基金supported by the National Natural Science Foundation of China(41725010 and 42107472)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB26000000 and XDB31000000)the Key Research Program of the Institute of Geology&Geophysics,Chinese Academy of Sciences(IGGCAS-201905)。
文摘上新世(5.33~2.58 Ma)是距今最近的大气CO_(2)浓度超过400 ppmv的暖期,是理解未来气候变化的地质历史相似型.地质记录显示,上新世气候主要响应地球倾角和岁差变化,比如深海氧同位素和高纬陆相记录表现出强的倾角周期(41 ka),低纬和地中海地区的粉尘和花粉记录以岁差周期(21 ka)为主.然而,这些气候周期空间差异的机制尚不清楚.我们使用全球海气耦合模式HadCM3,开展了轨道参数极值实验.结果表明:(1)倾角变化主要对高纬温度影响显著(>5℃),很好地解释了高纬记录和受高纬冰量调节的深海氧同位素记录的41 ka周期;(2)岁差变化主要影响低纬降水(>2 mm d-1),很好地解释了低纬和地中海地区与季风活动相关的21 ka气候周期.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA19050104 and XDB26020401)the National Key Research and Development Program of China(2017YFA0603404)+1 种基金the National Natural Science Foundation of China(42007282 and 42077409)the Key Research Program of the Institute of Geology&Geophysics,Chinese Academy of Sciences(IGGCAS-201905)。
