Exploring the seasonality of rapid Arctic changes from space : monitoring of permafrost disturbance snow cover and vegetation in tundra environments with TerraSAR X Arctic warming has implications for the functioning of terrestrial Arctic ecosystems global climate and socioeconomic systems of northern communities. A research gap exists in high spatial resolution monitoring and understanding of the seasonality of permafrost degradation spring snowmelt and vegetation phenology. This thesis explores the diversity and utility of dense TerraSAR X (TSX) X Band time series for monitoring ice rich riverbank erosion snowmelt and phenology of Arctic vegetation at long term study sites in the central Lena Delta Russia and on Qikiqtaruk (Herschel Island) Canada. ...