Water vapor is a major component of the Earth’s atmosphere. Given its role in processes such as radiation, cloud formation, and energy exchange in the ocean–atmosphere system, water vapor is regarder to be the most important trace gas.
The study illustrates temporal and spatial variances in water vapor content in the troposphere over Europe and the North Atlantic both in a horizontal and vertical context from a climatological perspective.
A regionalization of water vapor content was created for the troposphere over Europe and the Northern Atlantic Ocean. The analysis of the spatial structures has shown a strong regional pattern of moisture conditions in Europe and the usefulness of total column water vapour (TCWV) as an indicator of the continental nature of the climate. Research results confirmed also the existence of differences in the vertical structure of water content in the troposphere: vertical profile types were identified. These sometimes differ substantially in terms of standard deviation, which is linked with variances in the physical characteristics of incoming air masses. Research has also shown the presence of moisture inversions not only in areas north of 60°N but also in temperate and subtropical zones.Although spatial - horizontal and vertical - structure of troposheric moisture content as well as its temporal evolution depends on atmospheric circulation at both continental and local scale, it differs seasonally. In winter water vapor content is affected by both pressure system type (key role of seasonal high) and the direction of advection (key role of drifting lows of extratropical areas). Then, in summer most of the study area does not experience a relationship between atmospheric circulation and moisture content. A large moisture deficit in air masses on days with extreme TCWV values confirms that summer atmospheric precipitation over Europe is rooted first and foremost in convection processes, while water vapor streams play a secondary role.