ESS55
Prof. Jin-Yi Yu
Seasons and the Elliptical Orbit
qSeasons
Solstices: mark the longest and shortest
days of the years (June 21 and December 21 in the northern
hemisphere, the reverse in the southern)
Equinoxes: the length of night and
day become equal in each hemisphere.
qAt the
present-day orbit, the winter and summer solstices differ
from the aphelion and perihelion by about 13 days.
(from Earth’s Climate: Past and Future)