Thermal Structures in the Lowest Layers of the Atmosphere

An analysis has been made of a number of records of simultaneous fluctuations of temperature at four heights. The results show that the correlation between temperatures at two heights is greatest when the records are displaced relatively to each other, so that earlier points in the upper record are considered together with later points in the lower, by an amount depending on the mean wind speed difference between the two heights. The correlation increases with height relatively to what would be expected in a locally isotropic turbulence.

Some Observations of Wind Velocity Autocorrelations in the Lowest Layers of the Atmosphere

From wind velocity observations in the lowest layers of the atmosphere, mean square velocity differences over a time interval at a point fixed in space are derived and their variation with the time interval is considered. The magnitude of these mean square differences is related to the rate of viscous dissipation of energy and to the shearing stress. On the average, fair agreement with predictions from the dimensional arguments of the theory of local isotropy is shown even though the results pertain to eddy sizes outside. the inertial subrange as usually defined.