Fig. 5: Estimated aerosol optical depth (AOD) over the outflow region of Southern Hemisphere Africa for AeroCom models.

The Default results refer to the original model output. Two corrections (EC and MFC) are adopted over the source region (Southern Hemisphere Africa) only, and their results are based on our multivariate linear regression for AeroCom models. For the EC case, only emissions are rescaled according to the AOD errors in the source region. For the MFC case, emission, lifetime, and MEC are corrected to our constrained values. The results for default, EC, and MFC cases are shown in green, orange, and blue, respectively. The spread of the model ensemble for default and EC cases are shown as dots (median) and the interquartile ranges (thick grey error bars) on the left. The thin error bars of EC case for individual models (1-17) and the MFC case show the 50% confidence intervals which considered the uncertainties in the input data (i.e., the rescaled emission in the EC case and the constrained values in the MFC case) and the meta-model regression (see Methods). Note that the MFC prediction is shown as a single dot (with error bar) since it is obtained from a single prediction by using the constrained emission, lifetime, and MEC (see Methods). For validation, the POLDER observation⁴³ is presented as the median (black dashed line) and interquartile (grey shaded area) obtained from the construction of regional AOD (see Methods).