Simulation of Ozone and Long Lived Tracers in the GSFC Two-Dimensional Model

The GSFC two-dimensional transport and chemistry model has been used for a wide variety of scientific and assessment studies of stratospheric ozone. Transport is a key element in the ozone simulations, and we have recently upgraded our model transport formulation to include much of the information about atmospheric transport processes available from existing data sets. To properly evaluate the model transport, it is desirable to examine the effects of transport and photochemistry separately. Recently, high quality observations of several long lived stratospheric tracers have become available from aircraft, balloon, and satellite measurement systems. This data provides a means to do a detailed model transport evaluation, as has been done in the recent Models and Measurements Intercomparison Project II. In this paper, we will discuss the GSFC 2D model simulations of ozone together with model-data comparisons of long lived tracers such as methane and the age of air transport diagnostic. We will show that the model can reproduce many of the transport-sensitive features observed in the stratosphere, and can compare reasonably well with measurements of both total ozone and long lived tracers simultaneously. We will also discuss the model deficiencies in simulating some of the detailed aspects of the observations.