Quantitative imaging of volcanic SO2 plumes using Fabry-Pérot interferometer correlation spectroscopy
<p><strong class="journal-contentHeaderColor">Abstract.</strong> We present first measurements with a novel imaging technique for atmospheric trace gases in the UV spectral range. Imaging Fabry-Pérot interferometer correlation spectroscopy (IFPICS) employs a Fabry-Pérot...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
14 January 2021
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| In: |
Atmospheric measurement techniques
Year: 2021, Volume: 14, Issue: 1, Pages: 295-307 |
| ISSN: | 1867-8548 |
| DOI: | https://doi.org/10.5194/amt-14-295-2021 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/https://doi.org/10.5194/amt-14-295-2021 Verlag, lizenzpflichtig, Volltext: https://amt.copernicus.org/articles/14/295/2021/ 
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| Author Notes: | Christopher Fuchs, Jonas Kuhn, Nicole Bobrowski, and Ulrich Platt |
| Summary: | <p><strong class="journal-contentHeaderColor">Abstract.</strong> We present first measurements with a novel imaging technique for atmospheric trace gases in the UV spectral range. Imaging Fabry-Pérot interferometer correlation spectroscopy (IFPICS) employs a Fabry-Pérot interferometer (FPI) as the wavelength-selective element. Matching the FPI's distinct, periodic transmission features to the characteristic differential absorption structures of the investigated trace gas allows us to measure differential atmospheric column density (CD) distributions of numerous trace gases with high spatial and temporal resolution. Here we demonstrate measurements of sulfur dioxide (<span class="inline-formula">SO<sub>2</sub></span>), while earlier model calculations show that bromine monoxide (<span class="inline-formula">BrO</span>) and nitrogen dioxide (<span class="inline-formula">NO<sub>2</sub></span>) are also possible. The high specificity in the spectral detection of IFPICS minimises cross-interferences to other trace gases and aerosol extinction, allowing precise determination of gas fluxes. Furthermore, the instrument response can be modelled using absorption cross sections and a solar atlas spectrum from the literature, thereby avoiding additional calibration procedures, e.g. using gas cells. In a field campaign, we recorded the temporal CD evolution of <span class="inline-formula">SO<sub>2</sub></span> in the volcanic plume of Mt. Etna, with an exposure time of <span class="inline-formula">1 s</span> and <span class="inline-formula">400×400</span> pixel spatial resolution. The temporal resolution of the time series was limited by the available non-ideal prototype hardware to about <span class="inline-formula">5.5 s</span>. Nevertheless, a detection limit of <span class="inline-formula">2.1×10<sup>17</sup></span> <span class="inline-formula">molec cm<sup>−2</sup></span> could be reached, which is comparable to traditional and much less selective volcanic <span class="inline-formula">SO<sub>2</sub></span> imaging techniques.</p> |
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| Item Description: | Im Titel ist "2" tiefgestellt Gesehen am 09.03.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1867-8548 |
| DOI: | https://doi.org/10.5194/amt-14-295-2021 |