Ozone and temperature trends in the upper stratosphere at five stations of the Network for the Detection of Atmospheric Composition Change

Abstract

International audienceUpper stratospheric ozone anomalies from the satellite-borne Solar Backscatter Ultra-Violet (SBUV), Stratospheric Aerosol and Gas Experiment II (SAGE II), Halogen Occultation Experiment (HALOE), Global Ozone Monitoring by Occultation of Stars (GOMOS), and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instruments agree within 5% or better with ground-based data from lidars and microwave radiometers at five stations of the Network for the Detection of Atmospheric Composition Change (NDACC), from 45°S to 48°N. From 1979 until the late 1990s, all available data show a clear decline of ozone near 40 km, by 10%–15%. This decline has not continued in the last 10 years. At some sites, ozone at 40 km appears to have increased since 2000, consistent with the beginning decline of stratospheric chlorine. The phaseout of chlorofluorocarbons after the International Montreal Protocol in 1987 has been successful, and is now showing positive effects on ozone in the upper stratosphere. Temperature anomalies near 40 km altitude from European Centre for Medium Range Weather Forecast reanalyses (ERA-40), from National Centers for Environmental Prediction (NCEP) operational analyses, and from HALOE and lidar measurements show good consistency at the five stations, within about 3 K. Since about 1985, upper stratospheric temperatures have been fluctuating around a constant level at all five NDACC stations. This non-decline of upper stratospheric temperatures is a significant change from the more or less linear cooling of the upper stratosphere up until the mid-1990s, reported in previous trend assessments. It is also at odds with the almost linear 1 K per decade cooling simulated over the entire 1979–2010 period by chemistry–climate models (CCMs). The same CCM simulations, however, track the historical ozone anomalies quite well, including the change of ozone tendency in the late 1990s

Drift-corrected trends and periodic variations in MIPAS IMK/IAA ozone measurements

“…These results agree better with recent findings (e.g. WMO, 2011;Steinbrecht et al, 2009a) A reasonable explanation for negative trends near the Equator is increased tropical upwelling, as has been suggested before (WMO, 2011), but only for altitudes slightly above the tropopause. So upwelling does not provide a sufficient explanation for the negative values in the tropical middle stratosphere.…”

“…Even though a decrease of stratospheric ODS concentrations was noted from the mid-1990s on, ozone did not recover consistently. Trends after 1995 were found to be either nonexistent or slightly positive (Steinbrecht et al, 2009a;WMO, 2011).…”

Unusual stratospheric ozone anomalies observed in 22 years of measurements from Lauder, New Zealand

“…The experimental technique was described in Parrish et al (1992), and technical details on the instrument used for this work are given in Parrish (1994). MOPI measurements have been employed in several validation and trend studies (e.g., Boyd et al, 2007;Steinbrecht et al, 2009).…”

A climatology of the diurnal variations in stratospheric and mesospheric ozone over Bern, Switzerland

“…GROMOS is part of the Network for the Detection of Atmospheric Composition Change (NDACC), and its data set is used for cross-validation of satellite experiments, studies of ozone-climate interactions and middle atmospheric dynamics, as well as for long-term monitoring of the ozone layer in the stratosphere (Peter and Kämpfer, 1995;Peter et al, 1996;Calisesi et al, 2001;Dumitru et al, 2006;Hocke et al, 2006;Steinbrecht et al, 2006;Hocke et al, 2007;Flury et al, 2009;Steinbrecht et al, 2009;Studer et al, 2012;Hocke et al, 2013).…”