ESS101C
Prof.
Jin-Yi Yu
The Orbital Monsoon Hypothesis
qThe 23,000-year cycle of orbital
procession
increases (decreases) summer insolation and at the same time decreases (increases) winter insolation at
low and middle
latitudes.
qDepartures from the modern
seasonal cycle of
solar radiation have driven stronger monsoon circulation in the past.
qGreater
summer radiation intensified the wet summer monsoon.
qDecreased winter insolation
intensified the dry winter monsoon.
(from Earth’s Climate: Past and Future)