Icelandic Volcanic Eruption - Significant Disruption to UK Flights

Caporegime
Joined
25 Jul 2005
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28,851
Location
Canada
Totally surreal at Aberdeen Airport. Total silence, nothing at all on radar. There was a light aircraft about half an hour ago to the south and I was willing him to contact me so that i would have something to do, lol.

Should have contacted him! I could just imagine the suprise if the conversation went something like..

You "Hi, this is abedeen airport are you ok"
Him "Yes i'm fine thanks"
*short pause*
You "So... what did you have for breakfast...?"
Him "Eh.. Don't you have anything better to do?"
You "Actually... nope.. i'm bored..."

:p
 
Soldato
Joined
21 Sep 2009
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5,241
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London
According to NATS website (holding page due to heavy traffic, unsurprisingly), the UK no-fly zone will now be in place until at least 0600 (local) Friday morning. Further review of the situation will be undertaken at 2000 (local) this evening.
 
Soldato
Joined
7 Apr 2004
Posts
4,212
BBC now saying everythings off till 6am BST tomorrow earliest.

On the plus side, it's really good for me as I get out of a thesis meeting ive not done the work for :p
 
Soldato
Joined
18 Oct 2002
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10,951
Location
Bristol
You can't identify ash clouds by taking a picture, not in visible in IR or any other band.

You have to take the brightness temperature difference between the ~11 and ~12 micron bands. In a normal atmosphere, there is greater absorption at 12 microns than 11 micros, so when you subtract the brightness temperature at 12 from that at 11 you get a +ve number.

When ash (or actually the silicates associated with the ash cloud) is present there is greater absorption at the 11 micron band than 12 so subtracting the BT at 12 from 11 now gives a -ve number and hence there is ash.
 
Soldato
Joined
21 Sep 2009
Posts
5,241
Location
London
You can't identify ash clouds by taking a picture, not in visible in IR or any other band.

You have to take the brightness temperature difference between the ~11 and ~12 micron bands. In a normal atmosphere, there is greater absorption at 12 microns than 11 micros, so when you subtract the brightness temperature at 12 from that at 11 you get a +ve number.

When ash (or actually the silicates associated with the ash cloud) is present there is greater absorption at the 11 micron band than 12 so subtracting the BT at 12 from 11 now gives a -ve number and hence there is ash.

It's a process of elimination really, if there's a cloud bank visible on IR and VIS but hardly any WV in the water vapour bands, plus this is where synoptics have forecast it to be, so it's highly likely that's what it is.
 
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