The climate and vegetation of Marine Isotope Stage 11 - Model results and proxy-based reconstructions at global and regional scale
The climate and vegetation of Marine Isotope Stage 11 - Model results and proxy-based reconstructions at global and regional scale
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DOI：
10.1016/j.quaint.2013.12.028
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发表时间：
2014-05
影响因子：
2.2
通讯作者：
T. Kleinen;Steffi Hildebrandt;M. Prange;R. Rachmayani;S. Müller;E. Bezrukova;V. Brovkin;P. Tarasov
中科院分区：
文献类型：
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作者：
T. Kleinen;Steffi Hildebrandt;M. Prange;R. Rachmayani;S. Müller;E. Bezrukova;V. Brovkin;P. Tarasov
本文对距今约40万年前的间冰期海洋同位素第11期（MIS 11）的气候进行了416、410、400和396 ka四个时间切片的研究。我们比较了两个气候模型，地球系统模型的中间复杂性CLIMBER 2-LPJ和大气环流模型CCSM 3，重建MIS 11温度，降水和植被，主要是从陆地记录的结果。总体情况是，与工业化前相比，MIS 11是一个相对温暖的间冰期，MIS 11（416-410 ka）早期的北方半球（NH）夏季温度比工业化前温暖，尽管冬季较冷。在MIS 11的后期，特别是在400 ka左右，北半球夏季的条件较冷，主要是在高纬度地区。模式模拟的气候变化主要是由日照变化驱动的，除了两个放大气候变化的本地反馈。在这里，北半球高纬度地区，海冰覆盖的减少导致了MIS 11早期的冬季变暖，以及热带地区，季风变化导致了比仅根据纬度平均日照变化所预期的更强的气候变化，这一点尤其突出。本研究中使用的两种模型都支持在MIS 11期间早期在北方高纬度地区，特别是在北方亚洲和北美，以牺牲草为代价向北扩张树木，这与现有的基于花粉的重建一致。关于温度和降水量的变化，模式和重建之间有一般的协议，但重建的降水量的变化往往大于模式模拟的。足够高的分辨率和定年质量的记录数量非常有限，阻碍了模型和重建之间的详细比较。
The climate of Marine Isotope Stage (MIS) 11, the interglacial roughly 400,000 years ago, is investigated for four time slices, 416, 410, 400, and 396 ka. We compare results from two climate models, the earth system model of intermediate complexity CLIMBER2-LPJ and the general circulation model CCSM3, to reconstructions of MIS 11 temperature, precipitation and vegetation, mainly from terrestrial records. The overall picture is that MIS 11 was a relatively warm interglacial in comparison to preindustrial, with Northern Hemisphere (NH) summer temperatures early in MIS 11 (416–410 ka) warmer than preindustrial, though winters were cooler. Later in MIS 11, especially around 400 ka, conditions were cooler in the NH summer, mainly in the high latitudes. Climate changes simulated by the models were mainly driven by insolation changes, with the exception of two local feedbacks that amplify climate changes. Here, the NH high latitudes, where reductions in sea ice cover lead to a winter warming early in MIS 11, as well as the tropics, where monsoon changes lead to stronger climate variations than one would expect on the basis of latitudinal mean insolation change alone, are especially prominent. Both models used in this study support a northward expansion of trees at the expense of grasses in the high northern latitudes early during MIS 11, especially in northern Asia and North America, in line with the available pollen-based reconstructions. With regard to temperature and precipitation changes, there is general agreement between models and reconstructions, but reconstructed precipitation changes are often larger than those simulated by the models. The very limited number of records of sufficiently high resolution and dating quality hinders detailed comparisons between models and reconstructions.