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| Titel |
Derivation of tropospheric methane from TCCON CH4 and HF total column observations |
| VerfasserIn |
K. M. Saad, D. Wunch, G. C. Toon, P. Bernath, C. Boone, B. Connor, N. M. Deutscher, D. W. T. Griffith, R. Kivi, J. Notholt, C. Roehl, M. Schneider, V. Sherlock, P. O. Wennberg |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 9 ; Nr. 7, no. 9 (2014-09-10), S.2907-2918 |
| Datensatznummer |
250115895
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| Publikation (Nr.) |
 copernicus.org/amt-7-2907-2014.pdf |
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| Zusammenfassung |
| The Total Carbon Column Observing Network (TCCON) is a global
ground-based network of Fourier transform spectrometers that produce
precise measurements of column-averaged dry-air mole fractions of
atmospheric methane (CH4). Temporal variability in the total
column of CH4 due to stratospheric dynamics obscures
fluctuations and trends driven by tropospheric transport and local surface fluxes
that are critical for understanding CH4 sources and sinks.
We reduce the contribution of stratospheric variability from the total
column average by subtracting an estimate
of the stratospheric CH4 derived from simultaneous
measurements of hydrogen fluoride (HF). HF provides a proxy for
stratospheric CH4 because it is strongly correlated to CH4 in the
stratosphere, has an accurately known tropospheric abundance (of zero), and
is measured at most TCCON stations. The stratospheric partial column of CH4 is
calculated as a function of the zonal and annual trends in the
relationship between CH4 and HF in the stratosphere, which
we determine from ACE-FTS satellite data. We also explicitly take
into account the CH4 column averaging kernel to estimate the
contribution of stratospheric CH4 to the total column. The
resulting tropospheric CH4 columns are consistent with in
situ aircraft measurements and augment existing observations in the
troposphere. |
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