DEPENDENCE OF GEOSTROPHIC DRAG ON INTENSITY OF CONVECTION, BAROCLINICITY, AND ACCELERATION

This paper examines the practical importance of stability, baroclinici ty, and acceleration in the bulk ABL similarity formulations, in light of the random errors inherent in field measurements. This is done by propagating the measurement uncertainties through a theoretical model for the bulk ABL similarity functions A(0) and B-0, under a range of a ssumed (but always unstable) conditions. It is shown that random measu rement errors and acceleration effects may overwhelm most effects of b aroclinicity and stability, once conditions are at least slightly unst able. Because of this, it is hard to discern a clear functional depend ence of A(0) and B-0 on degree of instability. Thus, for a given value of h(i)/z(0), where h(i) is the inversion height and z(0) is the surf ace roughness, the geostrophic drag coefficient, which depends on A(0) acid B-0, and weakly on h(i)/z(0), may also be taken to be nearly ind ependent of degree of instability.