 |
| Titel |
Short term geophysical excitation of the polar motion |
| VerfasserIn |
C. Bizouard, L. Seoane, D. Gambis |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250022809
|
|
|
|
|
|
| Zusammenfassung |
| Short term geophysical excitation of the polar motionThat study is devoted to the
interpretation of the short term polar motion (periods ranging from 2 to 20 days). Whereas it
represents less than 0.2% of the total polar motion amplitude, its variations are not less
interesting than the seasonal ones, but are more difficult to determine and to interpret.
According to the common view, they reflect weekly changes in the mass redistribution of the
atmosphere and oceans. That interpretation is revisited by comparing the later up to date
atmospheric and oceanic angular momentum series to the excitation found in various polar
motion series. Global comparison is very satisfactory. In particular, effect of the normal
atmospheric mode Ψ11 (10 days) is striking and the tidal oscillation in polar motion at 13.6
days is partly harmonic : it presents variation in amplitude and phase because of the
geophysical fluid influence. Finally we show the degradation of pole coordinates
determination for periods approaching the Nyquist period of 2 days in the routine pole
series. |
|
|
|
|
|
|