Tuesday, April 20, 2010
Missing Optics and Volcanic Lightning
Photo from Marco Fulle, National Geographic Daily News
In the lead-up to CLEO I have been trying to do some work in the MID-IR wavelength range. I have been waiting for some CaF2 lenses that were due to arrive a few days ago only to find that they were held up by the ash plume from Eyjafjallajokull's recent eruptions. It turns out that the distribution center from where my lenses were to be shipped is in Germany.
Searching the news for more information, I learned about the woes of poor stranded European travelers (rock stars, film-makers and pro-wrestlers included; it seems ash plumes don't discriminate),how to pronounce the name of the Icelandic volcano that caused all of this trouble (by the way it is EY-ya-fyat-lah-YOH-kuht), debate among officials about the safety of flying through ash plumes, but most interesting to the scientist in me, volcanic lightning.
I stumbled across these stunning pictures on the NY Times blog Lens from Icelandic photographer Ragnar Th. Sigurdsson. These photos that show the explosions, ash, and volcanic lightning from Eyjafjallajokull seem to be more like something from a George Lucas film (like that fiery lava planet in Star Wars: Episode III) than reality.
I then did some browsing on volcanic lightning to find some more photos and some explanation . The same ingredients in the eruption are found in thunderstorms: water droplets, ice, and particles all interacting. The ash plume provides lots of surface area for charging. I am reminded of stories I've read about the dust bowl in the plains of the U.S. during the 1930s when people refused to shake hands for fear of large static shock and that they also dragged chains from the tailgates of their cars to ground charge build-up. I guess it should be a no-brainer that lots of moving dust = lots of static build up.
I wish those still delayed in Western Europe safe and uninterrupted travel. May your delays be short. Maybe my lenses will arrive soon too...
Posted by Jim at 11:25 AM