A modeling study of the response of Asian summertime climate to the largest geologic forcings of the past 50 Ma
A modeling study of the response of Asian summertime climate to the largest geologic forcings of the past 50 Ma
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DOI：
10.1002/2015jd024370
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发表时间：
2016-05
期刊：
影响因子：
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通讯作者：
G. Roe;Q. Ding;D. Battisti;P. Molnar;M. Clark;C. Garzione
中科院分区：
文献类型：
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作者：
G. Roe;Q. Ding;D. Battisti;P. Molnar;M. Clark;C. Garzione
现代亚洲夏季风受现代大陆几何学、地形学、大气成分、间冰期气候状态和轨道结构的影响。然而，自从5000万年前印度和亚洲大陆相撞以来，所有这些因素都发生了重大变化。在一个大气环流模式的框架内，我们评估了这些因素中的每一个对夏季气候场和降水加权18O的空间格局的相对重要性。我们发现，季风环流的大陆尺度结构仍然强劲，但对当地环境条件有重要影响。最大的气候差异与轨道配置和地形的变化有关，因为这些因素如何影响夏季气候变量的当地梯度。最后，模式计算与现代对季风动力学的理解是一致的，其中环流的强度和降雨的分布与低层湿静力能量和对流层上部温度的空间模式紧密耦合。
The modern Asian summer monsoon is known to be affected by the modern continental geometry, orography, atmospheric composition, interglacial climate state, and orbital configuration. All of these factors, however, have undergone substantial changes since the Indian and Asian continents collided 50 million years ago. Within the framework of one general circulation model we evaluate the relative importance of each of these factors for the spatial patterns of summertime climate fields and precipitation‐weighted 18O. We find that the continental‐scale structure of the monsoon circulation remains robust, but there are important impacts on local environmental conditions. The largest differences in climate are associated with changes in orbital configuration and topography because of how those factors influence local gradients in the summer climate variables. Finally, model calculations are consistent with the modern understanding of monsoon dynamics in which the strength of the circulation and the distribution of rainfall are tightly coupled to the spatial patterns of low‐level moist static energy and upper tropospheric temperature.