The spatial variability of coastal surface water temperature during upwelling

Abstract Thermal scanner imagery acquired during a field experiment designed to study an upwelling event in Lake Superior is investigated. Temperature data were measured by the thermal scanner, with a spatial resolution of 7 m. These data were correlated with temperatures measured from boats. One- and two- dimensional Fourier transforms of the data were calculated and temperature variances as a function of wavenumber were plotted. A k−3 dependence of the temperature variance on wavenumber was found in the wavenumber range of 1 to 25 km−1. At wavenumbers >25 km−1. a k−5/3 dependence was found.