Аннотация:Atmospheric humidity, clouds, precipitation, and evapotranspiration are essential components of the Arctic climate system. During recent decades, specific humidity and precipitation have generally increasedintheArctic,butchangesinevapotranspirationarepoorlyknown.Trendsincloudsvarydepending on the region and season. Climate model experiments suggest that increases in precipitation are related to globalwarming.Inturn, feedbacksassociatedwiththeincreaseinatmosphericmoistureanddecreaseinsea ice and snow cover have contributed to the Arctic amplification of global warming. Climate models have capturedtheoverallwettingtrendbuthavelimitedsuccessinreproducingregionaldetails.Fortherestofthe 21stcentury,climatemodelsprojectstrong warmingandincreasingprecipitation, but differentmodelsyield different results for changes in cloud cover. The model differences are largest in months of minimum sea ice cover. Evapotranspiration is projected to increase in winter but in summer to decrease over the oceans and increase over land. Increasing net precipitation increases river discharge to the Arctic Ocean. Over sea ice in summer, projected increase in rain and decrease in snowfall decrease the surface albedo and, hence, further amplify snow/ice surface melt. With reducing sea ice, wind forcing on the Arctic Ocean increases with impacts on ocean currents and freshwater transport out of the Arctic. Improvements in observations, process understanding,andmodelingcapabilitiesareneededtobetterquantifytheatmosphericroleintheArcticwater cycle and its changes.