ИСТИНА

The Arctic coasts are dynamically active and vulnerable to environmental changes. The dynamics of Arctic seashore and underwater slope composed of dispersive permafrost ground is determined mainly by hydrometeorological factors, namely, waves and wave currents action coupled to thermal abrasion, which are active during ice-free period. The combined wave and thermal action together with ice and sea level conditions is called here “hydrometeorological stress”. Within climate change, the hydrometeorological stress at the Arctic coast is changing together with coastal retreat rate. In this study coastal dynamics hydrometeorological factors evolution in the second half of the XXth century and also the current conditions are analyzed for several sites in the Kara and Barents Seas. The term of hy-drometeorological forcing is intended as an increment of hydrometeorological stress, appeared due to hydrometeoro-logical factors change. It is shown that thermodenudation forcing amounts 15-50% of 1979-1988 mean level and thermoabrasion forcing – 35-130%. The last one in fact cannot be considered significant. Still, all the thermoabrasion (wave energy) components like ice-free period duration and storms frequency demonstrate the same evolution, like thermodenudation variations. This means that the periods 1989 (1993) – 1997 and 2005 – 2013 are characterized by extreme hydrometeorological stress, as far as both thermodenudation and thermoabrasion processes were in positive phase. In 1979 – 1988 and 1998 – 2004 both were in negative phase. The sparse coastal retreat rate data distilled from literature and field works come out in favor of this variations.