The natural Navigation: The Right Course, Naturally

Happy Winter Solstice One and All!

Here’s an interesting solstice fact for you: the Earth is actually receiving more solar radiation at this time of year than at any other time. This is because the Earth does not orbit the sun in a circle, but in an ellipse. In the northern hemisphere winter the Earth is at its closest to the sun, a point called ‘perihelion’, but in summer it is at its furthest point, or ‘aphelion’.

The Guardian have published a little article on the timing of the winter solstice.

However, my favourite solstice image is on a different page. The same technique used in the photo on that page, from the same position, but on the summer solstice would probably not catch the sun at all, or perhaps just a glimpse of it in the top corners.

At this time of year the sun is always…

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I took this picture a few minutes ago. For those of you interested in these sorts of cloudscapes then here is a good tip for finding them:

Take a really keen interest in the sky whenever bad weather is forecast after a good spell. Don’t wait for the change to become obvious though, the interesting higher clouds: the wispy cirrus, mares’ tails, mackerel skies etc. will all be found just before most people notice that the weather is changing, so you need to remain aware.

It works the other way round too of course, if you don’t have access to forecasts, or prefer to do your own, then this sort of sky after settled weather is a strong sign that a big change is on its way. More tips on weather lore here.

(There should be a great opportunity to see some moonlit cloudscapes tonight hopefully too.)

Sometimes I feel like a big game hunter. Not a very good one though, as the idea of shooting the last white rhino, or whatever poor soul is struggling to cling onto their mortal coil, fills me with as much horror as you might hope.

What I mean is that I often find myself creeping about rather stealthily, for fear of disturbing the animals (sometimes these animals are the kids who I dare not wake up too early for fear, in the words of Russell Crowe in Gladiator, of ‘unleashing hell’).

I move out and forward, toes on grass, silently caressing my Canon SLR in my hands like a rifle and then I wait. I wait for the Big Game.

This game is rarely actually an animal, more often it will be some unexpected quirk in nature’s portfolio.

This morning I made my way over a fence, and into the…

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Just saw and managed to snap a beautiful 22 degree moon halo. They are caused by the moon’s light refracting through the ice crystals in the high clouds. In this case almost certainly thin cirrus clouds which are presaging the arrival of bad weather. Halos are not the same as moonbows, although they are often called that in error.

Will write more about them tomorrow if I get the chance, but wanted to get the photo up while I could.

Venus and the brighter stars, like Arcturus, appeared shrouded in a veil this morning.

This was not mist close to the ground – horizontal visibility was excellent – but thin layers of high cirrus clouds. This effect has been used by navigators and travellers the world over as a sign that the a front may be approaching and a weather change is likely.

Cirrus on its own is not a guarantee of anything, but when followed, as it so often is, by cirrostratus and altostratus it is a strong indicator of an approaching warm front.

In my book I give the example of the frequent Greenland traveller, Gretel Ehrlich, who noted during a dog sled trip with a local hunter that a ring circling the sun in the morning signalled bad weather. Similar examples are to be found in deserts, on Pacific islands and among students of weather…

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Last night the conditions felt right for a walk in the woods. There were plenty of clouds, but large gaps suggested that the stars would not hide for long periods. The moon would not be getting up until later and the breeze was too light to be of help. I needed the stars.

I set off as the last light from the sun faded in the southwest. Cassiopeia and Cygnus neatly sketched out north for me, even when Polaris was well hidden. When moving south I used Jupiter and Aquila.

Four hours later I returned, having spent nearly all of it alone, in beech woodland and without using a torch. Moving at times with my left hand extended out to fend off inquisitive lower branches, I covered about six miles; this was no race.

In every woodland walk there are times when you feel the forest is on your side…

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Nearly all navigation is an attempt to join landmarks together. Even those on boats crossing oceans are probably hoping to find a landmark they recognise as the final part of their journey.

The word, ‘landmark’, simply means something that makes a location recognisable. It is deliberately vague as it can apply to anything, a landmark may be extraordinary – the statue of Christ the Redeemer towering over Rio de Janeiro’s from Corcovado mountain. Or it may be mundane – a red postbox at the edge of a village.

The more confident you can be that you have both successfully identified a landmark and that you know exactly where that landmark is, the more confident you can be that you know where you are.

A landmark does not need to be grand, it does not even need to be recognised by others, just so long as it is recognised by you.…

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These two photographs were taken this morning, within a few seconds of each other and from exactly the same spot. In the book I touch on the difference between viewing mist horizontally and vertically and these pictures illustrate the point nicely.

Mist and fog, which is just a word for intense mist, are low visibility caused by looking through millions of suspended water particles. When we look horizontally we have to look through hundreds of metres of these particles and the effect is very poor visibility. But since the mist often sits in a thin blanket that hugs the land, the story is very different when we look vertically upwards. (Or downwards if you are a pilot searching for somewhere to land.)

Looking upwards it is often possible to find clouds, as in the second picture, and if you have remained tuned to the direction the clouds are moving,…

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I was just ‘tweeted’ by Anne who had spotted what initially appeared to be an unusual light phenomenon appearing in some cirrus clouds. I think it is just a small arc of a standard ‘primary rainbow’, but part of me desperately wanted it to be a ‘fire rainbow’ which I have never knowingly seen.

Fire rainbows (see photo) are very rare and form in cirrus ice crystals at high altitudes; their coloured arcs are near horizontal and parallel to the horizon. Fire rainbows can only come into being if the sun and atmospheric conditions meet very stringent criteria, another of nature’s beautiful balancing acts. There is more background to these extraordinary light shows on the National Geographic website.

As this website explains, fire rainbows can only occur when the sun is high enough in the sky (58 degrees or more) and sadly that rules them out from…

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On Friday I enjoyed a warming cup of hot chocolate with adventurer and ocean rower extraordinaire, Sarah Outen. We arranged to meet in Brighton and I had hoped to saunter between the boutiques and purveyors of rare tat, before pulling up a chair in a bohemian cafe near the sea. Instead I sprinted twenty yards from the train station, felt the cold heavy rain run down my neck and then ducked into a disappointingly ordinary peddler of hot drinks.

Fortunately I got a chance to escape all that by listening to Sarah’s memories of rowing, alone, across the Indian Ocean. She experienced plenty of drama as you might imagine, and this will all out in her book that is being published early next year, but the details that seized me were the ones that many others may have found prosaic.

Sarah described how the birds changed as she…

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