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The ash caused great trouble to Europe and led to the closure of UK airspace from April 15th through 20th, for finer ash particles clogged airplane engines.
Plume Height
Image 1: Shows the plume height of the ash from the Eyjafjallajokul eruption. The average plume height is 7.3 km (approximately 2/3rds of the height of the troposphere).
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First we will simulate the eruption on its actual eruption date of April 14th.
We will also examine the constant pressure surface for an atmospheric pressure of 500 mb on the second day of the eruption in order to determine if the dispersal followed the expected wind patterns.
Constant Pressure Surface
Image 3: Shows the constant pressure surface for 500 mb on the second day of the eruption. The contour lines illustrate the wind patterns for horizontal wind flows on a constant pressure surface. Black arrows illustrate the relevant flows around Iceland. The winds move eastward towards England and then south. They also move north-westwards.
Simulation of Particle Positions for April 14-16 Eruption
Image 34: 3-day ash dispersal simulation for Eyjafjallajokull for actual eruption date of April 14, 2010. The The plume initially moves north-eastward and then south-westard. As the plume moves northward it deflects to the east and as it moves southward it deflects to the west as predicted by the rightward deflection of the coriolis force in the northern hemisphere. The The two layers closest to the Earth's surface spread the furthest.
The ash dispersal from the simulation follows the wind movements evident in the constant pressure surface graph.
Ash Dispersal by Py Plume Arrival Time for April 14-16 Eruption
Image 45: 3-day Ash dispersal by arrival time for Eyjafjallajokull for actual eruption date of April 14, 2010. The ash reaches the eastward regions.
We will now simulate the ash dispersal for if the eruption occurred a week earlier. We hope to establish a sense of the magnitude of weekly variations in ash dispersal before examining the dispersal for the eruption in different seasons.
April 7-9, 2010
Simulation of Particle Positions for April 7-9 Eruption
Image 56: 3-day ash dispersal simulation for Eyjafjallajokull for eruption date of April 7, 2010, a week earlier from its actual eruption date. The plume initially moves north-eastward and then south-westard. As the plume moves northward it deflects to the east and as it moves southward it deflects to the west as predicted by the rightward deflection of the coriolis force in the northern hemisphere. As opposed to the dispersal for the prior week, part of the northward plume was is swept into the polar regime. In contrast to what we would expect from theoretical predictions, the plume in the polar region moved moves clockwise when due to the coriolis force in the northern hemisphere, we would have anticipated it to move cyclonically.
counter-clockwise.
Unlike in the simulation for the eruption on its actual date of April 14th, in the simulation for the eruption a week earlier, part of the plume is swept into the polar region and causes dispersal in dramatically different regions.
Ash Dispersal by Py Plume Arrival Time for April 7-9 Eruption
Image 7: 3-day Ash dispersal by arrival time for Eyjafjallajokull for eruption date of April 7, 2010. The ash reaches Europe and encircles the north pole.
We will now simulate the eruption in January to investigate how the dispersion changes by season–specifically in the winter when the equator-pole temperature gradient peaks. We hope to determine if the variation by season exceeds that by week and if so, the patterns that characterize winter ash dispersal.wraps around pole. reaches europe
January 1-3, 2010
Immediately moves anticyclonically in conflict with what theory would predict about the mean flow near the north pole where the Earth's rotation has a strong influence. Additionally, the plume that moves southward deflects to the east rather than the west as the right-ward deflection from the coriolis force would predict.
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