Venus internal structure and global deformation
<p>Tidal forces acting on a planet cause a deformation and mass redistribution in&#160;its interior, involving surface motions and variation in the gravity field, which may be observed in geodetic experiments.&#160;The change in the gravitational&#160;field of the planet, due to the influence of an external gravity field, described&#160;primarily by its tidal Love number k of degree 2 (denoted by k<sub>2</sub>) can be observed&#160;from analysis of a spacecraft radio tracking. The planet&#8217;s deformation is linked to its internal structure, most effectively to&#160;its density and rigidity. Hence the tidal Love number k<sub>2</sub> can be theoretically approximated&#160;for different planetary models, which means comparing&#194;&#160;the observed and theoretical calculation of k<sub>2</sub> of a planet is a window to its internal&#160;structure.</p> <p>The terrestrial planet Venus is reminiscent of the Earth twin planet in size and&#160;density, which leads to the assumption that the Earth and Venus have similar internal&#160;structures.&#160;In this work, with a Venus&#160;we investigate the structure and elastic parameters of the planet&#8217;s major layers to calculate its frequency dependent tidal Love number k<sub>2</sub>. The calculation of k<sub>2</sub>&#160;is done with&#160;ALMA, a Fortran 90 program by <em>Spada [2008]</em>&#160;for computing the tidal and load Love&#160;numbers using the&#160;Post-Widder Laplace inversion formula. We test the effect of different parameters in the Venus model (as a layer&#8217;s density, rigidity, viscosity and thickness) on the tidal Love numbers k<sub>2 </sub>and different linear and non-linear combinations of k<sub>2</sub> and<sub> </sub>h<sub>2</sub> (as the tidal Love number h<sub>2</sub> describes the radial displacement due to tidal effects).</p>