Atmospheric optical turbulence strength, parametrized by the atmosphere refractive index Cn2, mainly depends on temperature fluctuations. Recently, using ultrasonic anemometers (USAM) for fast temperature measurements has become very attractive since it possesses the advantage of measuring Cn2 by a single-point device rather than along a path. Here, we performed a fundamental experiment with multiple devices measuring Cn2 in parallel, including a scintillometer and USAM at the center of its path on flat and uniform terrain. This campaign reveals that the main challenge for measuring turbulence strength using USAM occurs in meandering stable conditions, where the changes in wind speed and sonic temperature are lower than USAM sensitivity, and the energy budget deviates from the pure Kolmogorov spectrum. A detailed comparison of the scintillometer and USAM results enable us to optimize the calculation of Cn2 from the USAM measurements in meandering stable conditions.
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