Coupling between surface temperature and the surface energy balance and application to biomass heat storage

Surface skin temperatures (Tsfc) are of fundamental importance to physical processes that link the soil and atmosphere. Tsfc depends on soil thermal properties, meteorological conditions, and atmospheric surface layer turbulence:

  • Soil thermal properties include soil thermal conductivity and soil heat capacity, which depend strongly on soil moisture and soil texture. Soil parameters cause Tsfc variations on almost all spatial scales of O(mm-1000s of km) and temporal scales of 10s of days (Kleissl et al. 2007).
  • Weather conditions influence Tsfc primarily through modifications to the radiative energy that enters or leaves the soil leading to a pronounced diurnal temperature cycle. Meteorological factors cause Tsfc variations on large spatial scales of O(km) and temporal scales of 10s of minutes.
  • Atmospheric turbulence efficiently transports heat and water vapor from and to the soil surface and causes Tsfc variations on spatial scales of O(m-km) and temporal scales of seconds (Katul et al. 1998).

 An experiment was conducted to analyze the coupling between skin temperature, sensible heat fluxes, and evapotranspiration. Please consult the NCAR website for details. The photograph below shows the thermal IR camera pointing down at the orchard and a row of CSATs.

Typical thermal Infrared camera image of the orchard by day. Axis lables are pixels and colorbar is the surface temperature in degrees Kelvin.
Typical thermal Infrared camera image of the orchard by night.

Report on tree surface temperature averaged over height from TIR images.

Please email jkleissl at ucsd.edu to request thermal IR camera data.

Educational products: A lesson plan that illustrates the connection between albedo and surface temperatures has been created. The lesson plan is suitable for use in grades 6 through 12.

Acknowledgments: The analysis of the data was supported by the National Science Foundation under Grant No. EAR0739109. We would like to express our gratitude to Jan Hendrickx for the TIR camera, and Yoichi Shiga, Michael Sankur, and Mandana Farhadieh for field assistance. The experiment would not have been possible without the support of the NCAR Earth Observing Laboratory staff under the leadership of Ned Patton and Tom Horst. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.