20th March 2015

Penallt enjoyed clear blue skies throughout this morning’s partial solar eclipse and there were no excuses for not experiencing one of nature’s dramatic shows. At its maximum, the sun was obscured by the moon by a factor of 90%, as illustrated by the diagrams below:-

The 90% reduction in solar radiation was accompanied by a drop in air temperature as today’s Penallt temperature chart on the left clearly shows:-

The start and finish of the eclipse are shown with red dotted lines. The temperature at the eclipse maximum was 5.3°C whereas, without the eclipse, the interpolated temperature at the same time would have been 8.3°C. Thus the eclipse resulted in an air temperature cooling of 3°C at its peak.

The image on the left was taken through a 200mm telephoto lens with a Baader filter (filters 99.999% of visible) at the MARS event on the lawn at the Monmouth Boys School on Friday morning.