ESS101C
Prof.
Jin-Yi Yu
Eccentricity Variations
qToday’s eccentricity is 0.0167,
lies well toward the lower end of the variation range of Earth’s eccentricity (closer to
circular).
qThe long-term variations in
orbital eccentricity are concentrated at two periods: 100,000 years and 413,000 years.
qThe eccentricity variations
differ from the other two orbital variations (obliquity variations and the precessional variations) in one
important aspect: Eccentricity variations cause changes in the annually averaged amount of
sunlight hitting Earth.
(from Earth’s Climate: Past and Future)