Three-dimensional modeling of minor chemical constituents in the mesosphere, lower thermosphere region [Elektronische Ressource] / Mykhaylo Grygalashvyly

Informations

• Publié par: universitat_rostock
• Publié le: 01 janvier 2008
• Nombre de lectures: 12
• Langue: English
• Poids de l'ouvrage: 5 Mo

Extrait

Three-dimensional modeling of minor chemical
constituents in the mesosphere/lower thermosphere
region
Dissertation
am Leibniz-Institute für Atmosphärenphysik in Kühlungsborn zur Erlangung
der Doktorwürde der Mathematisch-Naturwissenschaftlichen Fakultät der
Universität Rostock
Mykhaylo Grygalashvyly
Juli 2008
urn:nbn:de:gbv:28-diss2008-0123-5Contents
1 Introduction 4
1.1 Motivation….........................................…..............................................................4
1.2 Thesis Outline…….….............................…...........................................................5
2 Model Description 7
2.1 Dynamic Model..…….…………………..............................................................8
2.2 Chemistry-Transport Model (CTM)…..................................................................9
2.2.1 Chemical Code….………………....................................................... .10
2.2.2 Radiation Code.....................................................................................10
2.2.3 Diffusion Code......................................................................................11
2.2.3.1 Eddy Diffusion………….......................................................11
2.2.3.2 Molecular Diffusion...............................................................12
2.2.4 Advection…………………………………..........................................14
2.3 Improvements......................................................................................................15
2.3.1 Walcek Scheme………………….................... ...................................15
2.3.2 Water Vapor Photolyses Rate………… ……......................................17
3 Modeling of Global Water Vapor 19
3.1 Results and Comparison with Observations........................................................19
3.2 Dependence on Solar Activity.............................................................................22
3.3 Autocatalytic Water Vapor Production...............................................................27
3.4 Summary and Conclusions.................................................................................35
4 Trend Calculations 37
4.1 General Problem..................................................................................................37
4.2 Chemical aspects.................................................................................................39
4.3 Water Vapor........................................................................................................41
4.4 Ozone...................................................................................................................44
4.5 Hydroxyl..............................................................................................................47
4.6 Carbon Monoxide................................................................................................48
4.7 NO ......................................................................................................................48X
4.8 Chemical Heat.....................................................................................................49
4.9 Summary and Conclusions..................................................................................51
5 Ozone 53
5.1 Middle Mesospheric Maximum (MMM) of Ozone Near the Polar Night
Terminator............................................................................................................53
5.2 Results..................................................................................................................54
5.3 Discussion.............................................................................................................56
5.4 Conclusions..........................................................................................................58
6 Non-Linear Effects in the MLT Region 60
6.1 General Discussion..................................................................................................60
6.2 Mesopause Region..................................................................................................62
26.3 Middle Mesospheric Ozone Oscillations at the Polar Day Terminator...................66
6.4 Summary and Conclusion........................................................................................68
7 Influence of Sudden Stratospheric Warmings (SSWs) on the chemistry in the
extended Mesopause Region 69
7.1 The Sudden Stratospheric Warming (SSW)..............................................................69
7.2 Effects During SSW in the Extended Mesopause Region.........................................70
7.3 Summary and Conclusions........................................................................................79
8 Other Results 81
8.1 Chemical Heating Rates
8.1.1 The Problem..............................................................................................81
8.1.2 Results.......................................................................................................82
8.2 Computation of OH* and OH
8.2.1 Introduction...............................................................................................83
8.2.2 Calculation of the Concentrations of OH* in the Different Exited
States........................................................................................................85
8.2.3 Results.......................................................................................................86
8.3 Summary and Conclusions 88
9 Summary and Outlook 89
9.1 The Most Important Results...................................................................................89
9.2 Open Questions and Future Improvements of the CTM.........................................90
A History 92
B Derivation of the Equation for Calculation of Eddy Diffusion 94
C Derivation of the Equation for Calculation of Molecular Diffusion 96
D Description of Walcek Scheme. 99
E The Cycles for Water Vapor 102
F The Chemical Reactions 103
References 105
3Chapter 1
Introduction
1.1 Motivation
The minor chemical constituents play a significant role in the middle atmosphere. These
constituents determine the radiation budget and influence the dynamics through heat, which
calorificate in chemical reactions. Very few constituents can be measured by various ground
based or rocket- and satellite-borne techniques available. For certain time periods or geographical
regions other constituents are unmeasurable. The mesosphere - sometimes also called the
“ignorosphere” - is still a region characterized by different unexplained phenomena. There is a
permanent lack of data required for different investigations to employ model data. Different
discrepancies between observations and model calculations have been reported in the recent past.
Examples of these discrepancies are: the so-called ozone deficit problem [e.g. Clancy et al., 1987;
Eluszkiewicz, 1993; Siskind et al., 1995; Summers et al., 1997], the HO dilemma [SummersX
et al., 1997; Offermann, 2000; Conway et al., 2000], and the upper mesospheric water vapor layer
explained in terms of the recombination of O and H on meteoric dust [Summers and Siskind,2
1999]. The intercomparison of observations revealed considerable differences between
individual measurements [Nedoluha and Hartogh, 2006]. However, the comparison between
different model results al