Building transport models from baroclinic wave experimental data

TL;DR

This study combines experimental data and theoretical modeling to analyze baroclinic waves in a rotating annulus, revealing transport barriers and flow structures that match observed patterns.

Contribution

It introduces a simple kinematic model and applies EOF analysis and Lagrangian descriptors to better understand baroclinic eddies and transport phenomena.

Findings

Transport barriers align with experimental flow patterns

Kinematic model effectively captures flow structures

EOF analysis reveals dominant modes in velocity and temperature fields

Abstract

In this paper we study baroclinic waves both from the experimental and the theoretical perspective. We obtain data from a rotating annulus experiment capable of producing a series of baroclinic eddies similar to those found in the mid-latitude atmosphere. We analyze the experimental outputs using two methods. First, we apply a technique that involves filtering data using Empirical Orthogonal Function (EOF) analysis, which is applied to both velocity and surface temperature fields. The second method relies on the construction of a simple kinematic model based on key parameters derived from the experimental data. To analyze eddy-driven fluid transport, we apply the method of Lagrangian descriptors to the underlying velocity field, revealing the attracting material curves that act as transport barriers in the system. These structures effectively capture the essential characteristics of the baroclinic flow and the associated transport phenomena. Our results show that these barriers are in good agreement with the transport patterns observed in the rotating annulus experiment. In particular, we observe that the structures obtained from the kinematic model, or the one derived in terms of filtered velocities, perform well in this regard.