CHARACTERIZATION OF PACIFIC OCEAN SURFACE TEMPERATURES USING EULERIAN MOTION MAGNIFICATION

Abstract:

The Eulerian Motion Magnification Method was used in order to identify the spatial-temporal patterns in the variability of sea-surface temperatures (SST) in the Pacific Ocean. This method, developed by a research team at MIT, consists in jointly applying spatial and temporal filters to a sequence of images with a known playback speed, and then amplifying the intensity of a signal associated with a certain frequency, so that periodic phenomena can be easily displayed. Magnifying the SST in the frequency band of 2-7 years – which corresponds to ENSO- various processes can be clearly observed, such as the dynamics of temperature variability in the Pacific Ocean associated with the occurrence of warm and cool episodes of the differentiated ocean warming type (Central-Pacific El Nino and Eastern-Pacific El Nino), the possible interaction between tropical and extra-tropical waves that may enhance or diminish the possible ENSO events, and it displays that the ocean heating and/or cooling patterns can be represented as Kelvin and Rosby wave propagation at inter-annual scale.