Climatology

Chapter 8

How does Earth's orbit change?

Milankovitch cycle
 
  1. Eccentricity (=amount by which its orbit around another body deviates from a perfect circle) of the Earths orbit varying from elliptical to more circular (leading to +/- 3% of solar raditation, becoming less elliprical over time, meaning also less seasonal)
  2. Obliquity (=angle of the tilt) is varying from 22° to 24.5° (cycle: 40.000 years) whereas smaller tilt means less seasonal variation. Current tilt: 23.5°, decreasing
  3. Precession (=change of orientation of rotational axes) of the equinoxes, changes distance between Earth and sun during the equinoxes with a cycle period of 22.000 years. Now, the earth is closest to the sun in January and farthest in July, and in 11.000 years the earth will be closest to the sun in July)

     

Diskussion