第四紀の氷期サイクルと日射量変動

抄録

The climate in the Quaternary is characterized by ice age cycles with periods in the range of tens of thousands to a hundred thousand years, triggered by long-term insolation variations due to the Earth's orbital and precessional motions. Although we can accurately calculate long-term insolation variations at the top of the Earth's atmosphere, we need to know the physical and dynamical processes occurring in the complicated climate system of the Earth in order to understand the true nature and origin of the ice age cycles. In this manuscript, first we briefly review how the gravitational interaction between planets causes insolation variations. Then, we summarize the recent status of large-scale numerical experiments as to how the ice age cycles take place in the climate system of the Earth, with a particular focus on dynamical modeling of ice sheets.