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| Titel |
Characteristics of early winter high Arctic atmospheric boundary layer profiles |
| VerfasserIn |
Siiri Wickström, Timo Vihma, Tiina Nygård, Daniel Kramer, Timo Palo, Marius Jonassen |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250151917
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| Publikation (Nr.) |
 EGU/EGU2017-16687.pdf |
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| Zusammenfassung |
| For a large part of the year, the Arctic climate system is characterised by a stably stratified atmospheric boundary layer, with strong temperature inversions isolating the surface from the air aloft. These nversions are typically driven by longwave radiative cooling, warm-air advection aloft,
or subsidence. All these mechanisms are affected by the synoptic sate of the atmosphere in the high Arctic.
In this study we present data from an intensive measurement campaign in Svalbard in October
2014, when atmospheric profiles were measured with a tethered balloon in Adventdalen and
Hornsund. In addition radiosonde soundings from Ny-Ålesund were analysed. A total of 115 individual
profiles were analysed, almost all of them showing a surface-based temperature inversion. Our
preliminary results show that the strongest and deepest inversions are observed at the
beginning of a warm-air advection event, but as the temperature, wind and cloudiness increase
the inversion strength and depth decrease rapidly. The inversion curvature parameter seems to be
strongly dependent on the longwave radiative balance with the highest curvatures (strongest vertical temperature gradient close to the surface) associated with strong longwave radiative heat loss from the
surface. The different processes affecting the stable atmospheric boundary layer during a low-pressure passage are determined, and the effects of the synoptic scale changes are isolated from
those caused by local topographic forcing. |
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