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| Titel |
WHU VHF radar observations of the diurnal tide and its variability in the lower atmosphere over Chongyang (114.14° E, 29.53° N), China |
| VerfasserIn |
C. Huang, S. Zhang, Q. Zhou, F. Yi, K. Huang, Y. Gong, Y. Zhang, Q. Gan |
| 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 ; 33, no. 7 ; Nr. 33, no. 7 (2015-07-23), S.865-874 |
| Datensatznummer |
250121222
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| Publikation (Nr.) |
 copernicus.org/angeo-33-865-2015.pdf |
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| Zusammenfassung |
| The diurnal tide (DT) and its variability in the lower atmosphere over
Chongyang (114.14° E, 29.53° N) were studied based on the
newly established Wuhan University (WHU) VHF radar observations with the
height intervals of 0.145 km (below 9 km) and 0.58 km (above 9 km) in the
whole year of 2012. We find that the DT was the dominant tidal component and
showed remarkable height and season variations. A prominent seasonally
dependent height variability characteristic is that maximum DT amplitude
usually occurs around 6 km in the winter and spring months, which might be
due to the tidal wave energy concentration arising from the reflections from
the strong eastward tropospheric jet around 13 km and the ground surface.
Our results suggest that the background wind is a crucial cause for height
variability and seasonal variability of DT. In April 2012, a notable
strengthening of DT is observed. Meanwhile, the
significant higher harmonics of
tides, i.e., the semidiurnal, terdiurnal, and even quarterdiurnal tides, can
also be observed, which has seldom been reported. Interestingly, these four
tidal components displayed consistent short-term variability, implying that
they were excited by the same dramatically varying tidal source. In addition,
we identified two symptoms of the coupling of DT and planetary waves (PWs),
which can also lead to the short-term DT variability. One is the sum and
difference interactions between DT and PWs, causing the tidal amplitude
short-term variability as a consequence of the energy exchange among the
interacting waves. The other one is the modulation of DT by PWs, leading to
that the amplitude of DT varies with the periods of the PWs. |
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