Infrared scintillation measurements were obtained along a 7.2 km path over San Diego Bay, concurrently withmean meteorological and turbulence measurements obtained from a buoy located along the path. Bulk estimates andturbulence measurements of Cn2 were computed from the buoy data and compared with the optical scintillation-derivedCn2 values. Similar to the results of previous experiments, the bulk Cn2 estimates agreed well with both the scintillationand turbulence measurements in unstable conditions, increasingly underestimated Cn2 as conditions approached neutral,and agreed less well with scintillation and turbulence Cn2 values in stable conditions. The mean differences betweenbulk Cn2 estimates and both the turbulence and scintillation measurements when conditions were not near-neutralexhibited an air-sea temperature difference and wind speed dependence, possibly indicating that the forms of theempirical stability functions used by the bulk model are incorrect. The turbulent Cn2 measurements from the buoyshowed excellent agreement with the scintillation values in unstable conditions, but had surprisingly large differences inweakly stable conditions. This disagreement may be related to the fact that humidity fluctuations begin to increasinglyinfluence refractive index fluctuations when the air-sea temperature difference is small and are not properly taken intoaccount by the sonic temperature measurements. As the absolute air-sea temperature difference approaches zero the bulkCn2 estimates decrease much more rapidly and to much smaller values than either the scintillation or turbulencemeasurements. Fortunately, in such near-neutral conditions scintillation is usually small enough to have little effect onmany optical system applications.
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