Cross your fingers for the Yucatan

Long time readers will know that I have a lot of colleagues in the Yucatan part of Mexico, mostly in the northeastern tip in the state of Quintana Roo.  That area is in the firing line for Hurrican Paula (yes, its still hurricane season!).  Cross your fingers in that ever-futile-but-nonetheless-self-soothing symbol of good luck for our colleagues and friends down there, especially the folks on Isla Mujeres, which is pretty exposed.  The map below shows the forecast cone for hurricane force winds in the next 24 hrs.  The cone for tropical storm force winds is MUCH bigger.

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Amazing satellite video of Hurricane Igor

Hurricane Igor is a big beast allright.  If you don’t believe me, check out this spectacular QuickTime movie from the Space Science and Engineering team at the University of Wisconsin, and after you pick your jaw up off the floor, go over to their blog and check out the rest of their great data.  Just look at that eye; I love the way the shadow casts across it as the sun goes down.  You can also see convection cells to the left and the lower right of the storm, where air is moving rapidly upwards. (if the video stops, double click it to restart).  Thats just made of awesome.

Why is this on a marine science blog?  Well, its over the ocean, so that counts, right?  Seriously, hurricanes are really marine phenomena.  They’re driven by the tremendous amount of heat that builds up in the tropical oceans during the summer months.  That heat warms and moistens the overlying atmosphere, as the energy stored in the ocean fluxes back into the air.  Warmer air is less dense and so you end up with a focused area of low pressure, and the moist air rising up to colder higher parts of the atmosphere, causing rain.  Add in some favourable winds and and dash of the coriolis effect and the whole thing starts to spin, forming into a tropical cyclone.

Via my colleague Brian Colle at Stony Brook U.