Spearman’s rank correlation coefficient for RFR as a function of static stability in the $65-75\mathrm{k}\mathrm{m}$ altitude range (top panel). The results present quite some uncertainty and scatter and there seems no evidence of any clear trends. In the bottom panel, we show the one-sided p value and we chose a level of p < 0.02 to claim significance, corresponding to about $2-\sigma$. This does not happen for any of the points.