Glacial landforms formed by multiple glaciations are well-preserved in the valleys around Karlik Mountain in the easternmost Tianshan range, Central Asia. These landforms are direct imprints of palaeoglaciers and represent important archives of past climatic and environmental conditions. Dating these landforms contributes to understanding the spatiotemporal variations of past glaciers and provides key information for reconstructing the palaeoclimate and palaeoenvironment in Central Asia. In this study, thirty-two boulder and bedrock samples were collected from two glaciated valleys on the southern slope of Karlik Mountain for terrestrial in situ cosmogenic nuclides (TCN)10Be surface exposure dating. Based on the geomorphic relationships and dating results, the innermost MS1 moraine complex was deposited during the Little Ice Age (LIA); the MS2 moraine complex was formed during the Late -glacial; the MS3 moraine complex was deposited during the global Last Glacial Maximum (LGMG); the MS4 moraine complex, which is the largest moraine complex, is marine oxygen isotope stage (MIS) 4 in ages; and the MS5 moraine complex, which is only preserved at the interfluve ridges, has a similar age to MS4. The age of MS4 demonstrates that the largest local last glacial maximum (LGML) occurred during the early part of the last glacial cycle rather than during the LGMG. The MS4 and MS5 glacial complexes imply that a large ice cap with outlet valley glaciers developed on the whole of Karlik Mountain during MIS 4. These ages, combined with previous landform mapping and dating on the northern slope of the mountain, show that glacial advances since MIS 4 in this mountainous area were restricted to the valleys, rather than large ice cap scale, which is consistent with moraine records in the other valleys across the Tianshan range. The pattern and nearly synchronous timing of palaeoglacier fluctuations during the last glaciation in arid Central Asia imply that the main determinant for glacier fluctuations in this region has been changes in precipitation brought by the westerlies during periods of low temperature.(c) 2023 Elsevier Ltd. All rights reserved.

The VAMPERS (Vrije Universiteit Amsterdam Permafrost Snow Model) has been coupled within iLOVECLIM, an earth system model. This advancement allows the thermal coupling between permafrost and climate to be examined from a millennial timescale using equilibrium experiments during the Last Glacial Maximum (21 ka) and transient experiments for the subsequent deglaciation period (21-11 ka). It appears that the role of permafrost during both stable and transitional (glacial-interglacial) climate periods is seasonal, resulting in cooler summers and warmer winters by approximately +/- 2 degrees C maximum. This conclusion reinforces the importance of including the active layer within climate models. In addition, the coupling of VAMPERS also yields a simulation of transient permafrost conditions, not only for estimating areal changes in extent but also total permafrost gain/loss.

利用大量的古多年冻土遗迹和古冰缘现象,并佐以古冰川、孢粉及动物化石等资料,重建了20ka以来中国多年冻土演化进程.结果表明,在末次冰期最盛期（LGM,或末次多年冻土最大期LPMax）,中国多年冻土面积达到了5.3×10～6～5.4×10～6km2（现今中国多年冻土面积的3倍多）,而全新世大暖期（HMP,或末次多年冻土最小期LPMin）,中国多年冻土面积曾缩减至0.80×10～6～0.85×10～6km2（约为现今中国多年冻土面积的50%）.按照古冻土遗迹的年代及分布等特征,在确定LGM和HMP两个主要时段的冻土格局基础上,将20ka以来中国多年冻土演化进程划分为7个阶段:晚更新世LGM（20000～10800a BP）多年冻土强烈扩展,达到LPMax;早全新世气候剧变期（10800至8500～7000a BP）多年冻土较稳定但相对缩减阶段;中全新世HMP（8500～7000至4000～3000a BP）多年冻土强烈退化阶段,多年冻土缩减到LPMin;晚全新世新冰期（4000～3000至1000a BP）冻土扩展阶段;晚全新世中世纪暖期（100...

The distributions of frozen ground and active layer thickness (ALT) during the last glacial maximum (LGM) and pre-industrial periods in China were investigated using Coupled Model Intercomparison Project Phase 5 (CMIP5) model experiments. Compared to the pre-industrial period, the LGM climate was similar to 5 degrees C colder and featured significantly higher freezing indices on the Tibetan Plateau and in Northeast China. Frozen ground expanded widely in the LGM. The extents of permafrost and seasonally frozen ground in China were 4.11 x 10(6) km(2) and 4.97 x 10(6) km(2), respectively, which are 2.42 x 10(6) km(2) larger and 1.45 x 10(6) km(2) smaller, respectively, than the pre-industrial levels. Moreover, the colder climate and longer duration also resulted in LGM ALT values that were 13 m less than the pre-industrial values in the permafrost areas common to both periods. Altitudinal permafrost was present mainly on the Tibetan Plateau and adjacent mountains in West China between 28 degrees N and 41 degrees 30'N and covered an area of similar to 2.63 x 10(6) km(2). Latitudinal permafrost was present mainly in Northeast China and occupied an area of 1.48 x 10(6) km(2). The southern limit of latitudinal permafrost was located similar to 10 degrees of latitude farther south during the LGM than during the pre-industrial period. The LGM simulation results agree reasonably well with previous reconstructions, with the exception of an underestimation in the permafrost extent. Although relatively high-level disagreement exists between the models in terms of the exact locations of the southern limits, the ensemble average is still able to represent the large-scale spatial pattern of frozen ground remarkably well. (C) 2016 Elsevier B.V. All rights reserved.