Cumbrian Lakes Monitoring thermal stratification timing 1951-2017

The data were calculated from temperature profiles taken in each lake at the deepest point, using a calibrated temperature-oxygen sensor. Water temperatures were converted to density and the lake was considered stratified when the density gradient between the surface and bottom of the lake was >0.1 kg m-3. The start day of the main summer stratified period was considered to be the latest day before day of year 200 where a stratified period had a duration >14 days, the end day was defined as the final day of stratification for that stratified period and the duration calculated as the difference between these two days. More detail on the method used can be found in the supporting documentation.