Open AccessLong term components in polar motion
Author(s) -
E. Proverbio,
Vı́ctor Quesada
Publication year - 2011
Publication title -
annals of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 60
eISSN - 2037-416X
pISSN - 1593-5213
DOI - 10.4401/ag-5101
Subject(s) - polar motion , nutation , homogeneous , polar , geology , earth's rotation , latitude , inner core , physics , mantle (geology) , geodesy , meteorology , geophysics , thermodynamics , astronomy
The analysis of a long series of l a t i t u d e observations carried
out in t h e International Latitude Station has allowed a very careful study
of forced motion due to meteorological effects and of t h e remaining motion
ascribed to the free nutation of an elastic Earth. The discussion of these
observations has, however, led to the discovery of the existence of long
term components in polar motion (<•• 8). These results have recently been
confirmed by Proverbio et al. (u ).
In this work, the latitudes observed in t h e period 1900.0 - 1969.0 reduced
to a single homogeneous system are analyzed separately for t h e five stations
of the ILS. The analysis of this q u a n t i t y points up t h e existence of two
different long term components in polar motion of about 16 and 26 years.
One possible interpretation of these phenomena is based on " beat " phenomena
between the n u t a t i o n of the mantle and the inner core of the E a r t
out in t h e International Latitude Station has allowed a very careful study
of forced motion due to meteorological effects and of t h e remaining motion
ascribed to the free nutation of an elastic Earth. The discussion of these
observations has, however, led to the discovery of the existence of long
term components in polar motion (<•• 8). These results have recently been
confirmed by Proverbio et al. (u ).
In this work, the latitudes observed in t h e period 1900.0 - 1969.0 reduced
to a single homogeneous system are analyzed separately for t h e five stations
of the ILS. The analysis of this q u a n t i t y points up t h e existence of two
different long term components in polar motion of about 16 and 26 years.
One possible interpretation of these phenomena is based on " beat " phenomena
between the n u t a t i o n of the mantle and the inner core of the E a r t