摘要: Under a cold climate, water exists in solid, liquid and gaseous states at, above below the surface. Water can undergo change of state on time scales that vary from hours to days seasons, multi-year periods. Phase involves energy thus balance plays major role detention or release runoff river flow. Hinzman et al. (1991) stated thermal moisture regimes are closely related each other characteristics active layer therefore have marked influence permafrost dynamics. This chapter reviews briefly fundamentals heat fluxes at atmospheric boundary below-ground.