Accelerated glacier mass loss in the largest river and lake source regions of the Tibetan Plateau and its links with local water balance over 1976–2017

Abstract

Variations in glacier meltwater in the source regions of the Tibetan Plateau's (TP) largest lake (Selin Co) and China's longest river (Yangtze River) regulate the local and downstream water balance under the warming climate. However, the magnitude of their variations over the past four decades is still unknown. Here, we examine long-term changes in glacier mass balance over 1976–2017 using KH-9 and CoSSC-TanDEM-X data. We find that the mean rate of glacier mass loss (GML) has accelerated from −0.21 ± 0.11 m a–1 over 1976–2000, to −0.28 ± 0.14 m a–1 over 2000–11, and subsequently to −0.48 ± 0.10 m a–1 over 2011–17. Changes in temperature and precipitation are the major causes of GML. Over 1976–2017, the contribution of decadal GML to Tuotuohe sub-basin runoff ranges from 4.3 to 8.0%, while its contribution to increased lake volume change in Selin Co and Chibzhang Co-Dorsoidong Co ranges from 3.5 to 16.3% and 19.2 to 21.4%, respectively. The GML of source regions made relatively small contributions to river runoff and lake supply, but plays a vital role when precipitation decreases. The quantitative evaluation of the water balance for the sources of great rivers and lakes over the TP is therefore important for water resource management and hydrological cycle studies.

Changing glacier firn in Central Asia and its impact on glacier mass balance

“…Paper II furthermore showed that the mass loss of Abramov glacier was relatively stable over the modelled 52 years, whereas an acceleration of mass loss was identified elsewhere in High Mountain Asia and many other regions of the world (Maurer et al, 2019;Zemp et al, 2015;Chen et al, 2021;Hugonnet et al, 2021). The geodetic mass balance results of , which are in the same range as the modelled mass balance presented in Paper II, confirm a rather constant mass loss of Abramov glacier.…”

What Controls Lake Contraction and Then Expansion in Tibetan Plateau’s Endorheic Basin Over the Past Half Century?

“…The changes in glacier surface elevation dating back to the 1970s were only reported for part of the study area over the TP (Bhattacharya et al., 2021; Chen et al., 2021; Y. Zhou et al., 2018), and the overall climatic processes regarding glacier thickness change in this region remain largely unknown. To address this knowledge gap, in addition to using the already available declassified KH‐9 data, we order as much on‐demand KH‐9 data sets as possible to cover the entire glacierized area of TP’s endorheic basin (Figure S2 in Supporting Information for KH‐9 data coverage).…”

“…The changes in glacier surface elevation dating back to the 1970s were only reported for part of the study area over the TP (Bhattacharya et al, 2021;Chen et al, 2021;Y. Zhou et al, 2018), and the overall climatic processes regarding glacier thickness change in this region remain largely unknown.…”

Recent 50-Year Glacier Mass Balance Changes over the Yellow River Source Region, Determined by Remote Sensing

“…Glacier surging is caused by internal ice instability, which is related to the glacier entropy balance, length, area, and slope [38][39][40]. Surge-type glaciers are generally characterized by terminus advance, and obvious thickening and thinning of the ablation and accumulation zones, respectively [41,42]. From Figure 4, it is clearly found that there were accumulation trends in the terminus of A, D, and E glaciers (see Figure 8) for the 1966-2000 period, suggesting the occurrence of surge events, which was in accordance with the previously identified results by [4,43].…”