The 2004/05 northern hemisphere polar winter through the eyes of a chemistry/transport model

The 2004/05 northern hemisphere winter exhibited an unusually cold and stable polar stratospheric vortex. The cold temperatures produced significant polar stratospheric cloud formation, chlorine processing, and ozone loss. At the time of writing this abstract (early February 2005), the vortex appears poised for large chemical ozone loss, on the scale of that observed in the year 2000 or greater. The vortex dynamics also showed interesting features including an in-mixing event in late January reminiscent of 1992. We have simulated this period with the Goddard stratospheric chemistry/transport model (CTM), using transport fields from meteorological data assimilation. The model provides a synoptic global view of the chemical distributions and a complete time series of constituent field evolution. In addition, the Polar Aura Validation Experiment (PAVE) conducted in January and February 2005 obtained in situ and remote sensing data from the NASA DC-8 aircraft; POAM data are available; and Aura MLS, OMI, and TES data will be available for comparison with model fields. This presentation will give an overview of the 2004/2005 polar winter from the global CTM perspective and will compare CTM output with POAM, Aura, and DC-8 data to evaluate the consistency between the model and data sets for a variety of chemical species.