Numerical simulation of the flow velocity and temperature of the Dongkemadi Glacier

Abstract

The flow velocity and ice temperature of a glacier reflect the response of the glacier to climate change. However, because of the restrictions of observation conditions, it is often difficult to acquire the ice velocity and temperature field for the entire glacier profile. In this study, we use a two-dimensional ice flow model and energy balance model to simulate the ice velocity and temperature using field measurements made with ground penetrating radar for the profile of the small Dongkemadi Glacier, and verify the simulated surface velocity with interferometric synthetic aperture radar data. The simulation for the flow velocity shows that the velocity depends on the surface and bedrock slopes, glacier profile shape and mass supply way, and the surface velocity increases with an increase in the surface slope. Sensitivity analysis shows that the terrain and slope affect the profile velocity. Simulation results for temperature show that the ice-body temperature is highest in the lower ice body at a subglacial position altitude of 5520 m a.s.l. This location not only gathers melt water most easily but also undergoes the strongest effect of geothermal heat flow. The distributions of the ice velocity and ice-body temperature provide a good reference for research on glacier vulnerability assessment and the response of glaciers to climate change.