Careful Measurements and Energy Balance Closure - The Case of Soil Heat Flux

As a scientist, one of John Norman's professional vocations was the discovery of weaknesses in theory or measurement and the development of creative solutions to those weaknesses. Frequently, this exercise involved both modeling and measurement with sequential improvement in both driven by the comprehensiveness of the model and verification by measurement. Field measurements in agricultural and forest meteorology are fraught with potential errors and uncertainty regarding their accuracy. Often, the consequences of this uncertainty are unseen or unknown. An exception is with respect to surface energy balance measurements where the desire to close the energy balance has driven scrutiny of error sources for many years. I will present a summary of several year's of research regarding errors associated with the measurement of the soil heat flux term of the surface energy balance. This exercise demonstrates the legacy of John's training and insightful approach to experimentation and problem solving.