Eccentricity, in the context of Milankovitch cycles, refers to the shape of Earth's orbit around the Sun. It describes how much Earth's orbit deviates from a perfect circle.
A perfectly circular orbit has an eccentricity of 0, while a highly elliptical orbit has an eccentricity closer to 1.
Earth's orbital eccentricity varies over a period of about 100,000 years, changing between more circular and more elliptical shapes.
This variation in eccentricity has a significant impact on the amount of solar radiation Earth receives throughout the year.
Here's how it works:
- More elliptical orbit: When Earth's orbit is more elliptical, the planet experiences greater variations in solar radiation throughout the year. This means that summers are hotter and winters are colder.
- More circular orbit: When Earth's orbit is more circular, the amount of solar radiation received remains relatively constant throughout the year, leading to less extreme seasonal variations.
Milankovitch cycles are long-term variations in Earth's orbit and orientation that influence the amount of solar radiation reaching the planet. Eccentricity is one of the three key factors that contribute to these cycles, alongside obliquity (Earth's axial tilt) and precession (Earth's wobble).
Practical Insights:
- Eccentricity, along with other Milankovitch cycles, plays a key role in long-term climate change, including the onset and end of ice ages.
- Understanding these cycles helps scientists to predict future climate changes and develop strategies to mitigate their impacts.
