CiteULike: chitah's library [462 articles]

Fog-induced variations in aerosol optical and physical properties over the Indo-Gangetic Basin and impact to aerosol radiative forcing

SK Das — 2008-07-04T09:30:29-00:00

Annales Geophysicae, Vol. 26, No. 6. (2008), pp. 1345-1354.

A detailed study on the changes in aerosol physical and optical properties during fog events were made in December 2004 at Hissar (29.13° N, 75.70° E), a city located in the Indo-Gangetic basin. The visible aerosol optical depth was relatively low (0.3) during the initial days, which, however, increased (0.86) as the month progressed. The increasing aerosol amount, the decreasing surface temperature and a higher relative humidity condition were found favoring the formation of fog. The fog event is also found to alter the aerosol size distribution. An increase in the number concentration of the nucleation mode (radius<0.1 μm) particles, along with a decrease in the mode radius showed the formation of freshly nucleated aerosols. In the case of accumulation mode (0.1 μm<radius<1.0 μm) an increase in the mode radius was observed showing the hygroscopic and coagulation growth of particles. The observed aerosol optical depth spectra are model fitted to infer the aerosol components which are further used to compute the aerosol radiative forcing. The top of the atmosphere forcing is found to increase during foggy days due to large backscattering of radiation back to space. It is also shown that during foggy days, as the day progresses the RH value decreases, which reduces the forcing value while the increasing solar elevation increases the forcing value. Thus the fog event which prolongs longer into the daytime has a stronger effect on the diurnally averaged aerosol radiative forcing than those events which are confined only to the early morning hours.

ATMOSPHERIC SCIENCE: Himalaya--Carbon Sink or Source?

Jerome Gaillardet — 2008-06-27T20:22:11-00:00

Science, Vol. 320, No. 5884. (27 June 2008), pp. 1727-1728.

10.1126/science.1159279

A spatio-temporal approach for global validation and analysis of MODIS aerosol products

Charles Ichoku — 2008-07-01T03:55:45-00:00

Geophysical Research Letters, Vol. 29, No. 12. (29 June 2002), 8006.

Chemically segregated optical and microphysical properties of ambient aerosols measured in a single-particle mass spectrometer

Ryan Moffet — 2008-06-30T04:16:26-00:00

Journal of Geophysical Research, Vol. 113 (27 June 2008), D12213.

A Multisensor satellite-based assessment of biomass burning aerosol radiative impact over Amazonia

Falguni Patadia — 2008-06-30T04:10:54-00:00

Journal of Geophysical Research, Vol. 113 (28 June 2008), D12214.

Global modeling of multicomponent aerosol species: Aerosol optical parameters

T Ayash — 2008-06-23T06:34:52-00:00

Journal of Geophysical Research, Vol. 113 (19 June 2008), D12203.

Laboratory investigation of fire radiative energy and smoke aerosol emissions

Charles Ichoku — 2008-06-23T04:44:18-00:00

Journal of Geophysical Research, Vol. 113 (21 June 2008), D14S09.

Aerosol remote sensing over land: A comparison of satellite retrievals using different algorithms and instruments

AA Kokhanovsky — 2008-06-17T04:22:34-00:00

Atmospheric Research, Vol. 85, No. 3-4. (September 2007), pp. 372-394.

An inter-comparison study of the aerosol optical thickness (AOT) at 0.55 [mu]m retrieved using different satellite instruments and algorithms based on the analysis of backscattered solar light is presented for a single scene over central Europe on October 13th, 2005. For the first time comparisons have been performed for as many as six instruments on multiple satellite platforms. Ten different algorithms are briefly discussed and inter-compared. It was found that on the scale of a single pixel there can be large differences in AOT retrieved over land using different retrieval techniques and instruments. However, these differences are not as pronounced for the average AOT over land. For instance, the average AOT at 0.55 [mu]m for the area 7-12E, 49-53N was equal to 0.14 for MISR, NASA MODIS and POLDER algorithms. It is smaller by 0.01 for the ESA MERIS aerosol product and larger by 0.04 for the MERIS BAER algorithm. AOT as derived using AATSR gives on average larger values as compared to all other instruments, while SCIAMACHY retrievals underestimate the aerosol loading. These discrepancies are explained by uncertainties in a priori assumptions used in the different algorithms and differences in the sensor characteristics. Validation against AERONET shows that MERIS provides the most accurate AOT retrievals for this scene.

Precisão das fun\\c cões estat\\\isticas de ferramentas spreadsheet: uma análise comparativa

MG Almiron — 2008-06-13T09:39:13-00:00

(2008)

Inter-comparison of receptor models for PM source apportionment: Case study in an industrial area

M Viana — 2008-06-13T09:16:06-00:00

Atmospheric Environment, Vol. 42, No. 16. (May 2008), pp. 3820-3832.

Receptor modelling techniques are used to identify and quantify the contributions from emission sources to the levels and major and trace components of ambient particulate matter (PM). A wide variety of receptor models are currently available, and consequently the comparability between models should be evaluated if source apportionment data are to be used as input in health effects studies or mitigation plans. Three of the most widespread receptor models (principal component analysis, PCA; positive matrix factorization, PMF; chemical mass balance, CMB) were applied to a single PM10 data set (n=328 samples, 2002-2005) obtained from an industrial area in NE Spain, dedicated to ceramic production. Sensitivity and temporal trend analyses (using the Mann-Kendall test) were applied. Results evidenced the good overall performance of the three models (r2>0.83 and [alpha]>0.91×between modelled and measured PM10 mass), with a good agreement regarding source identification and high correlations between input (CMB) and output (PCA, PMF) source profiles. Larger differences were obtained regarding the quantification of source contributions (up to a factor of 4 in some cases). The combined application of different types of receptor models would solve the limitations of each of the models, by constructing a more robust solution based on their strengths. The authors suggest the combined use of factor analysis techniques (PCA, PMF) to identify and interpret emission sources, and to obtain a first quantification of their contributions to the PM mass, and the subsequent application of CMB. Further research is needed to ensure that source apportionment methods are robust enough for application to PM health effects assessments.

Identification of PM sources by principal component analysis (PCA) coupled with wind direction data

M Viana — 2008-06-13T09:13:22-00:00

Chemosphere, Vol. 65, No. 11. (December 2006), pp. 2411-2418.

The effectiveness of combining principal component analysis (PCA) with multi-linear regression (MLRA) and wind direction data was demonstrated in this study. PM data from three grain-size fractions from a highly industrialised area in Northern Spain were analysed. Seven independent PM sources were identified by PCA: steel (Pb, Zn, Cd, Mn) and pigment (Cr, Mo, Ni) manufacture, road dust (Fe, Ba, Cd), traffic exhaust (P, OC + EC), regional-scale transport (, , V), crustal contributions (Al2O3, Sr, K) and sea spray (Na, Cl). The spatial distribution of the sources was obtained by coupling PCA with wind direction data, which helped identify regional drainage flows as the main source of crustal material. The same analysis showed that the contribution of motorway traffic to PM10 levels is 4-5 [mu]g m-3 higher than that of local traffic. The coupling of PCA-MLRA with wind direction data proved thus to be useful in extracting further information on source contributions and locations. Correct identification and characterisation of PM sources is essential for the design and application of effective abatement strategies.

Source apportionment of particulate matter in Europe: A review of methods and results

M Viana — 2008-06-12T07:30:23-00:00

Journal of Aerosol Science, Vol. In Press, Accepted Manuscript

Statistical functions and procedures in IDL 5.6 and 6.0

Oscar Bustos — 2008-06-12T06:24:42-00:00

Computational Statistics & Data Analysis, Vol. 50, No. 2. (30 January 2006), pp. 301-310.

This work presents the results of assessing the accuracy of statistical routines as implemented in the IDL platform, versions 5.6 and 6.0 for Windows XP and Linux. This is "a complete computing environment for the interactive analysis and visualization of data. IDL integrates a powerful, array-oriented language with numerous mathematical analysis and graphical display techniques (Research Systems Inc., IDL Versions 5.6 for Microsoft Windows, 2003 and 6.0.1 for Linux x86 m32, 2004. URL http://www.rsinc.com)". It is shown that, though it is an excellent platform for signal and image processing and analysis, it has flaws when statistical computing is concerned, mainly when dealing with non-linear regression by least squares fitting and, in particular, when computing in single precision floating point.

The Aethalometer

ADA Hansen — 2008-06-09T10:47:31-00:00

(April 2003)

Experiments with Cloud Properties: Impact on Surface Radiative Fluxes

H Wang — 2008-06-06T04:54:31-00:00

Journal of Atmospheric and Oceanic Technology, Vol. 25, No. 6. (1 June 2008), pp. 1034-1040.

Solar radiation reaching the earth’s surface provides the primary forcing of the climate system, and thus, information on this parameter is needed at a global scale. Several satellite-based estimates of surface radiative fluxes are available, but they differ from each other in many aspects. The focus of this study is to highlight one aspect of such differences, namely, the way satellite-observed radiances are used to derive information on cloud optical properties and the impact this has on derived parameters such as surface radiative fluxes. Frequently, satellite visible radiance in a single channel is used to infer cloud transmission; at times, several spectral channels are utilized to derive cloud optical properties and use these to infer cloud transmission. In this study, an evaluation of these two approaches will be performed in terms of impact on the accuracy in surface radiative fluxes. The University of Maryland Satellite Radiation Budget (UMD/SRB) model is used as a tool to perform such an evaluation over the central United States. The estimated shortwave fluxes are evaluated against ground observations at the Atmospheric Radiation Measurement Program (ARM) Central Facility and at four ARM extended sites. It is shown that the largest differences between these two approaches occur during the winter season when snow is on the ground.

Atmospheric Particulate Absorption and Black Carbon Measurement

James Lindberg — 2008-05-27T06:18:43-00:00

Appl. Opt., Vol. 38, No. 12. (20 April 1999), pp. 2369-2376.

It is convenient to measure the optical attenuation A of the combination of a layer of atmospheric particulate matter and the quartz fiber filter on which it has been collected. The problem of relating A to the absorption and scattering coefficients k and s of the particulate matter itself is treated as a problem in diffuse reflectance spectroscopy using the KubelkaMunk theory. The results show that although, in general, A is a nonlinear function strongly dependent on both s and k , for a limited range of s and sample thickness d , A can be a practically linear function of k . Fortunately, this range includes that common to atmospheric particulate samples. Furthermore, it is shown that if the filter’s reflectance is sufficiently high, A can be nearly independent of s . This is in agreement with experimental and, for the limiting case when the substrate filter reflectance is unity, theoretical results obtained by other researchers. Use of such measurements of A as a means of determining the black carbon mass loading C on a filter is also investigated. It is shown that when the black carbon mass fraction f c is high, as it is for samples collected in large urban areas, A is a predictable and practically linear function of C . However, when f c is low, as it is for many rural locations, then the slope of the function A ( C ) is strongly dependent on f c , leading to possible overestimates of C . This problem can be alleviated by making the measurement of A at near-infrared wavelengths rather than in the visible spectrum.

Design, calibration, and performance of MICROTOPS II handheld ozone monitor and Sun photometer

Marian Morys — 2008-05-08T11:16:49-00:00

Journal of Geophysical Research, Vol. 106, No. D13. (2001), pp. 14573-14582.

Carbonaceous Aerosol (Atmospheric and Oceanographic Sciences Library)

András Gelencsér — 2008-05-08T10:55:27-00:00

(06 April 2005)

This monograph provides a unique and comprehensive coverage of the nature and atmospheric role of carbonaceous aerosol particles, these big unknowns of the global atmosphere. Even the concept of carbonaceous aerosol has just recently grown out of atmospheric pollution studies, without ever being anchored to solidified nomenclature and terminology. It is beyond any doubt that no major breakthrough can be expected in resolving climate issues without a better understanding of the role carbonaceous particles play in the global atmosphere. This monograph may serve as an indispensable reference for all those interested in virtually any aspects of global atmospheric sciences, especially for those who are stakeholders in inadvertent climate modification. Thus atmospheric chemists, physicists, meteorologists, and modellers may well find this monograph a thought-inspiring and sometimes provocative overview of all global phenomena affected by or related to carbonaceous aerosol. An anticipated advantage of this monograph is that it brings together these diverse atmospheric phenomena under the umbrella of carbonaceous aerosol in an interdisciplinary way, which is a prerequisite of resolving global scientific issues.

Analysis of the performance characteristics of the five-channel Microtops II Sun photometer for measuring aerosol optical thickness and precipitable water vapor

Charles Ichoku — 2008-05-08T10:16:27-00:00

Journal of Geophysical Research, Vol. 107, No. D13. (12 July 2002), 4179.

Vi iMproved (VIM) (Landmark)

Steve Oualline — 2008-05-08T08:41:31-00:00

(21 April 2001)

<HTML>Real Linux users don't use GUIs. No matter how popular, slick and sophisticated the interfaces become for Linux and UNIX, you'll always need to be able to navigate in a text editor. The vi editor is the original standard UNIX full screen editor. It's been around almost since UNIX began and it has changed very little. To get around the limitations of vi the people at Bram Moolenaar created the vim editor (the name stand for VI iMproved). It contains many more features than the old vi editor including: help, multiple windows, syntax highlighting, programmer support, and HTML support. All of the books published to date focus on vi alone not the expanded vim shipping with every major Linux distribution. In true New Riders' form, the vim reference will be a definitive, concise reference for the professional Linux user and developer. This tutorial takes a task oriented approach allowing you to learn only the commands that make your job easier.</HTML>

Aerosol Properties

Williams Hinds — 2008-05-06T13:16:27-00:00

(28 December 2004)

As more attention is dedicated to understanding the occupational health risks associated with the industrial manufacture and use of nanotechnology, Aerosols Handbook: Measurement, Dosimetry, and Health Effects is a timely presentation of the latest research in the field of aerosol science. The book covers a multitude of topics on indoor, outdoor, and industrial aerosols, including aerosol measurement, deposition, particle size distribution, and biokinetic processes. Where harmful exposure to ultrafine particles may occur through inhalation, dermal contact, and ingestion, this book discusses how the size, shape, and chemical properties of particles affect aerosol deposition in the lungs, possibly other organs, and the overall toxicity. The book covers all relevant aspects of aerosols, from epidemiology to molecular biology, and emphasizes the importance of accurate aerosol measurement. The authors discuss Chernobyl accident and miners' lungs in detail to illustrate the effects of radioactive aerosols. The final section focuses on the health effects of specific aerosols, such as diesel aerosols and ultrafine particles. By converging research from both radioactive and non-radioactive aerosols, the editors give the book a unique and more complete perspective of how aerosols behave in the lungs. Aerosols Handbook: Measurement, Dosimetry, and Health Effects is an essential resource for those who study exposure, dosages, and toxicity to develop treatments for exposure, reduce air pollution, and establish better safety regulations, particularly in industries using nanotechnologies.

Aspects of Health Related Aerosols

James Gentry — 2008-05-06T13:12:56-00:00

Aerosols Handbook: Measurement, Dosimetry, and Health Effects

Lev Ruzer — 2008-05-06T13:11:18-00:00

Laser Remote Sensing

Takashi Fujii — 2008-05-06T13:04:12-00:00

(28 June 2005)

Information on recent progress in laser remote sensor (LIDAR) technology can be found scattered throughout numerous journal articles and conference proceedings, but until now there has been no work that summarizes recent advancements and achievements in the field in a detailed format. Laser Remote Sensing provides an up-to-date, comprehensive review on LIDAR, focusing mainly on applications to current topics in atmospheric science. The scope of the book includes laser remote sensing of the atmosphere, including measurement of aerosols, water vapor, clouds, winds, trace constituents, and temperature. It also covers other interesting applications such as vegetation monitoring and altimetry. LIDAR systems described in this volume include ground-based (fixed or mobile), airborne, and spaceborne (satellite-based) systems. The book emphasizes instrumentation and measurement techniques to enable the reader to understand what kind of a LIDAR system is necessary for a certain application. The individual chapters are self-contained and written by authors who are outstanding experts in each field. The book is intended for scientists, researchers, and students who have interest in the atmospheric environment and wish to learn about the measurement capabilities of state-of-the-art LIDAR systems

Aerosol Measurement: Principles, Techniques, and Applications

Paul Baron — 2008-05-06T13:02:24-00:00

(04 November 2005)

In recent years, industry has become increasingly interested in modern aerosol measurement methods, not only to protect the health of their workers but also to augment productivity and thereby gain competitive advantage. Aerosol Measurement: Principles, Techniques, and Applications, Second Edition offers scientists and practitioners the fundamental principles used in deciding which aerosol properties to measure and how to interpret the results. Divided into three parts, the material reviews the physical understanding of aerosols, covers specific instrumental techniques, and explains applications in fields ranging from health care to mining and upper-atmosphere research. Leading experts contribute to the review of such areas as direct-reading techniques, bioaerosol sampling, indoor air evaluations, industrial aerosol processing, and measurement in semiconductor clean rooms. Plus, all the chapters in this latest edition have been updated and some have been rewritten by new authors. Two new chapters have been added: one on historical aspects of aerosol measurements and the other on real-time single particle analysis.

Aerosol Optics: Light Absorption and Scattering by Particles in the Atmosphere (Springer Praxis Books / Environmental Sciences)

Alexander Kokhanovsky — 2008-05-06T12:59:34-00:00

(11 March 2008)

Springer/Praxis have a successful mini program of books on various aspects of light scattering, and now have a journal "Light Scattering Review" under consideration proposed by Alex Kokhanovsky. The atmospheric air contains not only gases but also various types of airborne particles (known as aerosols) ranging from dust grains to microbes. These small particles influence atmospheric visibility, the thermodynamics of the atmosphere, and they are also of great importance in any consideration of climate change problems. Aerosols may also be responsible for the loss of harvest, health problems among humans and ecological disasters. Therefore, it is of great importance to study aerosol properties on a global scale. Such studies ultimately should be based on global observations using instruments positioned on the space platforms.

Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles (Wiley-Interscience)

William Hinds — 2008-05-06T12:57:28-00:00

(19 January 1999)

The #1 guide to aerosol science and technology -now better than ever Since 1982, Aerosol Technology has been the text of choice among students and professionals who need to acquire a thorough working knowledge of modern aerosol theory and applications. Now revised to reflect the considerable advances that have been made over the past seventeen years across a broad spectrum of aerosol-related application areas - from occupational hygiene and biomedical technology to microelectronics and pollution control -this new edition includes: * A chapter on bioaerosols * New sections on resuspension, transport losses, respiratory deposition models, and fractal characterization of particles * Expanded coverage of atmospheric aerosols, including background aerosols and urban aerosols * A section on the impact of aerosols on global warming and ozone depletion. Aerosol Technology, Second Edition also features dozens of new, fully worked examples drawn from a wide range of industrial and research settings, plus new chapter-end practice problems to help readers master the material quickly.

Air Pollution and Health

Jon Ayres — 2008-05-06T12:55:12-00:00

(15 September 2006)

<Air Pollution Reviews, Volume 3> Univ. of Aberdeen, UK. Addresses questions relating to air pollution and its effect on health. Considers impact of nasal disease on lung exposure, how pollutants are distributed within the lung, and the uncertainties with regard to defining the dose of the lung. For clinicians and researchers. Expanded-outline format.

Contributions of natural sources to high PM10 and PM2.5 events in the eastern Mediterranean

Mustafa Koçak — 2008-05-06T11:52:55-00:00

Atmospheric Environment, Vol. 41, No. 18. (June 2007), pp. 3806-3818.

In total 562 daily PM10 and PM2.5 samples were collected from April 2001 to April 2002 at a rural site (Erdemli) located on the coast of the Eastern Mediterranean. The annual mean PM10 and PM2.5 levels were 36.4±27.8 and , respectively. PM10 and PM2.5 concentrations indicated orders of magnitude change from day to day (; ). The highest levels of PM10 were observed during the transition period (March, April and May) due to mineral dust transported from North Africa and during winter due to sea spray generation. However, PM2.5 levels exhibited higher concentrations during summer resulting from an enhanced production of secondary aerosols. The PM2.5/PM10 ratio (0.25) and categorization of air mass back trajectories indicated that PM10 at the study area is dominated by primary aerosol emissions (mineral dust particles from the Saharan Desert and sea salt particles from the Mediterranean Sea itself). During the whole sampling period 28 and 51 events exceeded the recommended maximum values of 50 and for PM10 and PM2.5, respectively. Source apportionment analysis indicated that PM10 exceedances originated as a consequence of natural events (mineral dust ~40%; sea salt ~50%) whereas PM2.5 exceedances were accounted primarily by pollution events (in 90% of the cases).

Chemistry of the Natural Atmosphere, Volume 71, Second Edition (International Geophysics)

Peter Warneck — 2008-05-06T11:43:37-00:00

(15 October 1999)

Knowledge of thc chemical behavior of trace compounds in the atmosphere has grown steadily, and sometimes even spectacularly, in recent decades. These developments have led to the emergence of atmospheric chemistry as a new branch of science. This book covers all aspects of atmospheric chemistry on a global scale, integrating information from chemistry and geochemistry, physics, and biology to provide a unified account. For each atmospheric constituent of interest, the text summarizes the principal observations on global distribution, chemical reactions, natural and anthropogenic sources, and physical removal processes. Coverage includes processes in the gas phase, in aerosols and c1ouds, and in precipitation, as well as biogeochemical cycles and the evolution of the atmosphere. Chemistry of the Natural Atmosphere, Second Edition, will serve as a textbook for senior undergraduate and graduate courses, and as an essential reference for atmospheric chemists, meteorologists, and anyone studying the biogeochemical cycles of trace gases. * Updated extensively from the highly respected first edition * Treats the global-scale chemistry and distribution of atmospheric trace constituents * Emphasizes observations and their interpretation * Provides background on transport and reaction kinetics for interpretation of observational data * Includes chemistry in the gas phase and in aerosols and clouds * Details chemical reaction pathways for the most important trace constituents * Describes pertinent biogeochemical cycles * Written by an author with more than 40 years of research experience in atmospheric chemistry

Aerosol Science: Theory and Practice

MMR Williams — 2008-05-06T11:40:51-00:00

(01 July 1991)

Hardbound. The subject of aerosols goes back many years and enters many aspects of science and technology. Optics, heat-transfer, biology, meteorology and pollution are just a few areas where the behaviour of small particles suspended in a gas is of vital importance. More recently, with increasing concern about the consequences of accidents in nuclear reactors and the effect of global nuclear war (i.e., the nuclear winter) a great deal of work has been directed towards the dispersal of radioactive aerosols in closed containers and in the atmosphere. The purpose of the book is twofold: to give a thorough treatment of the fundamentals of aerosol behaviour with rigorous proofs and detailed derivations of the basic equations and removal mechanisms and also to give practical examples with special attention to radioactive particles and their distribution in size following a release arising from an accident with a nuclear system. This book will be useful both as

Granular Filtration of Aerosols and Hydrosols, Second Edition

Chi Tien — 2008-05-06T11:38:34-00:00

(17 July 2007)

Granular filtration is a technique used extensively in the water and sewage industries, and we would all be quickly aware if it did not work properly.Designing and building an effective granular filter is a science and an art: this book covers both aspects. The theoretical basis of design is given considerable exposure, as are the behavioural characteristics of particles and fluids. This new edition contains extra material on stochastic simulations and the Lattice Bolzmann approach for studying deposition in granular media; more on prediction methods for collection efficiency; a chapter on the various available software programmes and a more industrial emphasis where appropriate. *New edition after over 15 years *New co-author *Still THE book on the subject

Light Scattering by Nonspherical Particles

2008-05-06T11:34:18-00:00

(15 January 2000)

There is hardly a field of science or engineering that does not have some interest in light scattering by small particles. For example, this subject is important to climatology because the energy budget for the Earth's atmosphere is strongly affected by scattering of solar radiation by cloud and aerosol particles, and the whole discipline of remote sensing relies largely on analyzing the parameters of radiation scattered by aerosols, clouds, and precipitation. The scattering of light by spherical particles can be easily computed using the conventional Mie theory. However, most small solid particles encountered in natural and laboratory conditions have nonspherical shapes. Examples are soot and mineral aerosols, cirrus cloud particles, snow and frost crystals, ocean hydrosols, interplanetary and cometary dust grains, and microorganisms. It is now well known that scattering properties of nonspherical particles can differ dramatically from those of "equivalent" (e.g., equal-volume or equal-surface-area) spheres. Therefore, the ability to accurately compute or measure light scattering by nonspherical particles in order to clearly understand the effects of particle nonsphericity on light scattering is very important. The rapid improvement of computers and experimental techniques over the past 20 years and the development of efficient numerical approaches have resulted in major advances in this field which have not been systematically summarized. Because of the universal importance of electromagnetic scattering by nonspherical particles, papers on different aspects of this subject are scattered over dozens of diverse research and engineering journals. Often experts in one discipline (e.g., biology) are unaware of potentially useful results obtained in another discipline (e.g., antennas and propagation). This leads to an inefficient use of the accumulated knowledge and unnecessary redundancy in research activities. This book offers the first systematic and unified discussion of light scattering by nonspherical particles and its practical applications and represents the state-of-the-art of this important research field. Individual chapters are written by leading experts in respective areas and cover three major disciplines: theoretical and numerical techniques, laboratory measurements, and practical applications. An overview chapter provides a concise general introduction to the subject of nonspherical scattering and should be especially useful to beginners and those interested in fast practical applications. The audience for this book will include graduate students, scientists, and engineers working on specific aspects of electromagnetic scattering by small particles and its applications in remote sensing, geophysics, astrophysics, biomedical optics, and optical engineering. * The first systematic and comprehensive treatment of electromagnetic scattering by nonspherical particles and its applications * Individual chapters are written by leading experts in respective areas * Includes a survey of all the relevant literature scattered over dozens of basic and applied research journals * Consistent use of unified definitions and notation makes the book a coherent volume * An overview chapter provides a concise general introduction to the subject of light scattering by nonspherical particles * Theoretical chapters describe specific easy-to-use computer codes publicly available on the World Wide Web * Extensively illustrated with over 200 figures, 4 in color

Ocean Waves Breaking and Marine Aerosol Fluxes (Atmospheric and Oceanographic Sciences Library)

Stanislaw Massel — 2008-05-06T07:02:56-00:00

(07 June 2007)

The energy flow from the atmosphere to the ocean generates an aerodynamically rough ocean surface. If the energy flow is sufficiently strong, in some points of the surface, waves loose their stability and eventually break in the form of whitecaps of various scales. The turbulence associated with the breakers produce the aerosols in the form of jet and film drops from the bursting of air bubbles. The aerosol droplets transfer water vapour, heat, pollutants and bacteria through the air-water interface. They are easily transported by wind over large distances. In this way, marine aerosols influence the optical features of the atmosphere, which are of fundamental importance for the remote sensing of the surface and they play an important role in climate variations. The amount of marine aerosols rising from the sea surface depends on the coverage of the sea by breaking waves or whitecaps, and the rate of intensity of breaking. Much of the uncertainty in sea aerosols production and gas transfer arises from weaknesses in the parameterization of wave breaking and related processes. This book describes the mechanisms of wave breaking, based on the theoretical and experimental achievements published in literature as well as on the author's experience. Special attention is paid to selection of the wave breaking criteria, and to development of the wave breaking probability and estimation of the energy dissipation due to breaking. Secondly, the book examines the relationships between wave breaking and marine aerosol fluxes and gas transfer from the sea surface. In general, an amount of marine aerosol rising from the sea surface depends on the coverage of the sea by breaking waves or whitecaps, and on the rate of intensity of breaking. The wind speed, commonly used in prediction of the whitecaps coverage, is only one of the factors determining the wave energy and probability of the breaking occurrence. It is more appropriate to find the linkage between the percentage of sea surface covered by whitecaps and the sea state characteristics (i.e. the significant wave height and spectrum peak frequency) and the amount of energy dissipated during wave breaking and its relationship with the aerosol fluxes.

Evaluation of the Moderate-Resolution Imaging Spectroradiometer (MODIS) retrievals of dust aerosol over the ocean during PRIDE

Robert Levy — 2008-05-05T10:18:54-00:00

Journal of Geophysical Research, Vol. 108, No. D19. (23 July 2003), 8594.

Comparison of the Ångström parameters retrieval in different spectral ranges with the use of different techniques

DG Kaskaoutis — 2008-05-05T09:38:08-00:00

Meteorology and Atmospheric Physics, Vol. 99, No. 3. (30 April 2008), pp. 233-246.

Summary Ground-based spectroradiometric measurements obtained in Athens have been used in order to derive the aerosol optical depth and the Ångström parameters. Their derivation is achieved using three well-established and widely used techniques; the Volz method, the direct method and the least-squares fit to the experimental aerosol optical depth values. This study aims at investigating the ability of the different methods to derive similar Ångström turbidity coefficients and their dependence on the spectral range used for their determination. In addition, the uncertainties revealed especially in the UV spectral band are highlighted. The various techniques lead to different Ångström turbidity coefficients especially if narrow spectral bands at the shorter wavelengths are used. It is also established that the Ångström turbidity coefficients derived by any of the three methods at short wavelengths are not representative of the whole spectrum, while their derivation exhibits large uncertainties especially under low turbidity conditions. Therefore, the comparison of α and β values obtained using the three above-mentioned techniques in several spectral bands is not an easy task, since these values differ significantly. From the whole analysis it is established that the least-squares method is the least imprecise, also exhibiting the least wavelength dependence.

Atmospheric Optical Phenomena and Radiative Transfer

Stanley Gedzelman — 2008-05-01T09:31:48-00:00

Bulletin of the American Meteorological Society, Vol. 89, No. 4. (1 April 2008), pp. 471-485.

We present simple radiative transfer models for the radiance and color of atmospheric optical phenomena. Skylight, halos, and rainbows are treated as singly scattered sunlight that is depleted by scattering as it passes through a plane-parallel atmosphere and a vertical rain shaft or a geometrically thin cloud layer. Skylight in a molecular atmosphere grades from deep blue at the zenith to pale blue near the horizon whenever the solar zenith angle φsun ≤ 80°. Skylight near the horizon is orange resulting from wavelength-dependent scattering by air molecules and aerosol particles through a long oblique path through the atmosphere when the sun is low in the sky (φsun ≥ 85°). Halos (and coronas) seen through clouds facing the sun are brightest for cloud optical depth τcld ≈ cos(φsun), and fade to obscurity for τcld ≥ 5. Rainbows (and glories), seen by light that is backscattered from clouds, also appear most dramatic when 0.2 ≤ τcld ≤ 1, but remain visible even in the thickest clouds.

The Role of Atmospheric Boundary Layer Processes in Atmospheric Chemistry

Vilà-Guerau — 2008-04-27T20:20:28-00:00

Bulletin of the American Meteorological Society, Vol. 88, No. 8. (1 August 2007), pp. 1245-1248.

No Abstract available.

Parameterization of the Atmospheric Boundary Layer: A View from Just Above the Inversion

J Teixeira — 2008-04-30T07:09:25-00:00

Bulletin of the American Meteorological Society, Vol. 89, No. 4. (1 April 2008), pp. 453-458.

No Abstract available.

Radiative fluxes from satellites: Focus on aerosols

Hongqing Liu — 2008-04-28T07:17:58-00:00

Journal of Geophysical Research, Vol. 113 (23 April 2008), D08208.

Effects of aerosol optical properties on deep convective clouds and radiative forcing

Jiwen Fan — 2008-04-28T07:16:42-00:00

Journal of Geophysical Research, Vol. 113 (23 April 2008), D08209.

Analyzing signatures of aerosol-cloud interactions from satellite retrievals and the GISS GCM to constrain the aerosol indirect effect

Surabi Menon — 2008-04-28T07:14:03-00:00

Journal of Geophysical Research, Vol. 113 (26 April 2008), D14S22.

The Innovative Leader: How to Inspire Your Team and Drive Creativity

Paul Sloane — 2008-04-24T08:53:20-00:00

(01 July 2007)

The Innovative Leader stresses the importance of innovation and creativity in modern business to help organizations secure competitive advantage over rivals. It shows how to apply methods of innovation and creativity to the individual, to business peers, and to the organization. Author Pual Sloane demonstrates the importance of setting out your vision clearly and emphasizes the need for continual evaluation of the process. Numerous international examples illustrate how organizations such as Virgin, Body Shop, Disney, and 3M have benefited from this approach, encouraging excellence and entrepreneurship through challenging goals that keep employees motivated and engaged.

Desert climate and its dynamics

DR Sikka — 2008-04-23T06:31:23-00:00

Current Science, Vol. 72, No. 1. (January 1997), pp. 35-42.

Role of remote sensing in resource management for arid regions with special reference to western Rajasthan

George Joseph — 2008-04-23T06:29:10-00:00

Current Science, Vol. 72, No. 1. (January 1997), pp. 47-54.

Distinguishing Aerosols from Clouds in Global, Multispectral Satellite Data with Automated Cloud Classification Algorithms

Keith Hutchison — 2008-04-23T06:17:18-00:00

Journal of Atmospheric and Oceanic Technology, Vol. 25, No. 4. (1 April 2008), pp. 501-518.

A new approach is presented to distinguish between clouds and heavy aerosols with automated cloud classification algorithms developed for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program. These new procedures exploit differences in both spectral and textural signatures between clouds and aerosols to isolate pixels originally classified as cloudy by the Visible/Infrared Imager/Radiometer Suite (VIIRS) cloud mask algorithm that in reality contains heavy aerosols. The procedures have been tested and found to accurately distinguish clouds from dust, smoke, volcanic ash, and industrial pollution over both land and ocean backgrounds in global datasets collected by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. This new methodology relies strongly upon data collected in the 0.412-μm bandpass, where smoke has a maximum reflectance in the VIIRS bands while dust simultaneously has a minimum reflectance. The procedures benefit from the VIIRS design, which is dual gain in this band, to avoid saturation in cloudy conditions. These new procedures also exploit other information available from the VIIRS cloud mask algorithm in addition to cloud confidence, including the phase of each cloudy pixel, which is critical to identify water clouds and restrict the use of spectral tests that would misclassify ice clouds as heavy aerosols. Comparisons between results from these new procedures, automated cloud analyses from VIIRS heritage algorithms, manually generated analyses, and MODIS imagery show the effectiveness of the new procedures and suggest that it is feasible to identify and distinguish between clouds and heavy aerosols in a single cloud mask algorithm.

કર્મયોગી ગુર્જિએફ

Bhogilal Gandhi — 2008-04-17T10:56:20-00:00

(March 1986)

તમે જ તમારા ઘડવૈયા

Orison Marden — 2008-04-17T10:50:42-00:00

(1988)

Wings of Fire: An Autobiography of APJ Abdul Kalam

Arun Tiwari — 2008-04-17T09:56:25-00:00

(11 January 2007)

Retrieval of the scattering and microphysical properties of aerosols from ground-based optical measurements including polarization. I. Method.

A Vermeulen — 2008-03-27T08:17:56-00:00

Appl Opt, Vol. 39, No. 33. (20 November 2000), pp. 6207-6220.

A method has been developed for retrieving the scattering and microphysical properties of atmospheric aerosol from measurements of solar transmission, aureole, and angular distribution of the scattered and polarized sky light in the solar principal plane. Numerical simulations of measurements have been used to investigate the feasibility of the method and to test the algorithm's performance. It is shown that the absorption and scattering properties of an aerosol, i.e., the single-scattering albedo, the phase function, and the polarization for single scattering of incident unpolarized light, can be obtained by use of radiative transfer calculations to correct the values of scattered radiance and polarized radiance for multiple scattering, Rayleigh scattering, and the influence of ground. The method requires only measurement of the aerosol's optical thickness and an estimate of the ground's reflectance and does not need any specific assumption about properties of the aerosol. The accuracy of the retrieved phase function and polarization of the aerosols is examined at near-infrared wavelengths (e.g., 0.870 mum). The aerosol's microphysical properties (size distribution and complex refractive index) are derived in a second step. The real part of the refractive index is a strong function of the polarization, whereas the imaginary part is strongly dependent on the sky's radiance and the retrieved single-scattering albedo. It is demonstrated that inclusion of polarization data yields the real part of the refractive index.