h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

its been a bit chilly of late, even in the direct afternoon sun

has the recent ash cloud contributed at all to global dimming over the UK and Europe?????

It's April and it's cloudless. I suspect that's more likely an explanation.

The southern UK is at frost risk until about the begining of May. Such is well known to those of us concerned with such things. That is anyone who takes gardening at all seriously.

But one has to wonder if the ash has had/will have any effect on Global warming...

I saw an interesting stat the other day that the net imbalance in CO2 delivered into the atmosphere by the Volcano as opposed to 60% of flights being cancelled - per day, it was impressive how much MORE CO2 the planes bung out than the Volcano...

forgot to say what I wanted to....

Given the Volcano continues to spew out ash, etc... how long until we get a global cooling due to heat being blocked from reaching the ground, or would we see a reverse and global warming due to heat being trapped more?

Oh and are the current "clear" skies a result of the ash - do any clouds forming over seas drop their moisture more quickly as they have the ash around which to form drops - or does the ash inhibit cloud formation?

it was found that after 9/11 light levels and temp. increased due to lack of upper atmosphere particles absorbing heat and radiating it back into space

there was a doccu. about it, the research team found an island off india where the prevailing winds carry the polution plume from one of indias industial areas across half the island and took measuremants under the plume and under clear skys

the conclusions were that "global dimming" due to polution had a cooling effect, and as we clean up the polution we pump out we might be increasing global warming rather than retarding it.

thats what lead me to this question, we are now having nice sunny days but its still a bit chilly even in the late afternoon with do desernable wind?????

could it be down to the ash cloud??

And again, no I don't think so - it's April.

I don't think this is that significant an eruption. Tambora, Karakatao and Mt Pinatuo going up - the most powerful volcanic eruptions in modern history - now they had a global cooling effect but that was felt much later - about a year later.

The atmosphere keeps heat in for some time - the greenhouse effect -without it we'd be a block of ice. Any effect will take some time to take effect. It is far too early to see such an effect at the moment.

And the forecast on the BBC last night predicted 22 °C by Sunday - hardly chilly. The average temperature in London in April is 13 °C http://www.bbc.co.uk/weather/world/city_guides/results.shtml?tt=TT003790 . These are not unusual temperatures.

Is the eyjafjallajokull eruption of an major consequence as far as volcanic eruptions go? I don't think it's a major blast. It's significance is that the weather blew the cloud of ash over us and disrupted air traffic.

In short I think you are making too much of this.

As two Argon0's second question there I would expect solid particles in the air to nucleate water precipitation and hence cause cloud and rain.

The height of the ash cloud will also effect this - from what they were saying on the news it's above the cloud line and possibly in a dry area of the atmosphere - but I would bow to someone with more meteorolical expertise than myself.

I read somewhere that the reduction in high-altitude CO2 emissions from aircraft will have a far greater and more direct effect on the climate than anything (gas or dust) emitted by the volcano.

I've received some superb photos by eMail - is there somewhere public I can post 'em?

Or have you all got (19 of) them too?

... and just in case you haven't seen them,

yelbakk @8535 in "Ask, What news story has caught your attention today" has posted this:
>>
http://www.spiegel.de/fotostrecke/fotostrecke-54158.html
t's not the story, but the picture. Keep clicking on the photo to see more.
<<

My oh my!

Is it possible for the ash plume to interupt satalite signals ? I am thinking GPS and communications. We would be seriously disrupted without these things.

<< possible for the ash plume to interupt satalite signals ?>>

hands up who has sky satalite?????

and now

hands up who has free view????

now!!!!!

who can read a map???

I already live without sky TV and do not have GPS in my car.
However modern ecomomies rely on communication and ships navigate by GPS. I have zero faith in all but a few old hands to navigate a ship safely without GPS.

it must still be taught?????

what happens when a ships GPS goess up????

they don't winch a repair man onto the deck!!!

In short, no, the ash cloud couldn't interfere with GPS. It's not a strong signal - thick tree cover can screw it up - but the ash cloud is really tenuous. It's only causing a problem because jet engines ingest a HUGE quantity of air, and abrasive particles in that air are a real issue. But the cloud is so thin you can't even see it.

Well, the volcanoe probly won't have done anything (unless your heaters are plugged in to planes ) but this years weather was always bound to be dogey as it is an el nino year. Expect bad wether and increased storms.