scholarly journals Energetic particle induced intra-seasonal variability of ozone inside the Antarctic polar vortex observed in satellite data

2015 ◽  
Vol 15 (6) ◽  
pp. 3327-3338 ◽  
Author(s):  
T. Fytterer ◽  
M. G. Mlynczak ◽  
H. Nieder ◽  
K. Pérot ◽  
M. Sinnhuber ◽  
...  
Keyword(s):  
Geomagnetic Activity ◽  
Seasonal Variability ◽  
Transport Model ◽  
Three Dimensional ◽  
Polar Vortex ◽  
Quiet Time ◽  
Significance Level ◽  
Antarctic Polar Vortex ◽  
Ap Index ◽  
The Antarctic

Abstract. Measurements from 2002 to 2011 by three independent satellite instruments, namely MIPAS, SABER, and SMR on board the ENVISAT, TIMED, and Odin satellites are used to investigate the intra-seasonal variability of stratospheric and mesospheric O3 volume mixing ratio (vmr) inside the Antarctic polar vortex due to solar and geomagnetic activity. In this study, we individually analysed the relative O3 vmr variations between maximum and minimum conditions of a number of solar and geomagnetic indices (F10.7 cm solar radio flux, Ap index, ≥ 2 MeV electron flux). The indices are 26-day averages centred at 1 April, 1 May, and 1 June while O3 is based on 26-day running means from 1 April to 1 November at altitudes from 20 to 70 km. During solar quiet time from 2005 to 2010, the composite of all three instruments reveals an apparent negative O3 signal associated to the geomagnetic activity (Ap index) around 1 April, on average reaching amplitudes between −5 and −10% of the respective O3 background. The O3 response exceeds the significance level of 95% and propagates downwards throughout the polar winter from the stratopause down to ~ 25 km. These observed results are in good qualitative agreement with the O3 vmr pattern simulated with a three-dimensional chemistry-transport model, which includes particle impact ionisation.

scholarly journals Energetic particle induced inter-annual variability of ozone inside the Antarctic polar vortex observed in satellite data

2014 ◽  
Vol 14 (22) ◽  
pp. 31249-31279
Author(s):  
T. Fytterer ◽  
M. G. Mlynczak ◽  
H. Nieder ◽  
K. Pérot ◽  
M. Sinnhuber ◽  
...  
Keyword(s):  
Geomagnetic Activity ◽  
Transport Model ◽  
Three Dimensional ◽  
Polar Vortex ◽  
Quiet Time ◽  
Significance Level ◽  
Annual Variability ◽  
Antarctic Polar Vortex ◽  
Ap Index ◽  
The Antarctic

Abstract. Measurements from 2002–2011 by three independent satellite instruments, namely MIPAS, SABER, and SMR on board the ENVISAT, TIMED, and Odin satellites are used to investigate the inter-annual variability of stratospheric and mesospheric O3 volume mixing ratio (vmr) inside the Antarctic polar vortex due to solar and geomagnetic activity. In this study, we individually analysed the relative O3 vmr variations between maximum and minimum conditions of a number of solar and geomagnetic indices (F10.7 cm solar radio flux, Ap index, ≥ 2 MeV electron flux). The indices are 26 day averages centred at 1 April, 1 May, and 1 June while O3 is based on 26 day running means from 1 April–1 November at altitudes from 20–70 km. During solar quiet time from 2005–2010, the composite of all three instruments reveals an apparent negative O3 feedback associated to the geomagnetic activity (Ap index) around 1 April, on average reaching amplitudes between −5 and −10% of the respective O3 background. The O3 response exceeds the significance level of 95% and propagates downwards throughout the polar winter from the stratopause down to ∼ 25 km. These observed results are in good qualitative agreement with the O3 vmr pattern simulated with a three-dimensional chemistry-transport model, which includes particle impact ionisation.

scholarly journals The Gradient Genesis of Stratospheric Trace Species in the Subtropics and around the Polar Vortex

2008 ◽  
Vol 65 (2) ◽  
pp. 490-508 ◽  
Author(s):  
Kazuyuki Miyazaki ◽  
Toshiki Iwasaki
Keyword(s):  
Transport Model ◽  
Polar Vortex ◽  
Vertical Transport ◽  
Chemical Transport Model ◽  
Meridional Transport ◽  
Trace Species ◽  
Smoothing Effects ◽  
Shearing Deformation ◽  
Antarctic Polar Vortex ◽  
The Antarctic

Abstract Mechanisms that control the formation and decay of meridional gradients in stratospheric trace species in the subtropics and around the polar vortex are investigated using a gradient genesis equation that uses mass-weighted isentropic zonal means. Application of this method to global nitrous oxide (N2O) data output from a global chemical transport model shows that mean vertical transport increases the meridional tracer gradient from the subtropics to midlatitudes through the shearing deformation, particularly related to overturning of the Brewer–Dobson circulation. Mean meridional transport advects the subtropical tracer gradient toward midlatitudes, while the eddy stairstep effect, steepening at the edge of the well-mixed region because of a meridional gradient in the diffusion coefficient, increases the tracer gradient in the subtropics and around the polar vortex. Mechanisms controlling the evolution of the tracer gradients in the subtropics differ between spring and autumn. The autumnal subtropical tracer gradient maximum is generated mainly from shearing deformation of the mean vertical transport, but less from mean and eddy meridional fluxes. In spring, the eddy stairstep effect also contributes to the generation of the subtropical tracer gradient maximum. Strong divergence forces stretching deformation that causes the springtime subtropical tracer gradient to decay. The gradient genesis mechanism around the Antarctic polar vortex is significantly different from that in the subtropics. Development of the tracer gradient around the Antarctic polar vortex is mostly controlled by mean meridional stretching motion in the middle stratosphere. Vertical advection and eddy smoothing effects flatten the tracer gradient as the polar vortex decays.

scholarly journals Insights into the three-dimensional Lagrangian geometry of the Antarctic polar vortex

2017 ◽  
Vol 24 (3) ◽  
pp. 379-392 ◽  
Author(s):  
Jezabel Curbelo ◽  
Víctor José García-Garrido ◽  
Carlos Roberto Mechoso ◽  
Ana Maria Mancho ◽  
Stephen Wiggins ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Polar Vortex ◽  
Reanalysis Data ◽  
Strong Mixing ◽  
Mixing Processes ◽  
Stratospheric Polar Vortex ◽  
Vertical Extension ◽  
Antarctic Polar Vortex ◽  
The Antarctic ◽  
Lagrangian Geometry

Abstract. In this paper we study the three-dimensional (3-D) Lagrangian structures in the stratospheric polar vortex (SPV) above Antarctica. We analyse and visualize these structures using Lagrangian descriptor function M. The procedure for calculation with reanalysis data is explained. Benchmarks are computed and analysed that allow us to compare 2-D and 3-D aspects of Lagrangian transport. Dynamical systems concepts appropriate to 3-D, such as normally hyperbolic invariant curves, are discussed and applied. In order to illustrate our approach we select an interval of time in which the SPV is relatively undisturbed (August 1979) and an interval of rapid SPV changes (October 1979). Our results provide new insights into the Lagrangian structure of the vertical extension of the stratospheric polar vortex and its evolution. Our results also show complex Lagrangian patterns indicative of strong mixing processes in the upper troposphere and lower stratosphere. Finally, during the transition to summer in the late spring, we illustrate the vertical structure of two counterrotating vortices, one the polar and the other an emerging one, and the invariant separatrix that divides them.

Supplementary material to "Insights on the three-dimensional Lagrangian geometry of the Antarctic Polar Vortex"

2017 ◽  
Author(s):  
Jezabel Curbelo ◽  
Victor J. García-Garrido ◽  
Carlos R. Mechoso ◽  
Ana M. Mancho ◽  
Stephen Wiggins ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Polar Vortex ◽  
Supplementary Material ◽  
Antarctic Polar Vortex ◽  
The Antarctic ◽  
Lagrangian Geometry

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

2008 ◽  
Vol 8 (4) ◽  
pp. 16123-16173 ◽  
Author(s):  
E. V. Ivanova ◽  
C. M. Volk ◽  
O. Riediger ◽  
H. Klein ◽  
N. M. Sitnikov ◽  
...  
Keyword(s):  
High Resolution ◽  
Coordinate System ◽  
Vortex Core ◽  
Polar Vortex ◽  
Mixing Ratio ◽  
Lagrangian Coordinate ◽  
Antarctic Polar Vortex ◽  
The Antarctic ◽  
Lagrangian Coordinate System

Abstract. 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 {χi, Δχi}, 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 {χi, Δχi} the mixing ratio χi is the vertical coordinate and Δχi = χi(Θ)−χivort(Θ) is the meridional coordinate (χivort(Θ) being a vertical reference profile in the vortex core). The quasi-Lagrangian coordinates {χi, Δχi} persist for much longer time than standard isentropic coordinates, potential temperature Θ and equivalent latitude φe, 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 {χN2O, ΔχN2O} 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 χi=χi(Θ) and attributes the inner vortex edge to a rapid change (δ-step) in the meridional profile of the mixing ratio χi, 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 χH2O gradient in the polar vortex area. For a well-developed Antarctic vortex, the ΔχN2O-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 χi : χN2O 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.

scholarly journals EOS Microwave Limb Sounder observations of the Antarctic polar vortex breakup in 2004

2005 ◽  
Vol 32 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
G. L. Manney ◽  
M. L. Santee ◽  
N. J. Livesey ◽  
L. Froidevaux ◽  
W. G. Read ◽  
...  
Keyword(s):  
Polar Vortex ◽  
Antarctic Polar Vortex ◽  
The Antarctic

Examination of the 2002 major warming in the southern hemisphere using ground-based and Odin/SMR assimilated data: stratospheric ozone distributions and tropic/mid-latitude exchange

2007 ◽  
Vol 85 (11) ◽  
pp. 1287-1300 ◽  
Author(s):  
H Bencherif ◽  
L El Amraoui ◽  
N Semane ◽  
S Massart ◽  
D Vidyaranya Charyulu ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Southern Hemisphere ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Polar Vortex ◽  
Low Latitude ◽  
Height Range ◽  
Weather Forecasts ◽  
European Centre

Following an exceptionally active winter, the 2002 Southern Hemisphere (SH) major warming occurred in late September. It was preceded by three minor warming events that occurred in late August and early September, and yielded vortex split and break-down over Antarctica. Ozone (O3 and nitrous oxide (N2O) profiles obtained during that period of time (15 August – 4 October) by the Sub-Millimetre Radiometer (SMR) aboard the Odin satellite are assimilated into MOCAGE (Modélisation Isentrope du transport Mésoéchelle de l'Ozone Stratosphérique par Advection), a global three-dimensional chemistry transport model of Météo-France. The assimilated algorithm is a three-dimensional-FGAT built by the European Centre for Research and Advance Training in Scientific Computation (CERFACS) using the PALM (Projet d'Assimilation par Logiciel Multi-méthode) software. The assimilated O3 and N2O profiles and isentropic distributions are compared to ground-based measurements (LIDAR and balloon-sonde) and to maps of advected potential vorticity (APV). The latter is computed by the MIMOSA (Modélisation Isentrope du transport Mésoéchelle de l'Ozone Stratosphérique par Advection) model, a high-resolution advection transport model, using meteorological fields from the European Centre for Medium-Range Weather Forecasts (ECMWF). It is found that O3 concentrations retrieved by the MOCAGE–PALM assimilation system show a reasonably good agreement in the 20–28 km height range when compared with ground-based profiles. This altitude range corresponds to the intersection between the MOCAGE levels (0–28 km) and SMR O3 retrievals (20–50 km). Moreover, comparison of N2O assimilated fields with MIMOSA APV maps indicates that the dramatic split and subsequent break-down of the polar vortex, as well as the associated mixing of mid- and low-latitude stratospheric air, are well resolved and pictured by MOCAGE–PALM. The present study demonstrates also that the tremendous dynamics and associated polar vortex deformations during the 2002-austral-winter have modified ozone and nitrous oxide distributions not only at the vicinity of the polar vortex, but over topics and subtropics as well. PACS Nos.: 92.60.H–, 92.60.Hd, 92.70.Cp, 92.70.Gt

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