Download or read book The Effects of Aerosol cloud Interactions on Warm Cloud Properties written by Alyson Douglas and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: When aerosols enter the atmosphere through anthropogenic and natural activities, they interact with clouds in the atmosphere in what is termed aerosol-cloud interactions (ACI). ACI alter the cloud's radiative properties by acting as cloud condensation nuclei within the cloud, thereby reducing the mean drop size and increasing the cloud's albedo and cooling the earth by reflecting incoming shortwave radiation in what is termed the first indirect effect. By reducing the mean drop size throughout the cloud, aerosol also act to delay precipitation formation, leading to larger, longer lived clouds and further cooling the earth in a process known as the second indirect effect. Using four years of satellite observations, the overall impact of aerosols on warm cloud radiative effect is evaluated. Warm clouds are defined as clouds with cloud top temperatures below freezing level. The estimates are constrained within regimes of stability, relative humidity of the free atmosphere, and by the scene liquid water path to control for how meteorology modulates the strength and sign of ACI. The sum of the first and second indirect effect, estimates of how aerosols alter the warm cloud shortwave effect and cloud fraction, are compared to an estimate of the full indirect effect, which includes all changes to the warm cloud shortwave radiative effect. The decomposed, or summative, indirect effect (-0.26 +/- .15 Wm2) is less than the full indirect effect (-0.32 +/- .16 Wm2), though they lie within each other's uncertainty estimates. When the decomposed indirect effect is further constrained by precipitation, the estimate decreases to .21 +/- .15 Wm2. The difference between the full indirect effect forcing and the decomposed forcings may be secondary indirect effects not included in our decomposition. The second indirect effect includes not only the cloud extent broadening, but the cloud depth increasing. This deepening response may increase warming due to a larger longwave cloud radiative effect. The longwave indirect effect susceptibility is decomposed to determine how large it may potentially be and whether it could offset any cooling due to the shortwave indirect effect. We find the longwave indirect effect does have the potential to offset cooling through cloud deepening in regions where the shortwave indirect effect is extremely small, however the magnitude of the longwave component is sensitive to the diurnal cycle. Cloud deepening signals clouds may be invigorated, or experiencing a state where precipitation formation and turbulence increase due to ACI. The effects of aerosol on precipitation formation and vertical motion are investigated using WALRUS, an algorithm of latent heating within the cloud determined using CloudSat radar returns. The LWP is constrained to thicker clouds 150 gm2

Download or read book Aerosol Cloud Climate Interactions written by Peter V. Hobbs and published by Academic Press. This book was released on 1993-07-22 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol and clouds play important roles in determining the earth's climate, in ways that we are only beginning to comprehend. In conjunction with molecular scattering from gases, aerosol and clouds determine in part what fraction of solar radiation reaches the earth's surface, and what fraction of the longwave radiation from the earth escapes to space. This book provides an overview of the latest research on atmospheric aerosol and clouds and their effects on global climate. Subjects reviewed include the direct and indirect effects of aerosol on climate, the radiative properties of clouds and their effects on the Earth's radiation balance, the incorporation of cloud effects in numerical weather prediction models, and stratospheric aerosol and clouds.

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 Remote Sensing of Aerosols Clouds and Precipitation written by Tanvir Islam and published by Elsevier. This book was released on 2017-10-18 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remote Sensing of Aerosols, Clouds, and Precipitation compiles recent advances in aerosol, cloud, and precipitation remote sensing from new satellite observations. The book examines a wide range of measurements from microwave (both active and passive), visible, and infrared portions of the spectrum. Contributors are experts conducting state-of-the-art research in atmospheric remote sensing using space, airborne, and ground-based datasets, focusing on supporting earth observation satellite missions for aerosol, cloud, and precipitation studies. A handy reference for scientists working in remote sensing, earth science, electromagnetics, climate physics, and space engineering. Valuable for operational forecasters, meteorologists, geospatial experts, modelers, and policymakers alike. - Presents new approaches in the field, along with further research opportunities, based on the latest satellite data - Focuses on how remote sensing systems can be designed/developed to solve outstanding problems in earth and atmospheric sciences - Edited by a dynamic team of editors with a mixture of highly skilled and qualified authors offering world-leading expertise in the field

Download or read book Aerosol Cloud Interactions from Urban Regional to Global Scales written by Yuan Wang and published by Springer. This book was released on 2015-05-05 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies in this dissertation aim at advancing our scientific understandings about physical processes involved in the aerosol-cloud-precipitation interaction and quantitatively assessing the impacts of aerosols on the cloud systems with diverse scales over the globe on the basis of the observational data analysis and various modeling studies. As recognized in the Fifth Assessment Report by the Inter-government Panel on Climate Change, the magnitude of radiative forcing by atmospheric aerosols is highly uncertain, representing the largest uncertainty in projections of future climate by anthropogenic activities. By using a newly implemented cloud microphysical scheme in the cloud-resolving model, the thesis assesses aerosol-cloud interaction for distinct weather systems, ranging from individual cumulus to mesoscale convective systems. This thesis also introduces a novel hierarchical modeling approach that solves a long outstanding mismatch between simulations by regional weather models and global climate models in the climate modeling community. More importantly, the thesis provides key scientific solutions to several challenging questions in climate science, including the global impacts of the Asian pollution. As scientists wrestle with the complexities of climate change in response to varied anthropogenic forcing, perhaps no problem is more challenging than the understanding of the impacts of atmospheric aerosols from air pollution on clouds and the global circulation.

Download or read book The Impact of Aerosol cloud radiation Interaction on California Weather written by Hsiang-He Lee and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The source-oriented Weather Research and Forecasting chemistry model (SOWC) was modified to include warm/cold cloud processes and applied to investigate 1) how source-oriented aerosols influence fog formation and optical properties in the atmosphere, 2) how aerosol mixing state influences cloud and ice formation and atmospheric optical properties during a winter storm, and 3) the direct, semi-direct, and indirect effects of long-range transport dust on severe weather over California and the Eastern Pacific. SOWC tracks 6-dimensional chemical variables (X, Z, Y, Size Bins, Source Types, Species) through an explicit simulation of atmospheric chemistry and physics. In this study, all aerosol source types can activate to form cloud condensation nuclei (CCN) based on the Köhler theory, but the dust is the only source of ice nuclei (IN). Furthermore, a new source-oriented cloud module in the two-moment Purdue Lin microphysics scheme, and a new module with all source-oriented hydrometeors (cloud, ice, rain, snow and graupel) in the Morrison two-moment microphysics scheme were implemented into the SOWC model to study fog events and winter storm cases, respectively. In Chapter 2, the enhanced SOWC model was used to study a fog event that occurred on January 17th, 2011, in the Central Valley of California. The SOWC reasonably portrays the spatial distribution and duration of the fog event consistent with observations. The source-oriented mixture representation of particles reduced cloud droplet number relative to the internal mixture approach that artificially coats hydrophobic particles with hygroscopic components. The fraction of aerosols activating into CCN at a supersaturation of 0.5% in the Central Valley decreased from 86% in the internal mixture model to 68% in the source-oriented model. This increased the surface energy flux by 3-5 W m-2 and surface temperature by as much as 0.15 K. In Chapter 3, the enhanced SOWC model was used to study a winter storm that occurred on March 6th, 2011, in California. Compared to ground based observations, SOWC with the modified Morrison microphysics scheme and modified Goddard radiation schemes predicted reasonable precipitation, but the onset of precipitation is delayed by 5 hours. Immersion freezing was the main mechanism for ice nuclei formation. Secondary coatings on dust particles increased IN from immersion freezing but decreased IN from contact freezing. Increasing CCN and IN in the internal mixing experiment produced more ice crystals and cloud droplets but did not significantly alter total perception under the conditions studied. However, because of the reducing riming efficiency from snow to graupel in the source-oriented mixing experiment, it resulted more snowfall (less rainfall) on the ground, especially over the mountain area. In Chapter 4, the SOWC model was used to understand the direct, semi-direct, and indirect effects of long-range transport dust on severe weather over Eastern Pacific Ocean. The maximum averaged IN nucleation rate increased 36% after adding long-range transport dust. Because clouds in mid-latitude originate precipitately via the ice phase, an increase in IN can enhance ice formation from supercooled water by heterogenetic freezing (mainly contact freezing) and then to alter hydrometer water amount. Adding long-range transport dust increased the mixing ratio and number concentration for almost all hydrometers. However, the changes of adding local dust in local+LR_dust from LR_dust is more complicated due to the importance of hydrometers in the cumulus scheme. The change in the strength of convection after adding long-range transport dust (or local dust) also produces a noticeable distinction in the precipitation pattern, but the total precipitation did not have major difference after adding long-range transport dust (or local dust).

Download or read book Clouds in the Perturbed Climate System written by Jost Heintzenberg and published by Strungmann Forum Reports. This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: More than half the globe is covered by visible clouds.

Download or read book Atmospheric Aerosol Properties and Climate Impacts written by and published by . This book was released on 2009 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerosols and Climate written by Ken S. Carslaw and published by Elsevier. This book was released on 2022-08-19 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ever-diversifying field of aerosol effects on climate is comprehensively presented here, describing the strong connection between fundamental research and model applications in a way that will allow both experienced researchers and those new to the field to gain an understanding of a wide range of topics. The material is consistently presented at three levels for each topic: (i) an accessible "quick read" of the essentials, (ii) a more detailed description, and (iii) a section dedicated to how the processes are handled in models. The modelling section in each chapter summarizes the current level of knowledge and what the gaps in this understanding mean for the effects of aerosols on climate, enabling readers to quickly understand how new research fits into established knowledge. Definitions, case studies, reference data, and examples are included throughout. Aerosols and Climate is a vital resource for graduate students, postdoctoral researchers, senior researchers, and lecturers in departments of atmospheric science, meteorology, engineering, and environment. It will also be of interest to those working in operational centers and policy-facing organizations, providing strong reference material on the current state of knowledge. - Includes a section in each chapter that focuses on the treatment of relevant aerosol processes in climate models - Provides clear exposition of the challenges in understanding and reducing persistent gaps in knowledge and uncertainties in the field of aerosol-climate interaction, going beyond the fundamentals and existing knowledge - Authored by experts in modeling and aerosol processes, analysis or observations to ensure accessibility and balance

Download or read book High Resolution Active Optical Remote Sensing Observations of Aerosols Clouds and Aerosol Cloud Interactions and Their Implication to Climate written by Simone Lolli and published by MDPI. This book was released on 2020-12-03 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remote Sensing is of paramount importance for Earth Observation to monitor and analyze the Earth’s vital signs. In this Special Issue are reported the latest research results involving active optical remote sensing instruments, both from ground-based to satellite platforms, that are involved in analyzing the vertical and horizontal aerosol and cloud distribution, other than their geometrical, optical and microphysical properties. Those active optical remote sensing techniques are also very useful in determining pollutant dispersion and the dynamics inside the boundary layer. The published studies put in evidence the hidden mechanisms on how pollution from the source is advected transnationally in other countries and the interaction with local meteorology.

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 Investigating Aerosol cloud Interactions written by Benjamin Stephen Grandey and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microphysical and dynamical interactions between aerosols and clouds are associated with some of the largest uncertainties in projections of future climate. Many possible aerosol effects on clouds have been suggested, but large uncertainties remain. In order to improve model projections of fu- ture climate, it is essential that we improve our quantitative understanding of anthropogenic aerosol effects. Several studies investigating interactions between satellite-observed aerosol and cloud prop- erties have been published in recent years. However, the observed relationships are not necessarily due to aerosol effects on clouds. They may be due to cloud and precipitation effects on aerosol, me- teorological covariation, observational data errors or methodological errors. An analysis of method- ological errors arising through climatological spatial gradients is performed. For region sizes larger than 40 x 40, commonly used in the literature, spurious spatial variations in retrieved cloud and aerosol properties are found to introduce widespread significant errors to calculations of aerosol- cloud relationships. Small scale analysis prior to error-weighted aggregation to larger region sizes is recommended. Appropriate ways of quantifying relationships between aerosol optical depth (T) and cloud properties are considered, and results are presented for three satellite datasets. There is much disagreement in observed relationships between T and liquid cloud droplet number concentration and between T and liquid cloud droplet effective radius, particularly over land. However, all three satellite datasets are in agreement about strong positive relationships between T and cloud top height and between T and cloud fraction (fc). Using reanalysis T data, which are less affected by retrieval artifacts, it is suggested that a large part of the observed Ie-r signal may fc-T be due to cloud contamination of T. General circulation model simulations further demonstrate that positive fc-T relationships may primarily arise due to covariation with relative humidity, and that negative fc-T relationships may arise due to scavenging of aerosol by precipitation. A new method of investigating the contribu- tion of meteorological covariation to the observed relationships is introduced. Extratropical cyclone storm-centric composites of retrieved aerosol and cloud properties are investigated. A storm-centric description of the synoptics is found to be capable of explaining spurious fc-T relationships, although the spurious relationships explained are considerably smaller than observed relationships.

Download or read book Encyclopedia of Atmospheric Sciences written by Gerald R. North and published by Elsevier. This book was released on 2014-09-14 with total page 2874 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Atmospheric Sciences, Second Edition, Six Volume Set is an authoritative resource covering all aspects of atmospheric sciences, including both theory and applications. With more than 320 articles and 1,600 figures and photographs, this revised version of the award-winning first edition offers comprehensive coverage of this important field. The six volumes in this set contain broad-ranging articles on topics such as atmospheric chemistry, biogeochemical cycles, boundary layers, clouds, general circulation, global change, mesoscale meteorology, ozone, radar, satellite remote sensing, and weather prediction. The Encyclopedia is an ideal resource for academia, government, and industry in the fields of atmospheric, ocean, and environmental sciences. It is written at a level that allows undergraduate students to understand the material, while providing active researchers with the latest information in the field. Covers all aspects of atmospheric sciences—including both theory and applications Presents more than 320 articles and more than 1,600 figures and photographs Broad-ranging articles include topics such as atmospheric chemistry, biogeochemical cycles, boundary layers, clouds, general circulation, global change, mesoscale meteorology, ozone, radar, satellite remote sensing, and weather prediction An ideal resource for academia, government, and industry in the fields of atmospheric, ocean, and environmental sciences

Download or read book Clouds and Their Climatic Impact written by Sylvia Sullivan and published by John Wiley & Sons. This book was released on 2023-12-19 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clouds and Their Climatic Impacts Clouds are an influential and complex element of Earth’s climate system. They evolve rapidly in time and exist over small spatial scales, but also affect global radiative balance and large-scale circulations. With more powerful models and extensive observations now at our disposal, the climate impact of clouds is receiving ever more research attention. Clouds and Their Climatic Impacts: Radiation, Circulation, and Precipitation presents an overview of our current understanding on various types of clouds and cloud systems and their multifaceted role in the radiative budget, circulation patterns, and rainfall. Volume highlights include: Interactions of aerosol with both liquid and ice clouds Surface and atmospheric cloud radiative feedbacks and effects Arctic, extratropical, and tropical clouds Cloud-circulation coupling at global, meso, and micro scales Precipitation efficiency, phase, and measurements The role of machine learning in understanding clouds and climate The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.

Download or read book The Future of the World s Climate written by Ann Henderson-Sellers and published by Elsevier. This book was released on 2012-01-31 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The study of climate today seems to be dominated by global warming, but these predictions of climatic models must be placed in their geological, paleo-climatic, and astronomical context to create a complete picture of the Earth's future climate. The Future of the World's Climate presents that perspective with data and projections that have emerged from more technologically advanced and accurate climate modeling"--Publisher's website.

Download or read book Clouds and Climate written by A. Pier Siebesma and published by Cambridge University Press. This book was released on 2020-08-20 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive overview of research on clouds and their role in our present and future climate, for advanced students and researchers.

Download or read book On the Representation of Aerosol cloud Interactions in Atmospheric Models written by Donifan Barahona and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic atmospheric aerosols (suspended particulate matter) can modify the radiative balance (and climate) of the Earth by altering the properties and global distribution of clouds. Current climate models however cannot adequately account for many important aspects of these aerosol-cloud interactions, ultimately leading to a large uncertainty in the estimation of the magnitude of the effect of aerosols on climate. This thesis focuses on the development of physically-based descriptions of aerosol-cloud processes in climate models that help to address some of such predictive uncertainty. It includes the formulation of a new analytical parameterization for the formation of ice clouds, and the inclusion of the effects of mixing and kinetic limitations in existing liquid cloud parameterizations. The parameterizations are analytical solutions to the cloud ice and water particle nucleation problem, developed within a framework that considers the mass and energy balances associated with the freezing and droplet activation of aerosol particles. The new frameworks explicitly account for the impact of cloud formation dynamics, the aerosol size and composition, and the dominant freezing mechanism (homogeneous vs. heterogeneous) on the ice crystal and droplet concentration and size distribution. Application of the new parameterizations is demonstrated in the NASA Global Modeling Initiative atmospheric and chemical and transport model to study the effect of aerosol emissions on the global distribution of ice crystal concentration, and, the effect of entrainment during cloud droplet activation on the global cloud radiative properties. The ice cloud formation framework is also used within a parcel ensemble model to understand the microphysical structure of cirrus clouds at very low temperature. The frameworks developed in this work provide an efficient, yet rigorous, representation of cloud formation processes from precursor aerosol. They are suitable for the study of the effect of anthropogenic aerosol emissions on cloud formation, and can contribute to the improvement of the predictive ability of atmospheric models and to the understanding of the impact of human activities on climate.