The natural Navigation: The Right Course, Naturally

As we approach the summer solstice the sun has so much north in it that no side of buildings, trees or other exposed areas will stay in the shade all day.

This is a northern roof getting a good late afternoon roasting. The moss, which in mid-winter is a plump dark green is in full retreat at this time of year. It is well-established and will survive until the sun starts moving south again in three weeks.

I have been reasonably self-disciplined with my writing over recent weeks. It is helped by the fact that I like to get up before anyone else, and so there are fewer distractions on the way to locking myself in the study. Even so, trips to the kitchen/loo/garden to feed the chickens need to be carefully monitored, lest they become games of football with the kids/random phone calls/endless grazing. I have managed to maintain some sense of purpose most of the time, but this morning a pair of mating dragonflies ambushed my attention for long enough to earn a spot in the blog.

Surely there can be no navigational information derived from the sight of a male dragonfly seizing the female’s thorax with his anus? I hear you cry. Dragonflies are normally found near freshwater. In this case our garden pond most likely.

I had been working on the chapter about the sea in my book last week, so was even more finely tuned to its vagaries than normal as we crossed to the Isle of Wight on Saturday morning.

The sea’s colour is influenced by its depth, the colour of the seabed, salinity, microorganisms, silt and light levels to name a few factors.

The subtle shift in colour can be seen as the sea shallows to the coast off Ryde. The dark horizontal strip in the middle distance is caused by a thin cumulus cloud.

The Gooleys were camping on the Isle of Wight over the weekend. It was great weather, the few hours of rain that are necessary to make it feel like proper British camping kept themselves to late at night and early in the morning, which was considerate. A few observations will creep into the blog in due course, but to save me a bit of time as I work to catch up on some emails, below is one that artfully saved me the need to blog properly. Thank you, Rob.

Tristan,

I hope you are well.

Emily and I attended your course at West Dean some months ago, and since then we have spent much time working out north from south based on the “tick” shaped branch formations.

I recall you showing us many pictures of trees and asking us to determine directions based on the tick shape. And I have now something to add…

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Early yesterday morning I was struck by the strong smell of smoke outside. It was not the smell of fresh fire, more the heavy scent of a diffuse smoke in a damp air, so I was not concerned. My initial thought was that a southerly breeze must be carrying the smoke from the nearest village up our way, but then there did not appear to be any breeze at all. The air was distinctly stagnant. The smell was not varying at all in the way that smoke carried on the wind does,  growing weaker and stronger each second.

When I looked down into a valley the cause became clear. There was a temperature inversion, where warmer air sits on top of cooler air trapping it and everything in it close to the ground. The inversion layer can just be made out in this photo.

My thanks to Richard, who sent in this picture from a lad’s walking weekend along the Jurassic Coast. He was given a private course as a birthday present and was on the lookout for natural signposts. Wind and trees don’t scream direction a lot louder than this. He also spotted sand blown only over the northeastern edge of a horse training area and found Polaris, but then struggled to see it from the inside of a pub.

Last night I went for a run through some beech woodland. The perfect tonic after twelve hours straight on the book.

Just came across this incredible video. I don’t think it’s new, but well worth watching if you’re interested in just what our senses are capable of. Inspiring.

The land’s wind shadow can be seen in the smooth water nearest the foreground of this picture of Nutbourne Marshes. This is an effect sailors, particularly dinghy sailors, will be very familiar with. It is the same effect that causes a build up of ice, sand and dust deposits on the lee side of obstacles on land. It is not usually quite as simple as the object getting in the way of the wind though, because of something called Bernoulli’s Law.

It is one of those laws that features a lot in our lives, but gets little credit. It helps chimneys to work properly and aircraft to fly. It causes the wind to accelerate as it travels over a curved surface and then decelerate as it reaches the other side. It probably deserves more credit as it is this effect that allows boats to sail into wind, a completely different physical…

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Two nights ago the strong winds brought an ivy-ravaged sycamore down into our garden, destroying two fences and killing an apple sapling in the process. I spent a few minutes looking over it this morning and found it to be a haven for lichens, there were at least five different types thriving and probably dozens making less of a splash. It was a rare opportunity to see the tops of the trees as they are, without having to scale them. Lichens are very sensitive to air quality so perhaps being thirty feet up was enough to keep them above the heavier pollutants.