Climate change will alter precipitation regimes. In a warming climate, precipitation across the Arctic will increase and become more variable. A larger proportion of precipitation will fall as rain rather than snow and extreme summer rainfall events are expected to occur more frequently. There is little experimental evidence of the impacts of rainfall extremes on Arctic soil ecosystems. In the intended project we will investigate how the expected extreme rainfall events will impact the freeze-thaw cycles of permafrost and thermal soil dynamics, and we will study the impact on soil fauna. These experiments will be conducted across a landscape gradient at different moments during the summer season, to include the role of landscape heterogeneity and the timing of the rain events in assessment of heavy rainfall impacts. We will use an established and controlled experimental setup in the field and expect to deliver high quality data on a multitude of aspects of ecosystem functioning under future increases in heavy rainfall on Svalbard.