Astronomical factors 5

Seasonal climatic variability is affected by precession,which changes the date at which the Earth reaches its perihelion (closest place to the sun).
If perihelion is reached in winter (currently on January 3), seasonal differences in insolation are reduced in the Northern hemisphere because this Hemisphere is closer to the Sun.

The elliptical shape of Earths orbit
slowly precesses in space, so that
the major and minor axes of the
ellipse slowly swift through time.


*Astronomical factors 5*
	3 - Variation in the excentricity
	Seasonal climatic variability is affected by precession,which changes the date at which the Earth reaches its perihelion (closest place to the sun). If perihelion is reached in winter (currently on January 3), seasonal differences in insolation are reduced in the Northern hemisphere because this Hemisphere is closer to the Sun. The elliptical shape of Earths orbit slowly precesses in space, so that the major and minor axes of the ellipse slowly swift through time.