| Models for polar motion | |||||
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Luni-solar tidal forcing
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Ocean loading
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Atmospheric loading |
Continental water loading or unknown cause
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POLAR MOTION Diurnal and subdiurnal* Solid Earth quasi-elastic response |
Brzezinski et al. 2002 |
tidal non tidal Brezinski et al. 2004 |
thermal + tidal Brzezinski et al. 2002 |
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POLAR MOTION > 2 days Solid Earth quasi-elastic response |
Brzezinski et al. 2002 | tidal PM and its excitation: Dickman, Weiss, and empirical models, Tab 1 of Gross (2008) |
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POLAR MOTION Decadal and secular Solid Earth Visco-elastic response |
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| * Only prograde diurnal terms of the polar motion are considered, retrograde diurnal components are actually estimated as nutation offsets. Semidiurnal, terdiurnal and other subdiurnal terms are composed of both prograde and
retrograde parts. | |||||
| Polar motion effects | |||||
| Solid Earth quasi-elastic contribution (solid Earth pole tide)
From 2 days to ~ 20 years |
Hydrostatic ocean contribution (ocean pole tide) From 10 days |
Secular / multi-decadal polar motion (post-glacial rebound,...) From ~ 20 years |
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| On degree 2 geopotential (or off-diagonal inertia moment) | IERS 2010 - Chapter 6.4: Eq. 6.22 | IERS 2010 - Chapter 6.5 (Eq. 6.23a/b and 6.24) from Desai model (2002) Eq. 24 | IERS 2010 polynomial trend Chapter 6.2 (Eq. 6.5) and Chapter 7 (Eq. 7.25) | ||
| On solid Earth deformation | Solid Earth pole tide IERS 2010 Update: Chapter 7.1.4: Eq. 7.23 + 7.22/7.24) | Ocean pole tide loading for periods < 20 years: --> IERS 2010 Update: Chapter 7.1.5 | Mean pole | ||