Analysis of stratospheric bromine monoxide from SCIAMACHY using comparison with model results [Elektronische Ressource] / von Ninad V. Sheode

Ninad Sheode <[e-mail]>

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2006
• Nombre de lectures: 19
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

Analysis of Stratospheric Bromine
Monoxide from SCIAMACHY using
Comparison with Model Results
Vom Fachbereich fur¨ Physik und Elektrotechnik
der Universitat¨ Bremen
Zur Erlangung des akademischen Grades eines
Doktor der Naturwissenschaften (Dr. rer. nat.)
genehmigte Dissertation
von
Ninad V. Sheode
Eingereicht am: 6 June 2006
Tag des Kolloquiums: 11 July 2006
Gutachter: Prof. Dr. J. P. Burrows
Prof. Dr. J. Notholt
Weitere Prufer¨ Prof. Dr. M. Rhein
Prof. Dr. P. RichterDedication
This thesis is dedicated to the Memory of my
grandmother
Prabhavati Sheode
ivContents
Abstract 1
Publications 3
1 Introduction 7
1.1 Motivation and objective . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2 Thesis content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2 The Earth’s atmosphere 11
2.1 Vertical thermal structure of the atmosphere . . . . . . . . . . . . . . . 11
2.2 Composition of the atmosphere . . . . . . . . . . . . . . . . . . . . . . 13
2.3 Ozone in the stratosphere . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3.1 Distribution of ozone . . . . . . . . . . . . . . . . . . . . . . . 17
2.4 The ozone hole in the Antarctic . . . . . . . . . . . . . . . . . . . . . . 17
2.4.1 The pre hole condition . . . . . . . . . . . . . . . . . . . . . . 17
2.4.2 The begining of O hole . . . . . . . . . . . . . . . . . . . . . 183
2.4.3 The end of O depletion . . . . . . . . . . . . . . . . . . . . . 203
2.5 The ozone hole in the Arctic . . . . . . . . . . . . . . . . . . . . . . . 21
2.6 Ozone at midlatitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.7 in the troposphere . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.7.1 The role of halogens in the ozone chemistry of the troposphere . 25
3 Chemical Modelling 27
3.1 Components of chemical models . . . . . . . . . . . . . . . . . . . . . 27
3.2 Model types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2.1 Zero dimensional models . . . . . . . . . . . . . . . . . . . . . 28
3.2.2 One . . . . . . . . . . . . . . . . . . . . . 29
3.2.3 Two dimensional models . . . . . . . . . . . . . . . . . . . . . 30
3.2.4 Three . . . . . . . . . . . . . . . . . . . . 31
3.3 One dimensional photochemical box model . . . . . . . . . . . . . . . 32
3.3.1 Chemical scheme . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.3.2 integration . . . . . . . . . . . . . . . . . . . . . . . 32
3.3.3 Photolysis rates calculation . . . . . . . . . . . . . . . . . . . . 34
3.3.4 Chemical reaction rates calculation . . . . . . . . . . . . . . . 35
3.3.5 Negative species concentration . . . . . . . . . . . . . . . . . . 36vi Contents
3.4 Heterogeneous chemistry . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.5 Application of the model . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.5.1 Nitrate radical in the stratosphere . . . . . . . . . . . . . . . . 38
3.5.2 Comparison of NO profiles with model calculations . . . . . . 403
3.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4 Stratospheric bromine and nitrogen chemistry 45
4.1 Stratospheric bromine chemistry . . . . . . . . . . . . . . . . . . . . . 45
4.1.1 Sources of bromine . . . . . . . . . . . . . . . . . . . . . . . . 45
4.2 nitrogen chemistry . . . . . . . . . . . . . . . . . . . . . 50
4.2.1 Sources of nitrogen . . . . . . . . . . . . . . . . . . . . . . . . 50
4.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5 The SCIAMACHY instrument and retrieval of BrO pro les 55
5.1CHY on ENVISAT . . . . . . . . . . . . . . . . . . . . . . . 56
5.2 Viewing geometries . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.2.1 The nadir mode . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.2.2 The limb mode . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.2.3 Occultation mode of observation . . . . . . . . . . . . . . . . . 58
5.2.4 Lunar occultation mode . . . . . . . . . . . . . . . . . . . . . 59
5.3 Instrument layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
5.4 Data products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5.5 Performance of the SCIAMACHY instrument . . . . . . . . . . . . . . 62
5.6 Retrieval of trace gases . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.6.1 Radiative transfer equation . . . . . . . . . . . . . . . . . . . . 64
5.6.2 Retrieval technique . . . . . . . . . . . . . . . . . . . . . . . . 64
5.7 Retrieval of BrO profiles from limb measurements . . . . . . . . . . . . 66
5.7.1 Sensitivity studies . . . . . . . . . . . . . . . . . . . . . . . . 67
5.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6 Validation of SCIAMACHY BrO limb pro les 73
6.1 Other measurement techniques . . . . . . . . . . . . . . . . . . . . . . 73
6.1.1 Chemical conversion resonance flurosescence . . . . . . . . . . 73
TRIPLE instrument . . . . . . . . . . . . . . . . . . . . . . . . 74
6.1.2 Balloon borne differential optical absorption spectroscopy . . . 75
LPMA/DOAS BrO measurements . . . . . . . . . . . . . . . . 78
SAOZ/DOAS BrO . . . . . . . . . . . . . . . . 78
6.2 Validation of BrO profiles . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
7 Global observations of stratospheric BrO 81
7.1 First global SCIAMACHY limb BrO retrievals . . . . . . . . . . . . . 81
7.2 Comparison with photochemical model output . . . . . . . . . . . . . . 82
7.2.1 Photochemical model . . . . . . . . . . . . . . . . . . . . . . . 83Contents vii
7.2.2 NO in the photochemical model . . . . . . . . . . . . . . . . . 832
7.3 Towards a climatology of stratospheric BrO . . . . . . . . . . . . . . . 85
7.3.1 Seasonal variation of BrO . . . . . . . . . . . . . 88
7.4 Influence of NO on BrO . . . . . . . . . . . . . . . . . . . . . . . . . 88x
7.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
8 Comparison with ground based measurements of BrO in the tropics 91
8.1 BrO and NO at the tropical site in Nairobi . . . . . . . . . . . . . . . 912
8.2 Comparison with photochemical model output . . . . . . . . . . . . . . 93
8.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
9 BrO in the troposphere 97
9.1 Bromine in the free troposphere from SCIAMACHY . . . . . . . . . . 97
9.1.1 Retrieval of SCIAMACHY BrO vertical column . . . . . . . . 98
9.1.2 Unresolved issues in BrO nadir retrieval . . . . . . . . . . . . . 98
9.2 Integration of statospheric profiles . . . . . . . . . . . . . . . . . . . . 102
9.3 BrO below 15 km in the atmosphere . . . . . . . . . . . . . . . . . . . 102
9.4 Sources of bromine in the troposphere . . . . . . . . . . . . . . . . . . 103
9.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
10 Total bromine in the stratosphere 105
10.1 The organic method . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
10.1.1 Estimate of bromine loading in the stratosphere . . . . . . . . . 106
10.2 The inorganic method . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
10.2.1 Estimate of bromine loading in the stratosphere . . . . . . . . . 109
10.3 Contribution of very short lived organic bromine species to total bromine 114
10.3.1 Transport of very short lived species to the stratosphere . . . . . 115
10.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
11 Summary, Conclusions, and Outlook 117
11.1 Summary and conclusions of chapters . . . . . . . . . . . . . . . . . . 117
11.2 Overall summary and conclusions . . . . . . . . . . . . . . . . . . . . 119
11.3 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Appendix 121
Acknowledgements 125
Bibliography 127viii ContentsAbstract
This thesis presents an analysis of the stratospheric bromine monoxide (BrO) profiles
retrieved globally from two years of limb measurements from the Scanning Imaging
Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument on
board ENVISAT.
In order to have a confidence in the quality of the retrieved SCIAMACHY BrO profiles,
they need to be validated with BrO measurements, performed using different methods.
Hence, as a first step towards a validation of SCIAMACHY BrO retrievals, BrO profiles
are compared with the set of balloon borne BrO measurements. The comparison with
a set of four balloon borne BrO profiles shows mean relative differences in the altitude
range from 18 to 30 km between +17% and 42%. In order to validate our current un
derstanding of bromine chemistry, the SCIAMACHY BrO retrievals are compared with
modeled BrO profiles, based on estimated inorganic bromine (Br ) from CFC 11 re y
trievals by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS),
also on ENVISAT, and the calculated BrO/Br ratio from a photochemical model con y
strained by SCIAMACHY nitrogen di oxide (NO ) retrievals. The BrO observations are2
found to be broadly consistent with our current understanding of stratospheric bromine
chemistry and a total stratospheric bromine loading of approximately 18.5 pptv.
Further a global climatology of stratospheric BrO is constructed using the two years’
retriev