Global warming and mesoscale eddy dynamics: An oceanic mechanism for dissipation of heat.

摘要

Is global warming increasing the amount of kinetic energy in the ocean? Meso-scale eddies dominate the kinetic energy of the oceans, and may be created by heat influenced baroclinic instability processes. Several novel mathematical techniques are developed for analyzing the mesoscale length and temporal periods using over eleven years of satellite altimetry. The first technique produces accurate, low-noise geostrophic currents from sea surface height measurements. Using this technique, a long-term secular trend in global eddy kinetic energy is found. Expanding the technique to two-dimensions, vorticity can be computed using future scanning altimeters. The most powerful new technique is the use of radial basis functions, which provide a continuous and infinitely differentiable function describing the sea surface topography from sparse altimeter samples. Using these functions, several regions of the globe are analyzed using higher-order dimensional fields to understand the processes present in the eddy field. By developing global and regional eddy statistics to understand the global circulation of energy, two hypotheses will be addressed: (1) increased heating of the ocean is generating an expansion of mesoscale eddy activity; and, (2) this eddy energy is the mechanism by which the ocean is dissipating the heat. Evidence is presented to show that baroclinic instabilities may be the generating force for eddies in certain regions along with model data showing increases in heat storage for the same regions.