[세미나] 김정훈 교수님

November 19, 2018

Research on Aviation Turbulence Forecasting


김정훈 교수 (서울대학교)

2018년 11월 20일 (화) 16:00

과학관 553호


Abstract

Research on Aviation Turbulence Forecasting

Operational Numerical Weather Prediction (NWP) model outputs are used to develop an algorithm of aviation turbulence forecasts. This computes a set of diagnostics that identify regions of strong spatial gradients of meteorological variables related to various generation mechanisms for Clear-Air and Mountain-Wave Turbulence. Then, using the empirical mapping technique, these indicators are converted into an equivalent Energy Dissipation Rate (EDR) to the 13 power. This atmospheric turbulence metric is the International Civil Aviation Organization standard for aircraft reporting and thus provides a convenient basis for verification. Implicit in the process is the assumption of a downscale cascade of energy from the large scales resolved by operational NWP models to the smaller scales aircraft feel as turbulence (~hundreds of meter) in the Upper Troposphere and Lower Stratosphere. Finally, probabilistic forecasts are provided from the diagnostic ensemble as well as from the NWP initial ensemble, so that it takes into account uncertainties in both the NWP model and turbulence diagnostics. Statistical verifications of the algorithm are examined using the Relative Operator Characteristic curves derived through comparisons to a global archive of in situ EDR data during the research period. It is found that probabilistic EDR forecast is superior to the current operational forecast product, which is based on a single turbulence index for turbulence potential. Related research topics like “Combined wind and turbulence prediction for automated Air-Traffic Management (ATM)“, “Impact of North Atlantic Oscillation (NAO) on transatlantic flight routes, and CAT potential”, and “Update of MWT by reducing unphysical topography” will be presented in the seminar as well.