Correlative and regression analyses of daily ERA-Interim reanalysis data for three separate solarmaximum periods confirm the existence of a temperature response to short-term (mainly ∼27 day) solarultraviolet variations at tropical latitudes in both the lower stratosphere and troposphere. The response,which occurs at a phase lag of 6–10 days after the solar forcing peak, consists of a warming in the lowerstratosphere, consistent with relative downwelling and a slowing of the mean meridional (Brewer-Dobson)circulation, and a cooling in the troposphere. The midtropospheric cooling response is most significant inthe tropical Pacific, especially under positive El Niño–Southern Oscillation conditions and may be relatedto a reduction in the number of Madden-Julian oscillation events that propagate eastward into the centralPacific following peaks in short-term solar forcing.

A new retrieval algorithm has been developed based on the Optimal Estimation (OE) approach, which retrieves lognormal aerosol size distribution parameters from multiwavelength aerosol extinction data, as measured by the Stratospheric Aerosol and Gas Experiment (SAGE) II in the lower stratosphere. Retrieving these aerosol properties becomes increasingly more difficult under aerosol background conditions, when tiny particles (« 0.1 µm) prevail, to which the experiment is nearly or entirely insensitive. A successful retrieval algorithm must then be able (a) to fill the 'blind spot' with suitable information about the practically invisible particles, and (b) to identify 'the best' of many possible solutions. The OE approach differs from other previously used aerosol retrieval techniques by taking a statistical approach to the multiple solution problem, in which the entire range of possible solutions are considered (including the smallest particles) and characterized by probability density functions. The three main parts of this thesis are (1) the development of the new OE retrieval algorithm, (2) the validation of this algorithm on the basis of synthetic extinction data, and (3) application of the new algorithm to SAGE II measurements of stratospheric background aerosol. The validation results indicate that the new method is able to retrieve the particle size of typical background aerosols reasonably well, and that the retrieved uncertainties are a good estimate of the true errors. The derived surface area densities (A), and volume densities (V ) tend to be closer to the correct solutions than the directly retrieved number density (N), median radius (R), and lognormal distribution width (S). Aerosol properties as retrieved from SAGE II measurements (recorded in 1999) are observed to be close to correlative in situ data. In many cases the OE and in situ data agree within the (OE and/or the in situ ) uncertainties. The retrieved error estimates are of the order of 69% (σN), 33% (σR), 14% (σS), 23% (σA), 12% (σV), and 13% (σReff ). The OE number densities are generally larger, and the OE median particle sizes are generally smaller than those N and R retrieved by Bingen et al. (2004a), who suggest that their results underestimate (N) or overestimate (R) correlative in situ data due to the 'small particle problem'. The OE surface area estimates are generally closer to correlative in situ profiles (courtesy of T. Deshler, University of Wyoming), and larger than Principal Component Analysis (PCA) retrieval solutions of A (courtesy of L. W. Thomason, NASA LaRC) that have been observed to underestimate correlative in situ data by 40-50%. These observations suggest that the new OE retrieval algorithm is a successful approach to the aerosol retrieval problem, which is able to add to the current knowledge by improving current estimates of aerosol properties in the lower stratosphere under low aerosol loading conditions.

A new retrieval algorithm has been developed based on the Optimal Estimation (OE) approach, which retrieves lognormal aerosol size distribution parameters from multiwavelength aerosol extinction data, as measured by the Stratospheric Aerosol and Gas Experiment (SAGE) II in the lower stratosphere. Retrieving these aerosol properties becomes increasingly more difficult under aerosol background conditions, when tiny particles (« 0.1 µm) prevail, to which the experiment is nearly or entirely insensitive. A successful retrieval algorithm must then be able (a) to fill the 'blind spot' with suitable information about the practically invisible particles, and (b) to identify 'the best' of many possible solutions. The OE approach differs from other previously used aerosol retrieval techniques by taking a statistical approach to the multiple solution problem, in which the entire range of possible solutions are considered (including the smallest particles) and characterized by probability density functions. The three main parts of this thesis are (1) the development of the new OE retrieval algorithm, (2) the validation of this algorithm on the basis of synthetic extinction data, and (3) application of the new algorithm to SAGE II measurements of stratospheric background aerosol. The validation results indicate that the new method is able to retrieve the particle size of typical background aerosols reasonably well, and that the retrieved uncertainties are a good estimate of the true errors. The derived surface area densities (A), and volume densities (V ) tend to be closer to the correct solutions than the directly retrieved number density (N), median radius (R), and lognormal distribution width (S). Aerosol properties as retrieved from SAGE II measurements (recorded in 1999) are observed to be close to correlative in situ data. In many cases the OE and in situ data agree within the (OE and/or the in situ ) uncertainties. The retrieved error estimates are of the order of 69% (σN), 33% (σR), 14% (σS), 23% (σA), 12% (σV), and 13% (σReff ). The OE number densities are generally larger, and the OE median particle sizes are generally smaller than those N and R retrieved by Bingen et al. (2004a), who suggest that their results underestimate (N) or overestimate (R) correlative in situ data due to the 'small particle problem'. The OE surface area estimates are generally closer to correlative in situ profiles (courtesy of T. Deshler, University of Wyoming), and larger than Principal Component Analysis (PCA) retrieval solutions of A (courtesy of L. W. Thomason, NASA LaRC) that have been observed to underestimate correlative in situ data by 40-50%. These observations suggest that the new OE retrieval algorithm is a successful approach to the aerosol retrieval problem, which is able to add to the current knowledge by improving current estimates of aerosol properties in the lower stratosphere under low aerosol loading conditions.

The upper troposphere-lower stratosphere (UTLS) is a transition region between the troposphere and the stratosphere. During the boreal summer, the UTLS is dominated by large-scale anticyclonic circulations over the Asian and North American monsoon regions, exhibiting complex dynamical and chemical characteristics. Re-cent studies have emphasized the important role of the summer monsoon systemin stratosphere-troposphere exchange of water vapor and chemical species, which strongly influences the atmospheric chemistry and climate system. The transport in the UTLS region occurs in both directions, stratosphere-troposphere transport (STT)and troposphere-stratosphere transport (TST). For example, observational studies indicate localized maxima of tropospheric pollutants and stratospheric water vapor(SWV) in the UTLS, which are controlled by deep convection and large-scale circulation. Meanwhile, stratospheric ozone (O3) can fold into tropospheric air and entrain into the planetary boundary layer (PBL) via deep STT, and thus affect air quality at the surface. In this thesis, we aim at improving the understanding of the transport processes in the UTLS that are linked to monsoon dynamics using observations and modelling tools.<div><br></div><div>First, we investigate the TST transport in association with the Asian summer monsoon. We examine the simulation of SWV in the Community Earth System Model, version 1 with the Whole Atmosphere Community Climate Model as its atmospheric component [CESM1(WACCM)]. CESM1(WACCM) generally tends to simulate a SWV maximum over the central Pacific Ocean instead of over the Asian continent as observed, but this bias is largely improved in the high vertical resolution version. The high vertical resolution model with increased vertical layers in the UTLS is found to have a less stratified UTLS over the central Pacific Ocean compared with the low vertical resolution model. It therefore simulates a steepened potential vorticity gradient over the central Pacific Ocean that better closes the upper-level anticyclone and confines the SWV within the enhanced transport barrier.<br></div><div><br></div><div>We further study the transport pathways connecting the Northern Hemisphere sur-face and the North American (NA) UTLS by diagnosing Boundary Impulse Response idealized tracers implemented at the Northern Hemisphere surface during summer. In ensemble average, air masses enter the NA UTLS region above Central America, and then slowly mix into the higher latitudes. However, fast transport pathways with modal age around two weeks are evident in some tracer ensembles. For these rapid transport pathways, the tracers first reach the UTLS region over the eastern Pacific and the Gulf of Mexico as a result of enhanced deep convection and vertical advection, followed by horizontal transport over the United States by a strengthened UTLS anticyclone circulation.<br></div><div><br></div><div>To the end, we evaluate the downward transport of stratospheric O3via STT using simulation from a state-of-the-art chemistry climate model implemented with an artificial stratospheric ozone tracer (O3S). We find that O3transported from the stratosphere makes a significant contribution to the surface O3variability where back-ground surface O3exceeds 95thpercentile, especially over the western U.S. Maximum covariance analysis is applied to O3anomalies paired with stratospheric O3traceranomalies to identify the stratospheric intrusion and the underlying dynamical mechanism. The first leading mode corresponds to deep stratospheric intrusions in the western and northern tier of the U.S., and intensified north easterlies in the mid-to-lower troposphere along the west coast, which also facilitate the transport to the eastern Pacific Ocean. The second leading mode corresponds to deep intrusions over the Intermountain Regions. Both modes are associated with eastward propagating baroclinic systems, which are amplified near the end of the North Pacific storm tracks, leading to strong descents over the western United States.<br></div>

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21579号 / 理博第4486号 / 新制||理||1644(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 橋口 浩之, 教授 塩谷 雅人, 教授 秋友 和典 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

To understand the contribution of aerosol particles to radiative forcing and heterogeneous chemical processes in the upper troposphere and lowermost stratosphere (UT/LMS), the knowledge of the particle size distribution is mandatory. Unfortunately, measurements in the UT/LMS are costly. Research aircrafts are expensive and thus their application is limited in time and space. Satellite remote sensing measurements provide a good temporal and spatial (horizontal) coverage, but only a limited vertical resolution and currently cannot resolve the particle size distribution. Therefore, within this thesis an optical particle counter (OPC) unit was modified for the application onboard a passenger long-haul aircraft within the CARIBIC project (www.caribic-atmospheric.com). The CARIBIC OPC unit provides regular and cost-efficient particle size distribution measurements of accumulation mode particles in the UT/LMS. In April 2010, the new OPC unit was installed for the first time onboard the Lufthansa Airbus A340 600 (D-AIHE) for the measurement of the volcanic ash cloud from the Eyjafjallajökull eruption (April to May 2010). Since June 2010 the OPC unit measures on usually four intercontinental flights per month the UT/LMS particle size distribution in the particle size range 125 to 1300 nm particle diameter. As the data acquisition stores the scattering raw signal and all housekeeping data as well, during the post flight data analysis the temporal- and size channel resolution can be flexible set. Within this work the data were analyzed with 32 size channels and 300 seconds. As aircraft-borne measurements are always time-consuming, the development of the OPC unit and the analysis routine, as well as its characterization and certification took more than two thirds of the total working time of this thesis. Therefore, the analysis of the data is limited to the first year of regular measurements until May 2011. Nevertheless, this dataset is sufficient to demonstrate the scientific relevance of these measurements. To validate the OPC data, a comparison to particle size distributions measured from board research aircraft was carried out. The analysis of the volcanic ash flights in April and May 2010 showed strongly enhanced particle mass concentrations inside the plumes and agreed in some regions very well to the particle mass concentration predicted by a dispersion model. A further case study shows the occurrence of a surprising large (1000 km) and high concentrated pollution plume over eastern Asia close to Osaka (Japan). Inside the plume the highest particle number- and mass concentrations measured with the OPC unit in the analysis period were observed (except volcanic ash flights). A detailed analysis of the in parallel measured trace gasses as well as meteorological- and LIDAR data showed, the observed plume originate from biomass burning and industrial emissions in eastern China. A third case study gives a first attempt of a mass closure/validation between the particle masses derived by the CARIBIC OPC unit and the CARIBIC impactor particle samples. First statistical analyses to the vertical, meridional, and seasonal variation of the accumulation mode particle size distribution and therefrom derived parameter indicate a stratospheric vertical increasing gradient for the particle number- and mass concentration. In general in the mid-latitude LMS the concentration of accumulation mode particles was found to be on average 120% higher than in the mid-latitude UT. The mid-latitude LMS particle size distribution shows a seasonal variation with on average 120% higher concentrations during spring compared to fall. This results can be explained with general dynamics in the stratosphere (Brewer-Dobson Circulation) and in the tropopause region (stratosphere-troposphere-exchange, STE). An anti-correlation of gaseous mercury to the stratospheric particle surface area concentration (R²=0.97) indicates that most likely stratospheric aerosol particles do act as a sink for gaseous mercury. Finally, two comparisons of the OPC data to data from satellite remote sensing and a global aerosol model underline the OPC potential and the benefits of creating an in situ measured reference dataset. / Um die Rolle von Aerosolpartikeln beim Strahlungsantrieb und der heterogenen chemischen Prozessen in der oberen Troposphäre und untersten Stratosphäre (OT/US) verstehen zu können, ist es unabdingbar die Partikelgrößenverteilung zu kennen. Messungen der Partikelgrößenverteilung in dieser Region sind allerdings aufwendig. Der Einsatz von Forschungsflugzeugen ist teuer und deshalb zeitlich und räumlich nur begrenzt. Satellitenmessungen bieten zwar eine gute zeitliche und räumliche (horizontal) Abdeckung, aber nur eine begrenzte vertikale Auflösung. Weiterhin können bisherige Satellitenmessungen die Partikelgrößenverteilung nicht auflösen. Im Rahmen dieser Arbeit wurde deshalb ein optischer Partikelzähler (OPC) Messeinschub für den Einsatz an Bord eines Langstrecken-Passagierflugzeugs aufgebaut (CARIBIC Projekt, www.caribic-atmospheric.com). Mit diesem Messeinschub kann regelmäßig und kosteneffizient die Partikelgrößenverteilung des Akkumulationsmodes in der OT/US gemessen werden. Im April 2010 wurde der neue OPC Einschub erstmals an Bord des Lufthansa Airbus A340-600 (D-AIHE) installiert um die Vulkanasche der Eyjafjallajökull Eruption (April bis Mai 2010) zu messen. Seit Juni 2010 misst der OPC Einschub auf durchschnittlich vier Interkontinentalflügen pro Monat die Partikelgrößenverteilung der OT/US im Größenbereich zwischen 125 und 1300 nm Partikeldurchmesser. Während des Fluges speichert die Datenerfassung alle Rohsignale ab und ermöglicht dadurch eine nutzerspezifische Datenauswertung nach dem Flug (z. B. Anzahl der Größenkanäle oder Zeitauflösung). Im Rahmen dieser Arbeit wurden die Daten mit 32 Größenkanälen und 300 Sekunden analysiert. Da fluggetragene Messungen immer sehr aufwendig sind, beanspruchte die Entwicklung des OPC Einschubs und des Analysealgorithmus, sowie die Charakterisierung und Zertifizierung mehr als zwei Drittel der Gesamtarbeitszeit dieser Arbeit. Daher ist die Analyse der Messdaten auf das erste Jahr der regulären Messungen bis Mai 2011 beschränkt. Dennoch ist dieser Datensatz geeignet um die wissenschaftliche Relevanz dieser Messungen zu demonstrieren. Um die OPC-Daten zu validieren, wurde ein Vergleich mit bisherigen OPC Messungen von Bord Forschungsflugzeugen durchgeführt. Die Analyse der Vulkanascheflüge im April und Mai 2010 zeigte in der Abluftfahne stark erhöhte Partikelmassekonzentrationen, welche in einigen Vergleichsregionen sehr gut mit der Vorhersage eines Disperionsmodells übereinstimmten. Eine weitere Fallstudie zeigt das Auftreten einer überraschend großen (1000 km) und hoch konzentrierten Abluftfahne über Ostasien nahe Osaka (Japan). In der Abluftfahne wurde die im Analysezeitraum höchste mit dem CARIBIC OPC gemessene Partikelanzahl- und Massenkonzentration beobachtet (ausgenommen Vulkanascheflüge). Eine detaillierte Analyse der parallel gemessenen Spurengase, sowie meteorologischer Daten und LIDAR Profile zeigte, dass die beobachtete Abluftfahne eine Mischung aus Biomasseverbrennungs- und Industrieabgasen aus Ost-China war. Eine dritte Fallstudie stellt einen ersten Versuch einer Massenschließung/Validierung zwischen der aus den CARIBIC OPC-Daten abgeleiteten Partikelmasse und der Partikelmasse aus CARIBIC Impaktorproben dar. Erste statistische Analysen zur vertikalen, meridionalen und saisonalen Variabilität der Partikelgrößenverteilung im Akkumulationsmode und daraus abgeleiteten Parametern zeigen einen vertikal ansteigenden Gradienten für die Partikelanzahl- und Massenkonzentration. Generell war in der US der mittleren Breiten die Konzentration von Akkumulationsmode Partikeln im Mittel um 120% höher als in der OT der mittleren Breiten. Weiterhin wurde in der US der mittleren Breiten eine jahreszeitliche Schwankung gefunden. Im Frühling war die mit dem OPC gemessene Partikelkonzentrationen im Mittel um 120% höher als im Herbst. Diese Befunde lassen sich mit der atmosphärischen Dynamik in der Stratosphäre (Brewer-Dobson Zirkulation) und in der Tropopausenregion (Stratosphäre-Troposphäre-Austauschprozesse) erklären. Eine gefundene negative Korrelation von gasförmigen Quecksilber mit der stratosphärischen Partikeloberflächenkonzentration (R²=0.97) ist ein starker Indikator dafür, dass in der US Aerosolpartikel eine Senke für gasförmiges Quecksilber darstellen. Zum Abschluss unterstreichen zwei Vergleiche der OPC-Daten mit Satellitenmessungen und Ergebnissen eines globalen Aerosolmodels das Potential und den Nutzen der CARIBIC OPC Daten als in-situ gemessenen Referenzdatensatz.

Title: Convective storms and lower stratospheric moisture Author: Jindřich Šťástka Department: Department of Atmospheric Physics Supervisor: RNDr. Martin Setvák, CSc., Czech Hydrometeorological Institute Abstract: The primary focus of this thesis is to diagnose contributions to upper tropo- spheric and lower stratospheric (UTLS) water vapor from convective storms. The first parts of this work introduces two approaches used for a detection of lower stratospheric water vapor above convective storm tops - brightness temperature difference (BTD) technique and EOS MLS measurements. The BTD technique is based on brightness temperature difference between the water vapor absorp- tion and infrared window bands, assuming a thermal inversion above the cloud top level. The most frequently offered explanation of positive BTD values above convective storms is presence of warmer water vapor in the lower stratosphere. Furthermore, so called BTD anomalies were described and it was proposed an algorithm for objective detection of such BTD anomalies. Characteristics of pa- rameters describing BTD, BTD anomaly, infrared window brightness temperature were investigated during storms evolution on dataset of 320 storms from the area of Europe. The analysis of these characteristics proved highly probable conection between positive...

L'objectif général de la thèse est de caractériser la distribution géographique, les cycles saisonniers et l'évolution récente de l'ozone et du monoxyde de carbone dans la haute troposphère - basse stratosphère (UT - LS) au-dessus de huit régions d'intérêt, aux moyennes latitudes de l'hémisphère Nord. Pour cela, nous avons analysé les observations aéroportées IAGOS. Nous avons montré une tendance positive de l'ozone dans l'UT sur 1994 - 2013, et une tendance négative du monoxyde de carbone liée à la décroissance des émissions en surface. Nous avons comparé les mesures à la simulation de composition chimique sur le climat récent issue du modèle MOCAGE dans l'exercice d'intercomparaison CCMI. Pour ce faire, nous avons développé une nouvelle méthode permettant de projeter les mesures IAGOS sur le maillage du modèle et de traiter ainsi 20 ans d'observations. Cette méthode s'est révélée pertinente pour évaluer la simulation et pourrait être étendue à d'autres simulations et d'autres modèles. / The overall objective of the thesis is to characterize the geographical distribution, seasonal cycles and recent trends of ozone and carbon monoxide in the upper troposphere- lower stratosphere (UT-LS) over eight regions of interest, in the northern mid-latitudes. For this purpose, we first analyzed the IAGOS airborne observations. We have shown a positive trend in ozone in the UT over 1994-2013, and a negative trend in carbon monoxide, the latter being linked to the decrease in surface emissions. We then compared the observations to the recent climate chemical composition simulation performed by the MOCAGE model in the CCMI intercomparison exercise. To do this, we have developed a new method to project IAGOS measurements onto the model grid, allowing us to process long observation periods. This method has proven to be relevant for evaluating the simulation and could be extended to other simulations and models.

To understand the contribution of aerosol particles to radiative forcing and heterogeneous chemical processes in the upper troposphere and lowermost stratosphere (UT/LMS), the knowledge of the particle size distribution is mandatory. Unfortunately, measurements in the UT/LMS are costly. Research aircrafts are expensive and thus their application is limited in time and space. Satellite remote sensing measurements provide a good temporal and spatial (horizontal) coverage, but only a limited vertical resolution and currently cannot resolve the particle size distribution. Therefore, within this thesis an optical particle counter (OPC) unit was modified for the application onboard a passenger long-haul aircraft within the CARIBIC project (www.caribic-atmospheric.com). The CARIBIC OPC unit provides regular and cost-efficient particle size distribution measurements of accumulation mode particles in the UT/LMS. In April 2010, the new OPC unit was installed for the first time onboard the Lufthansa Airbus A340 600 (D-AIHE) for the measurement of the volcanic ash cloud from the Eyjafjallajökull eruption (April to May 2010). Since June 2010 the OPC unit measures on usually four intercontinental flights per month the UT/LMS particle size distribution in the particle size range 125 to 1300 nm particle diameter. As the data acquisition stores the scattering raw signal and all housekeeping data as well, during the post flight data analysis the temporal- and size channel resolution can be flexible set. Within this work the data were analyzed with 32 size channels and 300 seconds. As aircraft-borne measurements are always time-consuming, the development of the OPC unit and the analysis routine, as well as its characterization and certification took more than two thirds of the total working time of this thesis. Therefore, the analysis of the data is limited to the first year of regular measurements until May 2011. Nevertheless, this dataset is sufficient to demonstrate the scientific relevance of these measurements. To validate the OPC data, a comparison to particle size distributions measured from board research aircraft was carried out. The analysis of the volcanic ash flights in April and May 2010 showed strongly enhanced particle mass concentrations inside the plumes and agreed in some regions very well to the particle mass concentration predicted by a dispersion model. A further case study shows the occurrence of a surprising large (1000 km) and high concentrated pollution plume over eastern Asia close to Osaka (Japan). Inside the plume the highest particle number- and mass concentrations measured with the OPC unit in the analysis period were observed (except volcanic ash flights). A detailed analysis of the in parallel measured trace gasses as well as meteorological- and LIDAR data showed, the observed plume originate from biomass burning and industrial emissions in eastern China. A third case study gives a first attempt of a mass closure/validation between the particle masses derived by the CARIBIC OPC unit and the CARIBIC impactor particle samples. First statistical analyses to the vertical, meridional, and seasonal variation of the accumulation mode particle size distribution and therefrom derived parameter indicate a stratospheric vertical increasing gradient for the particle number- and mass concentration. In general in the mid-latitude LMS the concentration of accumulation mode particles was found to be on average 120% higher than in the mid-latitude UT. The mid-latitude LMS particle size distribution shows a seasonal variation with on average 120% higher concentrations during spring compared to fall. This results can be explained with general dynamics in the stratosphere (Brewer-Dobson Circulation) and in the tropopause region (stratosphere-troposphere-exchange, STE). An anti-correlation of gaseous mercury to the stratospheric particle surface area concentration (R²=0.97) indicates that most likely stratospheric aerosol particles do act as a sink for gaseous mercury. Finally, two comparisons of the OPC data to data from satellite remote sensing and a global aerosol model underline the OPC potential and the benefits of creating an in situ measured reference dataset. / Um die Rolle von Aerosolpartikeln beim Strahlungsantrieb und der heterogenen chemischen Prozessen in der oberen Troposphäre und untersten Stratosphäre (OT/US) verstehen zu können, ist es unabdingbar die Partikelgrößenverteilung zu kennen. Messungen der Partikelgrößenverteilung in dieser Region sind allerdings aufwendig. Der Einsatz von Forschungsflugzeugen ist teuer und deshalb zeitlich und räumlich nur begrenzt. Satellitenmessungen bieten zwar eine gute zeitliche und räumliche (horizontal) Abdeckung, aber nur eine begrenzte vertikale Auflösung. Weiterhin können bisherige Satellitenmessungen die Partikelgrößenverteilung nicht auflösen. Im Rahmen dieser Arbeit wurde deshalb ein optischer Partikelzähler (OPC) Messeinschub für den Einsatz an Bord eines Langstrecken-Passagierflugzeugs aufgebaut (CARIBIC Projekt, www.caribic-atmospheric.com). Mit diesem Messeinschub kann regelmäßig und kosteneffizient die Partikelgrößenverteilung des Akkumulationsmodes in der OT/US gemessen werden. Im April 2010 wurde der neue OPC Einschub erstmals an Bord des Lufthansa Airbus A340-600 (D-AIHE) installiert um die Vulkanasche der Eyjafjallajökull Eruption (April bis Mai 2010) zu messen. Seit Juni 2010 misst der OPC Einschub auf durchschnittlich vier Interkontinentalflügen pro Monat die Partikelgrößenverteilung der OT/US im Größenbereich zwischen 125 und 1300 nm Partikeldurchmesser. Während des Fluges speichert die Datenerfassung alle Rohsignale ab und ermöglicht dadurch eine nutzerspezifische Datenauswertung nach dem Flug (z. B. Anzahl der Größenkanäle oder Zeitauflösung). Im Rahmen dieser Arbeit wurden die Daten mit 32 Größenkanälen und 300 Sekunden analysiert. Da fluggetragene Messungen immer sehr aufwendig sind, beanspruchte die Entwicklung des OPC Einschubs und des Analysealgorithmus, sowie die Charakterisierung und Zertifizierung mehr als zwei Drittel der Gesamtarbeitszeit dieser Arbeit. Daher ist die Analyse der Messdaten auf das erste Jahr der regulären Messungen bis Mai 2011 beschränkt. Dennoch ist dieser Datensatz geeignet um die wissenschaftliche Relevanz dieser Messungen zu demonstrieren. Um die OPC-Daten zu validieren, wurde ein Vergleich mit bisherigen OPC Messungen von Bord Forschungsflugzeugen durchgeführt. Die Analyse der Vulkanascheflüge im April und Mai 2010 zeigte in der Abluftfahne stark erhöhte Partikelmassekonzentrationen, welche in einigen Vergleichsregionen sehr gut mit der Vorhersage eines Disperionsmodells übereinstimmten. Eine weitere Fallstudie zeigt das Auftreten einer überraschend großen (1000 km) und hoch konzentrierten Abluftfahne über Ostasien nahe Osaka (Japan). In der Abluftfahne wurde die im Analysezeitraum höchste mit dem CARIBIC OPC gemessene Partikelanzahl- und Massenkonzentration beobachtet (ausgenommen Vulkanascheflüge). Eine detaillierte Analyse der parallel gemessenen Spurengase, sowie meteorologischer Daten und LIDAR Profile zeigte, dass die beobachtete Abluftfahne eine Mischung aus Biomasseverbrennungs- und Industrieabgasen aus Ost-China war. Eine dritte Fallstudie stellt einen ersten Versuch einer Massenschließung/Validierung zwischen der aus den CARIBIC OPC-Daten abgeleiteten Partikelmasse und der Partikelmasse aus CARIBIC Impaktorproben dar. Erste statistische Analysen zur vertikalen, meridionalen und saisonalen Variabilität der Partikelgrößenverteilung im Akkumulationsmode und daraus abgeleiteten Parametern zeigen einen vertikal ansteigenden Gradienten für die Partikelanzahl- und Massenkonzentration. Generell war in der US der mittleren Breiten die Konzentration von Akkumulationsmode Partikeln im Mittel um 120% höher als in der OT der mittleren Breiten. Weiterhin wurde in der US der mittleren Breiten eine jahreszeitliche Schwankung gefunden. Im Frühling war die mit dem OPC gemessene Partikelkonzentrationen im Mittel um 120% höher als im Herbst. Diese Befunde lassen sich mit der atmosphärischen Dynamik in der Stratosphäre (Brewer-Dobson Zirkulation) und in der Tropopausenregion (Stratosphäre-Troposphäre-Austauschprozesse) erklären. Eine gefundene negative Korrelation von gasförmigen Quecksilber mit der stratosphärischen Partikeloberflächenkonzentration (R²=0.97) ist ein starker Indikator dafür, dass in der US Aerosolpartikel eine Senke für gasförmiges Quecksilber darstellen. Zum Abschluss unterstreichen zwei Vergleiche der OPC-Daten mit Satellitenmessungen und Ergebnissen eines globalen Aerosolmodels das Potential und den Nutzen der CARIBIC OPC Daten als in-situ gemessenen Referenzdatensatz.