ESRL Global Systems Division

New FIM-CHEM-Ash Produces Real-time Volcanic Ash Forecasts

Last month European authorities canceled 100,000 flights affecting 10 million passengers and costing the aviation industry billions in lost business due to the eruption of Icelandic volcano Eyjafjallajökull. NOAA has established a volcanic ash forecast response effort toward improved international guidance. ESRL answered the request with a new forecasting model, the FIM-CHEM-Ash, that began producing experimental real-time volcanic ash forecasts in May. This is the first time that a global model has been run with in-line chemistry, with 17 aerosol and gas-phase tracer concentrations and four size bins of volcanic ash.

The model currently includes only eruption data from Eyjafjallajökull and has cycled 14 aerosol concentration and three gas-phase prognostic variables since April 14, the start of Eyjafjallajökull's explosive eruption. Using the Global Forecast System for atmospheric initial conditions, the FIM-CHEM-Ash is run at 30-km resolution and maintains the aerosol/ash cycling with new 5-day forecasts run on a daily basis. The inline treatment of chemistry and ash (interaction with other meteorological variables) within FIM-Chem-Ash will very likely provide a considerable improvement over current abilities to predict ash dispersion with regards to both accuracy and timeliness.

These new runs, though still under development and not considered official guidance, assist the international Volcanic Ash Advisory Center (VAAC) community as it continues to deal with new waves of dense volcanic ash in European airspaces and will be helpful for future volcanic eruptions worldwide. There are nine strategically located VAACs that were created when the International Civil Aviation Organization and other Aviation concerns recognized the need to keep aviators informed of volcanic hazards.

To learn more about the unique design features of the FIM Global model and to view real-time data snapshots of the FIM-Chem-Ash runs go to:

Contact information
Name: Stan Benjamin
Tel: 303-497-6387