ECN observations reveal increasing snow cover in the Cairngorms
Daily and weekly photographs collected as part of the ECN monitoring at our Cairngorm site, were used to determine the number of days snow was present in the upper Allt a’Mharcaidh catchment for each winter between 2002 and 2015. The results are published in the journal Weather.
The period of time that snow was present was found to vary between a minimum of 157 days in 2002/2003 and a maximum of 260 days in 2012/2013.
Although variable from year to year, the period of time that snow was present was unexpectedly found to have increased significantly over the 13 year period, mainly as a result of melting later in the spring/summer. This increasing period of persisting snow appears to be primarily driven by small changes in the mean winter/spring temperature, with modest decreases in temperature resulting in longer periods of snow cover.
Photographs like this were used to determine the extent of snow lying at the ECN Cairngorms site [Photo © CEH]
The duration of snow cover in mountain regions such as the highlands of Scotland is important from both ecological and socio-economic perspectives. For example, it determines the length of the plant growing season and influences large-scale water regulation (e.g. flooding risks), as well as being crucial for snow sports and wider winter tourism. Changes in the duration of snow cover could, therefore, affect both the ecology and the economy of the area. Despite the clear trend for increasing snow presence over the past 13 winters, it would seem unlikely that this will continue in the long-term. With high elevation snow cover models predicting reductions in snow cover under all climate scenarios, it is likely this trend will be reversed in the near future.