TY - JOUR
A1 - Ivanova, Elena V.
A1 - Volk, C.-Michael
A1 - Riediger, Oliver
A1 - Klein, Holger
A1 - Sitnikov, Nikolay
A1 - Ulanovskii, Alexey
A1 - Yushkov, Vladimir
A1 - Ravegnani, Fabrizio
A1 - Möbius, Tanja
A1 - Schmidt, Ulrich
T1 - A quasi-Lagrangian coordinate system based on high resolution tracer observations: implementation for the Antarctic polar vortex
T2 - Atmospheric chemistry and physics / Discussions, 8.2010, S. 16123-16173
N2 - 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.
Y1 - 2008
UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/20113
UR - https://nbn-resolving.org/urn:nbn:de:hebis:30-83871
SN - 1680-7375
SN - 1680-7367
N1 - © Author(s) 2008. This work is distributed under the Creative Commons Attribution 3.0 License.
VL - 8
SP - 16123
EP - 16173
PB - European Geosciences Union
CY - Katlenburg-Lindau
ER -