Dynamical modes associated with the Antarctic ozone hole Atmospheric Science Program, Department of Land, Air and Water Resources, University of California-Davis, Davis, CA 95616, USA
Received: 11 Dec 2008 – Published in Atmos. Chem. Phys. Discuss.: 25 Feb 2009 – Published: 03 Aug 2009Abstract. Generalized Maximum Covariance Analysis (GMCA) has been developed and
applied to diagnosing the dynamical modes associated with variations in the
Antarctic spring ozone hole. GMCA is used to identify the most important
patterns of co-variability between interannual ozone mixing ratio variations
in the Antarctic region and temperature, zonal, meridional and vertical
velocities between 100 and 10 hPa in the same region. The most important two
pairs of GMCA time coefficients show large year-to-year variations and
trends, which are connected with the growth of the Antarctic Ozone Hole and
the increase of ozone depleting substances. The associated spatial patterns
of ozone variations may be characterized as being quasi-symmetric and
asymmetric about the pole. These patterns of ozone variations are associated
with comparable patterns of variations of temperature and winds through most
of the vertical domain.
The year 2000 is shown to be dominated by the asymmetric mode, whereas the
adjacent year 2001 is dominated by the quasi-symmetric mode. A case study,
focusing on the asymmetric differences between these two years, shows the
magnitude of the ozone mixing ratio, temperature and zonal wind differences
to be in the range of 2 e–6 kg/kg, 10°C and 10 m/s,
respectively. Budget calculations show that transport processes contribute
substantially to the ozone and temperature changes in the middle
stratosphere over the Antarctic continent. However, both radiative and
chemical processes also play important roles in the changes.
Citation: Weare, B. C.: Dynamical modes associated with the Antarctic ozone hole, Atmos. Chem. Phys., 9, 5403-5416, doi:10.5194/acp-9-5403-2009, 2009.