Past week’s Weather
UK: A transient low brought cloud on Monday followed by a crisp, cold night but there was little variation for the rest of the working week as a waving cold front delivered rain to the south. A return to westerlies at the weekend gave rain and wind with sunny spells.
Falklands: A sunny start to the week but a chain of frontal systems arriving midweek gave periods of low cloud and rain. The theme into the weekend was patchy light rain overnight but dry and bright afternoons.
Ascension: Sunny afternoons this week but high humidity kept cloud covering the top of
St. Helena: Sunny afternoon for
The Green Flash
Beautiful sunsets are common here on Asi, but only the more eagle eyed among you might have spotted the illusive and mysterious green flash. They appear as a tiny green ball on the top of the sun, only for a second or so, just before it disappears below the horizon. Jules Verne wrote, in Le Rayon Vert, that seeing one allows you to briefly read the minds of those close to you but sadly it’s not true.
They are part of the mirage we see as the sun sets. The thicker atmosphere the sun light comes through causes light to bend but different colour light bends different amounts. Red light doesn’t curve much so the setting sun looks mainly orange or red. Blue light curves too much so we never see it. The green light bends in such a way so that we can see it only after the red light is obscured by the curvature of the earth but the sun has not completely set. They can be spotted anywhere in the world but a water horizon (as we have here) is the best for seeing them so if anyone gets a picture of a green flash we’d love to see it , just don’t blink or you’ll miss it.
The sun will set this week at 1922 hrs.
Compiled by Sir Russ Tratus
Crown Copyright 2011
Met Office Ascension Island base