Figure 1. Panel (a): Fractional data density of IAGOS combined water vapor dataset from June 2014 to December 2021 (logarithmic scale used to visualize maximum data coverage); inserted boxes indicate the regions of interest Eastern North America (Region 1), the North Atlantic (Region 2), Western Europe (Region 3) and Southeast Asian Subtropics (Region 4); Panel (b): vertical distribution of data for four pressure levels of thickness 30 hPa relative to the pressure level of the thermal tropopause pTTP; Panel (c) fraction of potential contrail-cirrus regions (PCCR; RHice 鲁 90%) for each pressure level; Panel (d) same as Panel (c) but for ice-supersaturated regions.
