A new wave-vortex decomposition method for one-dimensional spectra

New York University, New York NY

Investigators

Abstract

Buhler DMS-1516324 This project systematically extends a recently discovered data analysis method that allows a precise wave-vortex decomposition of flow measurements along a fast-moving aircraft, ship, or satellite trajectory. Such a decomposition is crucial for the understanding of the observed data in many cases, especially in atmosphere and ocean fluid dynamics, where we are often presented with a complex jigsaw puzzle of waves and vortices far beyond the threshold of our contemporary simulation and observation tools. For example, this is highly relevant for extracting the maximum value out of expensive measurements obtained by aircraft, ships, and satellite-based remote sensing. The method plays fundamentally into our understanding of difficult fluid-mechanical processes that are highly relevant for climate dynamics. Graduate students are included in the work of the project. The new method is generally applicable to any fluid mechanical problem that involves stable stratification and/or Coriolis forces due to background rotation. Preliminary results with the new technique have been promising, but the technique is limited by a number of restrictive assumptions that had to be made to derive it cleanly. These include assumptions about horizontal isotropy and three-dimensional spatial homogeneity of the data as well as an assumed lack of statistical correlations between waves and vortices. The present project seeks to remove these restrictions, to make the new technique much more broadly applicable. This is achieved through a combination of theoretical analysis, modelling, and numerical simulation, as well as comparison and testing with real data from the atmosphere and ocean. Graduate students are included in the work of the project.