Ozone tropospheric and stratospheric trends (1995-2012) at six ground-based FTIR stations (28°N to 79°N)

• Main Authors: Vigouroux, Corinne, De Mazière, Martine, Demoulin, Philippe, Servais, Christian, Blumenstock, Thomas, Hase, Frank, Kohlhepp, Regina, Barthlott, S., García, Omaira, Schneider, Matthias, Mellqvist, Johan, Personn, G., Palm, Mathias, Notholt, Justus, Hannigan, Jim, Coffey, M.
• Format: Conference Object
• Language: English
• Published: 2013
• Subjects: ozone; atmospheric composition; trace gases; trend; infrared solar spectroscopy; NDACC; Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; Greenland; Thule
• Online Access: https://orbi.uliege.be/handle/2268/163013; https://orbi.uliege.be/bitstream/2268/163013/1/Vigouroux%202013%20%28poster%20EGU%2c%20Vienna%29%20-%20Ozone%20tropospheric%20and%20stratospheric%20trends%20%281995-2012%29%20at%20six%20ground-based%20FTIR%20stations___.pdf

In the frame of the Network for the Detection of Atmospheric Composition Change (NDACC), contributing ground-based stations have joined their efforts to homogenize and optimize the retrievals of ozone profiles from FTIR (Fourier transform infrared) solar absorption spectra. Using the optimal estimation method, distinct vertical information can be obtained in four layers: ground-10 km, 10-18 km, 18-27 km, and 27-42 km, in addition to total column amounts. In a previous study, Vigouroux et al. (2008) applied a bootstrap resampling method to determine the trends of the ozone total and four partial columns, over the period 1995-2004 at Western European stations. The updated trends for the period 1995-2009 have been published in the WMO 2010 report. Here, we present the updated trends and their uncertainties, for the 1995-2012 period, for the different altitude ranges, above five European stations (28°N-79°N) and above the station Thule, Greenland (77°N). In this work, the trends have been estimated using a multiple regression model including some explanatory variables responsible for the ozone variability, such as the Quasi Biennial Oscillation (QBO), the solar flux, the Arctic Oscillation (AO) or El Niño-Southern Oscillation (ENSO). A major result is the significant positive trend of ozone in the upper stratosphere, observed at the Jungfraujoch (47°N), which is a typical mid-latitude site, as well as at the high latitude stations. This positive trend in the upper stratosphere at Jungfraujoch provides a sign of ozone recovery at mid-latitudes.