Properties and Radiative Effect of Aerosol and Cirrus Clouds Over the European Arctic PDF Download

Author: Konstantina Nakoudi
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Over the last decades, the rate of near-surface warming in the Arctic is at least double than elsewhere on our planet (Arctic amplification). However, the relative contribution of different feedback processes to Arctic amplification is a topic of ongoing research, including the role of aerosol and clouds. Lidar systems are well-suited for the investigation of aerosol and optically-thin clouds as they provide vertically-resolved information on fine temporal scales. Global aerosol models fail to converge on the sign of the Arctic aerosol radiative effect (ARE). In the first part of this work, the optical and microphysical properties of Arctic aerosol were characterized at case study level in order to assess the short-wave (SW) ARE. A long-range transport episode was first investigated. Geometrically similar aerosol layers were captured over three locations. Although the aerosol size distribution was different between Fram Strait(bi-modal) and Ny-Ålesund (fine mono-modal), the atmospheric column ARE was similar. The latter was related to ...

Author: David K. Lynch
Publisher: Oxford University Press
ISBN: 0195351398
Category : Science
Languages : en
Pages : 499

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Book Description
Cirrus clouds are high, thin, tropospheric clouds composed predominately of ice. In the last ten years, considerable work has shown that cirrus is widespread--more common than previously believed--and has a significant impact on climate and global change. As the next generation weather satellites are being designed, the impact of cirrus on remote sensing and the global energy budget must be recognized and accommodated. This book, the first to be devoted entirely to cirrus clouds, captures the state of knowledge of cirrus and serves as a practical handbook as well. Each chapter is based on an invited review talk presented at Cirrus, a meeting hosted by the Optical Society of America and co-sponsored by the American Geophysical Union and the American Meteorological Society. All aspects of cirrus clouds are covered, an approach that reaches into diverse fields. Topics include: the definition of cirrus, cirrus climatologies, nucleation, evolution and dissipation, mixed-phase thermodynamics, crystallinity, orientation mechanisms, dynamics, scattering, radiative transfer, in situ sampling, processes that produce or influence cirrus (and vice versa), contrails, and the influence of cirrus on climate.

Author: Constantin Andronache
Publisher: Elsevier
ISBN: 012810550X
Category : Science
Languages : en
Pages : 302

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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: Shobha Srinivasan Chopra
Publisher: Tredition Gmbh
ISBN: 9783384279071
Category : Nature
Languages : en
Pages : 0

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Book Description
Arctic aerosol modulates the Arctic radiative energy balance through direct interaction with the solar and terrestrial radiation and by changing the cloud properties (Garrett et al. 2004) as well as atmospheric dynamics (Doherty et al. 2013). It therefore interacts with the feedback mechanisms that lead to the AA. The effects of the aerosol radiation interaction depend on the altitude of the aerosol particles, the underlying surface, the time of year, and the aerosol composition. BC is of special interest, since it is the aerosol species that absorbs solar radiation most efficiently. Mineral dust is important because of its effect on clouds globally, but also in the Arctic, with vertically integrated dust burdens in the range of 10 mg m-2, the majority of which is transported from outside of the Arctic, with 38 % being transported from Asia and 32 % from Africa (Groot Zwaaftink et al. 2016). There its interaction with solar radiation it is even more important because of the high surface albedo, which can decrease by the deposition of mineral dust (Groot Zwaaftink et al. 2016). Sulphate is typically associated with the reflection of solar radiation, an effect that is less relevant in the Arctic than elsewhere because of the high surface albedo, and is not active during polar night.

Author: Panel on Aerosol Radiative Forcing and Climate Change
Publisher: National Academies Press
ISBN: 0309588871
Category : Science
Languages : en
Pages : 180

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Book Description
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.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309133505
Category : Science
Languages : en
Pages : 222

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Book Description
Changes in climate are driven by natural and human-induced perturbations of the Earth's energy balance. These climate drivers or "forcings" include variations in greenhouse gases, aerosols, land use, and the amount of energy Earth receives from the Sun. Although climate throughout Earth's history has varied from "snowball" conditions with global ice cover to "hothouse" conditions when glaciers all but disappeared, the climate over the past 10,000 years has been remarkably stable and favorable to human civilization. Increasing evidence points to a large human impact on global climate over the past century. The report reviews current knowledge of climate forcings and recommends critical research needed to improve understanding. Whereas emphasis to date has been on how these climate forcings affect global mean temperature, the report finds that regional variation and climate impacts other than temperature deserve increased attention.

Author: Kirill I︠A︡kovlevich Kondratʹev
Publisher: Springer Science & Business Media
ISBN: 9783540204763
Category : Nature
Languages : en
Pages : 736

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Book Description
Opening with a survey of contemporary global ecodynamics, including its basic components, this book goes on to discuss greenhouse effect problems in the context of global carbon cycle dynamics. The coverage includes land ecosystem changes, air-sea exchange models, high-latitude environmental dynamics, and a discussion of basic aspects of global environmental modelling and relevant monitoring systems. The volume concludes by examining society systems with emphasis on the problems of sustainable development.

Author: John T. Sullivan
Publisher: Springer Nature
ISBN: 3031378180
Category : Science
Languages : en
Pages : 825

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Book Description
This volume presents papers from the biennial International Laser Radar Conference (ILRC), the world’s leading event in the field of atmospheric research using lidar. With growing environmental concerns to address such as air quality deterioration, stratospheric ozone depletion, extreme weather events, and changing climate, the lidar technique has never been as critical as it is today to monitor, alert, and help solve current and emerging problems of this century. The 30th occurrence of the ILRC unveils many of the newest results and discoveries in atmospheric science and laser remote sensing technology. The 30th ILRC conference program included all contemporary ILRC themes, leveraging on both the past events’ legacy and the latest advances in lidar technologies and scientific discoveries, with participation by young scientists particularly encouraged. This proceedings volume includes a compilation of cutting-edge research on the following themes: new lidar techniques and methodologies; measurement of clouds and aerosol properties; atmospheric temperature, wind, turbulence, and waves; atmospheric boundary layer processes and their role in air quality and climate; greenhouse gases, tracers, and transport in the free troposphere and above; the upper mesosphere and lower thermosphere; synergistic use of multiple instruments and techniques, networks and campaigns; model validation and data assimilation using lidar measurements; space-borne lidar missions, instruments and science; ocean lidar instrumentation, techniques, and retrievals; and past, present and future synergy of heterodyne and direct detection lidar applications. In addition, special sessions celebrated 50 years of lidar atmospheric observations since the first ILRC, comprising review talks followed by a plenary discussion on anticipated future directions.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 1

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During the report period, we have made the following research accomplishments. First, we performed analysis for a number of MODIS scenes comprising of heavy dust events and ice clouds, covering regions of frequent dust outbreaks in East Asia, Middle East, and West Africa, as well as areas associated with long-range dust transports over the Equatorial Tropical Atlantic Ocean. These scenes contain both dust/aerosols and clouds. We collected suitable aerosol/ice-cloud data, correlated ice cloud and aerosol parameters by means of statistical analysis, and interpreted resulting correlation trends based on the physical principles governing cloud microphysics. Aerosol and cloud optical depths and cloud effective particle size inferred from MODIS for selected domains were analyzed from which the parameters including dust aerosol number concentration, ice cloud water path, and ice particle number concentration were subsequently derived. We illustrated that the Twomey (solar albedo) effect can be statistically quantified based on the slope of best-fit straight lines in the correlation study. Analysis of aerosol and cloud retrieval products revealed that for all cases, the region with a larger dust aerosol optical depth is always characterized by a smaller cloud particle size, consistent with the Twomey hypothesis for aerosol-cloud interactions. Second, we developed mean correlation curves with uncertainties associated with small ice-crystal concentration observations for the mean effective ice crystal size (De) and ice water content (IWC) by dividing the atmosphere into three characteristic regions: Tropics cirrus, Midlatitude cirrus, including a temperature classification to improve correlation, and Arctic ice clouds. We illustrated that De has a high correlation with IWC based on theoretical consideration and analysis of thousands of observed ice crystal data obtained from a number of ARM-DOE field campaigns and other experiments. The correlation has the form: ln(De) = a + b ln(IWC) + c ((ln(IWC))2, where a, b, and c are fitting coefficients and are functions of three regions. We demonstrated that this correlation can be effectively incorporated in GCMs and climate models that predict IWC - a significant advance in ice microphysics parameterization for interactive cloud-radiation analysis and feedback. Substantial July mean differences are shown in the OLR (W/m2) and precipitation (mm/day) patterns between UCLA GCM simulations based on Des determined from the De-IWC correlations and the control run using a fixed ice crystal size. Third, in order to improve the computation of spectral radiative transfer processes in the WRF model, we developed a consistent and efficient radiation scheme that can better resolve the spectral bands, determine the cloud optical properties, and provide more reliable and accurate radiative heating fields. In the newly developed radiation module, we have implemented in WRF a modified and improved version referred to as the Fu-Liou-Gu scheme, which includes a combination of delta-four-stream and delta-two-stream approximations for solar and IR flux calculations, respectively. This combination has been proven to be computationally efficient and at the same time to produce a high degree of accuracy. The incorporation of nongray gaseous absorption in multiple scattering atmospheres was based on the correlated k-distribution method. The solar and IR spectra are divided into 6 and 12 bands, respectively, according to the location of absorption bands of H2O, CO2, O3, CH4, N2O, and CFCs. We further included absorption by the water vapor continuum and a number of minor absorbers in the solar spectrum leading to an additional absorption of solar flux in a clear atmosphere on the order of 1-3 W/m2. Additionally, we incorporated the ice microphysics parameterization that includes an interactive mean effective ice crystal size in association with radiation parameterizations. The Fu-Liou-Gu scheme is an ideal tool for t ...

Author: David K. Lynch
Publisher: Oxford University Press, USA
ISBN: 0195130723
Category : Cirrus clouds
Languages : en
Pages : 499

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Book Description
This text, devoted entirely to cirrus clouds, captures the state of knowledge of cirrus clouds and serves as a practical handbook as well.