Attribution of Last Glacial Maximum precipitation change in Northern Hemisphere monsoon and arid regions
Attribution of Last Glacial Maximum precipitation change in Northern Hemisphere monsoon and arid regions
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DOI：
10.1016/j.palaeo.2022.111053
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发表时间：
2022-08
期刊：
影响因子：
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通讯作者：
J. Lei;Zhengguo Shi;Xiaoning Xie;Xinzhou Li
中科院分区：
文献类型：
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作者：
J. Lei;Zhengguo Shi;Xiaoning Xie;Xinzhou Li
根据地质记录的重建，末次盛冰期（LGM）的降水量与前工业化时期（PI）的降水量有明显的不同。特别是在陆地季风区和北方半球干旱区（以下分别简称为NHTMR和NHTAR），降水对边界条件的变化更敏感。然而，在NHTMR和NHTAR中，个别LGM强迫降水的相对贡献仍然不清楚。在这项研究中，进行了一系列的气候模式试验，以评估其贡献。结果表明，与PI期相比，末次盛冰期降水量减少，NHTMR面积减少。在NHTAR，降水量显着减少，但总面积增加。敏感性试验表明，海表温度的降低和冰盖的扩张是NHTMR降水减少的两个主要原因，而NHTAR降水的减少主要是由于冰盖引起的地形和地形变化。相比之下，冰盖覆盖效应对降水变化的影响要大于地形效应。与各强迫相关的大气环流异常是驱动降水变化的动力机制。
Based on reconstructions from geological records, the precipitation during the Last Glacial Maximum (LGM) was markedly different from that of the preindustrial (PI) period. Especially in the terrestrial monsoon regions and arid regions of the Northern Hemisphere (hereafter referred to as NHTMR and NHTAR, respectively), the precipitation is more sensitive to changes in boundary conditions. However, the relative contributions of individual LGM forcings to precipitation in NHTMR and in NHTAR are still unclear. In this study, a series of climate model experiments were carried out to evaluate their contributions. The results showed that, compared with the PI period, the precipitation and area of NHTMR were both reduced in the LGM. In NHTAR, the precipitation was significantly reduced, but there was an increase in total area. Sensitivity experiments demonstrated that a decrease in sea surface temperature and an expansion of the ice sheet were the two principal contributors to lessening NHTMR precipitation, while the decrease in precipitation in NHTAR can be mainly attributed to ice-sheet-induced albedo and topography changes. Comparatively, the ice-sheet albedo effect had a greater impact on precipitation change than the topographic effect. The atmospheric circulation anomalies associated with the individual forcings were the underlying dynamic mechanism that drive the precipitation changes.