7 Feb 2012

UK snow cover from space

After the first widespread snow of the winter last weekend, I thought it would be of interest to share a high resolution satellite picture that shows which parts of the UK still have snow lying on the ground.

The image was captured by NASA satellites from space and has had a filter applied that makes snow and ice appear bright red, allowing snow cover to be picked out very easily.

Given that high level clouds contain ice crystals, they also show up clearly – appearing a peachy colour. Low level clouds close to the ground appear white as they are made up of water droplets rather than ice.

You can see in the zoomed in image below that there is a real contrast in snow cover across England and Wales. Western areas have little or no snow cover, apart from the highest hills and mountains.

Across northern and eastern parts of England the ground is still extensively covered in snow, but there is some local variation.

London’s heat island effect is very noticeable in that snow cover has melted for much of the city. However, once reaching the M25 and beyond, snow is still lying on the ground as the urban warmth fades.

Another interesting contrast is across West Sussex, where some coastal areas had rain and sleet due to the warming effect of the English Channel. Further inland across the county, snow fell and the remaining snow cover closely hugs the higher elevations of the South Downs.

This image also allows us to deduce the type of clouds present. The peachy colour of the clouds over the Irish Sea and Ireland means that they contain ice crystals and are likely to be cirrus, given their thin, streaky nature.

The clouds across central areas of the UK are white and therefore consist of water droplets rather than ice crystals, suggesting that they are closer to the surface – stratus cloud, giving grey, leaden skies.

So the next time you look at a satellite image, take a closer look. It’s surprising how much information you can gain. As the saying goes, a picture is worth a thousand words…

If you ever look at a satellite picture and spot something interesting that you would like to ask me about, then feel free to do so. Twitter is the easiest way to get in touch – @liamdutton

Images courtesy of NASA/GSFC, Rapid Response.

Tweets by @liamdutton