Clear air turbulence over South Africa

Abstract

Clear air turbulence (CAT) at high altitude remains a hazard to aviation which can result in passenger injury and aircraft damage. Two limited surveys of CAT events over South Africa, 1993–1995 (inclusive) and 1998, are used to illustrate the most likely synoptic conditions under which CAT can be expected. A case study of CAT associated with an upper‐air trough and a mountain wave is presented. The study also evaluates the effectiveness of the Ellrod Turbulence Index (ETI) derived from model data provided by the UK Met. Office. A forecast of ETI derived from the Global Spectral Model of the United States National Center for Environmental Prediction (NCEP) is also reviewed. Copyright © 2001 Royal Meteorological Society

Global Response of Clear‐Air Turbulence to Climate Change

“…Without warning, aircraft can be violently thrown about by CAT. Any unsecured objects and unbuckled passengers and crew can be tossed around the cabin, causing serious injuries and even fatalities (De Villiers & van Heerden, 2001). The part of the flight most prone to injuries from CAT is the cruising phase above 10,000 ft, because passengers and crew are often unbuckled (Sharman et al, 2006).…”

Impacts of explicitly simulated gravity waves on large-scale circulation

“…Gravity waves have also been a major source of clear air turbulence (Knox 1997), which is a top hazard to aircraft (de Villiers andvan Heerden 2001, Clark et al 2000 andothers). They also trigger instabilities that cause severe weather (Hooke 1996).…”