Analysis of stratospheric NO2 trends above Jungfraujoch using ground-based UV-visible, FTIR, and satellite nadir observations
dc.contributor.author | Hendrick, F. | |
dc.contributor.author | Mahieu, E. | |
dc.contributor.author | Bodeker, G.E. | |
dc.contributor.author | Boersma, K.F. | |
dc.contributor.author | Chipperfield, M.P. | |
dc.contributor.author | De Maziere, M. | |
dc.contributor.author | De Smedt, I. | |
dc.contributor.author | Demoulin, P. | |
dc.contributor.author | Fayt, C. | |
dc.contributor.author | Hermans, C. | |
dc.contributor.author | Kreher, K. | |
dc.contributor.author | Lejeune, B. | |
dc.contributor.author | Pinardi, G. | |
dc.contributor.author | Servais, C. | |
dc.contributor.author | Stubi, R. | |
dc.contributor.author | Van Der A, R. | |
dc.contributor.author | Vernier, J.-P. | |
dc.contributor.author | Van Roozendael, M. | |
dc.date | 2012 | |
dc.date.accessioned | 2016-03-29T10:07:35Z | |
dc.date.available | 2016-03-29T10:07:35Z | |
dc.identifier.uri | https://orfeo.belnet.be/handle/internal/2976 | |
dc.description | The trend in stratospheric NO2 column at the NDACC (Network for the Detection of Atmospheric Composition Change) station of Jungfraujoch (46.5° N, 8.0° E) is assessed using ground-based FTIR and zenith-scattered visible sunlight SAOZ measurements over the period 1990 to 2009 as well as a composite satellite nadir data set constructed from ERS-2/GOME, ENVISAT/SCIAMACHY, and METOP-A/GOME-2 observations over the 1996–2009 period. To calculate the trends, a linear least squares regression model including explanatory variables for a linear trend, the mean annual cycle, the quasi-biennial oscillation (QBO), solar activity, and stratospheric aerosol loading is used. For the 1990–2009 period, statistically indistinguishable trends of −3.7 ± 1.1% decade−1 and −3.6 ± 0.9% decade−1 are derived for the SAOZ and FTIR NO2 column time series, respectively. SAOZ, FTIR, and satellite nadir data sets show a similar decrease over the 1996–2009 period, with trends of −2.4 ± 1.1% decade−1, −4.3 ± 1.4% decade−1, and −3.6 ± 2.2% decade−1, respectively. The fact that these declines are opposite in sign to the globally observed +2.5% decade−1 trend in N2O, suggests that factors other than N2O are driving the evolution of stratospheric NO2 at northern mid-latitudes. Possible causes of the decrease in stratospheric NO2 columns have been investigated. The most likely cause is a change in the NO2/NO partitioning in favor of NO, due to a possible stratospheric cooling and a decrease in stratospheric chlorine content, the latter being further confirmed by the negative trend in the ClONO2 column derived from FTIR observations at Jungfraujoch. Decreasing ClO concentrations slows the NO + ClO → NO2 + Cl reaction and a stratospheric cooling slows the NO + O3 → NO2 + O2 reaction, leaving more NOx in the form of NO. The slightly positive trends in ozone estimated from ground- and satellite-based data sets are also consistent with the decrease of NO2 through the NO2 + O3 → NO3 + O2 reaction. Finally, we cannot rule out the possibility that a strengthening of the Dobson-Brewer circulation, which reduces the time available for N2O photolysis in the stratosphere, could also contribute to the observed decline in stratospheric NO2 above Jungfraujoch. | |
dc.language | eng | |
dc.title | Analysis of stratospheric NO2 trends above Jungfraujoch using ground-based UV-visible, FTIR, and satellite nadir observations | |
dc.type | Article | |
dc.subject.frascati | Earth and related Environmental sciences | |
dc.audience | Scientific | |
dc.subject.free | aerosol | |
dc.subject.free | chlorine | |
dc.subject.free | concentration (composition) | |
dc.subject.free | data set | |
dc.subject.free | Envisat-1 | |
dc.subject.free | ERS-2 | |
dc.subject.free | FTIR spectroscopy | |
dc.subject.free | GOME | |
dc.subject.free | least squares method | |
dc.subject.free | nadir | |
dc.subject.free | nitrogen dioxide | |
dc.subject.free | photolysis | |
dc.subject.free | quasi-biennial oscillation | |
dc.subject.free | regression analysis | |
dc.subject.free | satellite data | |
dc.subject.free | SCIAMACHY | |
dc.subject.free | stratosphere | |
dc.subject.free | trend analysis | |
dc.subject.free | Bern [Switzerland] | |
dc.subject.free | Jungfraujoch | |
dc.subject.free | Switzerland | |
dc.source.title | Atmospheric Chemistry and Physics | |
dc.source.volume | 12 | |
dc.source.issue | 18 | |
dc.source.page | 8851-8864 | |
Orfeo.peerreviewed | Yes | |
dc.identifier.doi | 10.5194/acp-12-8851-2012 | |
dc.identifier.scopus | 2-s2.0-84877716111 |