An integrated geometric and topological approach for the identification and visual analysis of rossby wave packets

PANDEY, K and MONTEIRO, JM and NATARAJAN, V (2020) An integrated geometric and topological approach for the identification and visual analysis of rossby wave packets. In: Monthly Weather Review, 148 (8). pp. 3139-3155.

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Abstract

A new method for identifying Rossby wave packets (RWPs) using 6-hourly data from the ERA-Interim is presented. The method operates entirely in the spatial domain and relies on the geometric and topological properties of the meridional wind field to identify RWPs. The method represents RWPs as nodes and edges of a dual graph instead of the more common envelope representation. This novel representation allows access to both RWP phase and amplitude information. Local maxima and minima of the meridional wind field are collected into groups. Each group, called a y-max cluster or y-min cluster of the meridional wind field, represents a potential wave component. Nodes of the dual graph represent a y-max cluster or y-min cluster. Alternating y-max clusters and y-min clusters are linked by edges of the dual graph, called the RWP association graph. Amplitude and discrete gradient-based filtering applied on the association graph helps identify RWPs of interest. The method is inherently robust against noise and does not require smoothing of the input data. The main parameters that control the performance of the method and their impact on the identified RWPs are discussed. All filtering and RWP identification operations are performed on the association graph as opposed to directly on the wind field, leading to computational efficiency. Advantages and limitations of the method are discussed and are compared against (transform-based) envelope methods in a series of experiments. © 2020 American Meteorological Society.

Item Type:	Journal Article
Publication:	Monthly Weather Review
Publisher:	American Meteorological Society
Additional Information:	Copyright to this article belongs to American Meteorological Society
Keywords:	Computational efficiency; Mechanical waves; Wave packets, Amplitude information; Association graph; Discrete gradient; Envelope representation; Meridional winds; Topological approach; Topological properties; Visual analysis, Graph theory, cluster analysis; computational fluid dynamics; numerical model; Rossby wave; wind field; wind velocity
Department/Centre:	Division of Electrical Sciences > Computer Science & Automation
Date Deposited:	03 Dec 2020 11:50
Last Modified:	03 Dec 2020 11:50
URI:	http://eprints.iisc.ac.in/id/eprint/66761

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