Transverse Coherence Length (ro) Observations

The transverse coherence length (r0) was directly measured approximately every 5 minutes from 29 August to 28 September 1984 at MTh, I,=1). An MTF-device was used with stellar sources for the ro observations. The diurnal variation of ro is discussed and related to processes affecting optical turbulence in the planetary boundary layer. A complete heat exchange study involving radiative, sensible heat, latent heat and soil heat fluxes is presented and related to ro values as well as to surface measured Cn. Of particular interest to the problem is the observed surface thermal activity. Vertical profile measurements of Cn, obtained from thermosondes at various times of the day and night, are presented to show the contributions of optical turbulence at various levels in the atmosphere to r o . Cn2 development as related to solar activity is discussed. The measured Cn2 profiles are compared to appropriate models.