Entries tagged "wind"
2012-02-22
Although microchips have a childlike tendency to steal our attention away from almost anything else, I am not against technology itself. Once we have steeled ourselves to the risks of using any device, it is possible to have the best of all worlds: convenience, information, safety and awareness.
If I was forced to choose my favourite piece of navigation technology, I would find it hard. The GPS, for all its many known vices, really is an extraordinary piece of kit. But it will never be my favourite, because... of all its many known vices. Also, because I'm very…
2012-02-17
Over the next 48 there will be an opportunity to witness the passing of a classic cold front system in the UK.
A cold front is the leading edge of a mass of cold air as it displaces a warmer mass of air at ground level.
Cold air is denser than hot air (hot air balloons rise) and so as a cold front advances it slides under the warmer air forcing it up. As the warm air is forced up its moisture condenses. This movement of moist air upwards is often quite dramatic and this can lead…
2012-01-30
I'm just back from some micronavigation in the Black Mountains in Wales.
I should get a chance to blog in more detail in time, but for now I just wanted to share a couple of nice clues I found in the light snow and ice I walked amongst.
The first photo shows the first snow I encountered on a climb out of the Vale of Ewyas. We are looking east in this picture, the only snow to have survived the thawing warmth of the day are the thin strips hiding in the shade on the south…
2011-11-27
My thanks to Tim and Laura Moss, who braved the elements on Bignor Hill yesterday afternoon. They found themselves wrapping up warm and staring into the November wind thanks to a wedding present of a natural navigation course. (I didn't get to read the card, but maybe it said something along the lines of 'If you can smile through this, you'll be very happy!').
It was a fun afternoon, especially as I got to watch Tim and Laura's face expressions as they grappled with such fun concepts as 'How to find the south celestial pole from a field…
2011-09-08
My thanks to Richard Webber for sending in this photo. The telegraph poles in this picture are leaning from the southwest to the northeast. This is in line with the prevailing wind, which is easy to tell in the photo if you look at the straggly bits that have been combed over at the top of the hedge.
The question is, is this a coincidence or the cause?
Please could anyone pass on any observations they have of leaning telegraph poles and together we may be able to forge a new technique.
2010-12-29
Day in, day out, paths experience a different life to that of their verges.
Very often there is undergrowth on each side of a path, sheltering one side of them from the sun's drying rays, but their exposure to and shelter from wind also sets them apart. This can be seen most clearly when snow or frost is thawing. The path will either thaw first, or, as in this picture which I took about ten days ago, they hold onto their snow for longer.
As I mention in the book, this is something that can be…
2010-09-07
BBC Devon have a delightful story about the sculptor, Marcus Vergette, on their section of the BBC website.Marcus is sculpting a series of 'tidal bells' that will ring out at high tide around the country. There is no mention of springs or neaps in the article, so I'm presuming the bells are being placed low enough to ring at a neap tide (the narrowest range between high and low).In the book I touch on the fact that humans have become very adept at approximating tidal behaviour, but it is still impossible to predict tidal times or heights…
2010-07-01
I went for a short circuitous walk in the Lavington Plantation area yesterday morning. Always on the lookout for natural navigational treats, I was also secretly hoping to spot an adder - the area is known as a popular refuge for our island's only poisonous snake. In fact there is even a marked walk known as 'The Serpent's Trail', thought by many to be named after its twists and turns, but actually in testimony to the reptiles that enjoy the mixture of sand and mud on its heathland.The conditions were perfect, I could feel the summer heat rising up…
2010-02-18
I landed back at Gatwick last night following an accidental visit to Tenerife.The wind has been my friend on so many occasions recently, a dependable breeze helping me on my way through the woods or the clouds scudding overhead pointing the way home. It was probably time that it reminded me that it is not just in the business of helping me on my walks.The plan was simple: I wanted to use a one week gap in the diary to get out to one of the wildest spots within five hours of home to do some natural navigation research. Days…
2010-01-16
The snow is melting away, but not at the same speed everywhere. The warmer wind which is blowing from the southeast today is leaving green swathes wherever it reaches. In this photo, which is taken looking east, the snow in the top right corner is being sheltered by woodland, but the snow to the left is also being left relatively untouched by the same wind because it is partly in the lee of the hill, but also because the woodland to the left of the picture is forcing the airflow up over it. In aviation terms the wind appears to…
2009-11-30
I had hoped to sail to the Isle of Wight on Saturday with some old friends. We slipped Chichester marina at eight in the morning in my Contessa 32, fully aware that the forecast was a bit spicy. The sense of foreboding increased slightly when the Chichester marina lock-keeper called down to me, 'Have you seen the forecast?' I said 'Yes. Force 6 gusting 9.' He replied, 'OK, well when the lock gates open you will need to gun the engine full throttle and hold your line otherwise you will be blown straight onto the piles.' I thanked…
2009-10-24
It is a pity that I didn't have a video camera with me to capture the motion in this puddle. The wind was blowing in from the southwest, but the trees that can be seen in the reflection of this puddle were offering some shelter. The half of the puddle nearest the trees was in their lee and receiving little or no wind. The half that was further from the trees was catching a breeze as it dropped down over the trees. The net result was that the muddy bubbles were being corralled into the lee half, where they…
2009-08-04
Shortest blog, but a good' un, which way am I facing when I took this picture?
2009-07-06
I ran a private course in the South Downs on Saturday for a group of four friends. One of them gave me a great example of using our senses and a little lateral thought to better connect with nature. Rachel lives southwest of Medway power station and said that she could tell when it was going to snow in winter because these were the only times she could smell the power station itself. The colder northeasterly winds bringing snowy weather and local smells with them.
2009-06-12
I took this picture a week ago. It shows the lower fair-weather cumulus clouds against the upper cirrus clouds. It is not at all unusual to watch the lower clouds and upper clouds move in different directions and to feel a third wind direction on your face at the same time.
2009-05-21
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.
2009-05-15
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…
2009-05-13
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…
2009-04-30
One of the keys to navigating with nature is appreciating scale. It is vital that we do not spend too much time focusing too narrowly or widely. In this photograph, taken in the South Downs on Monday, our eyes are naturally led to the fallen tree. It would be very easy to miss both a bigger clue to direction and a smaller one.The heart of the tree is marginally closer to our side of the tree, which hints that we are south of it, looking north.If we peer through the undergrowth and bare tree branches we can see that the…
2009-04-27
The rape flowers are coming into bloom over the South Downs, but they don't all bloom at the same time.The crop tends to be on a field that will get a good amount of sunlight anyway, often south-facing, but even within the fields there are subtle shade differences. The flowers tend to appear first in the south-facing dips in the land. This is probably because they are getting plenty of sun, but being sheltered from the cooling winds. As a general rule, nature moves faster the warmer things are.
2009-04-03
This morning brought with it a nice thick radiation fog, which the sun will probably burn off soon. There is not forecast to be much wind today, but even a breeze deals with radiation fog, usually anything over 12 knots.No visible sun, no discernible wind, these are the conditions that remind us that the trees reflect their environment over a long period. They act as a giant USB stick of data about thousands of days of sun and wind. All we need to do is tune our senses and look for it. The thin branch in the bottom left of…
2009-03-30
On outdoor courses one of the ways that I try to keep participant's senses sharp is by telling them that I expect them to spot something that I have not, even if we are walking a route that I know well. This photo from the Pathfinder course on Saturday shows a phenomenon that I am very familiar with, but an example that my trainee, Guy, spotted before me. There are a lot of great wayfinding methods that revolve around deducing prevailing wind direction. It is always worth looking for lee build-up. It works in most parts of the world, and…
2008-09-17
When talking about heat and wind in the context of chillies, there is a risk that we might start to think some very un-navigational thoughts...
... however, this is a risky business, so here are two jalapeno chillies. One lived its life in a south-facing greenhouse, the other lived near it, outside near a south-facing wall. They both received identical amounts of sunlight. They both grew in the same soil and received plenty of water. The only serious differences to their environments were the temperature and wind exposure.
It is not too hard…
2008-08-13
On some days it is easier than others to tell which way the wind blows.
Today we enjoyed a nice 30kts/Force 7/35mph/56kph, depending how you like your porridge.
