Speaker
Description
HadISDH is a global gridded surface humidity climate monitoring product based on quality controlled and bias adjusted in situ observations from weather stations and ships. It shows that while the amount of surface water vapour has increased since the 1970s, the air has become less saturated. Similar results are found in the ERA5 reanalysis but there are temporal and spatial differences that are yet to be understood. Satellite estimates of water vapour may help to illucidate some of the reasons for these differences and help to understand changes in water vapour where there are no in situ observations. The respective uncertainties and differences in observing and representing water vapour will need to be taken into account in any comparison.