A simple model for the structure constant of temperature fluctuations in the lower atmosphere

A model for CT, the structure constant of temperature fluctuations, for the lowest 50-500 m of the atmosphere over land has been derived from similarity expressions and simple surface flux parametrisations. Only very few data are required by the model: standard weather data and estimates of ground characteristics. Universal flux profiles of the nocturnal boundary layer lead to CT profiles which increase in value near the top of the layer. Validation of model predictions by slant path laser scintillometer and differential thermometer measurements over flat terrain gives very good agreement for daytime and good agreement for night-time. Slant path scintillometer measurements show that even in extremely mountainous terrain the daytime model gives reasonable results.