Lanterna Rally

Author: Ralph M. Markson

Publisher:

Published: 1989

Total Pages: 342

ISBN-13:

This report is concerned with the relation of meteorological conditions to parameters and processes that influence the optical propagation properties of the turbulent atmosphere. The approach is centered around the use of aircraft and surface based remote sensors to investigate the relationship of the refractive index structure function parameter, Cn-sq, to various meteorological variables and to generally evaluate the accuracy of measurements of Cn-sq by in situ and remote means. the relationship of the atmospheric turbulence profile to the synoptic context and the use of physical models to predict the profile using standard meteorological profile data was also investigated. The study features two modes of data acquisition: 1) continuous archiving of 1 hr average wind profiles and turbulence levels with VHF doppler radar profiles, and 2) high time resolution aircraft measurements in association with other measurements (ground based optical scintillometers, thermosondes, radar profilers, and doppler sodar profilers). In one case all of the surface based systems were assembled in an intensive campaign given the acronym EWAK. The atmospheric turbulence profiles and resultant optical propagation parameters have been found to be strongly influenced by synoptic conditions. In particular, the turbulence is substantially affected by the strength and location of jet stream. A very strong correlation between wind shear (which is maximum above and below the core of the jet) and pilot reports of turbulence was found. Richardson number gave a much weaker indication possibly because of the poorer quality of the vertical temperature gradient data. (JHD).