The refractive index structure parameter, C 2 n , for a year over the frozen Beaufort Sea

The Arctic Ice Dynamics Joint Experiment (AIDJEX) produced a year of continuous, 6‐hourly observations of the surface fluxes of momentum and sensible and latent heat over the drifting ice of the Beaufort Sea. From this data set I compute the refractive index structure parameter C 2 n at four electromagnetic wavelengths—one each in the visible (0.55 μm), the mid‐infrared (10.6 μm), the near‐millimeter (0.337 mm or 890 GHz), and the radio regions. I present the resulting C 2 n values as histograms sorted according to the four seasons, spring, summer, autumn, and winter. Because each histogram derives from at least 300 C 2 n values, this is one of the largest studies of C 2 n climatology ever reported. For all four wavelengths the winter C 2 n histograms are the narrowest and have the highest peaks; the summer histograms are the broadest and most uniform. For the shorter wavelengths (0.55 and 10.6 μ) the mode value of C 2 n shows a seasonal progression; the maximum is in winter, the minimum in summer. The longer wavelengths (0.337 mm and radio) do not show a clear seasonal trend in the mode C 2 n value; although the C 2 n distributions change shape with season, the mode value is fairly constant. The beta distribution is a useful probabilistic model for the C 2 n histograms.