11:45 AM - 12:00 PM
[AAS12-11] A high-resolution global atmospheric composition data assimilation of multiple satellite measurements during NASA’s KORUS-AQ aircraft campaign
Keywords:atmospheric chemistry, atmospheric environment, data assimilation
In this study, we demonstrate the performance of high-resolution data assimilation during the NASA’s KORUS-AQ aircraft observation campaign conducted over South Korea in May 2016. The tropospheric NO2 column bias in the data assimilation compared to OMI satellite retrievals is reduced by 57% over South Korea and by 43% over central Japan, by increasing horizontal model resolution from 2.8° to 1.1°. The 1.1° analysis also led to improved agreements with vertical profiles by DC-8 aircraft measurements. Surface NOx emissions derived from the data assimilation also differed by 17% over South Korea and by 4% over central Japan by changing the model resolution, with substantial differences over many megacities in Asia. Data assimilation performance could further be improved using a model with horizontal resolution higher than 1.1°. Based on sensitivity calculations conducted under the post-K project, we will discuss the potential benefit of using a 0.5° resolution model in chemical data assimilation, in reproducing the spatio-temporal variations of major pollutants over Asia.
Miyazaki et al. (2017), Atmos. Chem. Phys., 17, 807–837.
Sekiya and Sudo (2012), J. Geophys. Res., 117, D18303.