The Surface Energy Balance System (SEBS) is a method for estimating atmospheric turbulent fluxes and evaporative fraction using satellite Earth observation data combined with meteorological information at appropriate scales. SEBS includes tools for determining land surface physical parameters such as albedo, emissivity, temperature, and vegetation coverage from spectral reflectance and radiance measurements. It also includes a model for determining the roughness length for heat transfer and a new formulation for determining the evaporative fraction based on energy balance at limiting cases. SEBS has been validated using four experimental datasets, showing its ability to estimate turbulent heat fluxes and evaporative fraction at various scales with acceptable accuracy. The uncertainties in the estimated heat fluxes are comparable to in-situ measurement uncertainties. SEBS is formulated more coherently and its details are evaluated for the first time. The system uses three sets of information: land surface parameters, air pressure, temperature, humidity, and wind speed at a reference height, and downward solar and longwave radiation. The formulation of SEBS is based on the surface energy balance equation, which relates net radiation, soil heat flux, sensible heat flux, and latent heat flux. The system uses similarity theory to derive sensible and latent heat fluxes. The roughness length for heat transfer is determined using an extended model. The evaporative fraction is calculated based on energy balance at limiting cases. SEBS has been applied to four different datasets, showing its effectiveness in estimating turbulent heat fluxes and evaporative fraction. The results indicate that SEBS can provide reliable estimates of turbulent heat fluxes and evaporative fraction with acceptable accuracy. The uncertainties in the estimated heat fluxes are comparable to in-situ measurement uncertainties. SEBS is a credible and independent approach that does not require prior knowledge of the actual turbulent heat fluxes. It can be used to validate and initialize hydrological, atmospheric, and ecological models. SEBS can also be extended to estimate actual evaporation, soil water availability, and drought stress of agricultural crops.The Surface Energy Balance System (SEBS) is a method for estimating atmospheric turbulent fluxes and evaporative fraction using satellite Earth observation data combined with meteorological information at appropriate scales. SEBS includes tools for determining land surface physical parameters such as albedo, emissivity, temperature, and vegetation coverage from spectral reflectance and radiance measurements. It also includes a model for determining the roughness length for heat transfer and a new formulation for determining the evaporative fraction based on energy balance at limiting cases. SEBS has been validated using four experimental datasets, showing its ability to estimate turbulent heat fluxes and evaporative fraction at various scales with acceptable accuracy. The uncertainties in the estimated heat fluxes are comparable to in-situ measurement uncertainties. SEBS is formulated more coherently and its details are evaluated for the first time. The system uses three sets of information: land surface parameters, air pressure, temperature, humidity, and wind speed at a reference height, and downward solar and longwave radiation. The formulation of SEBS is based on the surface energy balance equation, which relates net radiation, soil heat flux, sensible heat flux, and latent heat flux. The system uses similarity theory to derive sensible and latent heat fluxes. The roughness length for heat transfer is determined using an extended model. The evaporative fraction is calculated based on energy balance at limiting cases. SEBS has been applied to four different datasets, showing its effectiveness in estimating turbulent heat fluxes and evaporative fraction. The results indicate that SEBS can provide reliable estimates of turbulent heat fluxes and evaporative fraction with acceptable accuracy. The uncertainties in the estimated heat fluxes are comparable to in-situ measurement uncertainties. SEBS is a credible and independent approach that does not require prior knowledge of the actual turbulent heat fluxes. It can be used to validate and initialize hydrological, atmospheric, and ecological models. SEBS can also be extended to estimate actual evaporation, soil water availability, and drought stress of agricultural crops.