Numerical modelling of the dynamics response of glacier to changing climates

• Main Author: Lam, Joseph Kah-Wah
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Cambridge 1999
• Subjects: Arctic; Svalbard; Canada; Norway; White Glacier; Climate change; glacier; glacier*; Global warming; Sea ice
• Online Access: https://www.repository.cam.ac.uk/handle/1810/300979; https://doi.org/10.17863/CAM.48054

Simulations with General Circulation Models have indicated that global warming will be enhanced at high latitudes. Wetter conditions in these regions are quite plausible with global warming due to warmer sea surface temperatures, melting of sea ice and a greater moisture holding capacity of the atmosphere. Recent observations show a marked increase in precipitation in the High Arctic regions during the past decades. To make reliable predictions of the response of High Arctic glaciers to a warmer and wetter climate, and hence, their contribution to sea-level rise, an adaptive-grid finite-volume glacier model coupled with a surface mass balance model has been developed to investigate the interactions of the glaciers with climate change induced by global warming. The adaptive-grid finite-volume glacier model is an implicit one-dimensional dynamic flowline model. The discretized implicit finite-volume equations are solved by an iterative predictor-corrector method. The grid adapts as the terminus moves in response to changes in surface mass balance. Only the terminus grid point and the penultimate grid point are adapted as the terminus position changes in order to minimise computation. The surface mass balance model consists of two sub-models, an accumulation model and an ablation model. The accumulation model simply assumes that solid precipitation is the main process of accumulation and occurs when the air temperature is below a critical value. Ablation at the glacier surface is determined by the ablation model from the surface energy balance. The coupled model is applied to Austre Broggerbreen, Svalbard, Norway, and White Glacier, N.W.T., Canada. The two glaciers are in regions of different climate and represent two types of climates in the High Arctic. The two glaciers are subjected to 5 possible greenhouse scenarios with various precipitation increases. Since the glaciers are not in balance with the current climate, the results suggested that even with no further warming, High Arctic ice masses would continue ...