It is very windy here. […]\u00a0 It has reaffirmed my faith that the world is round, because if all this air wasn’t just doing a lap of Antarctica and coming back round again, then wherever it was coming from would surely have run out by now.<\/p><\/blockquote>\n
This week, I saw a great image that illustrates this concept beautifully, all thanks to a volcanic eruption in Chile.<\/p>\n
The eruption at the Puyehue-Cord\u00f3n Caulle began nearly a fortnight ago<\/a>, on the 4th June, producing an impressive eruption column over 12 km high and depositing a thick blanket of pumice on the surrounding landscape (Nice image gallery on the BBC website<\/a>).\u00a0 Since then, the finer-grained ash has been carried eastward on the wind, causing air travel disruption<\/a> and pretty sunsets<\/a> in South Africa, Australia, Tasmania, and New Zealand as it goes.<\/p>\n The image below is the output from a computer model simulation of the Puyehue-Cord\u00f3n Caulle eruption plume.\u00a0 It was produced by the Meteorological Service of Canada<\/a>, using their MLDP0 computer model.\u00a0 It shows the predicted distribution of the ash on Friday 17 June, with the cloud doing a lap of Antarctica and coming back round to Patagonia again<\/em>.\u00a0 The usual caveats and uncertainties of plume modelling<\/a> apply, especially with respect to concentration estimates, which are strongly dependant on the estimates of how much ash is being erupted per second.\u00a0 Consequently, they have published these maps for guidance only.\u00a0 [See also the first comments, below]<\/em><\/p>\n Especially cool is the animated version – click here<\/a> to see it.<\/p>\n Prediction of Cord\u00f3n Caulle ash cloud produced by the Meteorological Service of Canada using the MLDP0 model. The ash has made a complete circuit of the globe. Click to enlarge.<\/p><\/div>\n","protected":false},"excerpt":{"rendered":" The Patagonian experience is dominated by one thing: the wind.\u00a0 It is constant, incessant, and relentless.\u00a0 Windsocks at airports are permanently horizontal and the few trees that survive on the hillsides all point east.\u00a0 It doesn’t even have significant gusts … Continue reading ![\"Model](\"http:\/\/all-geo.org\/volcan01010\/wp-content\/uploads\/2011\/06\/cordon_caulle_map_small.png\")
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