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| Titel |
CH4, H2O, and CO spectroscopy for the Sentinel-5 Precursor mission: an assessment with TCCON spectra |
| VerfasserIn |
A. Galli, A. Butz, R. A. Scheepmaker, O. Hasekamp, J. Landgraf, P. Tol, D. Wunch, N. Deutscher, G. C. Toon, P. O. Wennberg, D. W. T. Griffith, I. Aben |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060998
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| Zusammenfassung |
| The TROPOspheric Monitoring Instrument (TROPOMI) will be part of ESA’s Sentinel-5
Precursor (S5P) satellite platform scheduled for launch in 2014. Two of TROPOMI’s goals
are to monitor methane and carbon monoxide concentrations in the Earth’s atmosphere by
measuring spectra of backscattered sunlight in the short-wave infrared.
S5P will be the first satellite mission to rely uniquely on the spectral window at 4190 –
4340 cm-1 to retrieve CH4 and CO. In this study, we investigated if the absorption features of
the three relevant molecules CH4, CO, and H2O are adequately known. To this end, we
retrieved total columns of CH4 and CO from absorption spectra measured by two
ground-based Fourier transform spectrometers that are part of the Total Carbon Column
Observing Network (TCCON). The retrieval results from the 4190 – 4340 cm-1 range at
TROPOMI resolution (0.45 cm-1) were then compared to the results obtained from the
6000 cm-1 (for CH4) and the 4190 – 4340 cm-1 (for CO) spectral ranges at high resolution
(0.02 cm-1).
For TROPOMI-like settings, the current spectroscopy databases allowed to reproduce the
CH4 columns to an accuracy of 0.3%. The CO retrieval accuracy was, through interference,
more strongly affected by the shortcomings of the CH4 and H2O spectroscopy. Contrary to
CH4, the CO column error also varied significantly with atmospheric H2O content. This
would introduce seasonal and latitudinal biases to the CO columns retrieved from
TROPOMI measurements. We therefore recommend further effort from the spectroscopic
community to be directed at the H2O and CH4 spectroscopy at 4190 – 4340 cm-1. |
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