MEASURING THE CHANGING MASS OF GLACIERS ON THE TIBETAN PLATEAU USING TIME-VARIABLE GRAVITY FROM THE GRACE MISSION

Abstract

The Tibetan Plateau is the largest region of high elevation in the world. The source of water for a number of important rivers, the Himalayan region is vital to the security of the Asian continent. In the last fifty years, the climate in the region has warmed more rapidly than anywhere else at the same latitude. Causes and effects, and the geographical details, of these alarming warming trends are as yet not fully known. One way of assessing the effects of climate change in this area is to measure the change in ice mass in the region, but ice mass loss trends to date have not been conclusive. In this study I examine the behavior of Tibetan glaciers in order to determine the effects of warming. Here, I use satellite gravimetry to derive an estimate of ice mass loss in this area. I use a technique known as spatiospectral localization using spherical Slepian functions in order to analyze global Gravity Recovery and Climate Experiment data on the Tibetan Plateau. I find that ice mass has been decreasing on the Tibetan Plateau between 2003 and 2015 but that this decrease exhibits spatial variability throughout the region. Specifically, in the regions of Himalaya, Pamir, Tibet Qilian, Tien Shan have been using ice mass at a rate of -9 ± 2, -1 ± 1, 8 ± 1, and -6 ± 1 Gt/yearrespectively over the last decade.