The graph below shows boxplots of the difference (left) and relative difference (right) between TROPOMI ROCINN_CAL cloud top height and CLOUDNET cloud top height. (© Update February 18, 2021, of Compernolle et al., AMT 2021). Stations are ordered by latitude. Transparent boxes are for S5P CLOUD v1 data and red boxes for S5P CLOUD v2 data (transition in July 2020). Box edges: ﬁrst and third quartile; line: median; whiskers: 5 and 95 percentiles; cross: mean. Note the high impact of the CLOUD version upgrade at the high-latitude site Ny-Alesund.