3:30 PM - 3:45 PM
[AAS06-22] A 0.56°-resolution global data assimilation of multi-chemical constituent satellite measurements
Keywords:Tropospheric chemistry, data assimilation, chemical transport model
In this study, we evaluate the performance of high-resolution (0.56°) and 64-member ensemble Kalman filter data assimilation for a week from April 23rd to 29th 2008. The tropospheric NO2 column bias with respect to OMI was reduced in the data assimilation by 45% over China, 85% over Europe, and 91% over the eastern United States, compared to the model simulation. Comparisons of NO2 with independent surface observation networks revealed mean bias reductions by 25% in the 39 selected urban agglomerations over Europe and the United States in the data assimilation. Compared to globally available ozonesonde observations, tropospheric O3 concentrations were also improved in the data assimilation, with negative bias reductions by 20% between 850-500 hPa and 22% between 500-200 hPa. These results suggest the potentials of using high-resolution global chemical data assimilation system for studying megacity-scale air pollution over the entire globe. We will show the results of one month-long data assimilation in the presentation.