 |
| Titel |
Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy – Part 1: Slant-columns and their ratios |
| VerfasserIn |
W. Stremme, A. Krueger, R. Harig, M. Grutter |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 2 ; Nr. 5, no. 2 (2012-02-02), S.275-288 |
| Datensatznummer |
250002458
|
| Publikation (Nr.) |
 copernicus.org/amt-5-275-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| The composition and emission rates of volcanic gas plumes provide insight of
the geologic internal activity, atmospheric chemistry, aerosol formation and
radiative processes around it. Observations are necessary for public security
and the aviation industry. Ground-based thermal emission infrared
spectroscopy, which uses the radiation of the volcanic gas itself, allows for
continuously monitoring during day and night from a safe distance. We present
measurements on Popocatépetl volcano based on thermal emission
spectroscopy during different campaigns between 2006–2009 using a Scanning
Infrared Gas Imaging System (SIGIS). The experimental set-up, measurement
geometries and analytical algorithms are described. The equipment was
operated from a safe distance of 12 km from the volcano at two different
spectral resolutions: 0.5 and 4 cm−1. The 2-dimensional scanning
capability of the instrument allows for an on-line visualization of the
volcanic SO2 plume and its animation.
SiF4 was also identified in the infrared spectra recorded at both
resolutions. The SiF4/SO2 molecular ratio can be calculated from
each image and used as a highly useful parameter to follow changes in
volcanic activity. A small Vulcanian eruption was monitored during the night
of 16 to 17 November 2008 and strong ash emission together with a pronounced
SO2 cloud was registered around 01:00 a.m. LST (Local Standard Time). Enhanced SiF4/SO2 ratios were observed
before and after the eruption. A validation of the results from thermal
emission measurements with those from absorption spectra of the moon taken at
the same time, as well as an error analysis, are presented. The inferred
propagation speed from sequential images is used in a subsequent paper (Part 2)
to calculate the emission rates at different distances from the crater. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|