| Summary: | An attempt to describe the atmospheric boundary layer during the MIZEX 84 from 11 July to 17 July was made using a sodar system. The computation of the temperature structure parameter CT^ in the surface layer using in situ measurements allowed the calibration of the system. CT^ was found to have the following functional dependence on the backscattered signal I: Log(CT2)= 8.63Log(I) -25.66. Time-height cross-sections showed very well the structure of the boundary layer. An especially good representation of the strength of CT^ in the inversion layer was achieved. A program was developed to obtain the inversion layer height Zi, where the signal reaches a maximum. The thickness of the inversion layer was also computed and was used with the calibration law to compute CT^ at the inversion layer. This allowed the computation of the jump of potential temperature and the refractive index gradient in the inversion under free convection. Refractive trapping conditions were evident on 15 July although the generally small value of the heat flux did not indicate a strongly unstable boundary layer. Comparaison with two radiosonde profiles shows good agreement in one case, but does not permit a reliable conclusion to be made concerning the method. However, the procedure could be extended to other areas, especially those with strong free convection. The method should provide a good estimate of the refractive condition in the atmospheric boundary layer. Approved for public release; distribution is unlimited. Lieutenant de Vaisseau, French Navy http://archive.org/details/aninvestigationo1094521394
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