Red sky at night, shepherd’s delight: the science of beautiful sunsets



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If you live in a place where the weather moves west to east, then an old proverb could help you predict the weather.
TimOve/flickr

Adam Morgan, Australian Bureau of Meteorology

“A red sky at night is a shepherd’s delight! A red sky in the morning is a shepherd’s warning.”

Perhaps this saying came to mind if you caught a spectacular sunrise or sunset recently.

Since biblical times and probably before, proverbs and folklore such as this developed as a way for societies to understand and foretell prevailing weather conditions.

The “red sky” proverb has endured across cultures for centuries, and modern science can explain why this is so.




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What causes a red sky at sunrise and sunset?

The Sun is low on the horizon at sunrise and sunset. At these times of the day, sunlight has had to travel through more of the atmosphere to reach us. When light hits the atmosphere it is scattered, particularly when dust, smoke and other particles are in the air.

This scattering affects the blue part of the light spectrum the most. So by the time the sunlight reaches our eyes there is generally more of the red and yellow parts of the spectrum remaining.

Dust and smoke particles commonly build up in the atmosphere beneath high-pressure systems, which are generally associated with dry and settled weather.

If you’ve ever been to Darwin in the Northern Territory during the dry season (the period between May and September), you’ll know glorious red and orange sunsets are an almost daily occurrence.

This makes sense – the sky across the Top End at this time of year is often full of dust particles whipped up off the land by dry southeasterly winds, as well as smoke from bushfires burning through the landscape.

What can red sky tell us about the weather?

In areas of the world where weather systems move routinely from the west to the east, including across southern areas of Australia, the “red sky” proverb often holds true.

A red sky sunrise suggests that an area of high pressure and fine weather, with its trapped dust and other particles, has moved out towards to the east. This allows for an area of lower pressure and deteriorating weather – perhaps a cold front and band of rain – to move in from the west during the day.

On the other hand, a red sky sunset tells us the worst of the weather has now eased, with higher pressure and improving weather approaching from the west for the following day.

Across northern Australia and other areas of the tropics, the “red sky” proverb is an unreliable method to predict the weather. In these regions, weather patterns are often very localised, moving in no particular direction at all, and larger tropical weather systems usually move from east to west.

Red skies and cloud

What often makes red sky sunrises and sunsets even more spectacular is the position of the Sun in the sky, relative to cloud.

When the Sun is low on the horizon, rays of light shine back up onto the underside of cloud high in the sky, reflecting back those bright orange and red colours that make it look as if the sky has turned to fire.

With a red sky sunrise, the eastern sky is more likely to be cloud-free with finer weather, allowing the Sun to shine upon the higher cloud moving in with the deteriorating weather from the west.

With a red sky sunset, it’s the western sky more likely to be clear, with the Sun’s rays shining up onto cloud further east.

So the next time you spot a spectacular sunrise or sunset, keep the “red sky” proverb in mind and you’ll become a pro at forecasting the weather in no time!




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The Conversation

Adam Morgan, Senior Meteorologist, Australian Bureau of Meteorology

This article was originally published on The Conversation. Read the original article.

6 Tips for Night Hiking


Girly Camping®

Tips for night hiking

The first time I went night hiking I’ll be honest with you- I was scared! I didn’t want bugs to get me, a bear to see me as a meal, or encounter a crazy woodsman! I was really nervous and didn’t know what to expect! But, like everything else I do, I feel in love and now, a third of when we hike is at night! (Check out my first night hiking experience- The Night Hiker ). But I could have used some tips when I first started so here are some tips for hiking at night:

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Check In: Day 2 of Holiday


I have had a most interesting couple of days on the road and in the bush. Currently I’m in a motel room at Woolgoolga, near Coffs Harbour on the mid-north coast of New South Wales, Australia. ‘Hardly the wild,’ I hear you say, and you’re quite right – it isn’t. The weather was beginning to change I noticed on the final leg of my day’s itinerary, so I decided to hide out in a motel room for the night – good decision, it’s pouring outside.

I won’t give all away – I’ll leave the main description of the holiday to the website – but just some of the ‘downlights’ of the first couple of days for this post.

I didn’t arrive at Cathedral Rock National Park until just on dark, but did get the tent up prior to darkness arriving – when it did, it was dark! The campfire took an eternity to get going as all of the timber was damp and by the time I got it started it was time for bed – all-be-it an early night (7.30pm). I had decided to not spend the money on replacing all of the gear I needed to replace for camping, following the loss of a lot of gear over the years due to storage, etc. I hadn’t done much in the way of bushwalking or camping for years due to injuries sustained in my car crash and a bad ankle injury, so I left it all a bit late. I figured that for this holiday I’d make do and replace the gear with quality gear before the next trip. In short, I’ll get by – but it would have been nice to have some good gear just the same. It was a very cold night let me tell you – and long.

When I reached the heights of my first walk today, standing on top of Cathedral Rock National Park, my digital camera decided to die on me. I knew there was something wrong with it during the ascent as it was really chugging away taking pictures. I did get a couple of reasonable panoramic shots on the top of Cathedral Rock before it died, so that was good. I took stills with the video camera I was using, so it wasn’t a complete loss. When I completed the Woolpack Rocks walk I made the trip to Coffs Harbour to seek a replacement and got one for a reasonable price. It’s just another compact and so I will also buy a digital SLR prior to my next trip I hope. My previous SLR was basically destroyed when the camera cap came off during a multiple day bushwalk and all manner of stuff got into it. It wasn’t digital so I didn’t bother repairing it.

So tomorrow – off to Dorrigo National Park I hope and several lengthy walks I haven’t done before. Hopefully the rain will clear.