Monthly Archives: May 2011

Methane Update

As we have noted previously, the second most important anthropogenic greenhouse gas (after carbon dioxide, or CO2), is methane (CH4), and although its concentration (only about 1.8 ppm) is far less than that of CO2 (at 390 ppm), it’s a stronger greenhouse gas on a per-molecule basis, and it ends up transformed into CO2 by atmospheric chemistry processes anyway. Also, more than half the atmospheric CH4 load is due to changes wrought by mankind. Atmospheric methane concentration had stabilized from about 1999 to 2007, but recently began rising again, as reported in Rigby et al (2008).

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Markov 2

In the last post we showed how Harold Brooks has applied a 1st-order Markov Chain model to the phenomenon of a significant tornado day (“STD”), in particular to explain the frequency of occurrence of long runs of consecutive STDs. An STD is defined as any day with at least one (possibly many more) tornados of strength F2 or greater (on the Fujita scale).

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Math Fun: the Markov Tornado

While looking around for tornado data, I found a fascinating page by Harold Brooks in which he builds a model of the likelihood of a “significant tornado day,” which I’ll call an “STD” (yeah, it’s a funny choice). This is defined as a day with at least one tornado of Fujita scale F2 or stronger.

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Year of the Twister

Shortly after it became clear that April 2011 broke the U.S. record for the most April tornados, the Washington Post reported that it was not a “legitimate” record … yet. That’s because earlier years’ counts are adjusted upward in an attempt to compensate for our increasing ability to detect tornados in the U.S. However, it didn’t take long for April to shatter, not only the actual record of observed number of tornados, but the adjusted record as well.

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Seven Months Ago

Anthony Watts is taking a poll of predictions for this summer’s minimum in Arctic sea ice. Some of you might want to join in the fun.

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Warts and All

Legend says that when Oliver Cromwell had his portrait painted by Sir Peter Lely (who had done the royal portrait of Charles I of England, and would later do the royal portrait of Charles II), Cromwell so disdained that personal vanity typical of royalty, that he instructed Lely to paint him as he was, “warts and all.”

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Hot … and Wet

The future will be hot, at least, hotter than the present. But temperature isn’t the only thing that will change with global warming — so will the water cycle. Some places will become drier, some wetter. In fact, some have already become wetter.

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