Low altitude boyancy wave turbulence - a potential aviation safety threat
May 13, 2002
Weather comprises one of the most significant safety hazards facing civilian aviation today. This hazard has been significantly reduced by the development and use of microburst wind shear detection technologies such as the Low Level Wind Shear Alert System (LLWAS), the Terminal Doppler Weather Radar (TDWR), the ASR-9 Weather Systems Processor (WSP) and the Integrated Terminal Weather System (ITWS). Each was designed to detect and warn for the presence of low altitude wind shear resulting from microburst and gust fronts. These systems have made an unquestionable improvement in aviation safety; however, there are other forms of low altitude wind shear hazardous to aviation. This paper provides a description of a low altitude buoyancy wave (BW) induced turbulence phenomena that appears to also be a significant hazard to aviation. Buoyancy wave turbulence can be particularly dangerous since it often occurs outside regions containing intense precipitation where pilots typically expect to encounter thunderstorm induced wind shear conditions. Section 2 of this paper contains a general description of BW phenomena based on laboratory and observational studies. Section 3 will briefly summarize several incidents where commercial and civilian aircraft have encountered buoyancy waved induced turbulence. A summary and conclusions are made in section 4.