Tropospheric moisture content variability as a factor of drought intensity in Central Europe

Water vapour content in the troposphere, regarding its close and complex relationship with air temperature, plays a crucial role in numerous processes in the ocean-atmosphere system. Contemporary global warming forces an increase in the water vapor absorption capacity by about 6-7% per 1K therefore in areas where a constant supply of water vapor is possible (oceans) simultaneously with the temperature growth, evaporation processes intensify and the specific humidity of the air increases. Over the land, especially with the continental nature of the climate, where evaporation possibilities are limited and atmospheric circulation is the main moisture source, a reduction in relative humidity and an increase in humidity deficit and increasing drought risk as a consequence has been observed. 

The aim of the study is to estimate the intensity of meteorological drought in Central Europe under present and future climate conditions resulting from increasing available water capacity of the troposphere.  

Variability of tropospheric moisture content up to 700 hPa pressure level will be examined, including its various characteristics in the period 1961-2022 and its future projections to 2100 using ERA5 and EUROCORDEX RCP 4.5 and RCP 8.5 scenarios data respectively. 

Drought risk will be assessed using moisture deficit information as well as its impact on particular drought indices. 

The preliminary results clearly confirm the increasing risk of moisture deficit in 21st century caused by increasing water vapor absorption capacity resulting from the temperature growth and no extra moisture sources in Central Europe.