Long-term patterns and changes of unglaciated High Arctic stream thermal regime.

Although water temperature is one of the most important factors influencing hydrochemistry and river ecology, long-term monitoring and modelling of stream thermal temporal variability are uncommon. There is sparse research regarding the thermal regimes of Arctic rivers, especially in Svalbard, a geographical hotspot affected by extreme climate change and Arctic amplification. There is a need for improvement and better understanding of the factors influencing the stream water temperature regime.

Linking drought indices to atmospheric circulation in Svalbard, in the Atlantic sector of the High Arctic.

Based on long-term climatological data from Ny-Ålesund, Svalbard Airport-Longyearbyen and the Polish Polar Station at Hornsund, we undertook an analysis of drought indices on Spitsbergen Island, Svalbard, for the period 1979-2019. The features and causes of spatiotemporal variability of atmospheric drought in Svalbard were identified, as expressed by the standardized precipitation evapotranspiration index (SPEI). There were several-year periods with SPEI indicating the dominance of drought or wet conditions.

Changes in the flow regime of High Arctic catchments with different stages of glaciation, SW Spitsbergen.

This study investigates the response of four High Arctic catchments with differing proportions of glacierization to changing climatic conditions. The study area located in SW Spitsbergen, has experienced a warming of 4.5 °C in the last 40 years along with a large increase in autumn rainfall.

Changing climate both increases and decreases European river floods.

Climate change has led to concerns about increasing river floods resulting from the greater water-holding capacity of a warmer atmosphere. These concerns are reinforced by evidence of increasing economic losses associated with flooding in many parts of the world, including Europe. Any changes in river floods would have lasting implications for the design of flood protection measures and flood risk zoning.

Changing climate shifts timing of European floods.

A warming climate is expected to have an impact on the magnitude and timing of river floods; however, no consistent large-scale climate change signal in observed flood magnitudes has been identified so far. We analyzed the timing of river floods in Europe over the past five decades, using a pan-European database from 4262 observational hydrometric stations, and found clear patterns of change in flood timing. Warmer temperatures have led to earlier spring snowmelt floods throughout northeastern Europe; delayed winter storms associated with polar warming have led to later winter floods around the North Sea and some sectors of the Mediterranean coast; and earlier soil moisture maxima have led to earlier winter floods in western Europe.