Download or read book Advanced Aerosol Characterization Using Sun sky Photometer and Multi wavelength Mie Raman Lidar Measurements written by Qiaoyun Hu and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are two objectives in this study : (i) aerosols characterization using multi-wavelength Mie-Raman lidar and (ii) the retrieval of aerosol properties through lidar and sun/sky photometer joint measurements. The measurements investigated were recorded in two observation sites : Lille (France) and M'bour, (Senegal). The measurements in M'bour were conducted in the SHADOW2 (Study of SaHAran Dust Over West Africa) campaign, in the framework of Labex CaPPA. Aerosol characterization presented in this study concerns Saharan dust in M'Bour, long-range transported dust and Canadian smoke, as well as dust-smoke mixtures. In the second part of this study, lidar volume linear depolarization ratio has been included in the aerosol retrieval algorithm GARRLiC/GRASP. Sensitivity tests are performed to test the performance of GARRLiC/GRASP under different aerosol content, with different sphere fraction and with different error levels of molecular depolarization ratio and calibration coefficient. Then GARRLiC/GRASP is applied to real sun/sky photometer and lidar measurements and the retrievals are compared with results from independent methods for verification. The comparison shows that GARRLiC/GRASP retrievals are very consistent with the results from independent methods, but tend to produce 10% lower dust particle depolarization ratio compared to the lidar measurements. Over all, our results are relevant to the European scientific community since GARRLiC/GRASP is being implemented in the ACTRIS data and service center. This work will benefit to the evaluation of future European space missions.
Download or read book Comparative Aerosol Studies Based on Multi wavelength Raman LIDAR at Ny lesund Spitsbergen written by Anne Hoffmann and published by . This book was released on 2011 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Arctic is a particularly sensitive area with respect to climate change due to the high surface albedo of snow and ice and the extreme radiative conditions. Clouds and aerosols as parts of the Arctic atmosphere play an important role in the radiation budget, which is, as yet, poorly quantified and understood. The LIDAR (Light Detection And Ranging) measurements presented in this PhD thesis contribute with continuous altitude resolved aerosol profiles to the understanding of occurrence and characteristics of aerosol layers above Ny-Ålesund, Spitsbergen. The attention was turned to the analysis of periods with high aerosol load. As the Arctic spring troposphere exhibits maximum aerosol optical depths (AODs) each year, March and April of both the years 2007 and 2009 were analyzed. Furthermore, stratospheric aerosol layers of volcanic origin were analyzed for several months, subsequently to the eruptions of the Kasatochi and Sarychev volcanoes in summer 2008 and 2009, respectively. The Koldewey Aerosol Raman LIDAR (KARL) is an instrument for the active remote sensing of atmospheric parameters using pulsed laser radiation. It is operated at the AWIPEV research base and was fundamentally upgraded within the framework of this PhD project. It is now equipped with a new telescope mirror and new detection optics, which facilitate atmospheric profiling from 450m above sea level up to the mid-stratosphere. KARL provides highly resolved profiles of the scattering characteristics of aerosol and cloud particles (backscattering, extinction and depolarization) as well as water vapor profiles within the lower troposphere. Combination of KARL data with data from other instruments on site, namely radiosondes, sun photometer, Micro Pulse LIDAR, and tethersonde system, resulted in a comprehensive data set of scattering phenomena in the Arctic atmosphere. The two spring periods March and April 2007 and 2009 were at first analyzed based on meteorological parameters, like local temperature and relative humidity profiles as well as large scale pressure patterns and air mass origin regions. Here, it was not possible to find a clear correlation between enhanced AOD and air mass origin. However, in a comparison of two cloud free periods in March 2007 and April 2009, large AOD values in 2009 coincided with air mass transport through the central Arctic. This suggests the occurrence of aerosol transformation processes during the aerosol transport to Ny-Ålesund. Measurements on 4 April 2009 revealed maximum AOD values of up to 0.12 and aerosol size distributions changing with altitude. This and other performed case studies suggest the differentiation between three aerosol event types and their origin: Vertically limited aerosol layers in dry air, highly variable hygroscopic boundary layer aerosols and enhanced aerosol load across wide portions of the troposphere. For the spring period 2007, the available KARL data were statistically analyzed using a characterization scheme, which is based on optical characteristics of the scattering particles. The scheme was validated using several case studies. Volcanic eruptions in the northern hemisphere in August 2008 and June 2009 arose the opportunity to analyze volcanic aerosol layers within the stratosphere. The rate of stratospheric AOD change was similar within both years with maximum values above 0.1 about three to five weeks after the respective eruption. In both years, the stratospheric AOD persisted at higher rates than usual until the measurements were stopped in late September due to technical reasons. In 2008, up to three aerosol layers were detected, the layer structure in 2009 was characterized by up to six distinct and thin layers which smeared out to one broad layer after about two months. The lowermost aerosol layer was continuously detected at the tropopause altitude. Three case studies were performed, all revealed rather large indices of refraction of m = (1.531.55) - 0.02i, suggesting the presence of an absorbing carbonaceous component. The particle radius, derived with inversion calculations, was also similar in both years with values ranging from 0.16 to 0.19 æm. However, in 2009, a second mode in the size distribution was detected at about 0.5 æm. The long term measurements with the Koldewey Aerosol Raman LIDAR in Ny-Ålesund provide the opportunity to study Arctic aerosols in the troposphere and the stratosphere not only in case studies but on longer time scales. In this PhD thesis, both, tropospheric aerosols in the Arctic spring and stratospheric aerosols following volcanic eruptions have been described qualitatively and quantitatively. Case studies and comparative studies with data of other instruments on site allowed for the analysis of microphysical aerosol characteristics and their temporal evolution.
Download or read book Aerosol Characterization by Multi wavelength Raman and Depolarization Lidar Observations written by Silke Martha Groß and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosols Properties as Retrieved from the GARRLIC Synergetic Approach Applied to Multi Wavelength Raman LiDAR Observations Performed Over Lille and Dakar Sites written by Valentyn Bovchaliuk and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol particles are a highly variable component of the atmosphere and are now studied by a wide community. Since 2005, LOA is developing a recognized expertize in LiDAR observation devoted to aerosols profiling. Since 2011 this activity is supported by ACTRIS (Aerosol Cloud and Trace gas Infrastructure) and CaPPA (Chemical And Physical Processes in the Atmosphere) projects. The first objective of this work was to built, set up and characterize a new multi-wavelength Raman Polarized LiDAR (LILAS) operating at LOA observation platform located on the Campus. This system has also been operated during the SHADOW-2 field campaign (2015-2016) at Dakar (IRD station, Senegal). The second objective of the thesis consisted in developing aerosols retrievals and analyzing aerosols retrievals in term of optical and microphysical properties. An innovating synergetic approach (GARRLIC/GRASP) has been used and improved to interpret several aerosol events (local pollution, mineral dust transported to Lille and mineral dust detected at Dakar, close to sources). This new technique is combining primary data obtained from sun/sky photometer (spectral AOD and spectral radiance) and elastic LiDAR backscattering profiles (355, 532 and 1064 nm). Ambient aerosols properties being also sensitive to the atmospheric humidity, a last part of the work has be devoted to profiling water vapor mixing ratio from LILAS night time data.
Download or read book Fundamentals and Applications in Aerosol Spectroscopy written by Ruth Signorell and published by CRC Press. This book was released on 2010-12-20 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helping you better understand the processes, instruments, and methods of aerosol spectroscopy, Fundamentals and Applications in Aerosol Spectroscopy provides an overview of the state of the art in this rapidly developing field. It covers fundamental aspects of aerosol spectroscopy, applications to atmospherically and astronomically relevant problem
Download or read book Satellite Aerosol Remote Sensing Over Land written by Alexander A. Kokhanovsky and published by Springer Science & Business Media. This book was released on 2009-08-24 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols have a significant influence on the Earth's radiation budget, but there is considerable uncertainty about the magnitude of their effect on the Earth's climate. Currently, satellite remote sensing is being increasingly utilized to improve our understanding of the effect of atmospheric aerosols on the climate system. Satellite Aerosol Remote Sensing Over Land is the only book that brings together in one volume the most up-to-date research and advances in this discipline. As well as describing the current academic theory, the book presents practical applications, utilizing state-of-the-art instrumentation, invaluable to the work of environmental scientists. With contributions by an international group of experts and leaders of correspondent aerosol retrieval groups, the book is an essential tool for all those working in the field of climate change.
Download or read book Arr t s et remontrances du parlement de Bordeaux au roi sur ce qui a suivi la r clamation de cette compagnie contre les lettres patentes accord es en 1752 au bureau des finances 21 juillet 1756 written by and published by . This book was released on 1756 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Free Tropospheris Particles With Multiwavelength Raman Lidar written by Detlef Müller and published by . This book was released on 2007 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Remote Sensing of Aerosols Using Sunphotometer written by Raghavendra Kumar Kanike and published by LAP Lambert Academic Publishing. This book was released on 2015-05-04 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, we have described the optical and physical properties of aerosol which are considered to be an important in the Earth's radiation budget. The method of detection of various aerosol properties using ground-based automated Sun-sky radiometer is mentioned, by illustrating the measurements taken over one of a station, as part of Sun photometer worldwide network, named AERONET (AErosol RObotic NETwork). Besides, the basic details of Sun photometer, we have also illustrated the importance of synoptic weather parameters and use of trajectory analysis. Aerosol measurements from Sun photometer and satellite are compared and assessed the instruments capabilities. Using a large amount of data measured over a sub-tropical site in South Africa, we have studied the various optical properties of aerosol and their mutual relationship for addressing aerosol types. Classification and identification of different types of aerosol are elucidated by various methods. Apart from the results obtained, the study location has been considered to be significant due to only very few studies reported on aerosol properties, especially in the Southern Hemisphere and in Southern Africa region.
Download or read book Characterization of Free Tropospheric Particles with Multiwavelength Raman Lidar written by Detlef Müller and published by . This book was released on 2007 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosol Optics written by Alexander A. Kokhanovsky and published by Springer Science & Business Media. This book was released on 2008-03-18 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new text offers experienced students a comprehensive review of available techniques for the remote sensing of aerosols. These small particles influence both atmospheric visibility and the thermodynamics of the atmosphere. They are also of great importance in any consideration of climate change problems. Aerosols may also be responsible for the loss of harvests, human health problems and ecological disasters. Thus, this detailed study of aerosol properties on a global scale could not be more timely.
Download or read book Cloud and Aerosol Properties Measured with a Lidar in the High Arctic at Eureka written by Christopher Perro and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ground Based Aerosol Optical Depth Measurement Using Sunphotometers written by Jedol Dayou and published by Springer. This book was released on 2014-06-03 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a detailed review on ground-based aerosol optical depth measurement with emphasis on the calibration issue. The review is written in chronological sequence to render better comprehension on the evolution of the classical Langley calibration from the past to present. It not only compiles the existing calibration methods but also presents a novel calibration algorithm in Langley sun-photometry over low altitude sites which conventionally is a common practice performed at high observatory stations. The proposed algorithm avoids travelling to high altitudes for frequent calibration that is difficult both in logistics and financial prospects. We addressed the problem by combining clear-sky detection model and statistical filter to strictly imitate the ideal clear-sky condition at high altitude for measurements taken over low altitudes. In this way, the possible temporal atmospheric drifts, abundant aerosol loadings and short time interval cloud transits are properly constrained. We believe that this finding has an integral part of practicality and versatility in ground-based aerosol optical depth measurement, which is nowadays an important climate agent in many atmospheric studies. Finally, the outcome of this book introduces a new calibration technique for the study and measurement of aerosol monitoring with emphasis on aerosol optical depth that we believe could be very beneficial to researchers and scientists in the similar area.
Download or read book Identification of Aerosol Composition from Multi wavelength Lidar Measurements written by Sidney Allen Wood and published by . This book was released on 1983 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosol Characterization Study Using Multi spectrum Remote Sensing Measurement Techniques written by and published by . This book was released on 2013 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique aerosol flow chamber coupled with a bistatic LIDAR system was implemented to measure the optical scattering cross sections and depolarization ratio of common atmospheric particulates. Each of seven particle types (ammonium sulfate, ammonium nitrate, sodium chloride, potassium chloride, black carbon and Arizona road dust) was aged by three anthropogenically relevant mechanisms: 1. Sulfuric acid deposition, 2. Toluene ozonolysis reactions, and 3. m-Xylene ozonolysis reactions. The results of pure particle scattering properties were compared with their aged equivalents. Results show that as most particles age under industrial plume conditions, their scattering cross sections are similar to pure black carbon, which has significant impacts to our understanding of aerosol impacts on climate. In addition, evidence emerges that suggest chloride-containing aerosols are chemically altered during the organic aging process. Here we present the direct measured scattering cross section and depolarization ratios for pure and aged atmospheric particulates.
Download or read book Determination of Optical and Microphysical Properties of Atmospheric Aerosols from Multi wavelength Airborne Sun Photometer written by Yana Karol and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microphysical Particle Properties from Lidar Measurements written by Ulla Wandlinger and published by . This book was released on 2001 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
