ESS101C
Prof.
Jin-Yi Yu
Precession and Seasonal Insolation
qFor the precessional changes that dominant low and
middle latitudes, the relative sense phasing between seasons and between
hemispheres is exactly reversed from of tilt.
qThe Earth-Sun
distance is the major control on precessional changes in insolation.
qA
precessional-cycle insolation maximum occurring at June 21 (or December 21) will
be simultaneous everywhere on the Earth, a summer season in one
hemisphere and a winter season in another hemisphere.
(from Earth’s Climate: Past and Future)