Ten miles an hour around the globe: travelling through a meteorology text book
We have crossed the equator! I still have my hair (the ceremony is sometime this week but we won't know when until it's too late to run) and the fish are still flying. Birds have now joined us as well, boobies they're called, that soar above the ocean, watching the fish and then, in the blink of an eye, turn upside down and sky rocket downwards into the ocean. In, deep in, maybe a metre or so, grab a fish and bounce out again. It's incredible to watch. The concentration, the energy... if only we could apply that to our daily activities!
As much as I love staring at infinity, it's nice to have some activity happening in the foreground as well, it keeps you alert I guess. Soaring, soaring, flying with the ship, flying at 10 knots. Mindboggling. No, not the birds speed, but ours. Our slow speed. You can ride a bike at 10 miles an hour can't you? OK, I know it's nautical miles but still, not far off. I am travelling around the circumference of the Earth at ten miles and hour. From Britain to Antarctica. Ten miles an hour! Doesn't anyone else find that utterly bizarre? That we get there at all, let alone in as little as two months.
A common reaction when I left was, "two months on a ship?! That's crazy". We are so time oriented. On the ship, it doesn't feel long at all. It feels, appropriate, I guess. I mean, it's a long way we're going and we're on a not-massive ship with an awful lot of Stuff on it. And we keep going. Ten miles an hour maybe but no traffic lights, roundabouts, jams, meetings. this is way beyond commuting, or even going for a Sunday drive.
One of the most remarkable things for me has been to watch the world go by, underneath us, past us, as it were. The weather hasn't improved, we've moved into better weather. We are the ones doing the moving. Leaving Immingham, cold and dreary, the first few days were cold, windy and wet. Then, in the Bay of Biscay, they were rough. Rough Seas. It's all about ocean circulation and wind systems and how they all meet and create this amazing chaotic regime right there. And there we were, right there, feeling the chaos in our stomachs. Somehow, the energy circulating around our bodies at that time, unpleasant as it was, had been sourced from the sun and the sea and the turning of the earth. I am sailing through a meteorology text book.
After the Bay of Biscay, we moved into calmer seas, warmer, gentler wind, past the Meditterranean, the Canaries, the east coast of Africa. It wasn't sweltering, it was perfect. The mid-latitudes. Of course! Then, as we sail further south the air has become hotter, the direct rays from the sun more intense and the weather, stormier again. Nothing like the Bay of Biscay but we're definitely rocking and afternoons have sen some ominous dark clouds. We must be near the equator!
I hadn't thought if it before, I'm desperate for my old notes on earth weather systems, but it makes sense, in my very amateur perception of what's going on. Imagine the earth, a round ball, with the sun above the equator. For now, neither are moving. Hot air at the equator rises and travels to cooler areas, the higher latitudes, towards the poles. So you have air rising from the middle and the separating, like a T-junction, at around cloud-height, some going south, some going north. This happens to air all around the Earth. From the side, two donuts: air rising at the equator, travelling high up towards the pole, sinking when it's no longer less dense than the surrounding air, and travelling back along the surface of the earth, this now-cold air seeking warmer climes. At the equator, therefore, you have winds from the south and the north converging and rising together, starting the whole circulation system again.
Now, add spin. Make the Earth spin. All that air that is moving up, out high, down and back low, is trapped within the spinning earth -system but not fixed to the earth. It creates a circulation system of its own in response to the spinning of the world. Like the ripples that happen in water when you skim stones. The combined effect of air flowing from the poles to the equator at the surface, and the spinning of the earth, makes the trade winds. At the equator, hot, damp air flowing from both poles meets and rises upwards. So there's your low pressure zone. As the air rises, it cools, water vapour condenses and clouds form. The waterless air then continues its way, high up, back towards the poles. Round and round and round and round. It's amazing. And that's not even mentioning what's going on in the oceans. The more you think about it, the more you realise how great, and complex, this place is, this Earth. And I'm honoured to be travelling around it, learning from it, at ten miles an hour.
---addendum: this is straight from distant memory as I haven't consulted any books recently, please, please, correct my misconceptions and broad generalisations!------
Posted by Rhian at 0:21 EST
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