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| Titel |
Promises and pitfalls of estimating CO2 fluxes from space-based measurements |
| VerfasserIn |
Sourish Basu, Sander Houweling, André Butz |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250100694
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| Publikation (Nr.) |
 EGU/EGU2014-16683.pdf |
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| Zusammenfassung |
| Atmospheric flux inversions, which use observed concentration gradients of atmospheric
CO2 to infer its surface sources and sinks, are presently limited by the surface observation
network. The current network is sparse near several areas with large surface exchange of
carbon, such as the Tropics and the oceans. Present (GOSAT) and future (OCO-2, CarbonSat,
GOSAT II, TanSat) satellite missions hope to make up for this sparsity by providing total
column CO2 (XCO2) measurements globally.
I will show with examples that satellite missions can indeed provide surface flux
information over under-sampled areas such as the Tropics and the Boreal region. However,
the increased spatial sampling density and coverage come at some cost: satellite-based XCO2
measurements are less accurate than in situ measurements, have systematic biases correlated
over thousands of kilometers, have a much higher data volume than what most inversion
systems are geared to handle, and are generally trying to measure a very small
signal on top of a very large background. I will show how each of these can be
a killer for atmospheric inversions, with strategies for separating robust results
from unrealistic flux estimates, and possible ways in which future CO2-sensing
satellites could minimize the impact of these pitfalls. In the end, remote sensed
XCO2 has the potential to add to our knowledge of surface exchange of CO2, but is
not a silver bullet to overcome all the limitations of current in situ observations. |
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