15 December 2010

Lightning could help warn aircraft of volcanic eruptions

Posted by mohi

Volcano lightning

Lightning from a 2009 eruption of Alaska's Mount Redoubt. Photo courtesy of AVO/Bretwood Higman

Volcanic ash can be hazardous for airplanes, as many thousands of people learned when their flights were disrupted due to the Eyafjallajökull volcano earlier this year. Thus, it’s important for aircraft to have warming of possible volcanic eruptions.

Volcanoes around Europe are well monitored from the ground-based sensors.  However, many flights take routes over the volcanoes in the northern Pacific like Alaska’s Mount Redoubt and Russia’s Shiveluch. Many volcanoes in this zone are not well monitored from the ground. Satellites detect some eruptions, but additional warning could be valuable.

Some volcanic eruptions emit lightning–volcanic plumes are a lot like dirty thunderclouds.  Scientists wonder: Could this lightning be used to help warn airplane pilots of volcanic eruptions so they can avoid ash?

John Ewert of USGS reported this morning in session AE31A: Volcano Lightning I that he and colleagues have begun investigating whether the World Wide Lightning Location Network (WWLLN), which tracks lightning worldwide in near real time, could detect volcanic eruptions that emit lightning and use this information as part of an alert system for aircraft.

The trial has been going on for about 3 months, and during that time the WWLLN-based system sent 190 alerts.  The WWLLN system detected most of the more explosive volcanic eruptions during the trial period so far, and network is growing and could eventually be able to detect smaller eruptions as well, Ewert said.

In two instances during in the past 3 months, the WWLLN system provided advance warning of a volcanic eruption before the eruption was detected by any satellite remote sensor.  “These data alone can be a useful indicator of explosive activity,” Ewert concluded, adding that lightning data is best used in conjunction with other types of volcano monitoring.

–Ernie Tretkoff is a science writer for AGU