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| Titel |
STEFLUX: a tool for investigating stratospheric intrusions |
| VerfasserIn |
Davide Putero, Paolo Cristofanelli, Michael Sprenger, Bojan Skerlak, Paolo Bonasoni |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133949
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| Publikation (Nr.) |
 EGU/EGU2016-14615.pdf |
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| Zusammenfassung |
| Stratosphere-to-Troposphere Exchange (STE) represents one of the natural processes that
have substantial impacts on atmospheric chemistry and is an important aspect of global
change. In particular, stratospheric intrusions (SI) are capable of changing the oxidation
capacity of the troposphere and their contribution to ozone (O3) levels in the troposphere was
estimated to be as large as the net photochemical production. SI is a topic of ongoing
research, especially for what concerns its possible impact on long-term trends of tropospheric
O3. In this work, a new tool called STEFLUX is presented. The main purpose of STEFLUX
is to obtain a fast and reliable identification of the SI occurring at a specific location and
during a selected time window, by using a set of Lagrangian trajectories. The database used
as input is a compiled STE climatology, which makes use of the ERA-Interim reanalysis
dataset from the ECMWF, as well as a refined version of a well-developed Lagrangian
methodology. In this work, STEFLUX outputs were compared to the observations from two
high-mountain stations in the Himalayas and in the Mediterranean basin, i.e. the
Nepal Climate Observatory-Pyramid (NCO-P, 5079 m a.s.l.) and Mt. Cimone in the
Italian northern Apennines (2165 m a.s.l.), which represent a suitable place for the
occurrence of SI events. The STEFLUX performance was assessed by observing that it
well represented the seasonal- and inter-annual variability of the frequency of SI
events at the two measurement sites; then, by following both a “backward” and a
“forward” approach, it was demonstrated that the tool is especially powerful in capturing
long-lasting SI events (i.e. longer than one day). Then, by exploiting the fact that the
ERA-Interim reanalysis extends back to 1979, STEFLUX was used to obtain a SI
occurrence climatology for the two sampling sites. A trend evaluation study was
performed for both cases, indicating no significant trends, except for the winter season. |
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