Sunday, 12 October 2008

My New Meteorological Watch

With one thing and another it has been a while since I last put ‘finger-to-keyboard’ so to speak, but felt I should share a few thoughts about my new meteorological watch.

At my age it is not often I get excited about my birthday (perhaps that is just because I am a bit miserable, as my wife reminds me), but this year I had a very exciting present – no not a vintage Harley Davidson bike, an antique Les Paul guitar, or tickets to see Catherine Jenkins in concert (front row seats); it was a meteorological watch. Yes, you did read correctly a watch that makes observations of the weather. I have had much fun with this, making observations of temperature pressure and altitude. It reminded me of a few things apart from how hopeless I am at finding out how it all works.

The first was how careful you have to be when making observations, to understand what is being observed (like the temperature of the atmosphere, or my wrist), and that the observations are well calibrated. I am waiting to my next blue sky day at the coast to set my altitude and pressure calibrations.

The second was that what I am measuring is all inter-related. Pressure, temperature and humidity are all related. For example in the troposphere, a very small layer of the earths atmosphere relatively speaking that is closest to the surface of the earth and where we have all of our weather, pressure decreases with height in the atmosphere and so does temperature, by roughly 6oC per kilometre (if we make some assumptions about what we call a standard atmosphere). I wonder whether my watch really does measure temperature, pressure and altitude independently or whether, as I suspect, it uses some of our understanding of how these things are linked.

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