Heard D.E. (editor) Analytical Techniques for Atmospheric Measurement
Подождите немного. Документ загружается.
Analytical Techniques for
Atmospheric Measurement
This page intentionally left blank
Analytical Techniques for
Atmospheric Measurement
Edited by
Dwayne E. Heard
University of Leeds
© 2006 by Blackwell Publishing Ltd
Editorial Offices:
Blackwell Publishing Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK
Tel: +44 (0)1865 776868
Blackwell Publishing Professional, 2121 State Avenue, Ames, Iowa 50014-8300, USA
Tel: +1 515 292 0140
Blackwell Publishing Asia, 550 Swanston Street, Carlton, Victoria 3053, Australia
Tel: +61 (0)3 8359 1011
The right of the Author to be identified as the Author of this Work has been asserted in
accordance with the Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic, mechanical, photocopying,
recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988,
without the prior permission of the publisher.
First published 2006 by Blackwell Publishing Ltd
ISBN-13: 978–1–4051–2357–0
ISBN-10: 1–4051–2357–5
Library of Congress Cataloging-in-Publication Data
Analytical techniques for atmospheric measurement / edited by Dwayne E. Heard.
p. cm.
Includes bibliographical references and index.
ISBN-13: 978–1–4051–2357–0 (acid-free paper)
ISBN-10: 1–4051–2357–5 (acid-free paper)
1. Atmosphere—Measurement. 2. Meteorological instruments.
3. Weather forecasting. I. Heard, Dwayne E.
QC876.A53 2006
551.51
1
028—dc22
2005024526
A catalogue record for this title is available from the British Library
Set in 10/12pt Minion
by Integra Software Services Pvt. Ltd, Pondicherry, India
Printed and bound in India
by Replika Press Pvt. Ltd
The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry
policy, and which has been manufactured from pulp processed using acid-free and elementary
chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover
board used have met acceptable environmental accreditation standards.
For further information on Blackwell Publishing, visit our website:
www.blackwellpublishing.com
Contents
Preface xii
Acknowledgements xv
Contributors xvi
1 Field Measurements of Atmospheric Composition 1
Dwayne E. Heard
1.1 The role of field measurements in atmospheric science 1
1.1.1 Our changing atmosphere 1
1.1.2 The importance of atmospheric chemistry 2
1.1.3 Why field measurements of atmospheric composition are
important 3
1.1.4 The challenges of field measurements in the atmosphere 7
1.1.5 Comparison with calculations from numerical models 9
1.2 Scope, structure and content of this book 13
1.2.1 Scope and structure of the book 13
1.2.2 Previous texts describing methods for determining atmospheric
composition 14
1.2.3 Content of the book: Summary of individual chapters 15
1.3 The measurement of atmospheric composition 19
1.3.1 Units of concentration 19
1.3.2 Selection criteria for instruments 20
1.3.3 Instruments organised by classification of trace species 22
1.3.4 Instruments organised by analytical technique 22
1.4 Instrument platforms 24
1.4.1 Ground-based platforms, including vehicle-based mobile
laboratories 25
1.4.2 Ship-borne platforms 31
1.4.3 Balloon-borne platforms 32
1.4.4 Aircraft-borne platforms 33
1.4.5 Commercial passenger or freight aircraft platforms 34
1.4.6 Uninhabited aerial vehicles 35
1.4.7 Rocket platforms 35
1.4.8 Satellites and other space-borne platforms 36
1.5 Analytical methods not covered elsewhere in this book 41
1.5.1 LIDAR methods 41
1.5.2 Matrix isolation electron spin resonance (MIESR) 42
vi Contents
1.5.3 Solid-state and electrochemical sensors 43
1.5.4 Far-infrared and microwave absorption and emission
spectroscopy 44
1.5.5 Measurement of fluxes of trace gases and aerosols 45
1.6 Quality assurance and quality control 46
1.6.1 Precision and accuracy 47
1.6.2 Calibration of instruments 48
1.6.3 Intercomparison of instruments 50
1.7 Atmospheric chemistry and policy 52
1.7.1 Health effects and environmental policy 52
1.7.2 Monitoring networks 53
1.8 Major field campaigns for measurement of atmospheric composition 57
1.8.1 The design of field campaigns 57
1.8.2 Case study of a field campaign: The 2002 NAMBLEX campaign 59
1.9 Instrumented chambers for the study of simulated atmospheres 62
1.10 Future directions 63
Acknowledgements 67
Further reading 67
References 68
2 Infrared Absorption Spectroscopy 72
Alan Fried and Dirk Richter
2.1 Introduction 72
2.2 Fundamentals of infrared absorption spectroscopy 73
2.2.1 Electromagnetic radiation in the infrared 73
2.2.2 Molecular interactions in the IR 75
2.2.3 Vibrational bands and rotational lines in the IR 77
2.2.4 Vibrational bands of atmospheric spectral features in the
mid-IR 81
2.2.5 Vibrational–rotational spectral line intensities 84
2.3 Quantitative trace gas measurements employing IR absorption
spectroscopy 87
2.3.1 IR absorption lineshapes and linewidths 87
2.3.2 Beer–Lambert absorption law and absorbance 94
2.4 Trace gases in the atmosphere 98
2.5 Measurement approaches employing IR absorption spectroscopy 99
2.5.1 In situ measurements 103
2.5.2 Remote measurements 134
2.6 Advances in atmospheric studies employing IR absorption
measurements and future directions 135
2.6.1 Measurements of CH
2
O mixing ratios and model comparisons 135
2.6.2 Flux measurements of CH
4
136
2.6.3 Measurements in the Antarctic polar vortex 137
2.6.4 Isotopic ratio measurements of water in the UT/LS 137
2.6.5 Remote FTIR measurements 138
2.6.6 Future directions 138
Contents vii
Acknowledgements 139
Further reading 139
References 140
3 UV-Visible Differential Optical Absorption Spectroscopy (DOAS) 147
John M.C. Plane and Alfonso Saiz-Lopez
3.1 Introduction 147
3.2 Principles of differential optical absorption spectroscopy 148
3.2.1 The Beer–Lambert law 148
3.2.2 Differential absorption spectroscopy 149
3.2.3 Wavelength regions and differential absorption cross-sections 151
3.2.4 Application to atmospheric measurements 153
3.3 DOAS using artificial light sources 154
3.3.1 Broad-band light sources 154
3.3.2 Laser sources 163
3.4 DOAS using scattered sunlight 168
3.4.1 Spectroscopic principles 169
3.4.2 Zenith-viewing geometry: Retrieval of NO
3
vertical
profiles 171
3.4.3 Multi-axis DOAS 173
3.5 Summary and conclusions 179
Further reading 180
References 180
4 Fluorescence Methods 189
Ezra C. Wood and Ronald C. Cohen
4.1 Introduction 189
4.2 Basic aspects of fluorescence measurements 190
4.2.1 Molecular and atomic photophysics 190
4.2.2 The fluorescence signal 191
4.2.3 The background 193
4.2.4 The signal-to-noise ratio and detection limit 194
4.2.5 General design of fluorescence instruments 195
4.3 The hydroxyl radical 198
4.3.1 Instruments for stratospheric and upper tropospheric OH
measurements 199
4.3.2 Instruments for lower tropospheric OH measurements 203
4.3.3 OH fluorescence as an indirect detection strategy 206
4.3.4 Naphthalene 206
4.3.5 Measurement of the OH lifetime 207
4.4 The nitrogen oxides 208
4.4.1 Photophysics of NO
2
209
4.4.2 Single-photon NO
2
instrument design 210
4.4.3 Supersonic expansions 212
4.4.4 Calibration of LIF NO
2
instruments 213
viii Contents
4.4.5 Intercomparisons 214
4.4.6 Thermal dissociation: LIF 215
4.4.7 Two-photon LIF detection of NO 217
4.4.8 Single-photon LIF detection of NO 218
4.4.9 Photofragmentation two-photon LIF detection of NO
2
219
4.4.10 NO
3
and N
2
O
5
219
4.5 Detection of halogen compounds 220
4.5.1 Spectroscopy and calibration 221
4.5.2 Balloon-borne instruments 222
4.5.3 Aircraft measurements 222
4.5.4 ClONO
2
and ClOOCl 222
4.6 Future directions 223
Further reading 223
References 224
5 Mass Spectrometric Methods for Atmospheric Trace Gases 229
Jonathan Williams
5.1 Introduction 229
5.1.1 Generating a mass spectrum 229
5.1.2 Historical development of the mass spectrometer for air
measurements 230
5.2 Fundamentals 234
5.2.1 The importance of vacuum 234
5.2.2 The atomic mass scale 234
5.2.3 Resolving power and resolution 236
5.3 Key elements of a mass spectrometer 237
5.3.1 Ionisation 237
5.3.2 Mass filters 239
5.3.3 Detectors 244
5.4 Mass spectrometry used in atmospheric chemistry 246
5.4.1 Atmospheric pressure ionisation-chemical ionisation mass
spectrometer (API-CIMS) 246
5.4.2 The proton transfer reaction mass spectrometer 249
5.4.3 The use of CIMS for radical measurement (OH) 253
5.4.4 Coupled GC-MS capabilities 256
5.4.5 The isotope ratio mass spectrometer 258
5.5 Future developments 260
Acknowledgements 261
Further reading 261
References 261
6 Mass Spectrometric Methods for Aerosol Composition Measurements 265
Hugh Coe and James D. Allan
6.1 Introduction to atmospheric aerosols 265
6.2 Physical aerosol measurements and sizing definitions 266
Contents ix
6.3 Particle composition 269
6.3.1 Offline methods 269
6.3.2 Online bulk sampling and analysis methods 271
6.4 Online aerosol mass spectrometry 272
6.4.1 Mass spectrometer types 273
6.4.2 Inlet technologies 276
6.4.3 Particle sizing methods 278
6.4.4 Ablation and ionisation techniques 281
6.5 Analysis of ambient data 291
6.6 Applications of aerosol mass spectrometric techniques to atmospheric
aerosol sampling 293
6.7 Summary 300
Further reading 301
References 302
7 Chemical Methods: Chemiluminescence, Chemical Amplification,
Electrochemistry, and Derivatization 311
Andrew J. Weinheimer
7.1 Introduction 311
7.1.1 Scope 311
7.1.2 Measurement highlights 312
7.2 O
3
via heterogeneous chemiluminescence 312
7.2.1 Early years (luminol and rhodamine-B) 313
7.2.2 Since mid-1980s (eosin Y, coumarin-47, chromotropic acid) 316
7.2.3 Summary 317
7.3 O
3
via electrochemistry 317
7.4 Nitrogen compounds NO NO
2
NO
y
via chemiluminescence with O
3
319
7.4.1 The NO + O
3
reaction 319
7.4.2 The measurement of nitric oxide (NO) 320
7.4.3 The measurement of nitrogen dioxide NO
2
323
7.4.4 The measurement of total reactive nitrogen (NO
y
) 328
7.4.5 Routine NO
x
monitoring 331
7.5 Ozone via homogeneous chemiluminescence 334
7.5.1 O
3
+ Ethene 334
7.5.2 O
3
+ NO 334
7.6 NO
2
via luminol 336
7.7 Peroxides, HCHO, and HONO via liquid techniques 337
7.7.1 H
2
O
2
via dissolution and chemiluminescence 337
7.7.2 Peroxides via dissolution, derivatization, and fluorimetry 338
7.7.3 HCHO via dissolution, derivatization, and fluorimetry 340
7.7.4 HCHO via dissolution, derivatization, and HPLC 340
7.7.5 HONO via liquid techniques 341
7.8 Isoprene via O
3
chemiluminescence 342
7.9 Peroxy radicals via chemical amplification 344
7.9.1 Using reagent NO and CO, followed by detection of NO
2
344
7.9.2 Using reagent NO and SO
2
, followed by CIMS detection of H
2
SO
4
349