 |
| Titel |
Low-level jet characteristics over the Arctic Ocean in spring and summer |
| VerfasserIn |
L. Jakobson, T. Vihma, E. Jakobson, T. Palo, A. Männik, J. Jaagus |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 21 ; Nr. 13, no. 21 (2013-11-14), S.11089-11099 |
| Datensatznummer |
250085812
|
| Publikation (Nr.) |
 copernicus.org/acp-13-11089-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Low-level jets (LLJ) are important for turbulence in the stably stratified
atmospheric boundary layer, but their occurrence, properties, and generation
mechanisms in the Arctic are not well known. We analysed LLJs over the
central Arctic Ocean in spring and summer 2007 on the basis of data collected
in the drifting ice station Tara. Instead of traditional radiosonde
soundings, data from tethersonde soundings with a high vertical resolution
were used. The Tara results showed a lower occurrence of LLJs
(46 ± 8%) than many previous studies over polar sea ice. Strong
jet core winds contributed to growth of the turbulent layer. Complex
relationships between the jet core height and the temperature inversion top
height were detected: substantial correlation (r = 0.72; p <
0.01) occurred when the jet core was above the turbulent layer, but when
inside the turbulent layer there was no correlation. The most important
forcing mechanism for LLJs was baroclinicity, which was responsible for
the generation of strong and warm LLJs, which on average occurred at lower
altitudes than other jets. Baroclinic jets were mostly associated with
transient cyclones instead of the climatological air temperature gradients.
Besides baroclinicity, cases related to inertial oscillations and gusts were
detected. As many as 49% of the LLJs observed were associated with a
frontal passage, which provides favourable conditions for baroclinicity,
inertial oscillations, and gusts. Further research needs on LLJs in the
Arctic include investigation of low-level jet streams and their effects on
the sea ice drift and atmospheric moisture transport. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|