Ocean first-modal Rossby wave signal separation and extraction method

Abstract

The invention discloses and relates to a separation and extraction technology and algorithm for a first oblique pressure mode Rossby wave signal of an ocean. The algorithm is based on an altimeter satellite sea surface height abnormal data fusion product and an altimeter vortex identification algorithm in 2016-2019, and is based on a series of theoretically designed 2D-FIR filters. According to the method, the true existence of ocean Rossby is proved, and the proportion of true Rossby wave signals in each ocean is quantitatively evaluated by introducing the initial vortex field signals. It is found that the dominant wave signal in the ocean is a two-year and annual-period Rossby wave signal which is most significant in the Pacific Ocean (as high as 25% in the middle latitude), the most significant annual-period Rossby wave signal exists in the Indian Ocean, and the Rossby variable wave signal in the Atlantic Ocean is weaker. According to the method, quantitative evaluation of the ocean Rossby wave energy is realized for the first time, data reference can be provided for updating an ocean numerical mode, and contributions are made to research on promoting air-sea interaction, climate change and the like.

Description

technical field [0001] The invention relates to the technical field of physical ocean monitoring and analysis, in particular to a method for separating and extracting Rossby wave signals of the first ocean mode. Background technique [0002] Oceanic Rossby waves and mesoscale eddies, as the two main manifestations of the ocean's response to atmospheric drives, play a vital role in the momentum balance and material circulation of the global ocean. The vortex has significant ocean current characteristics. In the horizontal direction, it presents an annular structure with closed streamlines, and the flow velocity is one to two orders of magnitude larger than that of the background circulation in the inner ocean; in the vertical direction, the cyclonic and anticyclonic vortices correspond to the thermocline respectively. The upflow and downflow generated by the uplift and downpressure are also one to two orders of magnitude larger than the vertical velocity of the background ci...

AI Technical Summary

Problems solved by technology

However, limited by the low spatio-temporal resolution of the single-point sampling mode of the contemporary satellite altimeter, the co-propagating eddy can be displayed as a wave-like structure mode in the sea level anomaly (SLA) field

Based on potential vortex conservation, vortices and Rossby waves have similar inherent westward propagation speeds, so vortices can also be disguised as Rossby waves in low-resolution altimetry data fields, which seriously hinders the clear extraction of oceanic Rossby waves , making the signal separation of oceanic Rossby and mesoscale eddies a century-old problem

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