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| Titel |
Arctic tidal characteristics at Eureka (80° N, 86° W) and Svalbard (78° N, 16° E) for 2006/07: seasonal and longitudinal variations, migrating and non-migrating tides |
| VerfasserIn |
A. H. Manson, C. E. Meek, T. Chshyolkova, X. Xu, T. Aso, J. R. Drummond, C. M. Hall, W. K. Hocking, Ch. Jacobi, M. Tsutsumi, W. E. Ward |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 27, no. 3 ; Nr. 27, no. 3 (2009-03-09), S.1153-1173 |
| Datensatznummer |
250016447
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| Publikation (Nr.) |
 copernicus.org/angeo-27-1153-2009.pdf |
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| Zusammenfassung |
Operation of a Meteor Radar at Eureka, Ellesmere Island (80° N,
86° W) began in February 2006. The first 12 months of wind data (82–97 km)
are combined with winds from the Adventdalen, Svalbard Island
(78° N, 16° E) Meteor Radar to provide the first contemporaneous
longitudinally spaced observations of mean winds, tides and planetary waves
at such high Arctic latitudes. Unique polar information on diurnal
non-migrating tides (NMT) is provided, as well as complementary information
to that existing for the Antarctic on the semidiurnal NMT.
Zonal and meridional monthly mean winds differed significantly between
Canada and Norway, indicating the influence of stationary planetary waves
(SPW) in the Arctic mesopause region. Both diurnal (D) and semi-diurnal (SD)
winds also demonstrated significantly different magnitudes at Eureka and
Svalbard. Typically the D tide was larger at Eureka and the SD tide was
larger at Svalbard. Tidal amplitudes in the Arctic were also generally
larger than expected from extrapolation of high mid-latitude data. For
example time-sequences from ~90 km showed D wind oscillations at
Eureka of 30 m/s in February–March, and four day bursts of SD winds at
Svalbard reached 40 m/s in June 2006.
Fitting of wave numbers for the migrating and non-migrating tides (MT, NMT)
successfully determines dominant tides for each month and height. For the
diurnal tide, NMT with s=0, +2 (westward) dominate in non-summer months,
while for the semi-diurnal tide NMT with s=+1, +3 occur most often during
equinoctial or early summer months. These wave numbers are consistent with
stationary planetary wave (SPW)-tidal interactions.
Assessment of the global topographic forcing and atmospheric propagation of
the SPW (S=1, 2) suggests these winter waves of the Northern Hemisphere are
associated with the 78–80° N diurnal NMT, but that the SPW of the
Southern Hemisphere winter have little influence on the summer Arctic tidal
fields. In contrast the large SPW and NMT of the Arctic winter may be
associated, consistent with Antarctic observations, with the observed
occurrence of the semidiurnal NMT in the Antarctic summer. |
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