Application of Atmosphere Transport Matrix in Constraining Historical Black Carbon Emissions Inventory

An emission inventory is an important representation of the anthropogenic impact on the atmosphere. In order to constrain the black carbon (BC) historical emission inventory over the period 1850-2000, we studied the transport of global BC emissions, ambient air concentrations, and deposition using the Community Atmosphere Model. We formulate the relationship between emission and concentration, and concentration and deposition, into matrices that allow reconstruction of ambient air concentration and deposition for a time-varying emission inventory. This formulation shows the influence of regional emission sources on the receptors. We reconstructed the BC concentration in California and New Jersey where coefficient of haze data are available. The discrepancy between the reconstructed concentration and the measurement identifies needed improvements to the emission inventory. In the comparison, we examine magnitudes and seasonality. For New Jersey, the east coast meteorology does not introduce much seasonality, and the observed seasonality should be attributable to the emission. Emissions should be about 30% higher in winter in New Jersey for 1970s, likely due to winter heating, which decreased over years until it disappeared in the 2000s due to pollution control and fuel switching. In California, there is strong seasonality in BC concentration, more than 100% higher in winter than summer, which mainly originates from lower wintertime wind speeds and mixing heights. The seasonality of emission in California is probably small and due to residential wood burning. A modified emission inventory for the period 1960-2000 is presented.