Articles | Volume 14, issue 24
Atmos. Chem. Phys., 14, 13455–13470, 2014

Special issue: Changes in the vertical distribution of ozone – the SI2N report...

Atmos. Chem. Phys., 14, 13455–13470, 2014

Research article 17 Dec 2014

Research article | 17 Dec 2014

Reevaluation of stratospheric ozone trends from SAGE II data using a simultaneous temporal and spatial analysis

R. P. Damadeo, J. M. Zawodny, and L. W. Thomason R. P. Damadeo et al.
  • NASA Langley Research Center, Hampton, VA, USA

Abstract. This paper details a new method of regression for sparsely sampled data sets for use with time-series analysis, in particular the Stratospheric Aerosol and Gas Experiment (SAGE) II ozone data set. Non-uniform spatial, temporal, and diurnal sampling present in the data set result in biased values for the long-term trend if not accounted for. This new method is performed close to the native resolution of measurements and is a simultaneous temporal and spatial analysis that accounts for potential diurnal ozone variation. Results show biases, introduced by the way data are prepared for use with traditional methods, can be as high as 10%. Derived long-term changes show declines in ozone similar to other studies but very different trends in the presumed recovery period, with differences up to 2% per decade. The regression model allows for a variable turnaround time and reveals a hemispheric asymmetry in derived trends in the middle to upper stratosphere. Similar methodology is also applied to SAGE II aerosol optical depth data to create a new volcanic proxy that covers the SAGE II mission period. Ultimately this technique may be extensible towards the inclusion of multiple data sets without the need for homogenization.

Final-revised paper