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| Titel |
MAMAP – a new spectrometer system for column-averaged methane and carbon dioxide observations from aircraft: retrieval algorithm and first inversions for point source emission rates |
| VerfasserIn |
T. Krings, K. Gerilowski, M. Buchwitz, M. Reuter, A. Tretner, J. Erzinger, D. Heinze, U. Pflüger, J. P. Burrows, H. Bovensmann |
| 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 ; 4, no. 9 ; Nr. 4, no. 9 (2011-09-06), S.1735-1758 |
| Datensatznummer |
250002087
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| Publikation (Nr.) |
 copernicus.org/amt-4-1735-2011.pdf |
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| Zusammenfassung |
| MAMAP is an airborne passive remote sensing instrument designed to measure the dry
columns of methane (CH4) and carbon dioxide (CO2). The MAMAP
instrument comprises two optical grating spectrometers: the first observing in the short
wave infrared band (SWIR) at 1590–1690 nm to measure CO2 and
CH4 absorptions, and the second in the near infrared (NIR) at
757–768 nm to measure O2 absorptions for reference/normalisation purposes.
MAMAP can be operated in both nadir and zenith geometry during the flight.
Mounted on an aeroplane, MAMAP surveys areas on regional to
local scales with a ground pixel resolution of approximately
29 m × 33 m for a typical aircraft altitude of 1250 m and
a velocity of 200 km h−1. The retrieval precision of the measured column
relative to background is typically ≲1% (1σ). MAMAP measurements are valuable
to close the gap between satellite data, having global coverage
but with a rather coarse resolution, on the one hand, and highly accurate in
situ measurements with sparse coverage on the other hand. In July 2007, test
flights were performed over two coal-fired power plants operated by Vattenfall
Europe Generation AG: Jänschwalde (27.4 Mt CO2 yr−1) and Schwarze
Pumpe (11.9 Mt CO2 yr−1), about 100 km southeast of Berlin,
Germany. By using two different inversion approaches, one based on an optimal
estimation scheme to fit Gaussian plume models from multiple sources to the
data, and another using a simple Gaussian integral method, the emission rates
can be determined and compared with emissions reported by Vattenfall Europe.
An extensive error analysis for the retrieval's dry column results (XCO2 and XCH4)
and for the two inversion methods has
been performed. Both methods – the Gaussian plume model fit and the Gaussian
integral method – are capable of deriving estimates for strong point source
emission rates that are within ±10% of the reported values, given
appropriate flight patterns and detailed knowledge of wind conditions. |
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