The Jet Stream seems to have slipped. [Archive]

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bindeweede

24th July 2007, 08:58 PM

Do scientists know why this is happening? Is it me and my little car, cows farting, China's industrialisation, 4-wheel drives, ? More importantly, can the psychics tell us what is going to happen? (For a small fee, possibly.)

http://news.bbc.co.uk/1/hi/world/europe/6914490.stm#maps

Cuddles

25th July 2007, 09:16 AM

Things like this just happen, but we don't really understand how and why yet. It is very likely that pollution and global warming contribute to it, but the exact cause and effect are far more complicated than that. Global warming and climate change are likely to make this sort of thing happen more often, but it is impossible to point to any single event and blame it squarely on any one cause.

Dr B

25th July 2007, 11:38 AM

I read somewhere (some time ago) how the earths magnetic field is slowly reversing. This has happened before - but not in recent history....I have no idea if this will have implications for climate behaviour.....maybe Cuddles has some ideas on this one :-\

Cuddles

25th July 2007, 01:04 PM

Not only do the Earth's poles reverse, but that actually provided the first direct proof for plate tectonics. The average inteval between reversals is about 250,000 years, but it is far from consistent, and while it seems that we are due another reversal soon, that could mean anything from tomorrow to another 100,000 years. The process behind the reversals is not really understood, unsurprising really when you consider that we've never seen it happen. What seems to happen is that the poles, which always wander around a bit, go through a period of much more pronounced wandering and then pretty much disappear. There is a short period of essentially random magnetic fields and then the dipole field reasserts itself, but pointing in the opposite direction.

What this means for the weather is also fairly unclear. Since the vast majority of the Earth is made of neutral there is no direct effect. However, the Earth's magnetic field is the main protection from the solar wind and from cosmic rays, both of which are thought to have noticeable effects on the weather. For example, it is thought that charged particles can act as nuclei of cloud formation, so the weakening, or possibly even disappearance, of the magnetosphere could mean lots more clouds and rain. On the other hand, it could mean less rain if clouds will form much faster and then dissipate.

Basically, no-one really knows exactly how cosmic rays affect the weather, so we can't really say what effect pole reversal would have. What is pretty certain is that there would be such a big impact on all communication and electronics that changes to the weather would be the least of our worries.

Dr B

25th July 2007, 02:54 PM

Cheers for that O0

You dont see it discussed in terms of climate change in the media - but it seems to me (and based on some of your comments above) as if it may indeed have implications.

Much appreciated. 8)

Jocky

25th July 2007, 03:02 PM

while it seems that we are due another reversal soon, that could mean anything from tomorrow to another 100,000 years

:scared:

How much notice could we expect to have of such an eventuality? I do hope that "Tomorrow" was a figure of speech!

Cuddles

26th July 2007, 09:14 AM

How much notice could we expect to have of such an eventuality? I do hope that "Tomorrow" was a figure of speech!

I'm not sure really. As I said, it's usually preceded by a big increase in how much the poles drift, so it's unlikely to actually happen tomorrow. However, it's quite possible that we would only have a few years notice. The idea of geological changes only taking place over very long timescales has just about been thrown out now, although many things happen slowly, there seem to be quite a few things that can happen on a human time scale, and it seems that pole reversal is one of them. Just to make everyone feel more comfortable, I should point out that the poles are in fact moving much further and faster than they have in the recent past.

bindeweede

26th July 2007, 08:34 PM