Establishing a national standard method for operational mixing height determination

Abstract

Since the 1960s the Holzworth method has remained a primary tool for operational mixed-layer height determination. The air volume through which ground-based pollutants vertically disperse defines the mixed layer. The appeal of this method rests on the simple mechanics of making a forecast where knowledge of the surface air temperature in concert with the background vertical structure is sufficient. The National Weather Service routinely issues forecasts using this method for air-quality and wildland fire activities.