"SUPER" OR NOT, VOLCANIC ASH IS A SERIOUS THREAT TO AVIATION

April 8, 2005 — "Supervolcano" - a television movie airing on the Discovery Channel - explores the global impacts of an extreme volcanic eruption occurring in Yellowstone National Park. While actual volcanic events typically occur on a much smaller scale, airborne ash is no less of a serious threat to aviation. One mission of the National Oceanic and Atmospheric Administration is to support safe aviation through the detection and forecast of ash plumes.

More than 100 commercial and military aircraft have encountered volcanic ash clouds in flight. Consequences of these encounters include degraded engine performance (including flameout), loss of visibility and failure of critical navigational and operational instruments. Encounters have resulted in multiple engine failures, and disastrous crashes have been only narrowly averted. In addition to the threat to lives, aircraft damage with its attendant economic loss can be severe.

While the obvious strategy for an aircraft is to avoid flying into an ash plume, avoidance requires knowing where an ash plume exists. Often, ash plumes simply look like normal clouds and many encounters occur at night.

Pilots, dispatchers and air traffic controllers must be quickly informed of pre-eruptive volcanic activity, explosive eruptions and the location and direction of ash plumes anywhere they may occur around the globe.

On average, 15 major explosive eruptions — those powerful enough to inject ash above 25,000 feet — occur each year. Ash plumes from a major eruption can affect aircraft thousands of miles downwind. For example, when Mt. St. Helens erupted in 1980, the plume reached an altitude of 90,000 feet in 30 minutes and was 50 miles wide.

NOAA Volcanic Ash Products

NOAA operates two Volcanic Ash Advisory Centers – one in Anchorage , Alaska and the other in Camp Springs , Md. The centers issue advisory statements, including graphics and text messages about the location and size of the ash clouds, which are distributed through several global networks and posted online in real-time.

NOAA's National Centers for Environmental Prediction, also in Camp Springs , runs a Volcanic Ash Forecast Transport and Dispersion model that projects the trajectory and location of the clouds at different altitudes on certain time scales.

These advisories and dispersion model forecasts are sent to the Federal Aviation Administration, the U.S. Geological Survey, National Weather Service Forecast Offices, climate analysts and scientists throughout the world.

NOAA scientists and researchers use geostationary and polar-orbiting satellite imagery to track volcanic ash eruptions and ash clouds. NOAA also operates moored and free-floating data buoys in the world’s oceans, research ships and aircraft, and land-based environmental stations – all provide data that is used to track near term events like a possible eruption or to help combat wildfires, or for the long-term observation of the planet.

On the Web :

Volcanic Ash Advisory Centers

Washington , DC : http://www.ssd.noaa.gov/VAAC/washington.html

Anchorage , Alaska : http://www.alaska.net/~aawu/vaac.html

Volcanic Ash Transport And Dispersion (HYSPLIT Model): http://www.arl.noaa.gov/ready/ash.html

Media contacts:

Carmeyia Gillis, National Centers for Environmental Prediction, (301) 763-8000 x7163

Chris Vaccaro, NOAA's National Weather Service, (301) 713-0622 x134