Evidence of a fluctuation theorem for the input of mechanical power
to the ocean at the air-sea interface from satellite data
Abstract. The ocean dynamics is predominantly driven by the shear between the atmospheric winds and ocean currents. The ocean mostly receives energy, but it can also lose energy. Building on 24-years of global satellite observations, the input of mechanical power to the ocean is analysed. A Fluctuation Theorem (FT) holds when the logarithm of the ratio between the occurrence of positive and negative events, of a certain magnitude of the power input, is a linear function of this magnitude and the averaging period. The input of mechanical power into the ocean shows evidence of a FT, for regions within the recirculation area of the subtropical gyre, but not over extensions of Western Boundary Currents. A FT puts a strong constraint on the temporal distribution of fluctuations of power input, connects variables obtained with different length of temporal averaging and guides the temporal down- and up-scaling and constrains the occurrence of extreme events.