Numerical Simulation Of Land Surface Process Over The Glacier Areas In Qilian Mountains

Land surface process refers to the exchange of material, energy and momentum between land and atmosphere. It has a profound impact on global climate and simulation of the state of atmospheric motion. In the context of global warming, the Laohugou Glacier No.12 changes obviously in the Qilian Mountains. Therefore, there is a significant important to protect glacier and source of life of the Hexi Corridor through the thorough analysis of micrometeorological characteristics, energy balance characteristics and land surface process characteristics at the surface layer of Laohugou Glacier No.12.The first chapter discusses the background and significance of this research and the course of development of the land surface model, put forward the main issues in research, and given the research method, structure and possible breakthrough. Chapter II introduces the Common Land Model (CoLM) all-around, including its structure and various parameters of the program, and some processing on the application of the glacier region. Chapter III analyses micrometeorological characteristics at the surface layer of Laohugou Glacier No.12 comprehensively. The results showed that, due to the influence of the glacier underlying surface, the rising rate of mean diurnal variations of temperature is larger than the decreasing rate. The phase variation of temperature is in advance of wind speed. Air pressure is low in winter and high in summer, it is a typical alpine air pressure. The glacier wind plays an important role in energy exchanges in the land-surface process. In sunny and cloudy day, the diurnal variation of surface albedo shows a "U" shaped distribution, and it is inversely relevance to surface temperature. Chapter IV analyses the characteristics of energy balance in glacier area and simulates the characteristics of its land surface process. The results show that, by the impact of changes in solar elevation angle of the year, net radiation changes obviously and the glacier surface radiation balance is positive in the observation period. Sensible heat flux is almost positive, so the glacier gains energy. Latent heat flux is basically positive and the glacier loses energy. The net radiation shares the revenue and expenditure ratio largest in the energy balance, and mainly effects glacier ablation. The CoLM model can simulate well the variation features of net radiation, sensible heat flux and latent heat flux in glacier surface. The simulated value is slightly smaller than the observed in energy expenditure stage. The fifth chapter summarizes the main conclusions, pointes out the inadequacies and proposes future research directions of this paper.