The Impact of Aerosol-cloud-radiation Interaction on California Weather PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download The Impact of Aerosol-cloud-radiation Interaction on California Weather PDF full book. Access full book title The Impact of Aerosol-cloud-radiation Interaction on California Weather by Hsiang-He Lee. Download full books in PDF and EPUB format.
Author: Hsiang-He Lee
Publisher:
ISBN: 9781321363142
Category :
Languages : en
Pages :
Get Book Here
Book Description
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).
Author: Hsiang-He Lee
Publisher:
ISBN: 9781321363142
Category :
Languages : en
Pages :
Get Book Here
Book Description
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).
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309443458
Category : Science
Languages : en
Pages : 53
Get Book Here
Book Description
One of the most significant and uncertain aspects of climate change projections is the impact of aerosols on the climate system. Aerosols influence the climate indirectly by interacting with nearby clouds leading to small changes in cloud cover, thickness, and altitude, which significantly affect Earth's radiative balance. Advancements have been made in recent years on understanding the complex processes and atmospheric interactions involved when aerosols interact with surrounding clouds, but further progress has been hindered by limited observations. The National Academies of Sciences, Engineering, and Medicine organized a workshop to discuss the usefulness of the classified observing systems in advancing understanding of cloud and aerosol interactions. Because these systems were not developed with weather and climate modeling as a primary mission objective, many participants said it is necessary for scientists to find creative ways to utilize the data. The data from these systems have the potential to be useful in advancing understanding of cloud and aerosol interactions. This publication summarizes the presentations and discussions from the workshop.
Author: Sylvia Sullivan
Publisher: John Wiley & Sons
ISBN: 1119700310
Category : Science
Languages : en
Pages : 371
Get Book Here
Book Description
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.
Author: Jessie Marie Creamean
Publisher:
ISBN: 9781267646668
Category :
Languages : en
Pages : 236
Get Book Here
Book Description
Atmospheric aerosols have significant implications for human health and climate. For instance, aerosols impact climate directly by scattering and absorbing solar and terrestrial radiation and indirectly by acting as cloud condensation nuclei (CCN) and ice nuclei (IN), which facilitate cloud droplet and ice crystal formation, respectively. Changes in chemistry, size, and number concentrations between different locations and over time alter how aerosols impact air quality and cloud formation, and can have broader implications on precipitation efficiency and phase. Further, aerosol composition largely depends on meteorology, which influences sources and chemical transformation in the atmosphere. Aerosol-cloud-precipitation interactions represent one of the largest sources of uncertainty in climate science; therefore, a better understanding of the aerosols that contribute to these effects is needed. To address this source of uncertainty, the chemical composition of individual ambient aerosols and aerosols as insoluble residues in precipitation samples was determined using aerosol time-of-flight mass spectrometry (ATOFMS) and provided insight into their potential to serve as cloud seeds at three different locations over time. A three-year summer study (2005-2007) in Riverside, CA afforded information on the inter-annual variability of the urban aerosol due to changes in aerosol transport and meteorological conditions. In the summer of 2008 in Atlanta, GA, tropical cyclones shifted the representative aged urban aerosol to a less-aged, less-CCN active aerosol population, having implications on regional cloud formation after extreme weather events. At a remote site in the Sierra Nevada Mountains in the winter of 2009, observations of newly-formed aerosols presented a new source of CCN. Inter-annual trends in precipitation at the same remote site showed how IN transported from the Sahara and Asia potentially influenced precipitation processes during three winter seasons (2009-2011). Investigating changes in cloud seeds represents a longer-term goal to reduce uncertainties associated with modeling aerosol-cloud-precipitation interactions. Larger spatial and temporal coverage is needed to better understand trends in cloud formation and precipitation and to provide more detail for regional and global model parameterization. The results presented herein represent a noteworthy advancement towards understanding variation in composition and sources of cloud seeds in different regions and in most cases long time periods.
Author: Peter V. Hobbs
Publisher: Academic Press
ISBN: 0080959962
Category : Science
Languages : en
Pages : 259
Get Book Here
Book Description
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.
Author: PRUPPACHER
Publisher: Birkhäuser
ISBN:
Category : Juvenile Nonfiction
Languages : en
Pages : 386
Get Book Here
Book Description
Author: Tanvir Islam
Publisher: Elsevier
ISBN: 0128104384
Category : Science
Languages : en
Pages : 366
Get Book Here
Book Description
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
Author: Constantin Andronache
Publisher: Elsevier
ISBN: 012810550X
Category : Science
Languages : en
Pages : 302
Get Book Here
Book Description
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
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309314852
Category : Science
Languages : en
Pages : 276
Get Book Here
Book Description
The growing problem of changing environmental conditions caused by climate destabilization is well recognized as one of the defining issues of our time. The root problem is greenhouse gas emissions, and the fundamental solution is curbing those emissions. Climate geoengineering has often been considered to be a "last-ditch" response to climate change, to be used only if climate change damage should produce extreme hardship. Although the likelihood of eventually needing to resort to these efforts grows with every year of inaction on emissions control, there is a lack of information on these ways of potentially intervening in the climate system. As one of a two-book report, this volume of Climate Intervention discusses albedo modification - changing the fraction of incoming solar radiation that reaches the surface. This approach would deliberately modify the energy budget of Earth to produce a cooling designed to compensate for some of the effects of warming associated with greenhouse gas increases. The prospect of large-scale albedo modification raises political and governance issues at national and global levels, as well as ethical concerns. Climate Intervention: Reflecting Sunlight to Cool Earth discusses some of the social, political, and legal issues surrounding these proposed techniques. It is far easier to modify Earth's albedo than to determine whether it should be done or what the consequences might be of such an action. One serious concern is that such an action could be unilaterally undertaken by a small nation or smaller entity for its own benefit without international sanction and regardless of international consequences. Transparency in discussing this subject is critical. In the spirit of that transparency, Climate Intervention: Reflecting Sunlight to Cool Earth was based on peer-reviewed literature and the judgments of the authoring committee; no new research was done as part of this study and all data and information used are from entirely open sources. By helping to bring light to this topic area, this book will help leaders to be far more knowledgeable about the consequences of albedo modification approaches before they face a decision whether or not to use them.
Author: Alyson Douglas
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
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
