On Friday, September 7, 2012 7:42:00 PM UTC+1, Len Wood wrote:


My point was that the much wetter than average summer just past was

not true for the whole of the UK.

Adam Scaife referred to the UK (north of 50) deg and spoke as follows:

'....for example, some studies suggest there is an increase risk of

wet low pressure summers over the UK as the ice melts, and the studies

suggest that the weather could become more easterly cold and snowy due

to the Arctic ice decline.

So he was referring to the UK here.


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Thanks. I didn't have the benefit of his exact words. I don't see where the putative "southern bias" is supposed to be, though.


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Good to see the UKMO is going to higher altitudes with its model.

The bulk of the stratosphere had already been include as it is about

12 to 50 km.

50 to 80 km is the mesosphere, clearly things like noctilucent clouds

can be considered here but their formation is still a bit of a

mystery.

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Of course. I meant to say *whole of* the stratosphere encompassed by the extended model. The success with re-forecasts clearly shows how important it is to model the whole... yea e'en unto the mesosphere.

Latest thoughts on noctilucent clouds from the University of Hampton, Virginia, are that microscopic dust particles left by meteor "smoke" act as nuclei around which ice crystals can form. Nobody seems to be sure where the water vapor comes from - maybe volcanoes can inject it that high or maybe chemical reactions in the stratosphere produce it. I'm no chemist. But there is a hypothesis that oxidization of methane produces methane that leaks upwards into the mesosphere, and that an apparent increase in the incidence of noctilucent clouds may be due to increased amounts of methane released from the Earth. Pretty speculative at the moment, though.

Stephen.