Simulating the Response to Astronomical Forcing with a Coupled Atmosphere-Ocean Model

Abstract:

Substantial variations in climate during the Quaternary Period have been reconstructed from a wide array of paleoclimate proxies, with much of the variance occurring on the same time scales as astronomical forcing. To understand the mechanisms that may be responsible for these variations, we employ a set of single-forcing simulations with a coupled atmosphere-ocean general circulation model and systematically examine the climatic responses to changes in Earth’s orbital parameters (i.e., perihelion date and axial tilt). We survey some of the highlights from our analysis of these simulations, including the response of tropical circulation to astronomical forcing and contributions of radiative feedbacks to the global and regional thermodynamic response.