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| Titel |
Solar-Induced Plant Fluorescence as seen from space-borne instruments |
| VerfasserIn |
Narges Khosravi, Marco Vountas, Vladimir V. Rozanov, Astrid Bracher, John P. Burrows |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250113808
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| Publikation (Nr.) |
 EGU/EGU2015-14039.pdf |
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| Zusammenfassung |
| Solar induced chlorophyll fluorescence (SIF) retrieval can be linked to vegetation
correspondence to global carbon cycle, and could be useful for terrestrial carbon budget
assessment as well as agricultural and environmental purposes. There have been several
investigations using space-borne SIF retrieval due to its good spatial coverage and time
efficiency. These methods are mainly based on the fact that plant leaves absorb sunlight
mainly within the visible spectral range and use it either for photosynthesis and/or release it
as heat or fluorescence (in red and Near Infra Red, NIR, spectral region) back to the
atmosphere. As a result, SIF can be considered an additive signal on top of the ground
reflectance reaching TOA (Top Of the Atmosphere). Chlorophyll fluorescence is mainly
emitted in the spectral range of red to the near-infrared with a pronounced peak at 690 and
another at 740 nm. Although it is a very weak signal and two orders of magnitude smaller
than the received radiance at TOA, it is feasible to retrieve it within spectral wavelength
windows in the NIR.
We developed a novel SIF retrieval method based on a modeled assumption of the emitted
fluorescence spectrum at canopy level as it would be seen at TOA. The application of it to 10
years of SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric
CHartographY) data showed promising results. Comparing our SIF retrieval with results from
other studies showed that SIF values of our retrieval are in a general agreement with
them.
With some variations. As there is no validated SIF retrieval, it is difficult to judge the
retrieval quality. Our approach is of generic nature and therefore, could be applied to other
data sets as well. Hence, the method is being applied on GOME-2 level 1 data, as the
instrument has a better spatial resolution (in the wavelength range needed) and a better global
coverage. |
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