Trends in stratospheric ozone derived from merged SAGE II and Odin-OSIRIS satellite observations

摘要

Stratospheric ozone profile measurements from the Stratospheric Aerosol andGas Experiment~(SAGE) II satellite instrument (1984–2005) are combined withthose from the Optical Spectrograph and InfraRed Imager System (OSIRIS)instrument on the Odin satellite (2001–Present) to quantify interannualvariability and decadal trends in stratospheric ozone between 60° S and 60° N. These data are merged into a multi-instrument,long-term stratospheric ozone record (1984–present) by analyzing themeasurements during the overlap period of 2002–2005 when both satelliteinstruments were operational. The variability in the deseasonalized timeseries is fit using multiple linear regression with predictor basisfunctions including the quasi-biennial oscillation, El Niño–SouthernOscillation index, solar activity proxy, and the pressure at the tropicaltropopause, in addition to two linear trends (one before and one after1997), from which the decadal trends in ozone are derived. From 1984 to 1997,there are statistically significant negative trends of 5–10% per decadethroughout the stratosphere between approximately 30 and 50 km. From1997 to present, a statistically significant recovery of 3–8% per decadehas taken place throughout most of the stratosphere with the notableexception between 40° S and 40° N below approximately 22 kmwhere the negative trend continues. The recovery is not significant between25 and 35 km altitudes when accounting for a conservative estimate of instrumentdrift.