A New Turbulence Microbarometer and Its Evaluation Using the Budget of Horizontal Heat Flux.

The construction, calibration, and application of a microbarometer that is capable of accurately measuring turbulence pressure fluctuations is described. The microbarometer consists of a quad-disk pressure probe and a highly sensitive high-pass pressure sensor. The accuracy of the instrument is tested by evaluating the budget of streamwise horizontal heat flux in the atmospheric surface layer. In this budget, shear and stratification production balance a pressure covariance term and a small turbulent transport term. The measured pressure covariance term is found to close the heat flux Abudget to within approximately 15%.