The Use of Remotely Sensed Surface Temperatures from an Aircraft-Based Thermal Infrared Multispectral Scanner (TIMS) to Estimate the Spatial and Temporal Variability of Latent Heat Fluxes and Thermal Response Numbers from a White Pine (Pinus strobus L.) Plantation

The difficulty lies in relating and scaling the latent heat flux estimates obtained using remotely sensed data to values obtained from conventional micrometeorological techniques and expansion from a point in space measurement to a landscape scale. One important use of thermal remote sensing is the estimation of latent heat fluxes on a larger scale and characterizing its spatial variability across the landscape. Seguin and Itier in their analysis of the TERGRA and TELLUS models concluded that accurate measurement of surface temperatures was necessary to obtain reliable latent heat flux estimates using remotely sensed data. Forests are characterized by several major structural and physiological differences from short vegetation or bare soil which cause differences in the sensible and latent heat fluxes. The variability in microclimate and vegetation found in mountainous terrain makes it difficult to extrapolate ground-based point measurements to landscape scales as evidenced by the variability in canopy temperatures in an even-aged white pine plantation.