A review of snow in Britain

Abstract

Climate change is likely to have a significant effect on snow globally, with most effect where current winter temperatures are close to 0°C, including parts of upland Britain. There is evidence of decreasing trends in observations of snowfall and lying snow in Britain, and climate projections suggest a continuation of this trend. Although river flows in Britain are generally dominated by rainfall rather than snowmelt, some upland catchments have a significant snowmelt contribution. There is evidence of changes in observed and projected river flows in some catchments in Britain, linked to changes in snow, but it can be difficult to distinguish the effects of snow changes from those of other concurrent changes (climatic and non-climatic). Flow regime changes in catchments with widespread and prolonged winter snow cover usually involve increases in winter flow and decreases in spring flow, but the effect on catchments with more transient snow cover is less clear, as is the effect on high flows and water quality. Snow can also affect a number of other factors of socioeconomic or environmental importance (e.g. transport and farming). There is some evidence that disruption due to snow may be less frequent in future, but disruption from other types of weather event may increase. The impacts of snow tend to be worse in areas where events occur less frequently, due to unpreparedness, so there is a need to guard against complacency when it comes to future snow events in Britain, which can still be expected despite a likely reduction in frequency. Further modelling of the potential impacts of climate change, including modelling the influence of snow changes as well as other climatic and non-climatic changes, would aid adaptation and encourage mitigation. KeywordsSnowfall, snowmelt, trends, river flows, transport disruption, climate change I IntroductionThe sensitivity of snow and ice to temperature change means that they may provide one of the most obvious signals for climate change (Vaughan et al. 2013). Global warming is already influencing snow and ice processes, with reductions in annual average snow cover extent and earlier snowmelt observed in regions across the northern hemisphere (Stewart 2009, Derksen andBrown 2012). However, the effect of changes in temperature on snowfall and snowmelt (and subsequently on river flows) may be complicated by coincident changes in precipitation, to the extent that impacts may be masked until thresholds are crossed (Stewart 2009). The effects are thus likely to vary by location, for example depending on altitude (Skaugen et al. 2012, Trivedi et al. 2007, Harrison et al. 2001) and atmospheric circulation patterns (Irannezhad et al. 2016, Stewart 2009. Studies suggest that the areas most affected have been those where current winter temperatures are close to 0°C, with less impact in colder or warmer regions (Stewart 2009, Hamlet andLettenmaier 2007). In 2 parts of Britain, particularly Scotland, the climate is in this transitional zone where only a small temperature increase c...

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National-scale analysis of simulated hydrological droughts (1891–2015)

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Tracing Snowmelt Paths in an Integrated Hydrological Model for Understanding Seasonal Snowmelt Contribution at Basin Scale

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