scholarly journals A global historical ozone data set and prominent features of stratospheric variability prior to 1979

2013 ◽  
Vol 13 (18) ◽  
pp. 9623-9639 ◽  
Author(s):  
S. Brönnimann ◽  
J. Bhend ◽  
J. Franke ◽  
S. Flückiger ◽  
A. M. Fischer ◽  
...  

Abstract. We present a vertically resolved zonal mean monthly mean global ozone data set spanning the period 1901 to 2007, called HISTOZ.1.0. It is based on a new approach that combines information from an ensemble of chemistry climate model (CCM) simulations with historical total column ozone information. The CCM simulations incorporate important external drivers of stratospheric chemistry and dynamics (in particular solar and volcanic effects, greenhouse gases and ozone depleting substances, sea surface temperatures, and the quasi-biennial oscillation). The historical total column ozone observations include ground-based measurements from the 1920s onward and satellite observations from 1970 to 1976. An off-line data assimilation approach is used to combine model simulations, observations, and information on the observation error. The period starting in 1979 was used for validation with existing ozone data sets and therefore only ground-based measurements were assimilated. Results demonstrate considerable skill from the CCM simulations alone. Assimilating observations provides additional skill for total column ozone. With respect to the vertical ozone distribution, assimilating observations increases on average the correlation with a reference data set, but does not decrease the mean squared error. Analyses of HISTOZ.1.0 with respect to the effects of El Niño–Southern Oscillation (ENSO) and of the 11 yr solar cycle on stratospheric ozone from 1934 to 1979 qualitatively confirm previous studies that focussed on the post-1979 period. The ENSO signature exhibits a much clearer imprint of a change in strength of the Brewer–Dobson circulation compared to the post-1979 period. The imprint of the 11 yr solar cycle is slightly weaker in the earlier period. Furthermore, the total column ozone increase from the 1950s to around 1970 at northern mid-latitudes is briefly discussed. Indications for contributions of a tropospheric ozone increase, greenhouse gases, and changes in atmospheric circulation are found. Finally, the paper points at several possible future improvements of HISTOZ.1.0.

2013 ◽  
Vol 13 (3) ◽  
pp. 7767-7809
Author(s):  
S. Brönnimann ◽  
J. Bhend ◽  
J. Franke ◽  
S. Flückiger ◽  
A. M. Fischer ◽  
...  

Abstract. We present a vertically resolved (with pressure as the vertical coordinate) zonal mean monthly mean global ozone data set spanning the period 1900 to 2008, called HISTOZ.1.0. It is based on a new approach that combines information from an ensemble of chemistry climate model (CCM) simulations with historical total ozone information. The CCM simulations incorporate important external drivers of stratospheric chemistry and dynamics (in particular solar and volcanic effects, greenhouse gases and ozone depleting substances, sea-surface temperatures, and the Quasi-Biennial Oscillation). The historical total ozone observations include ground-based measurements from the 1920s onward and satellite observations from 1970 to 1976. An off-line data assimilation approach (Ensemble Square Root Filter) is used to combine model simulations, observations, and information on the observation error. The period starting in 1979 was used for validation with existing ozone data sets and therefore only ground-based measurements were assimilated. Results demonstrate considerable skill from the CCM simulations alone. While the observations provide little additional skill at the full spatio-temporal resolution, they do increase the skill at lower spatio-temporal resolutions and specifically for total ozone. Analyses of HISTOZ.1.0 with respect to the effects of El Niño/Southern Oscillation (ENSO) and of the 11 yr solar cycle on stratospheric ozone from 1934 to 1979 qualitatively confirm previous studies that focussed on the post-1979 period. However, a more pronounced effect of ENSO and slightly weaker effect of the 11 yr solar cycle are found in the earlier period. Several possible future improvements of HISTOZ.1.0 are discussed.


2006 ◽  
Vol 6 (2) ◽  
pp. 525-537 ◽  
Author(s):  
S. Guillas ◽  
G. C. Tiao ◽  
D. J. Wuebbles ◽  
A. Zubrow

Abstract. In this paper, we introduce a statistical method for examining and adjusting chemical-transport models. We illustrate the findings with total column ozone predictions, based on the University of Illinois at Urbana-Champaign 2-D (UIUC 2-D) chemical-transport model of the global atmosphere. We propose a general diagnostic procedure for the model outputs in total ozone over the latitudes ranging from 60° South to 60° North to see if the model captures some typical patterns in the data. The method proceeds in two steps to avoid possible collinearity issues. First, we regress the measurements given by a cohesive data set from the SBUV(/2) satellite system on the model outputs with an autoregressive noise component. Second, we regress the residuals of this first regression on the solar flux, the annual cycle, the Antarctic or Arctic Oscillation, and the Quasi Biennial Oscillation. If the coefficients from this second regression are statistically significant, then they mean that the model did not simulate properly the pattern associated with these factors. Systematic anomalies of the model are identified using data from 1979 to 1995, and statistically corrected afterwards. The 1996–2003 validation sample confirms that the combined approach yields better predictions than the direct UIUC 2-D outputs.


2015 ◽  
Vol 8 (11) ◽  
pp. 4845-4850 ◽  
Author(s):  
R. D. McPeters ◽  
S. Frith ◽  
G. J. Labow

Abstract. The ozone data record from the Ozone Monitoring Instrument (OMI) onboard the NASA Earth Observing System (EOS) Aura satellite has proven to be very stable over the 10-plus years of operation. The OMI total column ozone processed through the Total Ozone Mapping Spectrometer (TOMS) ozone retrieval algorithm (version 8.5) has been compared with ground-based measurements and with ozone from a series of SBUV/2 (Solar Backscatter Ultraviolet) instruments. Comparison with an ensemble of Brewer–Dobson sites shows an absolute offset of about 1.5 % and almost no relative trend. Comparison with a merged ozone data set (MOD) created by combining data from a series of SBUV/2 instruments again shows an offset, of about 1 %, and a relative trend of less than 0.5 % over 10 years. The offset is mostly due to the use of the old Bass–Paur ozone cross sections in the OMI retrievals rather than the Brion–Daumont–Malicet cross sections that are now recommended. The bias in the Southern Hemisphere is smaller than that in the Northern Hemisphere, 0.9 % vs. 1.5 %, for reasons that are not completely understood. When OMI was compared with the European realization of a multi-instrument ozone time series, the GTO (GOME type Total Ozone) data set, there was a small trend of about −0.85 % decade−1. Since all the comparisons of OMI relative to other ozone measuring systems show relative trends that are less than 1 % decade−1, we conclude that the OMI total column ozone data are sufficiently stable that they can be used in studies of ozone trends.


2013 ◽  
Vol 13 (20) ◽  
pp. 10373-10384 ◽  
Author(s):  
P. J. Nair ◽  
S. Godin-Beekmann ◽  
J. Kuttippurath ◽  
G. Ancellet ◽  
F. Goutail ◽  
...  

Abstract. The trends and variability of ozone are assessed over a northern mid-latitude station, Haute-Provence Observatory (OHP: 43.93° N, 5.71° E), using total column ozone observations from the Dobson and Système d'Analyse par Observation Zénithale spectrometers, and stratospheric ozone profile measurements from light detection and ranging (lidar), ozonesondes, Stratospheric Aerosol and Gas Experiment (SAGE) II, Halogen Occultation Experiment (HALOE) and Aura Microwave Limb Sounder (MLS). A multivariate regression model with quasi-biennial oscillation (QBO), solar flux, aerosol optical thickness, heat flux, North Atlantic Oscillation (NAO) and a piecewise linear trend (PWLT) or equivalent effective stratospheric chlorine (EESC) functions is applied to the ozone anomalies. The maximum variability of ozone in winter/spring is explained by QBO and heat flux in the ranges 15–45 km and 15–24 km, respectively. The NAO shows maximum influence in the lower stratosphere during winter, while the solar flux influence is largest in the lower and middle stratosphere in summer. The total column ozone trends estimated from the PWLT and EESC functions are of −1.47 ± 0.27 and −1.40 ± 0.25 DU yr−1, respectively, over the period 1984–1996 and about 0.55 ± 0.30 and 0.42 ± 0.08 DU yr−1, respectively, over the period 1997–2010. The ozone profiles yield similar and significant EESC-based and PWLT trends for 1984–1996, and are about −0.5 and −0.8% yr−1 in the lower and upper stratosphere, respectively. For 1997–2010, the EESC-based and PWLT estimates are of the order of 0.3 and 0.1% yr−1, respectively, in the 18–28 km range, and at 40–45 km, EESC provides significant ozone trends larger than the insignificant PWLT results. Furthermore, very similar vertical trends for the respective time periods are also deduced from another long-term satellite-based data set (GOZCARDS–Global OZone Chemistry And Related trace gas Data records for the Stratosphere) sampled at northern mid-latitudes. Therefore, this analysis unveils ozone recovery signals from total column ozone and profile measurements at OHP, and hence in the northern mid-latitudes.


2014 ◽  
Vol 119 (16) ◽  
pp. 9735-9751 ◽  
Author(s):  
S. M. Frith ◽  
N. A. Kramarova ◽  
R. S. Stolarski ◽  
R. D. McPeters ◽  
P. K. Bhartia ◽  
...  

2015 ◽  
Vol 8 (7) ◽  
pp. 7491-7510 ◽  
Author(s):  
R. D. McPeters ◽  
S. Frith ◽  
G. J. Labow

Abstract. The ozone data record from the Ozone Monitoring Instrument (OMI) onboard the NASA EOS-Aura satellite has proven to be very stable over the ten plus years of operation. The OMI total column ozone processed through the TOMS ozone retrieval algorithm (version 8.5) has been compared with ground based measurements and with ozone from a series of SBUV/2 instruments. Comparison with an ensemble of Brewer and Dobson sites shows an absolute offset of about 1.5 % but stability over the ten years to better than half a percent. Comparison with a merged ozone (MOD) data set created by combining data from a series of SBUV/2 instruments again shows an offset, of about 1 %, and a relative trend of less than half a percent over ten years. The offset is mostly due to the use of the old Bass and Paur ozone cross sections in the OMI retrievals rather than the Brion/Daumont/Malicet cross sections that are now recommended. The bias in the Southern Hemisphere is smaller than that in the Northern Hemisphere, 1 vs. 1.5 %, for reasons that are not completely understood. When OMI was compared with the European realization of a multi-instrument ozone time series, the GTO (GOME type ozone) dataset, there was a small trend of about −0.85 % decade−1. Since all the comparisons of OMI relative to other ozone measuring systems show relative trends that are less than 1 % decade−1, we conclude that the OMI total column ozone data are sufficiently stable that they can be used in studies of ozone trends.


2011 ◽  
Vol 68 (9) ◽  
pp. 1911-1921 ◽  
Author(s):  
Jingqian Wang ◽  
Steven Pawson ◽  
Baijun Tian ◽  
Mao-Chang Liang ◽  
Run-Lie Shia ◽  
...  

Abstract The impacts of El Niño–Southern Oscillation (ENSO) on the tropical total column ozone, the tropical tropopause pressure, and the 3.5-yr ozone signal in the midlatitude total column ozone were examined using the Goddard Earth Observing System Chemistry–Climate Model (GEOS CCM). Observed monthly mean sea surface temperature and sea ice between 1951 and 2004 were used as boundary conditions for the model. Since the model includes no solar cycle, quasi-biennial oscillation, or volcanic forcing, the ENSO signal was found to dominate the tropical total column ozone variability. Principal component analysis was applied to the detrended, deseasonalized, and low-pass filtered model outputs. The first mode of model total column ozone captured 63.8% of the total variance. The spatial pattern of this mode was similar to that in Total Ozone Mapping Spectrometer (TOMS) observations. There was also a clear ENSO signal in the tropical tropopause pressure in the GEOS CCM, which is related to the ENSO signal in the total column ozone. The regression coefficient between the model total column ozone and the model tropopause pressure was 0.71 Dobson units (DU) hPa−1. The GEOS CCM was also used to investigate a possible mechanism for the 3.5-yr signal observed in the midlatitude total column ozone. The 3.5-yr signal in the GEOS CCM column ozone is similar to that in the observations, which suggests that a model with realistic ENSO can reproduce the 3.5-yr signal. Hence, it is likely that the 3.5-yr signal was caused by ENSO.


2012 ◽  
Vol 12 (5) ◽  
pp. 13161-13199 ◽  
Author(s):  
L. Frossard ◽  
H. E. Rieder ◽  
M. Ribatet ◽  
J. Staehelin ◽  
J. A. Maeder ◽  
...  

Abstract. We use models for mean and extreme values of total column ozone on spatial scales to analyze "fingerprints" of atmospheric dynamics and chemistry on long-term ozone changes at northern and southern mid-latitudes. The r-largest order statistics method is used for pointwise analysis of extreme events in low and high total ozone (termed ELOs and EHOs, respectively). For the corresponding mean value analysis a pointwise autoregressive moving average model (ARMA) is used. The statistical models include important atmospheric covariates to describe the dynamical and chemical state of the atmosphere: the solar cycle, the Quasi-Biennial Oscillation (QBO), ozone depleting substances (ODS) in terms of equivalent effective stratospheric chlorine (EESC), the North Atlantic Oscillation (NAO), the Antarctic Oscillation (AAO), the El~Niño/Southern Oscillation (ENSO), and aerosol load after the volcanic eruptions of El Chichón and Mt. Pinatubo. The influence of the individual covariates on mean and extreme levels in total column ozone is derived on a grid cell basis. The results show that "fingerprints", i.e., significant influence, of dynamical and chemical features are captured in both the "bulk" and the tails of the ozone distribution, respectively described by means and EHOs/ELOs. While results for the solar cycle, QBO and EESC are in good agreement with findings of earlier studies, unprecedented spatial fingerprints are retrieved for the dynamical covariates.


2012 ◽  
Vol 12 (1) ◽  
pp. 1867-1893 ◽  
Author(s):  
K.-F. Li ◽  
X. Jiang ◽  
M.-C. Liang ◽  
Y. L. Yung

Abstract. Total column ozone (XO3) abundance in Earth's atmosphere is intimately related to atmospheric chemistry and dynamics. Understanding the solar-cycle modulations of XO3 helps distinguish anthropogenic perturbations from natural variability during the ozone recovery. Here, the solar-cycle signal of tropical XO3 in the Whole Atmosphere Community Climate Model (WACCM) model has been examined using solar spectral irradiance (SSI) estimated from the Naval Research Laboratory (NRL) solar model and that from recent satellite measurements observed by the Solar Radiation and Climate Experiment (SORCE). Four experiments have been conducted with NRL/SORCE SSI and climatological/realistic sea surface temperatures and ice, and all other variability is fixed. In the tropical region 24° S–24° N, using the SORCE SSI as a model input leads to a solar-cycle response of ~5.4 DU/100F10.7, which is ~2 times of that obtained using NRL SSI. The results are slightly different in the presence of El Niño/Southern Oscillation (ENSO) when realistic SST/ice is used, but these differences are within the regression uncertainty of ~0.6 DU/100F10.7. The solar-cycle responses simulated using SORCE SSI agree with those obtained from the merged TOMS/SBUV satellite observations. Using NRL SSI as a model input results in solar-cycle responses that are closer to the ground-based observations, although the accuracy of the latter is limited by the number of stations in the tropics. In all model experiments, the tropical distribution of the solar-cycle response is constant to within ~0.5 DU/100F10.7, which is of the same order as the regression uncertainty. The spatial structures of the regression uncertainty are shown to be correlated with ENSO in the Pacific region. The solar-cycle response obtained using SORCE SSI implies a maximum change in lower stratospheric temperature of ~0.8 K. This may lead to significant impacts on the model solar-cycle responses in atmospheric circulation, precipitation and other hydrological variables that are important for the climate change.


2007 ◽  
Vol 7 (21) ◽  
pp. 5625-5637 ◽  
Author(s):  
G. E. Bodeker ◽  
H. Garny ◽  
D. Smale ◽  
M. Dameris ◽  
R. Deckert

Abstract. One of the most significant events in the evolution of the ozone layer over southern mid-latitudes since the late 1970s was the large decrease observed in 1985. This event remains unexplained and a detailed investigation of the mechanisms responsible for the event has not previously been undertaken. In this study, the 1985 Southern Hemisphere mid-latitude total column ozone anomaly is analyzed in detail based on observed daily total column ozone fields, stratospheric dynamical fields, and calculated diagnostics of stratospheric mixing. The 1985 anomaly appears to result from a combination of (i) an anomaly in the meridional circulation resulting from the westerly phase of the equatorial quasi-biennial oscillation (QBO), (ii) weaker transport of ozone from its tropical mid-stratosphere source across the sub-tropical barrier to mid-latitudes related to the particular phasing of the QBO with respect to the annual cycle, and (iii) a solar cycle induced reduction in ozone. Similar QBO and solar cycle influences prevailed in 1997 and 2006 when again total column ozone was found to be suppressed over southern mid-latitudes. The results based on observations are compared and contrasted with analyses of ozone and dynamical fields from the ECHAM4.L39(DLR)/CHEM coupled chemistry-climate model (hereafter referred to as E39C). Equatorial winds in the E39C model are nudged towards observed winds between 10° S and 10° N and the ability of this model to produce an ozone anomaly in 1985, similar to that observed, confirms the role of the QBO in effecting the anomaly.


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