Solar activity

[yorkie]

This is not directly rail related (hence why it's in general discussion) although obviously the weather can affect the operation of railways!

Apparently the sun is " on its way to another solar maximum" but is also "half way toward a Maunder Minimum condition"

So, we're going to have problems with satnavs as the Sun warms, while simultaneously we're going to have cold winters while the Sun cools. Can anyone make sense of that?

Should NR be preparing for a really cold winter and installing more heaters at points? Or should they be preparing for warmer Summers and try to mitigate against rails buckling in the heat?

 

[Peter Mugridge]

Yes, as an astronomer I can make sense of it.

In simple terms, the Sun has an 11 year cycle from low to high sunspot activity and back to low again. At the moment we are coming out of the minimum of one of these 11 year cycles.

At the same time, the overall level of solar activity - the long term trend - is declining.

Thus, the 11 year cycle is still running, but the peaks and troughs are progressively lower than the previous one.

 

[Geezertronic]

All the proper science terms will be forgotton or ignored and Global Warming will get the blame

 

[devon_metro]

Despite the fact that increased solar activity, often in the form of solar flares can actually cause warming of the earth.

 

[Peter Mugridge]

A warming of the atmosphere actually; not quite the same thing...

But that is why satellites in low orbits are vulnerable to increased atmospheric drag during solar flare periods; the heating causes the whole atmosphere to expand a little and this increases drag on low orbits.

This can affect quite some distance up - the ISS has to have it's orbit boosted regularly because atmospheric drag causes a slow deteioration which, if left unchecked, would result in it doing an unplanned re-entry.

Have a look at this:

http://www.heavens-above.com/IssHeight.aspx?lat=51.330&lng=-0.270&loc=Epsom&alt=0&tz=GMT

 

[CarterUSM]

Fascinating. By how much exactly does the atmosphere expand and contract? With regards to points heaters, there were some spectacular failures during the cold winter there.