Abstract: Forecast and ?analysis? (reference) trajectories were computed from six sites over North America at three altitudes (500, 1000, and 1500 m above ground) twice a day for a one-year period using Nested Grid Model wind fields. ...

Abstract: Perfluorocarbon tracer concentration profiles measured by aircraft 600?900 km downwind of the release locations during CAPTEX are discussed and compared with some model results. In general, the concentrations decreased ...

Abstract: The National Oceanic and Atmospheric Administration (NOAA) Air Resources Laboratory (ARL) has developed a Volcanic Ash Forecast Transport And Dispersion (VAFTAD) model for emergency response use focusing on hazards to ...

Abstract: The Redoubt Volcano in Alaska began a series of eruptions on 14 December 1989. Volcanic ash was often reported to reach heights where, as it moved with the upper-level flow, it could affect aircraft operations thousands ...

Abstract: In support of aircraft flight safety operations, daily comparisons between modeled, hypothetical, volcanic ash plumes calculated with meteorological forecasts and analyses were made over a 1.5-yr period. The Hybrid ...

Abstract: A detailed evaluation of NOAA?s Smoke Forecasting System (SFS) is a fundamental part of its development and further refinement. In this work, particulate matter with a diameter less than or equal to 2.5-?m (PM2.5) concentration ...