What are the periodic variations in Earth's rotation and orbit around the sun that alter the way solar radiation is distributed over Earth's surface?

1. The precession of the equinoxes.

2. Changes in the tilt angle of Earth's rotational axis relative to the plane of Earth's orbit around the Sun.

3. Variations in the eccentricity

Explanation:

These variations listed above; the precession of the equinoxes (refers, changes in the timing of the seasons of summer and winter), this occurs on a roughly about 26,000-year interval; changes in the tilt angle of Earth's rotational axis relative to the plane of Earth's orbit around the Sun, this occurs roughly in a 41,000-year interval; and changes in the eccentricity (that is a departure from a perfect circle) of Earth's orbit around the Sun, occurring on a roughly 100,000-year timescale. which influences the mean annual solar radiation at the top of Earth's atmosphere.