Aura satellite ozone measurements and chemistry modeling: large scale circulation signature

The satellite observations of large geographical scale ozone mean patterns and variations record important information about the mean states and deviations of the atmospheric circulation, particularly in the upper troposphere and lower stratosphere (UT/LS) regions where the surface emissions of ozone precursors have smaller influence. In this study, we apply the high resolution (1^o x 1^o x 40-layer x 0.5 hr) ozone simulation of the University of California, Irvine chemistry transport model as a transfer standard to compare non-coincident measurements of the three Aura satellite profilers (HIRDLS, MLS and TES) on monthly scale emphasizing the UT/LS regions. The level 2 swath/orbit satellite measurements are hindcasted by the high resolution (~100 km), swath specific (interpolated to within ~14 seconds) simulation for years 2005-2006. Therefore, our study takes into account the variations caused by local meteorology conditions and high-frequency (1-2 hours) processes (e.g., tropopause folds). We evaluate the model and the consistency across different measurements in terms of zonal and geographical structures. We also look at the longitudinal structures and find that all the ozone measurements are able to catch the longitudinal gradient driven by large scale circulations, such as the Walker circulation and monsoon. These results provide us some confidence that the Aura ozone profiles are capable of resolving and characterizing large scale UT/LS circulation patterns.