Snow Survey of Great Britain
The main data gathering phase of my PhD was to digitise the Scottish records for the Snow Survey of Great Britain (SSGB). I did this over the winter of 2011/12. Since then I’ve done a few different tasks and roles, not all related to my research. Most importantly I’ve written a paper detailing the newly available Scottish SSGB. For anyone who’s not been through the academic publishing process, even when you have a draft ready there’s lots of time to wait still as other authors provide their input and the document goes off to the journal editors and then reviewers. Thankfully this one made it through the review process without too many alterations, Richard‘s guidance was invaluable. There’s then some more waiting to do for proofs… Eventually, this week (7th April 2014), the paper was published!
The official abstract is:
Mountain snowline is important as it is an easily observable measure of the phase state of water in the landscape. Changes in seasonal snowline elevation can indicate long-term trends in temperature or other climate variables. Snow-cover influences local flora and fauna, and knowledge of snowline can inform management of water and associated risks. Between 1945 and 2007 voluntary observers collected a subjective record of snow cover across Great Britain called the Snow Survey of Great Britain (SSGB). The original paper copy SSGB data is held by the Met Office. This article details the digitisation of the Scottish SSGB data, its spatial and temporal extents, and a brief example comparison of Met Office snow-lying gridded data. The digitised SSGB data are available from the Met Office authors.
I’ve distilled the paper down into bullet points, but obviously encourage you to download it (it’s free):
- Why is snow cover important? Because it indicates change in climate, ecology and habitat and helps manage water and understand winter sports potential
- Detail and type of the various snow cover datasets for Scotland:
- Met Office station observations (point)
- Met Office grid (… grid interpolated from above)
- Satellite observations (grid), snow often too wet or sky too cloudy to get measurements
- Snow Survey of Great Britain, SSGB (subject of paper)
- History of the SSGB, began in 1937, generally discontinued during WW2, began again in 1945. Run originally by British Glaciological Society then by Met Office from 1953. Annual report produced until 1992, data collection ceased in 2007
- Coverage of the SSGB: 145 sites across Scotland, longest record (52 years) from Couligarten viewing Ben Lomond. See figure below for station locations and record lengths
- Snow Survey undertaken by volunteers looking out from a fixed location to local hills and assessing at what elevation snow cover was greater than 50%
- Comparing the area visible from the SSGB locations to the Met Office station observations, there are nearly no Met Office stations above 400 m in Scotland, but the SSGB observes >10% of the land above this elevation
- I compared the SSGB to the Met Office grid (interpolated from sparse low lying snow cover observations) at Dalwhinnie and Ben Alder and found strong similarities at the lower elevation, but the Met Office grid recorded fewer days of snow cover per annum than the SSGB for Ben Alder, indicating that the Met Office grid underestimates snow cover (by a median 40 days per annum) at higher elevations
- Conclusion is the SSGB is a detailed daily record of snow cover from station level to the highest mountains in Scotland with no other snow cover data product providing this resolution of data for this country.