Three-Dimensional Tracer Structure and Behavior as Simulated in Two Ozone Precursor Experiments

Abstract The GFDL 11-level general circulation/tracer model is used for two experiments designed to prepare the way for a self-consistent model of atmospheric ozone. The first experiment invokes a very simple condition at the top model level, an instantaneous relaxation to a specified 10 mb average observed ozone value. The tracer is inert below the top level until it is removed in the lower troposphere. The second experiment introduces a simplified, but reasonably realistic ozone chemistry at the top level including Chapman, nitrogen and hydrogen loss processes. Below the top level, ozone is inert, and is removed in the lower troposphere by the same mechanism as in the first experiment. These two experiments, in spite of their very different middle stratospheres, show remarkably similar behavior in the lower stratosphere. A comparison of model values and fluxes with available observations shows general qualitative agreement as well as some notable discrepancies. In the second experiment, a detailed analy...