Hypercane

A hypercane is a hypothetical class of extreme tropical cyclone that could form if ocean temperatures reached around convert|50|°C|°F, 15 °C higher than the warmest ocean temperature ever recorded [cite web |url=http://www.windows.ucar.edu/tour/link=/earth/Water/temp.html&edu=high |title=Temperature of Ocean Water |publisher=University Corporation for Atmospheric Research |work=Windows to the Universe |date=2001-08-31 |accessdate=2008-07-24] — which could in turn be caused by a large asteroid or comet impact, a large volcanic or supervolcanic eruption, or very extensive global warming. [cite web |url=http://ipsnews.net/news.asp?idnews=30308 |title=The Dawn of the Hypercane? |first=Stephen |last=Leahy |publisher=Inter Press Service |date=2005-09-16 |accessdate=2008-07-24] There is some speculation that some dinosaurs might have been killed off by a series of hypercanes, resulting from an asteroid or comet crashing into Earth. [cite journal |title=Did storms land the dinosaurs in hot water? |first=Jeff |last=Hecht |journal=New Scientist |date=1995-02-04 |url=http://www.newscientist.com/article/mg14519632.600-did-storms-land-the-dinosaurs-in-hot-water.html |issue=1963 |pages=p. 16 |accessdate=2008-07-24 ] The term was coined by atmospheric scientist Kerry Emanuel in 1994, at MIT.cite web |url=http://wind.mit.edu/~emanuel/holem/holem.html |title=Limits on Hurricane Intensity |first=Kerry |last=Emanuel |publisher=Center for Meteorology and Physical Oceanography , MIT |date=1996-09-16 |accessdate=2008-07-24 ] [cite journal |title=Hypercanes: A Possible Link to Global Extinction Scenarios |first=Kerry |last=Emanuel |coauthors=Kevin Speer, Richard Rotunno, Ramesh Srivastava, Mario Molina |journal= |date=1998-03-22 |volume=100 |issue=D7 |pages=pp. 13755–13765 |journal=Journal of Geophysical Research |url=http://www.agu.org/pubs/crossref/1995/95JD01368.shtml |accessdate=2008-07-24 ]

Physical description

Hypercanes would have wind speeds of over convert|800|km/h|mph, and would also have a central pressure of less than convert|700|hPa|inHg|abbr=off|lk=on, giving them an enormous lifespan. The extreme conditions needed to create such a storm could conceivably produce a system up to the size of North America, creating storm surges of convert|18|m|ft|abbr=off|lk=off and an eye nearly convert|300|km|mi|abbr=off|lk=off across. The waters could remain hot enough for weeks, allowing more hypercanes to be formed. A hypercane's clouds would reach convert|30|km|mi into the stratosphere. A hypercane would also damage the earth's ozone. Water molecules in the stratosphere would react with ozone to accelerate decay into O₂ and reduce absorption of ultraviolet light.

Other scientists have theorized that the system, compared to a normal hurricane, would be considerably smaller, about 10 miles in diameter. This would be more comparable to a tornado, which has been recorded at up to about 2.5 miles. [cite web | author=NOAA Storm Prediction Center | title=The Online Tornado FAQ | year=Apr 4, 2006 | url=http://www.spc.noaa.gov/faq/tornado/#History | accessdate=2008-09-11]

References