Analysis of spatial and temporal variability of carbon monoxide and carbonaceous aerosols using space-borne measurements: Implications for data assimilation with chemical transport models

Biomass and fossil fuel burning are efficient sources emitting carbonaceous aerosols as well as CO into the atmosphere. Both atmospheric species are central to many problems in atmospheric chemistry, air pollution, and climate change. Satellite remote sensing offers the best approach for obtaining global measurements of tropospheric trace gases and aerosols. Currently, several different satellite sensors are used to retrieve CO and aerosol optical depth, AOD. Given a growing interest in the development of the modeling tools capable of predicting the strength of emission sources as well as transport of gases and particulates in the atmosphere, satellite data can potentially provide useful information for testing and validating the chemical transport models. However because of existing differences in the spatial and temporal sampling between the satellite sensors and models, retrieved CO and AOD products are averages over different spatial fields, which are, in turn, different from the grid size of the chemical transport models. Thus, it is important to understand how spatial and temporal averaging can affect the correlation between CO and aerosol fields. To address this issue, we analyzed the collocated fields of CO retrieved from MOPITT and aerosol optical depth of fine size-mode retrieved from MODIS for several cases of biomass burning events. The CO/aerosol correlations found in satellite data were compared to in situ measurements and model simulations. The results of this study will be presented and implications for data assimilation by chemical transport model will be addressed.