Glaciological Studies in Asian Highland Regions

1989-1990年在西藏东部和尼泊尔喜马拉雅山脉对亚洲高原地区进行了冰川学研究。该项目在西藏的目的是研究不同气候下的冰川特征以及冰冻圈在青藏高原气象和水文过程中的作用。分别于5-6月和9-10月在东昆仑山、唐古拉山和念青唐古拉山进行了野外观测。在唐古拉山进行了密集的冰川学、气象学和水文学观测。尼泊尔喜马拉雅地区的这个项目的一个目的是在自1985年以来一直保持的郎塘喜马拉雅水文站和气象站连续收集数据。此外，还观察到昆布、肖荣、朗塘等地区近十年来的冰川波动。初步研究结果如下：1.藏东冰川一年中的主要堆积是夏季降水的补给。高原大陆型冰川位于降雨量较少的地区，融水再冻结形成的叠冰对该干旱地区的冰川物质平衡具有重要意义。青藏高原出现大量降雪，部分原因是大范围扰动，部分原因是局地对流较强。降水的氧同位素组成表明，降水可能来自局部来源的水汽。青藏高原积雪的形成导致大气降温，延缓了多年冻土活动层的加深。在雪面观察到大量的蒸发。尼泊尔东部的小型冰川自20世纪70年代以来一直在退缩30-50米，这取决于气温的变化。

Glaciological studies in Asian highland regions in 1989-1990 were made in eastern Tibet and the Nepal Himalaya. Purposes of this project in Tibet were studies of characteristics of glaciers in different climates and the role of the cryosphere in meteorological and hydrological processes on the Tibetan Plateau. Field observations were carried out during the two periods, May-June and September-October, in the East Kunlun Mountains, Tanggula Mountains and Nyaingentanglha Mountains. Intensive observations of glaciology, meteorology and hydrology were carried out in the Tanggula Mountains.A purpose of this project in the Nepal Himalaya was continuous data collection at the hydrological and meteorological station in Langtang Himal which has been maintained since 1985. In addition, glacier fluctuations for over ten years were observed in the Khumbu, Shorong and Langtang regions.Preliminary results of the research are as follows,1. Main accumulation of glaciers in eastern Tibet in a year is supplied with summer precipitation. Continental-type glaciers on the plateau are located in regions with low precipitation, and formation of superimposed ice by refreezing of melt water is important for glacier mass balance in such dry area.2. Abundant snowfall on the Tibetan Plateau occurs partly due to large scale disturbance and partly due to strong local convection. Oxygen isotopes composition of precipitation shows a possibility of precipitation from local origin water vapor.3. Formation of snow cover on the Tibetan Plateau results in cooling of atmosphere and retardation of deepening of the permafrost active layer. Abundant evaporation was observed at the snow surface.4. Small glaciers in east Nepal have been retreating in distance of 30-50m since 1970s depending on air temperature variation.