By Leam Howe
It might come as a surprise, but even in the relatively mild climate of Scotland, snow
manages to endure year-round in certain mountain locations. In fact, until recently, some
highland corries would house perennial snow patches for many decades without seeing
them melt. The fine balance between preferential snow deposition in winter and sheltering in
summer makes predicting the distribution of these snow patches a rigorous test for the kind
of physically based snow models used in climate projection and impacts studies. This is the
basis of my PhD research.
This summer, my fieldwork took me to Coire Cas on Cairngorm Mountain, where I aimed to
map the areal extent and measure the reflective properties of some persistent snow patches.
My tool for the job was a DJI M210 drone equipped with a multispectral sensor matched to
the Sentinel-2 satellite sensor. Conducting multispectral drone surveys requires two things
notoriously scarce in the Scottish Highlands: low winds and clear skies. Moreover, this
summer was dubbed ‘Scotland’s worst since 2015,’ limiting us to a single day of drone
surveys. The scarcity of cloud-free days this season is visualised in figure 1, which
showcases all the satellite images captured from the Sentinel-2 over Cairngorm Mountain
this summer.
Despite the inclement weather, we did manage to retrieve some spectral measurements of
the late-lying snow on the 24th June (figure 2 shows one of the short-lived sunny intervals on
the day). These data will help improve the snow mapping algorithms which, in turn, feed into
research and contribute to discussions concerning biodiversity, water resources, and risk
management in cold and mountainous regions.
In addition to my fieldwork, this summer I made my first ‘pilgrimage’ to a remote North-East
facing corrie on Braeriach mountain called Garbh Choire Mòr. This location is considered to
be the snowiest place in the UK and houses the famous Sphinx snow patch (see figure 3).
The Sphinx has made it to popular news platforms numerous times over the past few years,
and this year marks an unprecedented fourth consecutive year of its disappearance. Figure
4 shows a timeline marking the years that the Sphinx has disappeared; the trend seen here
mirrors the significant impacts of climate change on Scotland’s winter conditions. Current
projections suggest a stark future with ‘little to no snow by the 2080’ — a disheartening
forecast for chionophiles like myself.
