Earth’s Axial Tilt, or Obliquity [Credit: Wikipedia]
First let’s get the approximate target numbers for the model.
‘The inclination of Earth’s orbit varies with respect to the solar system’s invariant plane with a period of roughly 71000 years.
. . .
Taken in conjunction with the 26000-year spin-axis precession, the 71000-year orbit precession causes a 41000-year oscillation in the tilt of the earth’s axis, about plus or minus 1.3 degrees from its average value of 23.3 degrees. This number is not absolutely stable – it depends on the combined positions of all the planets through time.’
Astronomy: precession of Earth (Washington State University)
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Origin of the 100 kyr Glacial Cycle: eccentricity or orbital inclination?
‘Spectral analysis of climate data shows a strong narrow peak with period ~ 100 kyr, attributed by the Milankovitch theory to changes in the eccentricity of the earth’s orbit. The narrowness…
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