Evaluation of the structure parameter Cn2 over the sea surface

An estimate of the structure parameter C_n² is required to calculate the backscattering of radar energy by turbulent eddies in the surface layer over the sea. The theory of atmospheric boundary-layer turbulence may be applied, in conjunction with two spatial point measurements of meteorological parameters, to evaluate height profiles of C_n². The authors present contours of C_n² in the height/latitude plane using meteorological observations made on a cruise to Antarctica. Routinely monitored meteorological observations aboard ships have also been used to obtain the seasonal variations of C_n² over tropical oceans. The values of C_n² are found to be almost two order of magnitude higher at heights up to 30 m at tropical latitudes compared to those at high latitudes. The values of C_n² are higher in the winter-summer periods, compared to postmonsoon and monsoon periods