Changes of climate, glaciers and runoff in China's monsoonal temperate glacier region during the last several decades

摘要

Changes of climate, glaciers and runoff during the last several decades in China's monsoonal temperate glacier region have been studied. Temperature has increased in a fluctuating manner during the last several decades, and temperature rise has accelerated since the 1980s. Net accumulation of Dasuopu ice core has consistently declined, and the precipitation decrease was also obvious from the end of 1970s through the middle 1980s, and particularly after the 1990s in China's monsoonal temperate glacier region. As a response to climate change, eight monsoonal temperate glaciers were stationary or advancing between the 1900s-1930s and the 1960s-1980s, and were in retreat from the 1930s to the 1960s and from the 1980s to the present. Ablation is heavy in the glacier tongue areas, and the mean ablation water equivalent in Hailuogou glacier during 1990/91-1997/98 was 876 mm more than that in 1982/83. Ablation depth on the exposed ice area increased by 1.4 m a~(-1) over the period 1983/84-1990/ 91. Mass balance records also show that glaciers suffered a constant mass loss of snow and ice, and the accumulated mass balance in Hailuogou basin and Baishui glacier No.1 was -10.83 m water equivalent in the past 45 years, and -11.38 m in the past 52 years. As glaciers become shorter, narrower and thinner under the background of climate warming, changes of internal and upper surface morphology also occurred, providing evidence of the response to climatic warming in recent years. Local hydrological and climatic data demonstrated that, in Yanggong basin during 1979-2003 and Hailuogou basin during 1988-2004, runoff from the glacier areas has been increasing both seasonally and annually. Overall, it is clear that China's monsoonal temperate glaciers are losing mass and are retreating under the background of climate warming.