Near surface temperature is the air temperature measured at 1-2 m height. Subsurface and near surface temperature are commonly measured by standard meteorological stations, but the in-situ surface temperature is difficult to measure. Surface temperature For an ideal surface that has a uniform surface temperature, the temperature varies only with time in response to the time dependent energy fluxes at the surface. For a real soil, the surface is likely to have spatially varying surface temperature. The surface temperature at a given location is essentially given by the surface energy balance, which in turn depends on the radiation balance, atmospheric exchange processes in the immediate vicinity of the surface, presence of vegetation or plant cover, and thermal properties of the subsurface medium.
Surface temperature is difficult to measure.
The major reason for this is that the extremely large temperature gradient occurring between the boundary of air and soil is hard for a finite temperature sensor to detect. The difficulties in installing, ventilating and shielding the sensor made the measurement deviate from the actual temperature. Generally, surface temperature is calculated from easily measured parameters by theoretical methods. Surface emissivities for a black body and typical soils are 1 and 0.85, respectively. Subsurface temperature Subsurface soil temperature is easy to measure compared to the surface temperature.