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| Titel |
Column measurements and vertical profiling of CO2 and CH4 based on high resolution ground-based NIR heterodyne spetro-radiometry |
| VerfasserIn |
Artem Klimchuk, Vladimir Semenov, Dmitry Churbanov, Sergey Zenevich, Alexander Rodin |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250154352
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| Publikation (Nr.) |
 EGU/EGU2017-19434.pdf |
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| Zusammenfassung |
| A compact, lightweight heterodyne NIR spectro-radiometer suitable for ground-based
atmospheric sounding by direct spectro-radimetry of Sun spectrum with spectral resolution
∼0.0006 cm−1 has been used for column measurements and vertical profiling of methane
and carbon dioxide. Highly stabilized DFB laser was used as local oscillator. Radiation mixed
in the single mode fiber was detected by InGaAs photodiode within the bandpass of
∼20 MHz. Wavelength coverage of spectral measurement was provided by sweeping local
oscillator frequency in the range 1–1.5 cm−1. With the exposure time of 3 minutes, the
absorption spectrum of the atmosphere over Moscow has been recorded with S/N
∼300.
The retrieved methane profile demonstrates higher abundances in the lower scale height
compared to the assumed model profile, well expected in the megalopolis center. The
retrievals sensitivity is limited by 10 ppb, with the exception of the lower part of the profile
where the tendency to lower values is revealed. Thus the methane abundance variations may
be evaluated with relative accuracy better than 1%, which fits the requirements of
greenhouse gas monitoring. The CO2 column measurements was provided an accuracy
0.4% |
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