An improved method of using icesat altimetry data to extract Tibetan Plateau glacier thickness change rate

摘要

Glacier thickness change is a sensitive factor in response to global climate change, its quantitative assessment is critical to evaluate the variation of glacier mass balance. This paper analyzed and improved the method of planes fitted to repeat-tracks which uses Geoscience Laser Altimeter System (GLAS) data to extract glacier thickness change and applied it in the Tibetan Plateau area. The original plane fitting method was revised by curve fitting. Two extra parameters were added in the improved method so that the influence of complex terrain and of uncertainty due to sparse GLAS data on the estimate of glacier thickness change can be depressed. The improved method was applied to Naimona'Nyi glacier and Karakoram glacier in Tibetan Plateau area and results show that the glacier thinning rates reached -0.68±0.02 m/yr and -0.014±0.34m/yr respectively.