A Simple Kinematic Model for the Lagrangian Description of Relevant Nonlinear Processes in the Stratospheric Polar Vortex
Victor José García-Garrido1, Jezabel Curbelo1,2, Carlos Roberto Mechoso3, Ana María Mancho1, and Stephen Wiggins41Instituto de Ciencias Matemáticas, CSIC-UAM-UC3M-UCM. C/ Nicolás Cabrera 15, Campus de Cantoblanco UAM, 28049 Madrid, Spain 2Departamento de Matemáticas, Facultad de Ciencias, Universidad Autonóma de Madrid, 28049 Madrid, Spain 3Department of Atmospheric and Oceanic Sciences, University of California at Los Angeles, Los Angeles, California 4School of Mathematics, University of Bristol. Bristol BS8 1TW, UK
Received: 13 Dec 2016 – Accepted for review: 14 Dec 2016 – Discussion started: 14 Dec 2016
Abstract. In this work we study the Lagrangian footprint of the planetary waves present in the Southern Hemisphere stratosphere during the Sudden Stratospheric Warming event that took place during September 2002. The Lagrangian analysis of the transport and mixing processes is carried out in the framework of dynamical systems theory, by means of a Lagrangian descriptor. We seek to describe the Lagrangian skeleton of geometrical structures that lead to filamentation phenomena and the breakdown of the polar vortex, and establish its relation with how planetary waves interact. Our approach is based on the construction of a simple kinematic model, inspired by the Fourier decomposition of the geopotential field. We show that this model is capable of reproducing the key Lagrangian features present on the reanalysis data such as the formation of filaments eroding the stratospheric polar vortex and the breakdown of the vortex.
García-Garrido, V. J., Curbelo, J., Mechoso, C. R., Mancho, A. M., and Wiggins, S.: A Simple Kinematic Model for the Lagrangian Description of Relevant Nonlinear Processes in the Stratospheric Polar Vortex, Nonlin. Processes Geophys. Discuss., doi:10.5194/npg-2016-81, in review, 2016.