Clear Air Turbulence Indices Derived from U.S. Navy Numerical Model Data: AVerification Study

摘要

Two clear air turbulence indices (TI and CCAT) are computed using data from theNavy Operational Global Atmospheric Prediction System (NOGAPS) model. The TI index is based on deformation and vertical wind shear; the CCAT index is based on the advection of vertical stability and absolute vorticity. Verification of both indices is accomplished by comparing model-derived analyses and forecasts with pilot reports of turbulence intensity. Correlations between turbulence intensity and index value indicate that only the TI index has any ability (viz., minimal) in the forecasting of any arbitrary (smooth through severe) turbulence event. Verification statistics for both indices show high false alarm rates (indicative