Pastel colours at sunset

A little earlier, the sky was rather dull. Sunset brought out some pastel colours.

I've neglected this blog lately, having hunkered down indoors through the cold weather. This was taken through a window. Maybe things will begin to warm up now, though I'm not putting my thermals away just yet.

Cold cirrus

Last night it was cold and clear - perfect for the BBC's Stargazing Live programme. Today it was bright and sunny, with assorted cirrus clouds in all directions.

At about 11.30am, the sky was full of various cirrus clouds with contrails adding to the general confusion. There was a patch of cirrocumulus (the grainy-looking cloud in the last photo) to the south. Within half an hour or so, it was all hidden by an invading layer of stratus (see bottom right of the 2nd photo), and the sky turned grey.

Contrail

The day began with cirrostratus and contrails, like this. Later it was just boring stratus.

Pastel colours

Late afternoon - a gap in stratocumulus.

Contrail shadow

Evening moon

Dry sunset

Sun shone today, hooray!

A clear cold sky

In the morning there were lots of contrails but as the day warmed up they soon evaporated, like this one. It was only when I looked closer at the shot that I noticed the moon is in the picture, though it's very faint. Follow the line of the contrail to the left and it's just over half-way up the photo.

Man-made clouds

The only clouds in a clear cold sky today were contrails, the condensation trails left by aircraft exhaust gases turned to ice crystals at high altitudes. They're evidence of the pollution of our skies by aircraft. For three days after 9/11, all commercial flights over the US were grounded. The exhaust fumes containing water, carbon dioxide, oxides of sulphur and nitrogen, hydrocarbons, carbon monoxide, unburned fuel and particles of soot and metal were dispersed. The difference between daytime and night-time temperatures was greater than normal, showing that contrails, which can spread into sheets of persistent cirrus, have a warming blanket effect.

For another contrail picture, click on the thumbnail (right).