Atmospheric aerosol particle formation [Elektronische Ressource] : aircraft-based mass spectrometric measurements of gaseous and ionic aerosol precursors / presented by Michael Speidel

Publié le : samedi 1 janvier 2005
Lecture(s) : 22
Source : ARCHIV.UB.UNI-HEIDELBERG.DE/VOLLTEXTSERVER/VOLLTEXTE/2005/5937/PDF/DISSERTATION_SPEIDEL.PDF
Nombre de pages : 203
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Dissertation
submitted to the
Combined Faculties of the Natural Sciences and for Mathematics
of the Ruperto-Carola University of Heidelberg, Germany
for the degree of
Doctor of Natural Sciences
presented by
Diplom Physicist: Michael Speidel
born in: Essen
thOral examination: 16 of November 2005Atmospheric Aerosol Particle Formation:
Aircraft-Based Mass Spectrometric Measurements
of Gaseous and Ionic Aerosol Precursors.
Referees: Prof. Dr. Frank Arnold
Prof. Dr. Kurt RothDedicated to my parents.Bildung Atmosph˜arischer Aerosolpartikel: Flugzeuggetragene
Massenspektrometrische Messungen Gasf˜ormiger und Ionischer
Aerosolvorl˜aufer.
Kondensationswachstum von Aerosolpartikeln, sowie die Neubildung von Nanopartikeln,
h˜angen in erster Linie vom Vorhandensein von Schwefels˜aure ab. Durch kosmische Strahlung
gebildete atmosph˜arische Ionen k˜onnen die Bildung von Cluster-Ionen ausl˜osen, welche
dann durch gegenseitiges Anlagern sowie durch Kondensation von Schwefels˜aure wachsen.
Ein chemisches Ionisations Ionenfallen-Massenspektrometer (IT-CIMS) sowie ein Quadrupol
Massenspektrometer (QMS) dienten in der vorliegenden Arbeit zur quantitativen Bestim-
mungdesVorl˜aufergasesderSchwefels˜aure,SO ,sowiezurMessungatmosph˜arischerCluster-2
Ionen. Die zum Nachweis von SO verwendete Ionenmolekulreaktion˜ wurde isotopisch kalib-2
riert. Aus Wandverlusten und Ionenhydratisierung resultierende Messunsicherheiten werden
dadurch elegant umgangen. Das modiflzierte IT-CIMS konnte im Rahmen der Flugzeugkam-
pagne ITOP (International Transport of Ozone and Precursors) an Bord des deutschen
Forschungs ugzeuges Falcon erfolgreich eingesetzt werden. In einer weiteren Flugzeugkam-
pange, CONTRACE (Convective Transport of Trace Gases), diente das QMS an Bord
der Falcon zur Messung atmosph˜arischer Cluster-Ionen. Signiflkante Korrelationen zwis-
chen gemessenen kleinen Partikeln und Cluster-Ionen wurden festgestellt. Im Rahmen von
ITOP stie… man auf eine mit SO stark verschmutzte Luftmasse, im Bereich der unteren2
Stratosph˜are, welche aus ub˜ erschie…ender Konvektion in Nordamerika stammte. Modellsim-
ulationen auf Basis der SO Daten deuten an, dass die gemessenen Partikelallein aus bin˜arer2
Nukleation und anschlie…endem Wachstum (Kondensation und Anlagerung) von H SO und2 4
H O erkl˜art werden k˜onnen.2
Atmospheric Aerosol Particle Formation: Aircraft-Based Mass Spectrometric
Measurements of Gaseous and Ionic Aerosol Precursors.
The condensational growth of aerosol particles and the formation of fresh, nanometer-sized
particlesdependprimarilyuponthepresenceofH SO . Atmosphericionsproducedbycosmic2 4
rays can initialize the formation of cluster ions, which subsequently may grow by mutual
coagulation and condensation of H SO and H O. In the present work, measurements of the2 4 2
H SO precursorSO andatmosphericclusterionswereperformedusinganiontrapchemical2 4 2
ionisation mass spectrometer (IT-CIMS) and a quadrupole mass spectrometer (QMS). The
ion molecule reaction to determine atmospheric SO was calibrated isotopically. So problems2
arising from wall losses and ion hydration are circumvented in an elegant manner. The
modifled IT-CIMS was integrated into the German research aircraft Falcon and successfully
employedduringtheinternationalaircraftcampaignITOP(InternationalTransportofOzone
and Precursors). During another campaign, CONTRACE (Convective Transport of
Trace Gases), the QMS aboard the Falcon detected atmospheric cluster ions. Signiflcant
correlations between detected small particles and cluster ions were found. During ITOP a
plume of strongly enhanced SO concentrations in the lowermost stratosphere was observed,2
that originated from North America by overshooting deep convection. Model simulations
based on the SO data indicate that the measured particles can be explained by binary2
nucleation and growth (condensation and coagulation) of H SO and H O.2 4 2Contents
1 INTRODUCTION 1
1.1 Thesis Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Research Signiflcance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Health Impacts of SO . . . . . . . . . . . . . . . . . . . . . . . 22
1.2.2 Sulfur Emission Rates . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3.1 SO Sources and Sinks in the Atmosphere . . . . . . . . . . . . 52
1.3.2 SO Distribution in the Atmosphere. . . . . . . . . . . . . . . . 72
1.3.3 Airborne SO Measurement Techniques . . . . . . . . . . . . . . 82
1.3.4 Nucleation in the Atmosphere . . . . . . . . . . . . . . . . . . . 10
1.3.5 Previous Airborne Measurements of Charged Molecular Cluster 18
2 METHOD AND LABORATORY EXPERIMENTS 21
2.1 Quadrupole Mass Spectrometer (QMS) . . . . . . . . . . . . . . . . . . 21
2.1.1 Instrumental Schematics and Layout . . . . . . . . . . . . . . . 21
2.1.2 Ion Optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.1.3 Ion Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.1.4 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.1.5 Ion Transmission and Ion Sensitivity . . . . . . . . . . . . . . . 29
2.2 Ion Trap Mass Spectrometer (ITMS) . . . . . . . . . . . . . . . . . . . 39
2.2.1 Instrumental Schematics and Layout . . . . . . . . . . . . . . . 39
2.2.2 Ion Storage and Detection in a Trap . . . . . . . . . . . . . . . 42
2.2.3 Ion Optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.2.4 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
2.2.5 ITMS Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
2.3 Chemical Ionisation Mass Spectrometry (CIMS) . . . . . . . . . . . . . 45
2.3.1 Reaction Kinetics . . . . . . . . . . . . . . . . . . . . . . . . . . 46
iii CONTENTS
2.3.2 Association Reactions . . . . . . . . . . . . . . . . . . . . . . . 48
2.3.3 Ion Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.3.4 SO Detection with an Ion Trap . . . . . . . . . . . . . . . . . 522
2.3.5 Online Isotopic Calibration. . . . . . . . . . . . . . . . . . . . . 53
2.3.6 Water Vapor and Trapping E–ciency . . . . . . . . . . . . . . 55
2.3.7 Instrumental Background and Sensitivity . . . . . . . . . . . . . 58
2.3.8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3 ATMOSPHERIC CLUSTER ION MEASUREMENTS 65
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.2 Analysis of High Pass Mode Mass Spectra . . . . . . . . . . . . . . . . 66
3.2.1 Derived Condensable Gas Concentration . . . . . . . . . . . . . 71
3.3 Measurements during the CONTRACE Campaign 2003 . . . . . . . . . 73
3.3.1 Charged Cluster Measurements . . . . . . . . . . . . . . . . . . 73
3.3.2 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
4 ATMOSPHERIC SULFUR DIOXIDE MEASUREMENTS 85
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.2 Analysis and Evaluation of ITOP SO time series . . . . . . . . . . . . 852
4.2.1 ITOP Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.2.2 Overview of the ITOP SO Measurements . . . . . . . . . . . . 862
4.2.3 Flight 31: Detection of Subtropical Air . . . . . . . . . . . . . . 94
4.2.4 Flight 26: of an Urban Pollution Plume . . . . . . . . 95
4.2.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
5 ATMOSPHERIC SULFUR DIOXIDE TRANSPORT 101
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
5.2 Convective Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
5.3 Detection of a Lower Stratospheric SO Plume . . . . . . . . . . . . . . 1042
5.4 Meterological Situation . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.4.1 The FLEXPART Model . . . . . . . . . . . . . . . . . . . . . . 108
5.4.2 Model Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
5.4.3 Satellite Observations. . . . . . . . . . . . . . . . . . . . . . . . 111
5.4.4 Predicted SO and NO Mole Fractions . . . . . . . . . . . . . . 1122 y
5.5 Conclusions from Meteorology and Trace Gas Measurements . . . . . . 113
5.6 Particle Number Concentrations . . . . . . . . . . . . . . . . . . . . . . 114
5.6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
5.6.2 Particle Measurements . . . . . . . . . . . . . . . . . . . . . . . 115CONTENTS iii
5.7 Model Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
5.7.1 The AEROFOR Modell . . . . . . . . . . . . . . . . . . . . . . 118
5.7.2 Model Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
5.7.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
5.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6 SUMMARY AND OUTLOOK 123
6.1 Summary and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
A 127
A.1 A New Water Vapor Detection Method . . . . . . . . . . . . . . . . . . 127
A.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
A.1.2 Proposed Ion Molecule Reaction Path . . . . . . . . . . . . . . . 128
A.1.3 Calibration with a dew point mirror. . . . . . . . . . . . . . . . 131
A.1.4 IntercomparisonwithaLyman-fiDetectorduringtheITOPcam-
paign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
A.1.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
B 145
B.1 Overview Trace Gas Measurements during ITOP . . . . . . . . . . . . 146
B.1.1 Flight 19.07.2004 . . . . . . . . . . . . . . . . . . . . . . . . . . 146
B.1.2 Flight 22.07.2004 . . . . . . . . . . . . . . . . . . . . . . . . . . 147
B.1.3 Flight 25a.07.2004 and 25b.07.2004 . . . . . . . . . . . . . . . . 148
B.1.4 Flight 26.07.2004 . . . . . . . . . . . . . . . . . . . . . . . . . . 150
B.1.5 Flight 31.07.2004 . . . . . . . . . . . . . . . . . . . . . . . . . . 151
B.1.6 Flight 03.08.2004 . . . . . . . . . . . . . . . . . . . . . . . . . . 152
B.1.7 Scatter Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
B.2 Overview of SO Measurements during SHIPS . . . . . . . . . . . . . . 1562
B.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
B.2.2 Flight of 23. July 2004 . . . . . . . . . . . . . . . . . . . . . . . 157
B.2.3 Flight of 30. July 2004 . . . . . . . . . . . . . . . . . . . . . . . 158
B.2.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
C 167
C.1 ITMS implementation in the research aircraft FALCON . . . . . . . . . 167
LIST OF FIGURES 167iv CONTENTS
LIST OF TABLES 177
REFERENCES 179
GLOSSARY 192Chapter 1
INTRODUCTION
1.1 Thesis Objectives
Presented here is a detailed account of the development, testing, and application of
an instrumental apparatus called Ion Trap Chemical Ionisation Mass Spectrometer
(ITCIMS) to determine atmospheric mole fractions of SO from aircraft platforms. A2
precise characterization of a quadrupole mass spectrometer setup to determine cumu-
lativeabundancesofnaturalambientclusterionsintheatmosphereanditsapplication
during an aircraft campaign followed by a detailed data analysis comprises a second
major topic of this thesis. The objectives of this work were the following:
1. Design and construction of an ITCIMS setup which can be deployed on aircraft
platforms for in situ atmospheric studies.
2. Development of methods yielding high ITCIMS sensitivity and accuracy for SO2
under ambient conditions, including moist air environments such as the marine
boundary layer and altitudes from ground to 12 km.
3. Determine the vertical SO distributions above central Europe.2
4. Analysein uencesofsulfurdioxiderelatedlong-rangetransportphenomenafrom
northern America to Europe.
5. Validatethedepositionofsulfurdioxideintothemarineboundarylayerbyseago-
ing ships.
6. Characterize the occurrence of large natural ion clusters in terms of particle
nucleation in the ambient atmosphere.
12 CHAPTER 1. INTRODUCTION
The chapters in this thesis are logically divided into laboratory development and
airborne fleld deployments of the ITCIMS and QMS instruments. From a thematic
pointofview,thethesisisdividedintoSO chemistryanditsatmosphericoccurrenceon2
theonehandandthepotentialimpactofSO ontoparticlenucleationbyconversionto2
sulfuric acid on the other hand. The ITCIMS instrument served to determine ambient
sulfur dioxide mole fractions, whereas the QMS instrument was used to obtain the
abundanceofchargedclusters,predominantlyformedbycondensablegaseslikesulfuric
acid.
Chapter 1 provides background information on nucleation theory and results on
earlier performed charged-cluster measurements. An overview about the atmospheric
sulfurcycle,SO sourcesandsinksispresented. Otherairbornesulfurdioxidedetection2
methods are listed.
Chapter 2 presents a detailed account of the instrumentation and components
used to create an isotopically calibrated ITCIMS for the the measurement of SO in2
the atmosphere on aircraft platforms. In great detail the airborne QMS apparatus is
characterized.
Chapter 3 delivers results of the airborne deployment in continental air of the
QMS instrument in June 2003. Data analysis and results of the fleld campaign are
discussed.
Chapter 4 shows the determined vertical SO proflle. In particular two ights are2
described. The intersection with an urban pollution plume and the crossing through
very clean Atlantic air masses nicely illustrates the good performance, accuracy and
dynamic range of the ITCIMS instrument.
Chapter 5 discusses the detection of a highly polluted SO air parcel in the lower-2
most stratosphere during the ight campaign in July 2004. The resulting potential of
particlenucleationinthelowermoststratosphere(LS)aswellastransportmechanisms
capable to e–ciently uplift polluted air from the planetary boundary layer (PBL) to
the LS are elucidated.
1.2 Research Signiflcance
1.2.1 Health Impacts of SO2
Considerable attention has been given in recent years to epidemiological studies and
research into the health efiects of ambient air pollution [Schlatter, 1994]. Studies have
covered difierent acute and chronic health efiects which occur as a result of SO pollu-2
tionanditspotentialtoinducenanometer-sizedparticles[Imaietal.,1986],[Stjernberg

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