The monthly sand and dust deposition flux and modern dust storms were monitored in the northern Qaidam Basin of the Qinghai–Tibetan Plateau. The monthly sand and dust flux varied between 0.57 and 18.12 mg cm−2 month−1 from June 2003 to April 2005, and was well correlated with the monthly extreme wind velocity (Vextr) (r2=0.60, n=23). Sand and dust was mainly deposited in spring and early summer in the study area. The weight of settled sand and dust collected during dust storms exhibited a positive correlation with the mean 10-min wind velocity (r2=0.60, n=16) during the dust storms. For the typical dust storms, the weight and flux of settled sand and dust will linearly increase with the increasing wind strength and fluctuation amplitude of wind velocities. The coarse fraction (N63 μm) also increases with them, in contrast, the finegrained fraction (b63 μm) decreases. It is plausible to assume that most of the fine-grained dust particles are lifted and transported far from the region under dust storm conditions, especially under the stronger and more variable wind conditions. The results demonstrate that the wind regime (strength and variability) is a key control on the sand and dust deposition during dust storm; dust can be emitted from the Qaidam Basin as one of dust source areas in China.

The pedocomplex designated as S1 in the western part of the Chinese Loess Plateau, corresponding to MIS 5, has been investigated with the focus on the S1S3 unit (equivalent to Eemian in Europe). The high-resolution data (2-cm interval, ca. 150 years) of the particle size distribution and the frequency-dependent magnetic susceptibility were used to reconstruct variations in the winter and summer monsoon intensities. The data show that the summer monsoon was strongest and the winter monsoon weakest in the late part of the Eemian interglacial. Contrary to previous reports from the central part of the Chinese Loess Plateau, our results show that the East Asian monsoons in the western part of the Plateau were quite stable during the last interglacial. However, our data do exhibit four abrupt events of intensified winter monsoon during the transition from the penultimate glacial to the last interglacial. Also found were the existence of a time lag between the summer and winter monsoons. That is, the intensity of the winter monsoon started to decline prior to the sudden strengthening of the summer monsoon during the transition from MIS 6 to MIS 5e and it gradually returned to a glacial state after the intensity of the summer monsoon rapidly resumed its glacial state from MIS 5e to MIS 5d. The time lag between the two monsoons might have resulted from the different sensitivity of the two indirect driving forces (ice–snow coverage in high latitudes and sea-surface temperature in low latitudes) to global insolation as the ultimate direct forcing factor. Specifically, the winter monsoon had followed the insolation variations very closely, whereas the summer monsoon had delayed to respond to the insolation variations because of the buffering effect of lower latitude oceans.

Detailed examination of sedimentary cores retrieved from Sugan Lake in the northern Qaidam Basin of northwest China’s Tibetan Plateau reveal that fine laminated beddings form in the sediments where water depth exceeds 3 m. Seasonal surface sediments trapped at the bottom of the lake suggest that sediments deposited during summer and autumn are mainly light colored monohydrocalcites, while those deposited in winter are dark organic matter, indicating that varve layers form under modern limnological conditions. Continuous varve sediments comprising four types have accumulated in the upper 5.5m of Core SG03I from the center of the lake. All types exhibit clear seasonality indicative of annual deposition. Varve counts correspondence with 210Pb dates on recent sediments in the upper core suggest the continuous varves of the upper 5.5 m of the core formed in the late Holocene (2670 a BP). The Sugan Lake varve sequence is the first demonstration of annually laminated sediments reported in arid western China.

选择位于柴达木盆地北缘的苏干湖作为研究对象，利用210Pb，AMS 14C以及常规14C等测年手段，建立了苏干湖沉积岩芯2ka以来的时间序列。对湖泊沉积细颗粒中的碳酸盐进行碳、氧同位素分析。结合流域地表水δ18O值的变化以及气温观测资料，认为碳酸盐δ18O 值指示了流域有效湿度的变化；δ13C值的变化与湖泊年内冰封湖面时期的长短有关，间接指示了区域冬半年气温的变化，在此基础上，建立了2 ka来苏干湖地区气候变化序列，其气候变化过程经历了5个阶段: 0~190 AD，暖干；190~580 AD，冷干；580-1200AD（MWP），暖干；1200-1880 AD（LIA），冷湿；1880~1950 AD期间为冷干气候, 20 世纪50年代以来，气候变暖。碳同位素反映的2 ka 以来冬半年气温的变化与历史文献记录以及其他地质记录有很好的一致性，表明苏干湖同位素记录的2ka来气候变化具有普遍意义。

文章通过分析苏干湖表层沉积物、流域表层沉积物、大气降尘以及湖泊冰面囚固碎屑颗粒等的粒度组成，比较了流域地表沉积与湖泊沉积物粒度组成的差异和苏干湖表层沉积粒度组成的空间变化。初步认为苏干湖沉积物粗颗粒组分（>63μm）主要由风力搬运入湖，> 63μm组分的含量可以用来指示研究区尘暴事件的演化。结合湖泊沉积岩芯纹层计数年龄，重建的1000年来尘暴演化历史显示,在1210A. D. 之前尘暴事件较弱,且变化幅度较小；1210A. D. 以来则表现出高频率或者高强度,其中13世纪上半叶以及17世纪的高值段与东部降尘变化历史一致。就气候变化的特征时段（中世纪暖期、小冰期等）而言，尘暴事件主要与气候变冷情况下较强的盛行风场有关；而极端干旱区有效湿度的增加可能有利于地表粉尘的释放,助长了尘暴事件的发生。