Why has the sun gone red today?

Odd weather we’re having right now. It’s 23 Celsius outside, albeit with a stiff windchill. The wind is apparently down to the ex-hurricane we know as Ophelia. The heat…definitely not what you’d expect for mid-October, more like late July, but probably a jet stream phenomenon combined with that tropical storm pushing warm air towards us (here in the South of England, anyway; your mileage may vary).

But, it’s 3 pm and the sun is looking distinctly like it’s a sunset but too high in the sky. The fact that the cars are all covered in desiccated, dusty raindrops from last night suggests we’ve had a load of dust blow northwards from the Sahara Desert. A quick Google confirms this. That said, there are forest fires in Spain and/or Portugal that would also generate plenty of dust.

Ophelia has stirred up a storm and carried megatonnes of dust into the atmosphere of the British Isles and elsewhere. As we know from high school science lessons (you were listening, weren’t you?) tiny particles of dust in the atmosphere scatter light of different wavelength to different degrees. So, the blue end of the spectrum of the white light from the sun is scattered away from your line of vision while the lower energy red is scattered so little it passes straight to your viewpoint.

Anyway, the fat ol’ sun, the hurricane sun, above was snapped at 3 pm on my Canon dSLR with a 600mm lens #nofilter. (Sunset isn’t for another 3 hours).

All that desert/fire dust might also explain the sore eyes Mrs Sciencebase and myself are both suffering today.

UPDATE: 17:25, half an hour before sunset, this is how it looks: