Extreme events, in particular extreme precipitation, present natural hazards for population and result in immense losses for economic. They involve such dangerous phenomena as floods, mud torrents, land slips, avalanches, present risks for aviation. The special attention may be drawn to the coastal zones, where intensive economic use of territory increases the losses resulting from inundation.
The climate change involves the change of specific components of climate system, in particular the precipitation amount. However the trends of annual precipitation are not always consistent with the changes of extreme precipitation occurrence, the latter being the most dangerous for population. The assessment of extreme precipitation occurrence changes in the warming climate is the task of current investigation. As a first step the threshold of extreme precipitation is defined for observations and climate model GFDL-ESM2M. Further the large-scale synoptical indicators of extreme precipitation are evaluated. It is shown that for the purpose of current study the optimal indicators are the followings:
• The specific structure of sea level pressure (for all coastal zones under investigation);
• The intensive frontal zone over the region of extreme precipitation (for Black sea region it is defined on the ground of air temperature horizontal gradient at 850 hPa, for Arctic seaside - on the ground of frontal parameter ).
To exclude the cases of “dry” fronts the threshold for near surface temperature is introduced.
The validation of GFDL-ESM2M model showed that the model is skillful in simulation of large scale indicators of extreme precipitation and therefore may be used for assessment of their changes in the future climate.
The analysis of synoptical indicators of precipitation in the warming climate of XXI century allows to estimate the changes of extreme precipitation occurrence: in the Black sea region the slow increasing of extreme precipitation is attended in summer, while on the Arctic seaside the probability of extreme precipitation increases in the cold season.