The sensitivity of the African- Asian monsoonal climate to orbital parameter changes for 9000 years B.P. in a low-resolution general circulation model.

The earth's orbital parameters, precession, obliquity and eccentricity, produce solar radiation differences (compared to present) of ca.7% at the solstices 9000 years before present (B.P.) : more radiation in June-July-August, less in December-January-February. When this amplified seasonal cycle of solar radiation is used to drive a low-resolution general circulation model, an intensified monsoon circulation is simulated for Northern Hemisphere summer. Certain features of the simulated monsoon climate from this orbital-parameter sensitivity experiment agree with the paleoclimatic evidence. -from Authors