Study on the influence of seasonal frozen thawing process on the surface flux in the Loess Plateau

The effects of soil seasonal freezing and thawing process on land surface heat fluxes were analyzed with two years observation data from 2013 to 2014 . The results showed that the sensible heat, latent heat and soil heat flux have no change significantly during the soil freezing stage. The sensible heat flux increased significantly, the latent heat flux decreased significantly, and the corresponding wave ratio increased during the frozen period. The soil moisture and soil heat flux increases rapidly, sensible heat flux and surface long wave radiation decrease rapidly, latent heat flux increases rapidly during the thawing stage. The thawing process of frozen soil has an obvious effect on the heat flux of soil, which increases the heat flux from surface soil to deep soil because of that the heat absorption of ice in thawing process.