Summary

Description

<p align="LEFT">  </p> <p> <font size="3">Near-simultaneously deployed chemical tracer trails over an extended horizontal range will be used to obtain measurements of the turbulent structure function and (the pair) relative velocity distribution over a range of spatial scales covering a full decade. </font></p> <p> <font size="3">Trimethyl aluminum trails (TMA) released in the mesosphere and lower thermosphere have been used to trace the neutral motions over 500 times since 1958. Such releases are a simple and reliable method for obtaining horizontal velocities with good accuracy and height resolution. Deriving the diffusion characteristics is more difficult but two detailed studies of the expansion rates have been carried out. Analyses from the earlier experiments show enhanced or anomalous diffusion rates in a 10 to 15 km altitude range above the turbopause. (MAJOR)</font></p> <p> <font size="3">Even if only partially successful, this study is expected to contribute significantly to our understanding of turbulent motions in the atmosphere as turbulence at small scales is currently poorly understood. (MINOR)</font></p> <p>  </p>