Download or read book Studies of Aerosol Scavenging by Ice Particles in Clouds written by Randolph D. Borys and published by . This book was released on 1987 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ice Microdynamics written by Pao K. Wang and published by . This book was released on 2002 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric ice particles play crucial roles in cloud and storm dynamics, atmospheric chemistry, climatological processes, and other atmospheric processes. Ice Microdynamics introduces the elementary physics and dynamics of atmospheric ice particles in clouds; subsequent sections explain their formation from water vapor, why ice crystal shape and concentration in cirrus clouds influence the heating of air, and describe how ice crystals cleanse the atmosphere by scavenging aerosol particles. Pao Wang's lucid writing style will appeal to atmospheric scientists, climatologists, and meteorologists with an interest in understanding the role of ice particles in the atmosphere of our planet.
Download or read book Mixed Phase Clouds written by Constantin Andronache and published by Elsevier. This book was released on 2017-09-28 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed-Phase Clouds: Observations and Modeling presents advanced research topics on mixed-phase clouds. As the societal impacts of extreme weather and its forecasting grow, there is a continuous need to refine atmospheric observations, techniques and numerical models. Understanding the role of clouds in the atmosphere is increasingly vital for current applications, such as prediction and prevention of aircraft icing, weather modification, and the assessment of the effects of cloud phase partition in climate models. This book provides the essential information needed to address these problems with a focus on current observations, simulations and applications. - Provides in-depth knowledge and simulation of mixed-phase clouds over many regions of Earth, explaining their role in weather and climate - Features current research examples and case studies, including those on advanced research methods from authors with experience in both academia and the industry - Discusses the latest advances in this subject area, providing the reader with access to best practices for remote sensing and numerical modeling
Download or read book Ice Microdynamics written by Pao K. Wang and published by Elsevier. This book was released on 2002-09-06 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric ice particles play crucial roles in cloud and storm dynamics, atmospheric chemistry, climatological processes, and other atmospheric processes. Ice Microdynamics introduces the elementary physics and dynamics of atmospheric ice particles in clouds; subsequent sections explain their formation from water vapor, why ice crystal shape and concentration in cirrus clouds influence the heating of air, and describe how ice crystals cleanse the atmosphere by scavenging aerosol particles. Pao Wang's lucid writing style will appeal to atmospheric scientists, climatologists, and meteorologists with an interest in understanding the role of ice particles in the atmosphere of our planet.
Download or read book PHYSICOCHEMICAL PROPERTIES OF ATMOSPHERIC AEROSOLS AND THEIR EFFECT ON ICE CLOUD FORMATION written by and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Atmospheric aerosols play a vital role in the Earth's energy budget-directly by scattering and absorbing solar radiation and indirectly by acting as cloud condensation nuclei and ice-nucleating particles [1, 2]. The cloud formation potential of aerosol is driven by multiple factors, including surface properties, size distribution, composition, mixing state, phase state, and morphology [3]. The interaction of aerosols with clouds alters the aerosol's physicochemical properties. Those properties can also evolve during transport due to atmospheric processing, in turn, affect the aerosol's ice nucleation and cloud formation activities. This thesis presents experimental studies to understand the role of physicochemical properties of aerosol on the formation of ice. To get a detailed understanding of the aerosol effect on ice nucleation, we conducted controlled ice nucleation experiments on a known surface (muscovite mica) with controlled properties (e.g., surface cations) as well as ice nucleation experiments on complex atmospheric particles, which were characterized with multimodal microspectroscopic techniques. The results from controlled experiments suggest that the ice nucleation activity of a surface can be modified by simply changing the surface cations. In contrast, ice nucleation experiments with complex atmospheric particles indicates a more complicated dependence on the physicochemical properties.
Download or read book Analysis of Some Cloud and Frontal Events written by and published by . This book was released on 1984 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Plan for a Research Program on Aerosol Radiative Forcing and Climate Change written by Panel on Aerosol Radiative Forcing and Climate Change and published by National Academies Press. This book was released on 1996-05-01 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book recommends the initiation of an "integrated" research program to study the role of aerosols in the predicted global climate change. Current understanding suggest that, even now, aerosols, primarily from anthropogenic sources, may be reducing the rate of warming caused by greenhouse gas emissions. In addition to specific research recommendations, this book forcefully argues for two kinds of research program integration: integration of the individual laboratory, field, and theoretical research activities and an integrated management structure that involves all of the concerned federal agencies.
Download or read book Aerosol Scavenging by Ice in Supercooled Clouds written by Naihui Song and published by . This book was released on 1991 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microphysics of Clouds and Precipitation written by H.R. Pruppacher and published by Springer Science & Business Media. This book was released on 1996-12-31 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cloud physics has achieved such a voluminous literature over the past few decades that a significant quantitative study of the entire field would prove unwieldy. This book concentrates on one major aspect: cloud microphysics, which involves the processes that lead to the formation of individual cloud and precipitation particles. Common practice has shown that one may distinguish among the following addi tional major aspects: cloud dynamics, which is concerned with the physics respon sible for the macroscopic features of clouds; cloud electricity, which deals with the electrical structure of clouds and the electrification processes of cloud and precipi tation particles; and cloud optics and radar meteorology, which describe the effects of electromagnetic waves interacting with clouds and precipitation. Another field intimately related to cloud physics is atmospheric chemistry, which involves the chemical composition ofthe atmosphere and the life cycle and characteristics of its gaseous and particulate constituents. In view of the natural interdependence of the various aspects of cloud physics, the subject of microphysics cannot be discussed very meaningfully out of context. Therefore, we have found it necessary to touch briefly upon a few simple and basic concepts of cloud dynamics and thermodynamics, and to provide an account of the major characteristics of atmospheric aerosol particles. We have also included a separate chapter on some of the effects of electric fields and charges on the precipitation-forming processes.
Download or read book Aerosol Scavenging by Natural Ice Crystals written by David P. Sauter and published by . This book was released on 1984 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field and Laboratory Perspectives on the Cloud Nucleating Abilities of Aerosol Particles written by Beth Friedman and published by . This book was released on 2014 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol-cloud interactions represent a significant uncertainty with respect to radiative forcing and future climate change. Both particle composition and size play key, yet poorly understood, roles in determining the cloud nucleating capabilities of aerosols. The following describes ambient and laboratory measurements of cloud condensation nuclei (CCN) and ice nuclei (IN) measurements from a variety of sources, with the goal of understanding how composition and size interact in forming cloud droplets and ice crystals and the potential importance of aerosol composition and atmospheric aging processes on constraining uncertainties associated with the cloud nucleating properties of aerosols. Motivated by the anthropogenic emissions of soot particles as well as the potential properties of aged soot particles, ice formation and droplet activation of soot particles of various size and composition were studied. Generated soot particles were coated with a variety of atmospherically relevant acids of varying solubility properties. The particles were also exposed to ozone in order to simulate atmospheric oxidation and aging. A custom-built ice chamber was utilized to show that both uncoated and coated soot particles comparable to those generated in our studies are unlikely to significantly contribute to the global budget of heterogeneous IN at relevant atmospheric temperatures. This result is emphasized by comparison to an efficient ice nucleus, such as mineral dust. Coatings and oxidation by ozone also did not significantly alter the ice nucleation behavior of soot particles but aided in the uptake of water, suggesting the altered composition of a hydrophobic particle is important to take into account for cloud droplet activation. To assess the importance of particle composition in cloud droplet activation, measurements of CCN concentrations, single particle composition, and number size distributions were conducted at a high-elevation research site. The temporal evolution of detailed single particle chemical composition was compared with changes in CCN activation. A variety of particle types were observed; CCN activation largely followed the behavior of the sulfate-containing particle types; biomass burning particles also contained hygroscopic material that impacted CCN activation. The observed particles were largely aged; few local sources contributed to the particle composition due to the high elevation of the site. The results were also interpreted in terms of the assumed hygroscopicity of free tropospheric aerosol. As a further examination of the impacts of aging processes on aerosol hygroscopicity measurements of CCN concentrations, aerosol composition, and number size distributions were conducted during the winter season from of a variety of air masses, including aged marine, continental, and urban sources. Based on the measured chemistry and size properties of the ambient aerosol, CCN concentrations were predicted in order to assess the amount of composition detail necessary to explain droplet activation. Direct measurements of the composition of the activated droplets were also conducted with a novel technique to separate activated droplets from un-activated aerosol. Results suggest the importance of inorganic species in droplet activation, with non-oxidized organic species having negligible impacts on total aerosol hygroscopicity. Using the same novel separation technique, measurements of the single particle composition of activated droplet residual particles were determined at an urban site in the summertime, with similar air mass trajectories as the previous wintertime site, as well as influence from local urban aerosol sources. As a function of atmospheric supersaturation conditions the composition of activated droplet residual particles was compared to the ambient aerosol composition. The study was utilized to determine the level of composition and size detail required to describe droplet activation at a site with similar aged air mass trajectories to the previous study.
Download or read book An Introduction to Clouds written by Ulrike Lohmann and published by Cambridge University Press. This book was released on 2016-06-23 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Introduction to Clouds provides a fundamental understanding of clouds, ranging from cloud microphysics to the large-scale impacts of clouds on climate. On the microscale, phase changes and ice nucleation are covered comprehensively, including aerosol particles and thermodynamics relevant for the formation of clouds and precipitation. At larger scales, cloud dynamics, mid-latitude storms and tropical cyclones are discussed leading to the role of clouds on the hydrological cycle and climate. Each chapter ends with problem sets and multiple-choice questions that can be completed online, and important equations are highlighted in boxes for ease of reference. Combining mathematical formulations with qualitative explanations of underlying concepts, this accessible book requires relatively little previous knowledge, making it ideal for advanced undergraduate and graduate students in atmospheric science, environmental sciences and related disciplines.
Download or read book A Numerical Study of Aerosol Scavenging by Ice Crystals written by Renyi Zhang and published by . This book was released on 1989 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanisms for the Influence from Ice Nucleus Aerosols on Clouds and Their Indirect Effects Cloud Modelling written by Deepak Waman and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of multiple groups of primary biological aerosol particles (PBAPs) as ice nucleating particles (INPs), and of ice formation processes such as time-dependent freezing of various INPs, and various secondary ice production (SIP) mechanisms in overall ice concentration has been evaluated in a range of cloud systems by simulating them numerically with the state-of-the-art 'Aerosol-Cloud' (AC) model in a 3D mesoscale domain. Also, the mechanisms of aerosol indirect effects (AIEs) arising from anthropogenic INPs, and the responses to these AIEs from time-dependent INP freezing and SIP processes are investigated in the simulated clouds. The cloud systems simulated with AC are: events of summertime deep convection observed over Oklahoma, USA during the Midlatitude Continental Convective Cloud Experiment (MC3E) in 2011 on 1) 11 May, and 2) 20 May, and wintertime 3) orographic clouds observed during the Atmospheric Radiation Measurement Cloud Aerosol Precipitation Experiment (ACAPEX) on 07 February 2015 over North California, and 4) supercooled layer clouds observed over Larkhill, UK, during the Aerosol Properties, Processes And Influences on the Earth's climate (APPRAISE) campaign on 18 February 2009. AC uses the dynamical core of the Weather Research and Forecasting (WRF) model, modified Geophysical Fluid Dynamic Laboratory (GFDL) radiation scheme, and hybrid bin-bulk microphysics scheme. AC is validated adequately with the coincident aircraft, ground-based, and satellite observations for all four cases. AC forms secondary ice through the Hallett-Mossop (HM) process of rime-splintering, and fragmentation during ice-ice collisions, raindrop freezing, and sublimation of dendritic snow and graupel. A measure of SIP is defined using the term 'ice enhancement' (IE) ratio which is the ratio between the number concentration of total ice particles and active INPs at cloud tops. For both cases in MC3E, overall, PBAPs have little effect (+1-6%) on the cloud-liquid (droplet mean sizes, number concentrations, and their water contents) properties, overall ice concentration, and on precipitation. AC predicts the activity of various INPs with an empirical parameterization (EP). The EP is modified to represent the time-dependent approach of INP freezing in light of our published laboratory observations. It is predicted that the time dependence of INP freezing is not the main cause for continuous ice nucleation and precipitation in all simulated cases. Rather, the main mechanism of precipitation formation is the combination of various SIP mechanisms (in convection) and recirculation-reactivation of dust particles (in APPRAISE layer cloud episode). Also, for all cases, the inclusion of time dependence of INP freezing causes little increase (about 10-20%) in the total ice concentration and ice from all SIP. Regarding SIP, in young developing convective clouds of MC3E (11 May), with tops > −15oC, the initial explosive growth is from the fast HM process, creating IE ratios as high as 103. By contrast, in mature convective clouds (tops
Download or read book Mechanisms for the Influence from Ice Nucleus Aerosols on Clouds and Their Indirect Effects Clous Modelling written by Deepak Waman and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of multiple groups of primary biological aerosol particles (PBAPs) as ice nucleating particles (INPs), and of ice formation processes such as time-dependent freezing of various INPs, and various secondary ice production (SIP) mechanisms in overall ice concentration has been evaluated in a range of cloud systems by simulating them numerically with the state-of-the-art 'Aerosol-Cloud' (AC) model in a 3D mesoscale domain. Also, the mechanisms of aerosol indirect effects (AIEs) arising from anthropogenic INPs, and the responses to these AIEs from time-dependent INP freezing and SIP processes are investigated in the simulated clouds. The cloud systems simulated with AC are: events of summertime deep convection observed over Oklahoma, USA during the Midlatitude Continental Convective Cloud Experiment (MC3E) in 2011 on 1) 11 May, and 2) 20 May, and wintertime 3) orographic clouds observed during the Atmospheric Radiation Measurement Cloud Aerosol Precipitation Experiment (ACAPEX) on 07 February 2015 over North California, and 4) supercooled layer clouds observed over Larkhill, UK, during the Aerosol Properties, Processes And Influences on the Earth's climate (APPRAISE) campaign on 18 February 2009. AC uses the dynamical core of the Weather Research and Forecasting (WRF) model, modified Geophysical Fluid Dynamic Laboratory (GFDL) radiation scheme, and hybrid bin-bulk microphysics scheme. AC is validated adequately with the coincident aircraft, ground-based, and satellite observations for all four cases. AC forms secondary ice through the Hallett-Mossop (HM) process of rime-splintering, and fragmentation during ice-ice collisions, raindrop freezing, and sublimation of dendritic snow and graupel. A measure of SIP is defined using the term 'ice enhancement' (IE) ratio which is the ratio between the number concentration of total ice particles and active INPs at cloud tops. For both cases in MC3E, overall, PBAPs have little effect (+1-6%) on the cloud-liquid (droplet mean sizes, number concentrations, and their water contents) properties, overall ice concentration, and on precipitation. AC predicts the activity of various INPs with an empirical parameterization (EP). The EP is modified to represent the time-dependent approach of INP freezing in light of our published laboratory observations. It is predicted that the time dependence of INP freezing is not the main cause for continuous ice nucleation and precipitation in all simulated cases. Rather, the main mechanism of precipitation formation is the combination of various SIP mechanisms (in convection) and recirculation-reactivation of dust particles (in APPRAISE layer cloud episode). Also, for all cases, the inclusion of time dependence of INP freezing causes little increase (about 10-20%) in the total ice concentration and ice from all SIP. Regarding SIP, in young developing convective clouds of MC3E (11 May), with tops > −15oC, the initial explosive growth is from the fast HM process, creating IE ratios as high as 103. By contrast, in mature convective clouds (tops
Download or read book A Plan for a Research Program on Aerosol Radiative Forcing and Climate Change written by National Research Council and published by National Academies Press. This book was released on 1996-04-17 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book recommends the initiation of an "integrated" research program to study the role of aerosols in the predicted global climate change. Current understanding suggest that, even now, aerosols, primarily from anthropogenic sources, may be reducing the rate of warming caused by greenhouse gas emissions. In addition to specific research recommendations, this book forcefully argues for two kinds of research program integration: integration of the individual laboratory, field, and theoretical research activities and an integrated management structure that involves all of the concerned federal agencies.
Download or read book Precipitation Scavenging Dry Deposition and Resuspension written by Hans R. Pruppacher and published by . This book was released on 1983 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt:
