A first-order global model of late Cenozoic climatic change II. Further analysis based on a simplification of CO2 dynamics
A first-order global model of late Cenozoic climatic change II. Further analysis based on a simplification of CO2 dynamics
复制标题
晚新生代气候变化的一阶全球模型II。
DOI：
10.1017/s0263593300020824
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发表时间：
1991
期刊：
影响因子：
4.6
通讯作者：
K. Maasch
中科院分区：
文献类型：
--
作者：
B. Saltzman;K. Maasch
A model developed recently for the long-term variations of global ice mass, carbon dioxide, and mean ocean temperature through the late Cenozoic is simplified by hypothesizing a new equation for the CO2 variations containing one less adjustable parameter, but retaining the essential physical content of the previous equation (including nonlinearity and the potential for instability). By assuming plausible time constants for the glacial ice mass and global mean ocean temperature, and setting the values of six adjustable parameters (rate constants), a solution for the last 5 My is obtained displaying many of the features observed over this period, including the transition to the near-100 ky major ice-age oscillations of the late Pleistocene. In obtaining this solution it is also assumed that variations in tectonic forcing lead to a reduction of the equilibrium CO2 concentration (perhaps due to increased weathering of rapidly uplifted mountain ranges over this period). As a consequence of this CO2 reduction, the model dynamical system can bifurcate to a free oscillatory ice-age regime that is under the “pacemaker” influence of earthorbital (Milankovitch) forcing. Expanded discussions are given of the surface temperature variations accompanying the evolution of ice, CO2, and ocean temperature, and of the bifurcation properties of the model from both mathematical and physical viewpoints.
