Turbulence Generated by Mesoscale Convective Systems

Mesoscale convective systems generate turbulence both within cloudy air and in the clear air surrounding them. Convectively-induced turbulence (CIT) is an aviation hazard, and the out-of-cloud CIT can pose a significant risk of unexpected encounters because it is invisible and is unable to be detected using standard on-board radar technology. In the last decade there have been a significant improvements in the understanding of CIT generation mechanisms. Case studies, high-resolution simulations, and new measurements from commercial aircraft have facilitated these improvements, and have identified specific regions within and around mesoscale convective systems as preferred regions of turbulence occurrence.

In this presentation, the recent advances in the understanding of CIT will be summarized. A number of case studies will be presented as well as attempts to characterize the turbulence and its intensity using very high resolution idealized simulations. These cases and simulations highlight the importance of gravity waves and dynamic instabilities induced by mesoscale circulations in the CIT generation process.