Fig. 3
a Number of MODIS retrievals in each grid cell when a cloud was present in MODIS or WRF-Chem. b Fraction of retrievals for which WRF-Chem correctly simulated the presence of clouds (see Eq. (5) in Methods section). c Pearson’s correlation coefficient and d root mean squared error for cloud top heights (hPa) between MODIS and WRF-Chem. The first column shows results for no NPF simulations; the second column is with NPF turned on with a prefactor of 2 × 10−5 × [H2SO4]. The rippling is an artifact of the strict criteria for matching a MODIS retrieval with the model grid (i.e. overlapping assuming a 5 × 5 km footprint). In reality, the retrieval footprint is larger off-nadir, resulting in the pattern
