[Matt Ribar]

Matt Ribar asked the Naked Scientists:

Does lightning hit water? If it does, which I presume, how far does the current go in depth and breadth? How many fish die from electrocution? This has been bothering me for years!

I love your podcasts, please keep them going! Thank You.
What do you think?

[LeeE]

Lightning does hit water but a study by Richard Orville and Bernard Vonnegut, using satellite imagery, showed that it happened only rarely over sea (at least at night-time, as only the night-time images could be used).  Google lightning and water for a lot of web pages on this topic.

[paul.fr]

Yes, lightning does hit water. This has been studied by the National Severe Storms Laboratory. According to Don MacGorman "When lightning strikes the ocean or other large water bodies, it spreads out over the conducting surface. It also penetrates down and can kill fish in the nearby region"..."Lightning strikes have killed or injured people on the surface more than 30 yards away," says David Schultz of the NSSL.
In fact, the 45th Weather Squadron lists water as the second most dangerous place to be during a thunderstorm. (The first is an open field.)
Lightning, however, rarely strikes most of the open ocean although some sea regions are lightning "hot spots". The Gulf Stream, for example, where fish abound, has as many lightning strikes as the southern plains of the USA.
Lightning-producing storms arrive on the west coast of the U.S. frequently during the winter, says Schultz. "Winter storms passing off the east coast often erupt with electrical activity when they cross the warm waters of the Gulf Stream."
But, as Schultz says: "We really have no idea about the mortality rate of marine animals due to thunderstorms." Fortunately, only 10 to 20% of humans hit by lightning die, and probably the same holds true for marine animals.

http://www.usatoday.com/tech/columnist/aprilholloday/2004-03-05-wonderquest_x.htm


You may also be aware that lightning is associated with hurricanes. There are (to my knowledge) two major occurances of lightning in the life cycle of a hurricane; the first being the transitional stage from tropical storm to hurricane and when there are significant changes inthe internal structure of a powerful hurricane.

There are ongoing studies, and some data, that suggests that the greater and more intense the lightning in the center of a hurricane, the stronger the hurricane.

Lightning locations from the National
Lightning Detection Network have proven to be a
useful indicator of convective outbreaks in incipient
and mature hurricanes that are within 400-500 km of
the U.S. coast. Such outbreaks often signal
substantial deepening of the storms (Molinari et al.
1994, 2004; Demetriades and Holle 2006). Lightning
distribution in tropical cyclones also gives insight
into their evolving thermodynamic structure.
Because major questions still remain about how
tropical cyclones form, lightning information is
potentially of significant value, both for prediction
and understanding of storms, during the early stages
of development.
though it remained over warm water. This writeup
will focus on the period that Claudette suddenly
gained, then lost, hurricane intensity. Of interest is
whether long range lightning data provide some
insight into the behavior of the storm.
2. RESULTS
Vertical wind shear represents a key variable
in tropical cyclone intensity change. Shelton (2005)
showed that vertical wind shear was strong from the
southwest and west-southwest during most of the
lifetime of TS/Hurricane Claudette. The distribution
of lightning flashes with respect to the storm center

http://ams.confex.com/ams/pdfpapers/103732.pdf