Data sifting by atmospheric stability classification at a potential wind energy site in complex terrain

Abstract

The rather complicated theories of atmospheric boundary layer modelling are not discussed in this paper. References for those wishing to introduce themselves to this area of study are Sutton (1953), Monin and Yaglom (1971), Tennekes and Lumley (1972) and Plate (1982). This paper will simply introduce the terminology and parameters used in stability classification schemes and give the specifications for the various classes of stability. Extending to approximately 1000 metres above the surface of the earth is the so-called 'planetary boundary layer', a zone of transition from the disturbed flow of air near the surface to the frictionless flow of the free atmosphere. It is obviously very difficult (and expensive) to measure accurately and overall the various physical quantities for the wind in this zone, especially if studied under the Lagrangian system of following each parcel of fluid. It is much easier (and cheaper) to take a few earth-bound Eulerian system measurements and then from the theories of the shapes of the vertical profiles of the various atmospheric quantities obtain an approximate, but hopefully sufficiently accurate picture of the planetary boundary layer for the purposes intended.