Vector-Valued Spectral Analysis of Indo-Pacific Climate Variability — Australian Meteorological and Oceanographic Society

Vector-Valued Spectral Analysis of Indo-Pacific Climate Variability (#155)

Joanna Slawinska 1 , Dimitrios Giannakis 2
  1. Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
  2. Courant Institute of Mathematical Sciences, New York University, New York, NY, United States

We study Indo-Pacific variability using a recently developed framework for spatiotemporal pattern extraction called Vector-Valued Spectral Analysis (VSA). This approach is based on the eigendecomposition of a kernel integral operator acting on vector-valued observables (spatially extended fields) of the dynamical system generating the data, constructed by combining elements of the theory of operator-valued kernels for multitask machine learning with delay-coordinate maps of dynamical systems. A key aspect of this method is that it utilizes a kernel measure of similarity that takes into account both temporal and spatial degrees of freedom (whereas classical techniques such as EOF analysis are based on aggregate measures of similarity between “snapshots”). As a result, VSA has high skill in extracting physically meaningful patterns with intermittency in both space and time, while factoring out any symmetries present in the data. We demonstrate the efficacy of this method with applications to various model and observational datasets of oceanic and atmospheric variability in the Indo-Pacific sector. In particular, the recovered VSA patterns provide a more realistic representation of ENSO diversity than conventional kernel algorithms.

#AMOS2019