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| Titel |
Atmosphere–ice forcing in the transpolar drift stream: results from the DAMOCLES ice-buoy campaigns 2007-2009 |
| VerfasserIn |
M. Haller, B. Brümmer, G. Müller |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 8, no. 1 ; Nr. 8, no. 1 (2014-02-20), S.275-288 |
| Datensatznummer |
250116022
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| Publikation (Nr.) |
 copernicus.org/tc-8-275-2014.pdf |
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| Zusammenfassung |
| During the EU research project Developing Arctic
Modelling and Observing Capabilities for Long-term Environmental Studies (DAMOCLES), 18 ice buoys were deployed in the
region of the Arctic transpolar drift (TPD). Sixteen of them formed a
quadratic grid with 400 km side length. The measurements lasted from 2007 to
2009. The properties of the TPD and the impact of synoptic weather systems
on the ice drift are analysed. Within the TPD, the speed increases by a
factor of almost three from the North Pole to the Fram Strait region. The
hourly buoy position fixes would show that the speed is underestimated by
10–20% if positions were taken at only 1–3 day intervals as it is
usually done for satellite drift estimates. The geostrophic wind factor
Ui / Ug (i.e. the ratio of ice speed Ui and geostrophic wind
speed Ug), in the TPD amounts to 0.012 on average, but with regional and
seasonal differences. The constant Ui / Ug relation breaks down for
Ug < 5 m s−1. The impact of synoptic weather systems is studied
applying a composite method. Cyclones (anticyclones) cause cyclonic
(anticyclonic) vorticity and divergence (convergence) of the ice drift. The
amplitudes are twice as large for cyclones as for anticyclones. The
divergence caused by cyclones corresponds to a 0.1–0.5% per 6 h open water
area increase based on the composite averages, but reached almost 4%
within one day during a strong August 2007 storm. This storm also caused a
long-lasting (over several weeks) rise of Ui and Ui / Ug and
changed the ice conditions in a way which allowed large amplitudes of inertial
ice motion. The consequences of an increasing Arctic storm activity for the
ice cover are discussed. |
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