A quasi-Lagrangian coordinate system based on high resolution tracer observations: implementation for the Antarctic polar vortex

In order to quantitatively analyse the chemical and dynamical evolution of the polar vortex it has proven extremely useful to work with coordinate systems that follow the vortex flow. We propose here a two-dimensional qu
In order to quantitatively analyse the chemical and dynamical evolution of the polar vortex it has proven extremely useful to work with coordinate systems that follow the vortex flow. We propose here a two-dimensional quasi-Lagrangian coordinate system {X i, delta X i}, based on the mixing ratio of a long-lived stratospheric trace gas i, and its systematic use with i = N2O, in order to describe the structure of a well-developed Antarctic polar vortex. In the coordinate system {X i, delta X i} the mixing ratio X i is the vertical coordinate and delta X i = X i(theta) - X i vort(theta) is the meridional coordinate (X i vort(theta) being a vertical reference profile in the vortex core). The quasi-Lagrangian coordinates {X i, delta X i} persist for much longer time than standard isentropic coordinates, potential temperature theta and equivalent latitude Phi e, do not require explicit reference to geographic space, and can be derived directly from high-resolution in situ measurements. They are therefore well-suited for studying the evolution of the Antarctic polar vortex throughout the polar winter with respect to the relevant chemical and microphysical processes. By using the introduced coordinate system {X N2O, delta X N2O} we analyze the well-developed Antarctic vortex investigated during the APE-GAIA (Airborne Polar Experiment – Geophysica Aircraft in Antarctica – 1999) campaign (Carli et al., 2000). A criterion, which uses the local in-situ measurements of X i=X i(theta) and attributes the inner vortex edge to a rapid change (delta-step) in the meridional profile of the mixing ratio X i, is developed to determine the (Antarctic) inner vortex edge. In turn, we suggest that the outer vortex edge of a well-developed Antarctic vortex can be attributed to the position of a local minimum of the X H2O gradient in the polar vortex area. For a well-developed Antarctic vortex, the delta X N2O-parametrization of tracer-tracer relationships allows to distinguish the tracer inter-relationships in the vortex core, vortex boundary region and surf zone and to examine their meridional variation throughout these regions. This is illustrated by analyzing the tracer-tracer relationships X i : X N2O obtained from the in-situ data of the APE-GAIA campaign for i = CFC-11, CFC-12, H-1211 and SF6. A number of solitary anomalous points in the CFC-11 : N2O correlation, observed in the Antarctic vortex core, are interpreted in terms of small-scale cross-isentropic dispersion.
show moreshow less

Download full text files

Export metadata

  • Export Bibtex
  • Export RIS

Additional Services

    Share in Twitter Search Google Scholar
Metadaten
Author:Elena V. Ivanova, C.-Michael Volk, Oliver Riediger, Holger Klein, Nikolay Sitnikov, Alexey Ulanovskii, Vladimir Yushkov, Fabrizio Ravegnani, Tanja Möbius, Ulrich Schmidt
URN:urn:nbn:de:hebis:30-83871
DOI:http://dx.doi.org/doi:10.5194/acpd-8-16123-2008
ISSN:1680-7375
Parent Title (English):Atmospheric chemistry and physics / Discussions
Publisher:European Geosciences Union
Place of publication:Katlenburg-Lindau
Document Type:Article
Language:English
Date of Publication (online):2010/10/26
Year of first Publication:2008
Publishing Institution:Univ.-Bibliothek Frankfurt am Main
Release Date:2010/10/26
Volume:8
Pagenumber:51
First Page:16123
Last Page:16173
Note:
© Author(s) 2008. This work is distributed under the Creative Commons Attribution 3.0 License.
HeBIS PPN:229859518
Institutes:Geowissenschaften
Dewey Decimal Classification:550 Geowissenschaften
Sammlungen:Universitätspublikationen
Licence (German):License Logo Veröffentlichungsvertrag für Publikationen

$Rev: 11761 $