Late-Holocene glacier advances and related climate conditions in the Hailuogou catchment, Gongga Shan, eastern Tibetan Plateau

Abstract

We present simulations for the late-Holocene glacier advances in the Hailuogou catchment, Gongga Shan, in attempts to test the glacier sensitivity to climate changes and constrain the climate conditions that support these glacier advances. We use a coupled mass-balance and ice-flow model parameterized using empirical glaciological and climatological data to simulate the glacier extents by fitting modeled glaciers to corresponding glacial landforms. The glacier sensitivity test showed that in the Hailuogou catchment, glacier area expands increasingly quickly until 4°C cooling, beyond which decreased expansion occurs up to at least 5°C cooling, but the modeled glacier volume increases steadily up to 5°C with an approximate linear rate being 1.1 × 109 m3/0.5°C. The temperatures were estimated to be 1.9–3.1°C, 1.5–2.6°C, and 1.0–2.2°C cooler than present for the respective Guanjingtai, Hailuogou, and ‘Little Ice Age’ (‘LIA’) Maximum glacial stages, considering a realistic precipitation field being 80–120% of present value. Model results also suggested that the Hailuogou catchment was covered by glaciers of 64.1, 59.3, and 53.8 km2 and ice volumes of 8.79 × 109, 7.99 × 109, and 6.92 × 109 m3 in the Guanjingtai, Hailuogou, and ‘LIA’ Maximum glacial stages, respectively. These findings help to understand the relationships between glacier dynamic and climate change and the hydrological evolution in the Hailuogou catchment. We therefore encourage using the model as a powerful tool to retrieve past ice extents and evaluate their related climate conditions on the vast Tibetan Plateau.