Slashdot Mirror

← Back to Stories (view on slashdot.org)

World Map of Lightning Activity

Posted by chrisd on from the maybe-not-a-good-night-to-fly-a-kite dept.

Ian writes "NewScientist.com is >reporting that you can now see the lightning activity on the entire planet Earth at one time. The article states, "The NASA map also shows that lightning very rarely occurs at sea and is almost never seen at the Earth's poles." Anyone care to speculate on why that is?"

7 of 33 comments (clear)

  1. My Estimation by Nater · · Score: 3, Insightful

    My estimation is that the extremely low lightning at sea is caused by a general lack of geographic anomalies to disturb airflow.

    You'll notice in the map a wide swath of sea to the west of South America which follows the equator and then curves south following the coast. This is approximately the path of the Humbolt and equatorial currents in the South Pacific. Winds and sea currents have a strong influence on each other, and so we may presume that the winds over these strong ocean currents are less turbulent than those over the Polynesians or the Carribean islands. This is consistent with the hypothesis that a lack of turbulence is the cause of low lightning occurrence at sea.

    At the poles, the temperature is very low. I'm not sure of the mechanics involved, but I do know that regions with surfaces heated by the sun experience more lightning in general, so we could reasonably presume the opposite about regions of cold surfaces, explaining the lack of lightning at the poles.

    --

    I like to play children's songs in minor keys.
    "We're all sons of bitches now." --J. Robert Oppenheimer

    1. Re:My Estimation by dstone · · Score: 3, Interesting

      Care to venture a theory as to why there would be gradient patches of BOTH white and grey on that map, then? Maybe grey is where they didn't take measurements, and white is where the really, really didn't take measurements. ;-)

  2. If you are more interested in just the US... by CheshireCatCO · · Score: 4, Interesting

    Yeah, I know it's sort of egocentric for we Americans, but you can visit http://www.lightningstorm.com/ls2/gpg/lex1/mapdisp lay_free.jsp?jrunsessionid=1007697160371304360 to see recent lightening activity in the continental US. When things are lively, you can see a lot of really nifty patterns with the fronts.

  3. Naturally. by Black+Parrot · · Score: 3, Funny


    > The NASA map also shows that lightning very rarely occurs at sea and is almost never seen at the Earth's poles. Anyone care to speculate on why that is?

    Far fewer blasphemers in those regions, of course.

    --
    Sheesh, evil *and* a jerk. -- Jade
  4. One theory by Wolfger · · Score: 3, Funny

    No lightning at the poles, and very little at sea? Obviously lightning is herbivorous, and tends to roam areas where there are trees to eat.

    --
    Nothing to see here. Move along.
  5. No lightning at the poles. by Yazeran · · Score: 3, Informative
    The reason for no lightning at the poles, is thet in order for a cloud to be electrically charged it has to be composed of droplets of liquid water. The current theory about how clouds charge is by colisions of drops in the cloud.
    Large drops falls through the cloud and collides with smaller drops going up. These collisions transfer charge from the down-going drops to the up-going drops, and thus a larde charge difference between top and bottom of the cloud develops. The large charge in the bottom of the cloud results in the formation of a 'mirror charge' in the ground beneath it and these charges are responsible for the lightning.


    Yours Yazeran


    Plan: To go to Mars one day with a hammer.

  6. Re:Neat by sphealey · · Score: 3, Interesting
    Thunderstorms are the thing I miss most about the midwest (I'm from Illinois, live in California), but it looks like the "third coast" (TX, LA, MS, AL, FL) is the place to be in the US for lightning.
    Actually, if you Google on National Lightning Detection Network, you will find some information on this topic. When lighting researchers shifted from "thunder days" (as reported by weather station observers using the Mark I Human Ear) to RF-based detection systems, they discovered that the central Midwest had a lightning frequency as high as Florida. Just not as many people around to report it!

    sPh