Abstract

Results are presented relating the presence of cloud to aircraft turbulence encounters. Specifically, positive and negative turbulence pilot reports (PIREPs) are compared to cloud top height and base (as determined from the Integrated Icing Detection Algorithm (IIDA)), to determine if the turbule... Show moreResults are presented relating the presence of cloud to aircraft turbulence encounters. Specifically, positive and negative turbulence pilot reports (PIREPs) are compared to cloud top height and base (as determined from the Integrated Icing Detection Algorithm (IIDA)), to determine if the turbulence reports were in cloud, above cloud, below cloud or in clear air. The data encompasses about a year and a half of continuous records of both IIDA output and PIREPs. Percentages of null, light, moderate, and severe encounters and their relations to cloud are presented as functions of aircraft altitude, time of year and cloud depth. A major finding is that for all positive turbulence encounters, only about 25-30% of the turbulence occurs in the absence of any type of cloud (convective or nonconvective). Show less