This is not really to do with ecology, and certainly not based in Grantham, so you’ll have to forgive me straying off message!
We went down to stay on a campsite at the base of the South Downs in the campervan just before New Years. We set off in dense fog which, but for a few breaks, persisted all the way down the country. We arrived an hour before sunset, pulled on coats and boots and headed off up the hillside near Ditchling Beacon in the optimistic hope that we could climb up above the pea-souper which had enveloped us all day. Optimistic but not expectant, we were rewarded for our efforts!
Walking up the track was like ascending in an aeroplane on an overcast day, when you break through to find that it’s a sunny day above the clouds. This is effectively the same thing – the clouds in this case are lying over the land due to a temperature difference known as an ‘inversion’ – when there is colder air below and warmer air above meaning that the cloud becomes trapped close to the land. As well as the temperature inversion, you need other conditions such as lack of precipitation and little or no wind to maintain this. This is an excellent blog post to explain more about cloud inversions, and how, when and where to catch them!
What inspired this optimism was another recent experience – just before Christmas we were staying in Freiburg and left the city on a murky foggy day to catch a cablecar to 1000m up. We found an incredible sight awaiting us – not only were we above a thick layer of cloud but there was a further layer of cloud above us meaning that the setting sun lit both layers in one of the most magical experiences I have ever witnessed – a few photographs below to give you an idea!