The special issue aims at collecting research papers from the WAVACS final workshop and, more in general, from the broader community involved in the action.

Main topics are:

- Water vapor time series and trends;
- Cirrus inhomogeneities and relationship to the environmental water vapor field and radiative transfer Submissions of papers dealing with broader WAVACS objectives are also encouraged:

- Accuracy of atmospheric water vapor observations and harmonization;
- Results from specific field campaign;
- Process related to water vapor isotopes;
- Regional/Global modelling and data assimilation.