Orbital, precessional, and insolation quantities for the earth from -20 Myr to +10 Myr.
Abstract
The solution for the precession and obliquity of the Earth derived from the orbital solution La90 (Laskar, 1990) is presented. This solution provides the necessary data for the computation of insolation at the surface of the Earth from -20 Myr to +10 Myr. When the tidal dissipation is taken into consideration, this solution presents very good agreement with the 3-Myr numerical integration of (Quinn et al., 1991). The main source of uncertainty in the computation of precession and obliquity of the Earth is found to arise from the changes of dynamical ellipticity of the Earth which can occur during an ice age. This change is especially important because of the existence of a resonant effect with a secular term of frequency s6 - g6 + g5 resulting from the perturbations of Jupiter and Saturn. In order to overcome this difficulty, the nominal solution is provided together with FORTRAN programs which would allow the unknown parameters of the solution to be fitted to geological records.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1993
- Bibcode:
- 1993A&A...270..522L
- Keywords:
-
- Earth Surface;
- Orbit Perturbation;
- Secular Variations;
- Solar Orbits;
- Solar System;
- Elliptical Orbits;
- Jupiter (Planet);
- Saturn (Planet);
- Geophysics