High Precision Measurement of Atmospheric Trace Gases Using Fourier Transform Infrared Spectroscopy PDF Download

Author: Michael Brian Esler
Publisher:
ISBN:
Category : Atmospheric chemistry
Languages : en
Pages : 606

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Author: Aldona Wiacek
Publisher:
ISBN: 9780494220177
Category : Physics Theses
Languages : en
Pages : 233

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Book Description
A systematic study showed that the effect of several different layering schemes (implicit retrieval constraints) on the retrieved vertical profile is less than 5% for N2O and HF, and less than 2% for NO, NO 2, CH4 and HCl; however, retrieved profiles of H2O showed differences up to 13% when the layering scheme was varied. A maximum tropospheric layer thickness of 0.8 km is inferred for accurate H2O retrievals. A new high-resolution (0.004 cm-1) research-grade Fourier transform spectrometer was installed at the University of Toronto Atmospheric Observatory (TAO), and commissioned in October 2001. TAO fills a coverage gap in North America in the Network for the Detection of Atmospheric Composition Change (NDACC), and was accepted as a Complementary Station in March 2004 as a direct result of work presented in this thesis. Finally, the usefulness of Fourier Transform InfraRed (FTIR) observations for studying different regions of the atmosphere was demonstrated by (1) documenting a limited sensitivity of ground-based measurements to mesospheric-lower thermospheric concentrations of NO, (2) correlating anomalously high stratospheric HCl, HF and O3 concentrations derived at TAO with the passage of a polar air filament above Toronto, and (3) showing very good agreement between monthly mean abundances of tropospheric CO between January 2002--September 2003 and spatially coincident MOPITT satellite measurements. Trace gas concentrations are derived using an existing Optimal Estimation Method (OEM) retrieval algorithm implemented at TAO as part of this work. A set of prior constraints necessary for retrievals of vertical profiles of trace gases using the OEM approach was optimized, and includes a priori volume mixing ratio profiles suited to TAO's location, and the prior and measurement noise covariances. A three-year time series of O3, NO. NO2, HCl, HF, N2O and CH4 (exhibiting the known seasonal cycles) was submitted to the NDACC database for long-terra monitoring, trend detection, and satellite validation purposes. A quantitative retrieval characterization was performed whereby the averaging kernels, weighting functions, measurement, smoothing and temperature error covariances of the retrievals of these seven gases were calculated. The degrees of freedom for signal ranged from 1.10 for NO2 to 4.12 for N2O.

Author:
Publisher:
ISBN:
Category : Atmosphere
Languages : en
Pages : 4

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Author: Mark P. Esplin
Publisher:
ISBN:
Category : Atmospheric carbon dioxide
Languages : en
Pages : 72

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Although both Carbon Dioxide and Nitrous Oxide are minor constituents of the terrestrial atmosphere, they play leading roles in several current atmospheric problems. Both CO2 and N2O are greenhouse gases, and while it is known that the atmospheric concentrations of both gases is increasing, the impact of these trends on global temperature is not yet adequately understood. In addition to being a greenhouse gas, N2O plays an indirect part in ozone chemistry. Heating a molecule makes possible the observations of molecular transitions originating from highly excited rotation-vibration states. Heating a molecule makes possible the observations of molecular transitions originating from highly excited rotation-vibration states. These observations can then be used to characterize the shape of the molecular potential function at increasing distances from the minimum of the potential function. The infrared spectra of linear molecules like CO2 and N2O are composed of vibration bands made up of a number of nearly equally spaced rotation lines. A Fourier Spectrometer is ideally suited to the study of high temperature gases since it meets both of these needs by providing high resolution over a wide spectral region.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 26

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Author: Thomas Foken
Publisher: Springer Nature
ISBN: 3030521710
Category : Science
Languages : en
Pages : 1761

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This practical handbook provides a clearly structured, concise and comprehensive account of the huge variety of atmospheric and related measurements relevant to meteorologists and for the purpose of weather forecasting and climate research, but also to the practitioner in the wider field of environmental physics and ecology. The Springer Handbook of Atmospheric Measurements is divided into six parts: The first part offers instructive descriptions of the basics of atmospheric measurements and the multitude of their influencing factors, fundamentals of quality control and standardization, as well as equations and tables of atmospheric, water, and soil quantities. The subsequent parts present classical in-situ measurements as well as remote sensing techniques from both ground-based as well as airborn or satellite-based methods. The next part focusses on complex measurements and methods that integrate different techniques to establish more holistic data. Brief discussions of measurements in soils and water, at plants, in urban and rural environments and for renewable energies demonstrate the potential of such applications. The final part provides an overview of atmospheric and ecological networks. Written by distinguished experts from academia and industry, each of the 64 chapters provides in-depth discussions of the available devices with their specifications, aspects of quality control, maintenance as well as their potential for the future. A large number of thoroughly compiled tables of physical quantities, sensors and system characteristics make this handbook a unique, universal and useful reference for the practitioner and absolutely essential for researchers, students, and technicians.

Author: Wormhoudt
Publisher: CRC Press
ISBN: 9780824774295
Category : Technology & Engineering
Languages : en
Pages : 312

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Book Description
This interdisciplinary volume is an excellent resource for anyone who wants an in-depth understanding of current and emerging trends in gaseous measurement techniques. It provides both qualitative and quantitative introductions to the physics involved in using remote observations to collect data, and offers numerous examples that encourage new applications of existing technologies. Compiled by an authority on spectroscopy, chemical kinetics and infrared emissions from combustible sources, this volume compares burnoff flare and stack plume emission spectra with parametric calculations performed with equally high spectral resolution ... discusses sensitivity of spectra to source temperature, and behavior of emission and absorption linewidths with temperature ... reviews the emission-absorption techniques for determining temperature and species concentration profiles ... and much more. Infrared Methods for Gaseous Measurements is a vital research tool for photo-optical instrumentation engineers; electro-optical engineers; chemical, aerospace, automotive, combustion, environmental, and mechanical engineers; and technologists involved in radiation, infrared or laser research. The book also serves as an excellent resource for graduate molecular spectroscopy courses and postgraduate infrared technology seminars. Book jacket.

Author: Abdullahi Hagi-Mohamud Aw-Musse
Publisher:
ISBN:
Category :
Languages : en
Pages : 146

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Author: P. A. Matson
Publisher: John Wiley & Sons
ISBN: 1444313819
Category : Science
Languages : en
Pages : 408

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Book Description
Trace gases are those that are present in the atmosphere at relatively low concentrations. Small changes in their concentrations can have profound implications for major atmospheric fluxes, and thereore, can be used as indicators in studies of global change, global biogeochemical cycling and global warming. This new how-to guide will detail the concepts and techniques involved in the detection and measurement of trace gases, and the impact they have on ecological studies. Introductory chapters look at the role of trace gases in global cycles, while later chapters go on to consider techniques for the measurement of gases in various environments and at a range of scales. A how-to guide for measuring atmospheric trace gases. Techniques described are of value in addressing current concerns over global climate change.

Author: Aaron Goldman
Publisher: CRC Press
ISBN: 1351363050
Category : Science
Languages : en
Pages : 266

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The handbook presents spectra to be utilized for the detection and measurement of new constituents in the earth's atmosphere and to obtain data for common minor species with large gas amounts in the absorption cell (such as CH/sub 4/ and N/sub 2/O). These results can be applied in the identification of absorption features in atmospheric spectra determined over long atmospheric paths. The spectra were recorded with Fourier Transform Spectrometers which are more precise than grating spectrometers. Each molecule spectrum was plotted on two scales: a condensed scale covering the range from 75 to 300/cm in one frame, and an expanded view covering 20 or 10/cm per frame. Each plot contains the name of the molecule, chemical formula, the gas pressure, cell length, and estimated resolution of the spectrum.