Quantitative Untersuchung der Chemie von SO2 und reaktiver Halogenverbindungen in Vulkanfahnen mittels einer neuartigen Fabry-Pérot Kamera Methode

• Antragsteller: Professor Dr. Ulrich Platt
• Fachliche Zuordnung: Physik und Chemie der Atmosphäre ; Physik des Erdkörpers
• Förderung: Förderung von 2018 bis 2023
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 399112922

• Erstellungsjahr: 2023

Zusammenfassung der Projektergebnisse

The initial goal of the project was to exploit the fundamental advantages of modern Fabry-Pèrot interferometers (FPI) with respect to light throughput, spectral resolution, and the possibility to make 2-dimensional imaging measurements. A particular aim of the project was to enable measurements of volcanic gases (volcanic plumes) at higher spatial and temporal resolution. While present imaging techniques for volcanic gases are limited to SO2 and suffer from severe interferences FPI-based instruments allow to measure SO2 more sensitively and virtually interference free and allow the imaging of other – much less abundant gases (e.g. BrO). The project developed as planned and essentially all project goals are achieved. Moreover, important further research was conducted within the frame of the project and a novel ultrahigh resolution FPI instrument was developed and field-tested. The proposed tasks of the technical instrument developments were performed and operational prototypes of Imaging FPI Correlation Spectroscopy (IFPICS) instruments (for SO2 and BrO) were built and tested during field campaigns at volcanoes. In addition a novel type of high resolution spectrograph of unprecedented light throughput and compactness was developed. Also a novel imaging technique for atmospheric NO2 distributions based on gas correlation spectroscopy was developed. All instruments proved their applicability in the field and are subject to one or more peer-reviewed publications. While the goal of a highly resolved comparison of measured with trace gas distributions with modelled ones could not be achieved within the period of the project we were able to significantly contribute to the removal of severe deficiencies in present volcanic plum models. For this purpose, we developed a kinetic high-temperature chemistry model for hot volcanic gas emissions, which, inter alia, allows the quantitative assessment of available radical amounts in volcanic plumes. Furthermore we designed and constructed a compact drone-based chemiluminescence ozone monitor which overcomes the problems of the customary short-path UV O3-sensors due to interference to SO2 in volcanic plumes. Besides processing the majority of the proposed work packages with great success, the exploratory nature of the project inspired us to extend our studies to further approaches to volcanic gas measurements, imaging spectroscopy, and modelling. In summary, the project has led to an even larger scientific progress than initially expected. The high resolution data will allow to refine the future analysis of chemistry models and contribute to understanding of chemistry in volcanic plumes.

Projektbezogene Publikationen (Auswahl)

• Towards imaging of atmospheric trace gases using Fabry–Pérot interferometer correlation spectroscopy in the UV and visible spectral range. Atmospheric Measurement Techniques, 12(1), 735-747.
  Kuhn, Jonas; Platt, Ulrich; Bobrowski, Nicole & Wagner, Thomas
  
• Mobile and high-spectral-resolution Fabry–Pérot interferometer spectrographs for atmospheric remote sensing. Atmospheric Measurement Techniques, 14(12), 7873-7892.
  Kuhn, Jonas; Bobrowski, Nicole; Wagner, Thomas & Platt, Ulrich
  
• Quantitative imaging of volcanic SO2 plumes using Fabry–Pérot interferometer correlation spectroscopy. Atmospheric Measurement Techniques, 14(1), 295-307.
  Fuchs, Christopher; Kuhn, Jonas; Bobrowski, Nicole & Platt, Ulrich
  
• The “ideal” spectrograph for atmospheric observations. Atmospheric Measurement Techniques, 14(10), 6867-6883.
  Platt, Ulrich; Wagner, Thomas; Kuhn, Jonas & Leisner, Thomas
  
• Auf den Spuren des Empedokles. 7. ( 2022 )
  Kuhn, J.; Bobrowski, N. & Platt, U.
  
• Novel approaches to the analysis of volcanic degassing, Dissertation, Heidelberg University
  Kuhn, J.
  
• The Interface Between Magma and Earth's Atmosphere. Geochemistry, Geophysics, Geosystems, 23(12).
  Kuhn, J.; Bobrowski, N. & Platt, U.
  
• The NO2 camera based on gas correlation spectroscopy. Atmospheric Measurement Techniques, 15(5), 1395-1414.
  Kuhn, Leon; Kuhn, Jonas; Wagner, Thomas & Platt, Ulrich
  
• High-spectral-resolution Fabry-Pérot interferometers overcome fundamental limitations of present volcanic gas remote sensing techniques. Frontiers in Earth Science, 11.
  Kuhn, Jonas; Bobrowski, Nicole; Boudoire, Guillaume; Calabrese, Sergio; Giuffrida, Giovanni; Liuzzo, Marco; Karume, Katcho; Tedesco, Dario; Wagner, Thomas & Platt, Ulrich
  
• Quantifying BrO and SO2 distributions in volcanic plumes—Recent advances in imaging Fabry-Pérot interferometer correlation spectroscopy. Frontiers in Earth Science, 11.
  Nies, Alexander; Heimann, Jaro; Fuchs, Christopher; Kuhn, Jonas; Bobrowski, Nicole & Platt, Ulrich