Some aspects of turbulence in the atmospheric boundary layer.

The general structure of the convectively unstable atmospheric boundary layer is discussed by examining the turbulence kinetic energy budget. This examination is based on results from three field experiments during which measurements of the various terms in the turbulence kinetic budget were made over the entire depth of the boundary layer. The importance of various terms in the budget is a function of static stability in the boundary layer. Thus, the budget is examined for conditions ranging from forced convection (such as might occur in a trade wind boundary layer over the ocean) to nearly free convection (such as occurs when the earth's surface is much warmer than the air above). One of the most interesting features of the budget is the behaviour of the so-called production terms. In the atmosphere, these therms may act to either increase or decrease the turbulence kinetic energy of the fluid. (A)