Figure S4 . Total Column ozone (DU) on March
18th 2020 (a) observed by OMI, (b) from model run CNTL
and (c) from model run WA. The 220 DU contour is indicated by the white
line. Panel (d) shows the difference in column ozone (DU) between runs
WA and CNTL. The -100 DU contour is indicated by the dotted white line.
Panels (a) and (b) show the same data as Figure 3 in the main paper but
on a different colour scale to accommodate results from run WA.