Surface fluxes of bromoform and dibromomethane over the tropical western Pacific inferred from airborne in situ measurements

Numerical closed-loop experiments show that the spatial and temporal distribution of boundary layer aircraft data have the potential to substantially improve current knowledge of these fluxes, with improvements related to data density. Using the aircraft data, we estimate aggregated regional fluxes of 3.6±0.3×108 and 0.7±0.1×108g month-1 for CHBr3 and CH2Br2 over 130-155°E and 0-12°N, respectively, which represent reductions of 20%-40% of the prior inventories by Ordóñez et al. (2012) and substantial spatial deviations from different a priori inventories.

We find no evidence to support a robust linear relationship between CHBr3 and CH2Br2 oceanic emissions, as used by previous studies. We find that over regions with dense observation coverage, our choice of a priori inventory does not significantly impact our reported a posteriori flux estimates.