P–P plot showing the ECDFs of Q(${\theta }_{\text{gt}}^i$) against a uniform CDF for different atmospheric parameters and for both FMPE and NPE. The shaded regions indicate the respective 95% confidence interval computed by scipy.stats.ecdf(). Panels a and b show the results for the atmospheric parameters with the largest visual deviation from the diagonal (“worst case”), while panels c and d show the “best case.” All results are from the default test set.