An Analysis on Frozen-Melting Behavior of Periodic Change of Surface Temperature (Continuation) (Dual Periodic Temperature Changes with Daily and Annual Cycles)

Abstract

It is important to understand the frozen-melting behavior of thermal active layer in permafrost area for dual periodic temperature changes combined with daily and annual cycles. The numerical results are compared with the single cyclic change and discussed on the temperature profiles in detail. The thermal structures are revealed to be consisted of dual Stokes depths and, in consequence, the net heat fluxes at the surface are illustrated to be affected by daily cycle to a certain extent. The influences on temperature profiles due to daily cycle penetrate only in Stokes depth pertinent to its own cycle, while the entire tempkrature distributions are decided by the annual cycle. Additionally, a simple experiment is performed to demonstrate the validity of the findings, predicted in former paper, regading the temperature decreases in deep underground compared with an average (or initial) surface temperature, which is essential to form the permafrost structure.