5:15 PM - 6:30 PM
[AGE28-P05] Identifying glacier sensitive zones based on mass balance anomaly and its linkage to climate change
Keywords:La Niña, North Atlantic Oscillation, heterogeneity, Mann-Kendall (MK) anomaly test
Glaciers have been considered as a key indicator of climate change. Taking the Urumqi River Glacier No.1 in the Chinese Tienshan Mts., China as an example, this paper analyzed the responses of glacier mass balance at different elevations to climate changes. First, we collected the glacier mass balance data of Tienshan Mts. during the observation periods of 1979-2018. The glacier mass balance data were classified into seven groups based on an elevation interval of 100m (i.e., 3700-3800, 3800-3900, 3900-4000, 4000-4100, 4100-4200, 4200-4300 and 4300-4400 m a.s.l.). Then, the anomaly periods of mass balance in the seven groups were identified by the Mann-Kendall (MK) anomaly test. The results showed that the frequency of anomaly in the equilibrium zone (3900-4200 m a.s.l.) was high. Subsequently, by defining an anomaly coefficient that describes the degree of the anomaly, the sensitive zones of Tienshan Mts. were detected (i.e., 4100-4400m a.s.l.). For confirming the sensitive zones, we analyzed the responses of the glacier mass balance of the seven groups to climate teleconnections, which included El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), and Arctic Oscillation (AO). We figured out positive and negative phases for each of the climate mode, and then calculated the percent deviation of glacier mass balance in the positive and negative phases, respectively. Based on the percent deviations, one can see that the glacier mass balance in the zones between the elevation of 4100-4400m a.s.l. were sensitive to climate anomaly. Moreover, the NAO cold period and La Niña are the most dominant factor that controls the mass balance of Urumqi River Glacier No.1 compared with others. The impact of La Niña mainly concentrated on the low and middle elevation zones. While NAO cold phase mainly influenced high elevation zones.