Enhanced upper stratospheric ozone: Sign of recovery or solar cycle effect?

Abstract

Ozone data measured since 1987 in the 35‐ to 45‐km altitude region by differential absorption laser‐radar (DIAL) at Hohenpeissenberg (47.8°N, 11.0°E) confirm the long‐term ozone decline observed by the satellite‐borne Stratospheric Aerosol and Gas Experiment (SAGE) and Halogen Occultation Experiment (HALOE) instruments, as well as interannual ozone fluctuations. Analysis of the DIAL data indicates that the amplitude of ozone variations related to the 11‐year solar cycle might reach up to 7%, much larger than 4% reported in other studies. Higher ozone values observed in the years 2001 to 2003 might, therefore, be a consequence of the ending solar maximum and not necessarily indicate a beginning recovery of upper stratospheric ozone. Much clearer evidence for a recovery is expected in a few years, near the end of the solar minimum starting now.

Interannual variation patterns of total ozone and lower stratospheric temperature in observations and model simulations

“…It transports the fairly large (5%) solar signal observed in low and midlatitude upper stratospheric ozone (e.g. Newchurch et al, 2003;Steinbrecht et al, 2004) to certain regions near the winter poles (Tourpali et al, 2003(Tourpali et al, , 2005. For 50 hPa temperature at latitudes lower than about 30 • , both models show a weaker solar cycle signal than the NCEP reanalysis.…”

“…It is now being discussed whether ozone also might show signs of a beginning recovery (Newchurch et al, 2003;Steinbrecht et al, 2004;Reinsel et al, 2005). Unfortunately, the simulations have not yet been extended past 1999.…”

Analysis of HCl and ClO time series in the upper stratosphere using satellite data sets

“…By being able to separate the relative contributions of known variation (by the process of linear regression), we will be left with the unexplained variability of the monthly mean signal to which a linear trend can be applied. We follow similar approaches to that of Newchurch et al (2003), and Steinbrecht et al (2004Steinbrecht et al ( , 2006, where we firstly remove the seasonal cycle from the HCl time series. This is simply done for each instrument by finding the difference between each monthly mean value from their corresponding average (climatological) annual cycle.…”

Statistical modeling of total ozone: Selection of appropriate explanatory variables

“…[59] Different to other current studies [e.g., Reinsel, 2002;Reinsel et al, 2002Reinsel et al, , 2005Newchurch et al, 2003;Steinbrecht et al, 2004;Weatherhead and Andersen, 2006;Brunner et al, 2006a] our analysis is not focused on trends and possible changes of them.…”