Due to different orbital configurations, high northern latitude summer insolation was higher during the Last Interglacial period (LIG; 129–116 thousand years before present, ka) than during the pre-industrial period (PI), while high southern latitude summer insolation was lower. The climatic response to these changes is studied here with focus on the Southern Hemisphere monsoons, by performing an equilibrium experiment of the LIG at 127 ka with the Australian Earth System Model, ACCESS-ESM1.5, as part of the Paleoclimate Model Intercomparison Project 4 (PMIP4). Simulated mean surface air temperature between 40 and 60^∘ N over land during boreal summer is 6.5 ^∘C higher at the LIG compared to PI, which leads to a northward shift of the Intertropical Convergence Zone (ITCZ) and a strengthening of the North African and Indian monsoons. Despite 0.4 ^∘C cooler conditions in austral summer in the Southern Hemisphere (0–90^∘ S), annual mean air temperatures are 1.2 ^∘C higher at southern mid-latitudes to high latitudes (40–80^∘ S). These differences in temperature are coincident with a large-scale reorganisation of the atmospheric circulation. The ITCZ shifts southward in the Atlantic and Indian sectors during the LIG austral summer compared to PI, leading to increased precipitation over the southern tropical oceans. However, weaker Southern Hemisphere insolation during LIG austral summer induces a significant cooling over land, which in turn weakens the land–sea temperature contrast, leading to an overall reduction (−20 %) in monsoonal precipitation over the Southern Hemisphere's continental regions compared to PI. The intensity and areal extent of the Australian, South American and South African monsoons are consistently reduced in LIG. This is associated with greater pressure and subsidence over land due to a strengthening of the Southern Hemisphere Hadley cell during austral summer.

中文翻译：

---

最后一次冰期之间的陆海温度对比及其对水文循环的影响

由于不同的轨道构型，北冰期夏季高日照度比工业化前时期高（LIG；距今129-11.6万年前，ka），而南冰期高日照度较低。 。本文以古地球气候模式比较项目4的一部分，通过澳大利亚地球系统模型ACCESS-ESM1.5对127 ka的LIG进行了平衡实验，重点研究了南半球季风对这些变化的气候响应。 （PMIP4）。 北方夏季，陆地上的模拟平均地面气温在40至^60∘N之间，为 ^6.5∘LIG上的PI较PI高C，这导致了热带辐合带（ITCZ）向北移动并增强了北非和印度季风。尽管0.4  ^∘在南半球（0-90在南半球夏季ç凉爽的天气^∘  S），年平均气温1.2是 ^∘ C时，在南半球中纬度地区到高纬度地区（40-80 ^∘ S）。这些温度差异与大气环流的大规模重组相吻合。与PI相比，LIG夏季，ITCZ在大西洋和印度地区向南移动，导致南部热带海洋上的降水增加。但是，LIG南半球夏季南半球的日照减弱，导致陆地上出现明显的降温，进而削弱了陆海温度的反差，导致总体下降（-与PI相比，南半球大陆地区的季风降水量为20％）。LIG不断降低澳大利亚，南美和南非季风的强度和面积。由于南半球夏季南半球哈德利单元的加强，这与土地上更大的压力和沉降有关。