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 lower at any time of day than it would be in the summer. This means the number of times when it is out of sight is also much greater. In one sense, of course, the sun is out of sight when it is nighttime – I always like to think of the sun being due north at midnight, even though it is underground. But there are many times when it is not night, but the sun is still so low that it is hard to find.

At the start of end of the day the sun will often hide behind clouds, buildings, woodland etc. Even in the middle of the day it will still be a full 47 degrees lower in the sky than in late June. That is to say you could fit almost five outstretched fists between the two solstice suns at midday, one on top of the other.

The fact that the sun is lower and there are more clouds in winter make it a good idea to remain aware of a simple technique. It is the sort of thing that when you think about it, it seems ridiculously obvious, yet it is easy to not consider it at all.

Clouds can act as a mirror, much in the way the moon does, and reveal the approximate direction of the sun. In the image above, which I took a few days ago, the sun has long since abandoned the surrounding land. It would be all too easy to imagine that it was lost as a source of direction-finding altogether. However, if you look at the clouds they are pointing the general direction of the sun for us, it is to the right of the picture. Since this was taken in the afternoon, the sun will be in the southwestern part of the sky and so we must be looking in a southerly direction.

If you are lucky you can find clouds in more than one direction that are lit on one side, sometimes a collection of mirrors forms that allow you to pinpoint the sun fairly accurately, despite the fact you cannot see it. (This is a technique I often find myself using on aircraft, if I am keen to work out the direction the aircraft is heading, but only have a perspective that does not include the sun).

There is one other aspect to this technique that makes it a favourite in winter. We get more unsettled weather in the winter months and the accompanying tall clouds. Bad weather is often preceded by towering cumuli and arrives with cumulonimbi, these giants can block out the sun, but they do occasionally hint at its whereabouts too.

The example above is obviously at the simplest end of the spectrum, sometimes it is much trickier – and can be more fun, if the pieces of the jigsaw fit! Which reminds me, it is nearly time for me click into Christmas mode.

I shall doubtless shortly be encouraged to help with some ludicrous jigsaw puzzle of the cardboard variety. But I shall seek my revenge by dragging everyone’s turkey-swollen bodies outside to do a cloud and sun jigsaw puzzle afterwards.

Happy Puzzling Times!

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.)

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 field of sheep. The sheep, which are not as endangered as some species, did not fear the camera. They coughed and farted around me.

I was being drawn by the beacon of the Morning Star, as some are wont to call the planet Venus at such times. More particularly my magnet was the constellation Scorpius to the south of it. Many are fond of saying that Scorpius cannot be seen in the winter, but that betrays a heavy bias towards evening stargazing rather than the pre-dawn form of the sport.

Then I felt the cold northerly breeze and thinking that I might have caught the scent of some new prey in the air, I turned and as I did the sky drew me in. There it was, the big game! A moonlit mackerel sky. Bang! It fell into the lens and I hauled it back to share with you, round this, the campfire blog.

PS. The star that can be seen near the top of the picture is Arcturus, one of the brightest in the sky.

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

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 lore the world over.

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 and times when it is inviting you to make haste the exit. When the sun has gone down, the trees never lose their ability to thrill and scare.

The only light I used all night was the single flash from my camera to catch my nemesis. I closed and shielded my eyes, to protect my night vision, and then pointed the camera and ‘shot blind’. This picture, which I did not look at until reaching the end of my walk, must have been of some ogre, a menacing hunched figure, one who crouched silently by the path of those who were foolish to walk alone at night in the woods. Turns out it was a tree stump.

Or perhaps it only turned into a tree stump when my camera came out? Heisenberg wrote of stranger things and called them physics.

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. Like other key parts of the navigation puzzle, landmarks are so critical to us that they weave their way into popular culture. The pirates in childrens’ stories bury their treasure and retrieve it using maps, but the maps nearly always guide them through a series of landmarks: past the hull of the shipwreck, behind the tree with a skeleton propped up against it…

From a walk in the a garden, to following the peaks of the Pyrenees, land journeys of all scales can be seen as a threaded line of landmarks, each one recognised and then registered. If you phone someone and ask them for directions to their home, and if they don’t palm you off with a postcode, then they are highly likely to reel off a series of landmarks:

‘Go past the bus-stop, then turn right at the junction by the big white house, then keep on going until you see a bridge…”. (The reason these directions are often more confusing than the homeowner intends is that we all find it hard to remember that landmarks that are totally familiar to us can seem very foreign to someone who has never come across them. They are often subjective.)

In remote areas, a feature that can be easily identified can be like a gift after several hours of waning confidence. Perhaps a lake shaped unmistakeably like a bird appears, where you expected it, as you cross over the brow of a hill.

In the case of urban navigation the fear that food or shelter will completely abandon you if you make a serious mistake is less real, but the navigation challenges can be every bit as demanding. Unknown streets have a tendency to blur into each other, taunting and goading us to feel lost with their homogeneity. This may be the reason that unique buildings can give such a warm feeling in any city. They are the landmarks that give a town its shape and as soon as one appears from around a corner, the town itself arranges itself more neatly in our thoughts.

So it was the other night, when the Albert Hall beamed at me from between two tall dark rows of buildings. I knew where I was before I saw it, I know the area well, being so near the Royal Geographical Society, and yet its appearance still gave me that warm feeling of confirmed position.

The clouds had been moving from the east during my walk. I glanced up, watched a few cumuli amble over the rooftops and confirmed my suspicions that I was southeast of the Albert Hall. I was clearly less lost than the hundreds of souls who queued in desperate snakes to see Cliff Richard perform there that night.

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, you will be able to orientate yourself, as those around you stagger around in the mist and bump into trees!

This thin mist effect is likely to be repeated at times both tonight and tomorrow morning in large parts of the UK, especially in the south. Happy mist hunting!

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 highish latitudes like the UK for most of the year.

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 closed on land, how the quantity of litter grew and the formation of clouds altered noticeably. My favourite moment that day was Sarah’s recollection that all the whales she encountered were heading south. Now that is what I call a pod of wonderful compasses!

Unsurprisingly, perhaps, Sarah is not staying in the UK for too long. Her next big adventure begins soon and as she puts it, ‘I knew my next project had to involve both green and blue bits of the globe.’ There is more information about London to London: Via the World on Sarah’s website.