Authors:	Mayer, Amelie Wirth, Volkmar
Title:	Lagrangian description of the atmospheric flow from Eulerian tracer advection with relaxation
Online publication date:	3-Aug-2023
Year of first publication:	2023
Language:	english
Abstract:	The Lagrangian representation of fluid flows offers a natural perspective to study many kinds of physical mechanisms. By contrast, the Eulerian representation is more convenient from a diagnostic point of view. This article attempts to combine elements of both worlds by proposing an Eulerian method that allows one to extract Lagrangian information about the atmospheric flow. The method is based on the offline advection of passive tracer fields and includes a relaxation term. The latter device allows one to run the integration in a continuous fashion without the need for reinitialization. As a result one obtains accumulated Lagrangian information, for example, about the recent parcel displacement or the recent parcel-based diabatic heating, at each point of an Eulerian grid at any time step. The method is implemented with a pseudospectral algorithm suitable for gridded global atmospheric data and compared with the more traditional trajectory method. The method's utility is demonstrated on the basis of a few examples, which relate to cloud formation and the development of temperature anomalies. The examples highlight that the method provides a convenient diagnostic of parcel-based changes, paving an intuitive way to explore the physical processes involved. Due to its gridpoint-based nature, the proposed method can be applied to large data sets in a straightforward and computationally efficient manner, suggesting that the method is particularly useful for climatological analyses.
DDC:	530 Physik 530 Physics 550 Geowissenschaften 550 Earth sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 08 Physik, Mathematik u. Informatik
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-9341
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Journal:	Quarterly journal of the Royal Meteorological Society 149 753
Pages or article number:	1271 1292
Publisher:	Wiley
Publisher place:	Weinheim u.a.
Issue date:	2023
ISSN:	0035-9009
Publisher DOI:	10.1002/qj.4453
Appears in collections:	DFG-491381577-H