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Update: Here is the latest image from the European Space Agency’s Envisat satellite, taken yesterday afternoon. A plume of brownish-grey ash from the Eyjafjallajökull volcano can be seen leaving Iceland in a roughly south-easterly direction.
(Edited 20 April 2010 – the original story follows below.)
New satellite image of ash spewing from Iceland’s volcano.
(Image acquired 19 April 2010, 1:45 PM) Credit: ESA
Volcanic ash cloud as viewed from space.
(Image acquired 15 April 2010, 12:25 PM) Credit: ESA
By Louise Mayor
This image, taken yesterday, shows the extent of the volcanic ash that has been spewing out of Iceland’s Eyjafjallajökull volcano since Wednesday. The ash, which contains tiny particles of rock and glass, can be seen as a grey streak in the upper half of the image, being swept by winds high in the atmosphere towards the rest of western Europe.
In the bottom-right of the image you can just about make out the Republic of Ireland, and the UK where all but a few individually permitted flights have been grounded for a second day running as a result of the ash cloud.
The picture was acquired by the Medium Resolution Imaging Spectrometer (MERIS) on board the European Space Agency’s Envisat satellite. Launched in 2002, the satellite’s primary purpose is to image the colour of the Earth’s oceans using 15 spectral bands over the 390–1040 nm range. These images reveal characteristics of water such as its concentration of chlorophyll, which can then be used to understand the role of our oceans in the carbon cycle.
It truly is a dreadful point in time for the airline industry, yet our prayers – regardless of whether the photographs of the volcanic eruption are really spectacular – need to be with all those individuals stuck far from home. Thanks regarding your post.
I am a glider pilot (though I believe otherwise sane) and find the ESA 1:45 p.m. picture fascinating.
Along the centre of the plume is a line of cumulus which marks a zone of convergence convection. Similar features are often seen running down the centre of Italy or even Great Britain. (See for example “Spacious Skies” by Scorer and Verkaik). There are also clear zones along the edge of the plume where the descending air suppresses “normal” convection. On the NE boundary we even see something reminiscent of a sea breeze front.
Note that convection starts some way down stream from the heat source (i.e. the volcano) indicating that that the heating which produces the convection is most probably due to turbidity transferring solar energy to the atmosphere.
This means we have what are normally tropospheric phenomena occurring in the stratosphere.
It occurs to me that the eruption might offer useful data to test weather and climatic models by comparing simultaneous balloon ascents into the plume and adjacent air.