elsevier Ltd.

关键词： aerosols Multi-angle photopolarimetric measurements Polarization Radiative transfer Retrieving algorithm

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Solar Brightening/Dimming over China's Mainland: Effects of Atmospheric aerosols, Anthropogenic Emissions, and Meteorological Conditions

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REMOTE SENSING 2021年第1期13卷 88-88页

作者： Fang, Hejin Qin, Wenmin Wang, Lunche Zhang, Ming Yang, Xuefang China Univ Geosci Sch Geog & Informat Engn Key Lab Reg Ecol & Environm Change Wuhan 430074 Peoples R China China Univ Geosci Sch Geog & Informat Engn Hubei Key Lab Crit Zone Evolut Wuhan 430074 Peoples R China

Surface solar radiation (SSR) is the main factor affecting the earth's climate and environment and its variations and the reason for these variations are an important part of climate change research. In this research, we investigated the long-term variations of SSR during 1984-2016 and the quantitative influences of atmospheric aerosols, anthropogenic emissions, and meteorological conditions on SSR over China's mainland. The results show the following: (1) The annual average SSR values had a decline trend at a rate of -0.371 Wm(-2) yr(-1) from 1984 to 2016 over China. (2) The aerosol optical depth (AOD) plays the main role in inducing variations in SSR over China, with r values of -0.75. Moreover, there are marked regional differences in the influence of anthropogenic emissions and meteorological conditions on SSR trends. (3) From a regional perspective, AOD is the main influencing factor on SSR in northeast China (NEC), Yunnan Plateau and surrounding regions (YPS), North China (NC), and Loess Plateau (LP), with r values of -0.65, -0.60, -0.89, and -0.50, respectively. However, the main driving factors for SSR in northwest China (NWC) are "in cloud optical thickness of all clouds" (TAUTOT) (-0.26) and black carbon (BC) anthropogenic emissions (-0.21). TAUTOT (-0.39) and total precipitable water vapor (TQV) (-0.29) are the main influencing factors of SSR in the middle-lower Yangtze Plain (MYP). The main factors that influence SSR in southern China (SC) are surface pressure (PS) (-0.66) and AOD (-0.43). This research provides insights in understanding the variations of SSR and its relationships with anthropogenic conditions and meteorological factors.

关键词： aerosols surface solar radiation anthropogenic and meteorological drivers China

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Cold traps as reliable devices for quantitative determination of SARS-CoV-2 load in aerosols

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ENVIRONMENTAL MONITORING AND ASSESSMENT 2021年第12期193卷 778-778页

作者： Gehrke, Sven G. Foerderer, Claudia Weiskirchen, Ralf Stremmel, Wolfgang Med Ctr Baden Baden Beethovenstr 2 CH-76530 Baden Switzerland RWTH Univ Hosp Aachen Inst Mol Pathobiochem Expt Gene Therapy & Clin Ch D-52074 Aachen Germany

Spread of the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a demanding challenge. This is of particular importance in schools and public areas of unavoidable access. New viral mutations may increase infectivity and require even better methods to identify areas of potential hazards. High-throughput SARS-CoV-2 testing and legal restrictions are not effective in order to get the current outbreak under control. The occurrence of new SARS-CoV-2 variants with a higher transmissibility requires efficient strategies for early detection and surveillance. Until today, testing focuses on nasal or pharyngeal mucosa swabs, neglecting the origin of aerosolic transmission, thus failing to detect the spread by carriers of the virus. Therefore, in this study, SARS-CoV-2 RNA levels were determined by quantitative real time PCR in aerosols collected by non-powered cold traps. SARS-CoV-2 spreading kinetics were recorded in indoor hotspots within a high-endemic area. These hotspots included a SARS-CoV-2 isolation unit, an outpatient endoscopy facility, a concert hall, and a shopping mall. For determination of viral presence aerosols were collected by cold traps positioned at different locations in the area of interest over a period of 4-6 h. Indoor SARS-CoV-2 hotspots were found in non-ventilated areas and in zones that are predisposed to a buoyancy (chimney) effect. SARS-CoV-2 RNA in those aerosols reached concentrations of 10(5) copies/mL, while extensive outdoor air ventilation reliably eliminated SARS-CoV-2 aerosol contamination. The method presented herein is effective for the identification of SARS-CoV-2 indoor hotspots and may help to characterize the spreading kinetics of SARS-CoV-2. Moreover, it can be used for the surveillance of emerging SARS-CoV-2 variants. Due to low costs and easy handling, the procedure might enable efficient algorithms for COVID-19 screening and prevention.

关键词： COVID-19 SARS-CoV-2 aerosols Spreading kinetics Indoor hotspots Public places

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Effect of aerosols, Tropospheric NO₂ and Clouds on Surface Solar Radiation over the Eastern Mediterranean (Greece)

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REMOTE SENSING 2021年第13期13卷 2587-2587页

作者： Alexandri, Georgia Georgoulias, Aristeidis K. Balis, Dimitris Aristotle Univ Thessaloniki Phys Dept Lab Atmospher Phys Thessaloniki 54124 Greece

In this work, the effect that two basic air quality indexes, aerosols and tropospheric NO2, exert on surface solar radiation (SSR) is studied, along with the effect of liquid and ice clouds over 16 locations in Greece, in the heart of the Eastern Mediterranean. State-of-the-art satellite-based observations and climatological data for the 15-year period 2005-2019, and a radiative transfer system based on a modified version of the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model are used. Our SSR simulations are in good agreement with ground observations and two satellite products. It is shown that liquid clouds dominate, with an annual radiative effect (RE) of -36 W/m(2), with ice clouds (-19 W/m(2)) and aerosols (-13 W/m(2)) following. The radiative effect of tropospheric NO2 is smaller by two orders of magnitude (-0.074 W/m(2)). Under clear skies, REaer is about 3-4 times larger than for liquid and ice cloud-covered skies, while RENO2 doubles. The radiative effect of all the parameters exhibits a distinct seasonal cycle. An increase in SSR is observed for the period 2005-2019 (positive trends ranging from 0.01 to 0.52 W/m(2)/year), which is mostly related to a decrease in the aerosol optical depth and the liquid cloud fraction.

关键词： surface solar radiation aerosols clouds tropospheric NO2 Greece SBDART MODIS CALIPSO CM SAF CERES

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Bubbles spray aerosols: Certitudes and mysteries

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PNAS NEXUS 2022年第5期1卷 pgac261页

作者： Villermaux, Emmanuel Wang, Xiaofei Deike, Luc Aix Marseille Univ CNRS Cent Marseille IRPHE UMR 7342 F-13384 Marseille France Inst Univ France F-75005 Paris France Fudan Univ Shanghai Key Lab Atmospher Particle Pollut & Prev Dept Environm Sci & Engn Shanghai 200433 Peoples R China Princeton Univ Dept Mech & Aerosp Engn Princeton NJ 08544 USA Princeton Univ High Meadows Environm Inst Princeton NJ 08544 USA

Ocean spray aerosol formed by bubble bursting are at the core of a broad range of atmospheric processes: they are efficient cloud condensation nuclei and carry a variety of chemical, biological, and biomass material from the surface of the ocean to the atmosphere. The origin and composition of these aerosols is sensibly controlled by the detailed fluid mechanics of bubble bursting. This perspective summarizes our present-day knowledge on how bursting bubbles at the surface of a liquid pool contribute to its fragmentation, namely to the formation of droplets stripped from the pool, and associated mechanisms. In particular, we describe bounds and yields for each distinct mechanism, and the way they are sensitive to the bubble production and environmental conditions. We also underline the consequences of each mechanism on some of the many air-sea interactions phenomena identified to date. Attention is specifically payed at delimiting the known from the unknown and the certitudes from the speculations.

关键词： aerosols sprays bubble bursting air-sea interactions

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The Radiative Forcing of aerosols in a West Africa Sahelian Urban City: Case Study of Ouagadougou

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Atmospheric and Climate Sciences 2021年第1期11卷 73-85页

作者： Bruno Korgo Pétronille Kafando Bernard Zouma Nebon Bado Issa Zerbo Jean-Claude Roger Joseph D. Bathiebo Laboratory of Thermal and Renewable Energy Department of Physics University Joseph KI-ZERBO Ouagadougou Burkina Faso Laboratory of Environmental Physics and Chemistry Department of Physics University Joseph KI-ZERBO Ouagadougou Burkina Faso Department of Geographical Sciences University of Maryland College Park MD USA

This paper is an assessment of radiative forcing caused by atmospheric aerosols in an urban city in West Africa. It is carried out in Ouagadougou in Burkina Faso and is an illustration of the radiative impact in most of the large Sahelian urban cities which are under the same climatic influences and whose populations present similarities in their socio-economic aspects. Using the GAME code, the radiative forcing was calculated at the top of the atmosphere, in the atmospheric layer and at the earth’s surface. The results showed overall a cooling effect at the top of the atmosphere due to the backscattering in space of the incident radiation, a heating in the atmospheric layer due to the absorption effect and a surface cooling justified by the attenuation of radiation crossing the atmosphere. Using monthly average values of optical properties, vertical temperature and humidity profiles, daily temperatures and surface albedo, the simulation yielded forcing values ranging from -6.77 W/m² to -2.56 W/m² at the top of the atmosphere, from 15.8 W/m² to 34.7 W/m² in the atmospheric layer and from -41.00 W/m² to -21.68 W/m² at the earth’s surface. In addition, the warming was simulated in the first atmospheric layer (in contact with the surface), and the results show values ranging from 0.8°C to 1.8°C. The study of the annual variability of the results showed a strong correlation between the radiative forcing and the seasonal succession characteristic of the climate in West Africa with the extreme values in the month of March (characteristic of the dry and hot season) and in the month of August (characteristic of the rainy season).

关键词： aerosols Radiative Forcing Scattering Absorption GAME Code AERONET

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aerosols impact on the convective and non-convective rain distribution over the Indian region: Results from WRF-Chem simulation

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ATMOSPHERIC ENVIRONMENT 2019年第Apr.期202卷 64-74页

作者： Kedia, Sumita Das, Subrata Kumar Islam, Sahidul Hazra, Anupam Kumar, Naveen Ctr Dev Adv Comp Pune Pune Maharashtra India Indian Inst Trop Meteorol Pune Maharashtra India Minist Elect & Informat Technol New Delhi India

The Weather Research and Forecasting (WRF) model coupled with chemistry (WRF-Chem) is used to simulate rainfall pattern over the Indian landmass during a normal monsoon year (June-September 2010). Sensitivity analysis is performed using three different microphysical (MP) schemes (Thompson, Morrison, and Lin) to simulate the rainfall pattern and distribution over India. A significant difference in the rainfall amount, as well as distribution, is observed among the MP schemes, despite using the same model configuration and the meteorological and chemical initial and boundary condition. Lin MP scheme performed better than other schemes in simulating the rainfall over the Indian domain. Heavy rainfall along the foothills of the Himalayas, the mountainous coastal region of western India, and the northeastern part of India and sparse rainfall over northwest India are captured realistically in the model, which agrees well with the observed rainfall pattern over India. The spatial distribution of aerosol optical depths retrieved from the MODIS satellites is broadly well simulated by the model. The model simulated convective and non-convective rainfall characteristics over the Indian landmass are found to be consistent with the monsoon precipitation climatology. It is shown that the change in both convective and non-convective rainfall due to aerosols and chemistry is non-negligible over India during monsoon season. The total rainfall is found to increase significantly over the entire Western Ghats and some part of northeast India, while it is diminished over the northwest, north and east India when aerosol chemistry effects are considered in the model simulation. Additional analysis is performed to simulate the perturbations in convective and non-convective rainfall due to aerosols (e.g., dust, sea salt, black carbon etc.). Results show that the effect of aerosols on convective and non-convective rainfall distribution over India is non-linear. Depending on the meteorologica

关键词： aerosols Monsoon Rain Convective and non-convective rain WRF-Chem

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OBSERVING URBAN aerosols USING CO-LOCATED NO2 ENHANCEMENT FROM TROPOMI

OBSERVING URBAN AEROSOLS USING CO-LOCATED NO2 ENHANCEMENT FR...

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IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Jiang, Fang-Qing Zeng, Zhao-Cheng Chengdu Univ Informat Technol Chengdu Sichuan Peoples R China CALTECH Pasadena CA 91125 USA

ISBN: (纸本)9781728163741

This study uses observations of NO2 and aerosol index (AI) from tropospheric monitoring instrument (TROPOMI) in China to study the feasibility of using NO2 as a tracer to track the urban emission of air pollutants. Urban aerosol emissions are difficult to track due to its mixing with background. Nitrogen dioxide gas is an important urban emissions from human activities, and an effective indicator of emissions sources, because it is short-lived and chemically decayed rapidly away from its sources. In view of the fact that nitrogen dioxide and aerosol are mainly emitted simultaneously in cities, the spatial distribution map of nitrogen dioxide concentration can be used to monitor the urban aerosol emission trajectory caused by atmospheric transport. In this study, we selected two cities (Shijiazhuang, Baotou) in China, and used observation data from the high spatial resolution TROPOMI satellite to compare the spatial distribution of NO2 concentration and AI. First, the enhancement of NO2 concentration is used to identify urban plumes, and then these plumes are analyzed to indicate the optical characteristics of aerosols. The results show that the concentration of NO2 as a tracer can be a good indicator of the spatial distribution of urban aerosol emissions.

关键词： aerosols

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Airborne transmission of SARS-CoV-2 via aerosols

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REVIEWS IN MEDICAL VIROLOGY 2021年第3期31卷 e2184-e2184页

作者： Comber, Laura Murchu, Eamon Drummond, Linda Carty, Paul G. Walsh, Kieran A. De Gascun, Cillian F. Connolly, Maire A. Smith, Susan M. O'Neill, Michelle Ryan, Mairin Harrington, Patricia Hlth Informat & Qual Author Hlth Technol Assessment Directorate Dublin Ireland Univ Coll Dublin Natl Virus Reference Lab Dublin Ireland Natl Univ Ireland Galway Sch Med Galway Ireland Royal Coll Surgeons Ireland Hlth Res Board Ctr Primary Care Res Dept Gen Practice Dublin Ireland Trinity Coll Dublin Dept Pharmacol & Therapeut Dublin Ireland

A key consideration in the Covid-19 pandemic is the dominant modes of transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The objective of this review was to synthesise the evidence for the potential airborne transmission of SARS-CoV-2 via aerosols. Systematic literature searches were conducted in PubMed, Embase, Europe PMC and National Health Service UK evidence up to 27 July 2020. A protocol was published and Cochrane guidance for rapid review methodology was adhered to throughout. Twenty-eight studies were identified. Seven out of eight epidemiological studies suggest aerosol transmission may occur, with enclosed environments and poor ventilation noted as possible contextual factors. Ten of the 16 air sampling studies detected SARS-CoV-2 ribonucleic acid;however, only three of these studies attempted to culture the virus with one being successful in a limited number of samples. Two of four virological studies using artificially generated aerosols indicated that SARS-CoV-2 is viable in aerosols. The results of this review indicate there is inconclusive evidence regarding the viability and infectivity of SARS-CoV-2 in aerosols. Epidemiological studies suggest possible transmission, with contextual factors noted. Viral particles have been detected in air sampling studies with some evidence of clinical infectivity, and virological studies indicate these particles may represent live virus, adding further plausibility. However, there is uncertainty as to the nature and impact of aerosol transmission of SARS-CoV-2, and its relative contribution to the Covid-19 pandemic compared with other modes of transmission.

关键词： aerosols coronavirus Covid-19 infection control review SARS-CoV-2 transmission

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Elemental composition and mass concentration of near surface aerosols in Moscow region during unusual weather conditions in the fall 2019 26

Elemental composition and mass concentration of near surface...

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26th International Symposium on Atmospheric and Ocean Optics, Atmospheric Physics

作者： Gubanova, D. P. Iordanskii, M. A. Anikin, P. P. Kuderina, T. M. Skorokhod, A., I Elansky, N. F. Russian Acad Sci AM Obukhov Inst Atmospher Phys Moscow Russia Karpov Inst Phys Chem Moscow Russia Russian Acad Sci Inst Geog Moscow Russia

ISBN: (纸本)9781510639423

The results on elemental composition of the surface aerosols in Moscow region were studied from the data of the integrated autumn experiment. Elemental composition of aerosol particles in the atmosphere of Moscow city and in the suburb in the fall 2019 under unusual weather conditions are presented. The average daily mass concentration and fractional composition are compared with synoptic and meteorological factors, as well as with local aerosol sources. Meteorological conditions and local sources play great roles in forming aerosol elemental composition variability and its mass concentration.

关键词： Moscow region atmosphere aerosols mass concentration elemental composition fractional composition meteorological parameters

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