Collaborative Research: NSWP: Generation of Global Forecasts of Middle and Upper Atmospheric Gravity Wave Activity as Applied to the Prediction of Equatorial Spread-F (ESF)

A global gravity wave model using ray-tracing techniques is produced and verified with ground-based and satellite data.. The methodology begins by ingesting daily analysis and five-day forecasts from the National Weather Service to identify tropospheric structures (synoptic and mesoscale systems, thunderstorms, hurricanes, etc.) that are known to be gravity wave sources. Gravity wave spectra assigned at the identified tropospheric sources are then propagated from the troposphere through the middle atmosphere and to 400 km altitude using extant linear ray-tracing numerical codes. The background atmosphere above the tropopause is characterized by models and by available data. The over-arching purpose is to evaluate the hypothesis that gravity-wave sources as triggers of Equatorial Spread-F (ESF), a phenomenon in the equatorial ionosphere characterized by large ion density depletions, or bubbles, reaching altitudes of 500 km and higher. These ionospheric irregularities are known to produce Global Positioning System radio frequency scintillations, and stand as an outstanding forecasting challenge for the Space Weather community.