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| Titel |
On the observation of climate-relevant processes in the UTLS |
| VerfasserIn |
Martin Riese, Jörn Ungermann |
| 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 |
250093647
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| Publikation (Nr.) |
 EGU/EGU2014-8563.pdf |
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| Zusammenfassung |
| Changes and variability of UTLS composition are major drivers of surface climate change
(e.g. Solomon et al., 2010). Even small changes of spatially highly variable concentrations of
greenhouse gases such as water vapor (H2O) and ozone (O3), aerosols and cirrus
clouds have significant effects on the atmospheric radiation balance. Improved
prediction capabilities of chemistry-climate models (CCM) therefore rely on a realistic
representation of physical and chemical processes affecting UTLS composition. This is
problematic, because UTLS composition is governed by the complex interactions of
various physical and chemical processes that operate at a wide range of temporal and
spatial scales (local to global). Water vapor and ozone are particularly sensitive to
atmospheric transport due to their steep spatial mixing ratio gradients in this region.
Small-scale trace gas filaments in the UTLS represent an important example of
structures that are not yet adequately characterized. The same applies to small-scale
gravity-waves that are important for the dynamical coupling between different atmospheric
layers.
In the past, most progress in our understanding of the UTLS and small-scale processes in
this region was made on the basis of detailed airborne in-situ observations. Satellite limb
observations, e. g. by the Michelson Interferometer for Passive Atmospheric Sounding
(MIPAS) onboard Envisat, provided the global view, however, at limited spatial resolution.
For this reason, there is a gap of observations concerning small-scale trace gas structures and
temperature fluctuations, with a vertical extent of less than 500 m and a horizontal extent of
less than 100 km.
The talk will give an overview on climate-relevant processes in the UTLS and important
associated scientific questions. Limitations of current observation system are discussed as
well as need for three-dimensional observation of trace gases, clouds and temperature
structures with adequate spatial resolution. |
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