A stratospheric ozone profile data set for 1979–2005: Variability, trends, and comparisons with column ozone data

Abstract. High-quality stratospheric ozone profile data sets are a key requirement for accurate quantification and attribution of long-term ozone changes. Satellite instruments provide stratospheric ozone profile measurements over typical mission durations of 5–15 years. Various methodologies have then been applied to merge and homogenise the different satellite data in order to create long-term observation-based ozone profile data sets with minimal data gaps. However, individual satellite instruments use different measurement methods, sampling patterns and retrieval algorithms which complicate the merging of these different data sets. In contrast, atmospheric chemical models can produce chemically consistent long-term ozone simulations based on specified changes in external forcings, but they are subject to the deficiencies associated with incomplete understanding of complex atmospheric processes and uncertain photochemical parameters. Here, we use chemically self-consistent output from the TOMCAT 3-D chemical transport model (CTM) and a random-forest (RF) ensemble learning method to create a merged 42-year (1979–2020) stratospheric ozone profile data set (ML-TOMCAT V1.0). The underlying CTM simulation was forced by meteorological reanalyses, specified trends in long-lived source gases, solar flux and aerosol variations. The RF is trained using the Stratospheric Water and OzOne Satellite Homogenized (SWOOSH) data set over the time periods of the Microwave Limb Sounder (MLS) from the Upper Atmosphere Research Satellite (UARS) (1991–1998) and Aura (2005–2016) missions. We find that ML-TOMCAT shows excellent agreement with available independent satellite-based data sets which use pressure as a vertical coordinate (e.g. GOZCARDS, SWOOSH for non-MLS periods) but weaker agreement with the data sets which are altitude-based (e.g. SAGE-CCI-OMPS, SCIAMACHY-OMPS). We find that at almost all stratospheric levels ML-TOMCAT ozone concentrations are well within uncertainties of the observational data sets. The ML-TOMCAT (V1.0) data set is ideally suited for the evaluation of chemical model ozone profiles from the tropopause to 0.1 hPa and is freely available via https://doi.org/10.5281/zenodo.5651194 (Dhomse et al., 2021).

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Estimating uncertainties in the SBUV Version 8.6 merged profile ozone data set

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-14695-2017 ◽

2017 ◽

Vol 17 (23) ◽

pp. 14695-14707 ◽

Cited By ~ 17

Author(s):

Stacey M. Frith ◽

Richard S. Stolarski ◽

Natalya A. Kramarova ◽

Richard D. McPeters

Keyword(s):

Total Ozone ◽

Climate Models ◽

Pressure Level ◽

Profile Data ◽

Data Set ◽

Ozone Data ◽

Instrument Type ◽

Ozone Profile ◽

Ozone Trend ◽

Single Instrument

Abstract. The combined record of total and profile ozone measurements from the solar backscatter ultraviolet (SBUV) and SBUV/2 series of instruments, known as the SBUV Merged Ozone Data (MOD) product, constitutes the longest satellite-based ozone time series from a single instrument type and as such plays a key role in ozone trend analyses.Following the approach documented in Frith et al. (2014) to analyze the merging uncertainties in the MOD total ozone record, we use Monte Carlo simulations to estimate the potential for uncertainties in the calibration and drift of individual instruments in the profile ozone merged data set. We focus our discussion on the trends and associated merging uncertainty since 2001 in an effort to verify the start of ozone recovery as predicted by chemistry climate models. We find that merging uncertainty dominates the overall estimated uncertainty when considering only the 15 years of data since 2001. We derive trends versus pressure level for the MOD data set that are positive in the upper stratosphere as expected for ozone recovery. These trends appear to be significant when only statistical uncertainties are included but become not significant at the 2σ level when instrument uncertainties are accounted for. However, when we use the entire data set from 1979 through 2015 and fit to the EESC (equivalent effective stratospheric chlorine) we find statistically significant fits throughout the upper stratosphere at all latitudes. This implies that the ozone profile data remain consistent with our expectation that chlorine is the dominant ozone forcing term.

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Evaluation of ozone profile and tropospheric ozone retrievals from GEMS and OMI spectra

Atmospheric Measurement Techniques ◽

10.5194/amt-6-239-2013 ◽

2013 ◽

Vol 6 (2) ◽

pp. 239-249 ◽

Cited By ~ 27

Author(s):

J. Bak ◽

J. H. Kim ◽

X. Liu ◽

K. Chance ◽

J. Kim

Keyword(s):

Spectral Resolution ◽

Tropospheric Ozone ◽

Stratospheric Ozone ◽

A Priori ◽

Ozone Monitoring Instrument ◽

Satellite Platform ◽

Ozone Profile ◽

Retrieval Errors ◽

Standard Deviations ◽

Column Ozone

Abstract. South Korea is planning to launch the GEMS (Geostationary Environment Monitoring Spectrometer) instrument into the GeoKOMPSAT (Geostationary Korea Multi-Purpose SATellite) platform in 2018 to monitor tropospheric air pollutants on an hourly basis over East Asia. GEMS will measure backscattered UV radiances covering the 300–500 nm wavelength range with a spectral resolution of 0.6 nm. The main objective of this study is to evaluate ozone profiles and stratospheric column ozone amounts retrieved from simulated GEMS measurements. Ozone Monitoring Instrument (OMI) Level 1B radiances, which have the spectral range 270–500 nm at spectral resolution of 0.42–0.63 nm, are used to simulate the GEMS radiances. An optimal estimation-based ozone profile algorithm is used to retrieve ozone profiles from simulated GEMS radiances. Firstly, we compare the retrieval characteristics (including averaging kernels, degrees of freedom for signal, and retrieval error) derived from the 270–330 nm (OMI) and 300–330 nm (GEMS) wavelength ranges. This comparison shows that the effect of not using measurements below 300 nm on retrieval characteristics in the troposphere is insignificant. However, the stratospheric ozone information in terms of DFS decreases greatly from OMI to GEMS, by a factor of ∼2. The number of the independent pieces of information available from GEMS measurements is estimated to 3 on average in the stratosphere, with associated retrieval errors of ~1% in stratospheric column ozone. The difference between OMI and GEMS retrieval characteristics is apparent for retrieving ozone layers above ~20 km, with a reduction in the sensitivity and an increase in the retrieval errors for GEMS. We further investigate whether GEMS can resolve the stratospheric ozone variation observed from high vertical resolution Earth Observing System (EOS) Microwave Limb Sounder (MLS). The differences in stratospheric ozone profiles between GEMS and MLS are comparable to those between OMI and MLS below ~3 hPa (~40 km), except with slightly larger biases and larger standard deviations by up to 5%. At pressure altitudes above ~3 hPa, GEMS retrievals show strong influence of a priori and large differences with MLS, which, however, can be sufficiently improved by using better a priori information. The GEMS-MLS differences show negative biases of less than 4% for stratospheric column ozone, with standard deviations of 1–3%, while OMI retrievals show similar agreements with MLS except for 1% smaller biases at middle and high latitudes. Based on the comparisons, we conclude that GEMS will measure tropospheric ozone and stratospheric ozone columns with accuracy comparable to that of OMI and ozone profiles with slightly worse performance than that of OMI below ~3 hPa.

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Homogenizing and Estimating the Uncertainty in NOAA’s Long Term Vertical Ozone Profile Records Measured with the Electrochemical Concentration Cell Ozonesonde

10.5194/amt-2017-397 ◽

2017 ◽

Cited By ~ 4

Author(s):

Chance W. Sterling ◽

Bryan J. Johnson ◽

Samuel J. Oltmans ◽

Herman G. J. Smit ◽

Allen F. Jordan ◽

...

Keyword(s):

Concentration Cell ◽

Data Set ◽

Total Column Ozone ◽

Ozone Profile ◽

Uncertainty Calculation ◽

Cell Current ◽

Column Ozone ◽

The Vertical Distribution ◽

Vertical Ozone

Abstract. NOAA’s program of long term monitoring of the vertical distribution of ozone with Electrochemical Concentration Cell (ECC) ozonesondes has undergone a number of changes over the 50 year record. In order to produce a homogenous data set, these changes must be documented and where necessary, appropriate corrections applied. This is the first comprehensive and consistent reprocessing of NOAA’s ozonesonde data records that corrects for these changes using the rawest form of the data (cell current and pump temperature) in native resolution as well as a point by point uncertainty calculation that is unique to each sounding. The reprocessing is carried out uniformly at all eight ozonesonde sites in NOAA’s network with differences in sensing solution and ozonesonde types accounted for in the same way at all sites. The corrections used to homogenize the NOAA ozonesonde data records greatly improve the ozonesonde measurements with an average one sigma uncertainty of ±4–6 % in the stratosphere and ±5–20 % in the troposphere. A comparison of the integrated column ozone from the ozonesonde profile with co-located Dobson spectrophotometers total column ozone measurements shows agreement within ±5 % for > 70 % of the profiles. Very good agreement is also found in the stratosphere between ozonesonde profiles and profiles retrieved from the Solar Backscatter Ultraviolet Instruments (SBUV).

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GOMOS bright limb ozone data set

Atmospheric Measurement Techniques ◽

10.5194/amt-8-3107-2015 ◽

2015 ◽

Vol 8 (8) ◽

pp. 3107-3115 ◽

Cited By ~ 3

Author(s):

S. Tukiainen ◽

E. Kyrölä ◽

J. Tamminen ◽

J. Kujanpää ◽

L. Blanot

Keyword(s):

Stray Light ◽

Atmospheric Composition ◽

Profile Data ◽

Satellite Measurements ◽

Data Set ◽

Infrared Imager ◽

Ozone Profile ◽

Stellar Occultation ◽

Ozone Monitoring ◽

Better Than

Abstract. We have created a daytime ozone profile data set from the measurements of the Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument on board the Envisat satellite. This so-called GOMOS bright limb (GBL) data set contains ∼ 358 000 stratospheric daytime ozone profiles measured by GOMOS in 2002–2012. The GBL data set complements the widely used GOMOS nighttime data based on stellar occultation measurements. The GBL data set is based on the GOMOS daytime occultations but instead of the transmitted star light we use limb-scattered solar light. The ozone profiles retrieved from these radiance spectra cover the 18–60 km altitude range and have approximately 2–3 km vertical resolution. We show that these profiles are generally in better than 10 % agreement with the NDACC (Network for the Detection of Atmospheric Composition Change) ozonesonde profiles and with the GOMOS nighttime, MLS (Microwave Limb Sounder), and OSIRIS (Optical Spectrograph and InfraRed Imager System) satellite measurements. However, there is a 10–13 % negative bias at 40 km altitude and a 10–50 % positive bias at 50 km for solar zenith angles > 75°. These biases are most likely caused by stray light which is difficult to characterize and to remove entirely from the measured spectra. Nevertheless, the GBL data set approximately doubles the amount of useful GOMOS ozone profiles and improves coverage of the summer pole.

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-9623-2013 ◽

2013 ◽

Vol 13 (18) ◽

pp. 9623-9639 ◽

Cited By ~ 13

Author(s):

S. Brönnimann ◽

J. Bhend ◽

J. Franke ◽

S. Flückiger ◽

A. M. Fischer ◽

...

Keyword(s):

Solar Cycle ◽

Greenhouse Gases ◽

Southern Oscillation ◽

Observation Error ◽

Quasi Biennial Oscillation ◽

Data Set ◽

Total Column Ozone ◽

Ozone Data ◽

Column Ozone ◽

Total Column

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.

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OMI total column ozone: extending the long-term data record

Atmospheric Measurement Techniques ◽

10.5194/amt-8-4845-2015 ◽

2015 ◽

Vol 8 (11) ◽

pp. 4845-4850 ◽

Cited By ~ 37

Author(s):

R. D. McPeters ◽

S. Frith ◽

G. J. Labow

Keyword(s):

Cross Sections ◽

Total Ozone ◽

Retrieval Algorithm ◽

Data Set ◽

Total Column Ozone ◽

Ozone Data ◽

Combining Data ◽

Data Record ◽

Column Ozone ◽

Total Column

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.

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Validation of 10-year SAO OMI ozone profile (PROFOZ) product using Aura MLS measurements

Atmospheric Measurement Techniques ◽

10.5194/amt-11-17-2018 ◽

2018 ◽

Vol 11 (1) ◽

pp. 17-32 ◽

Cited By ~ 10

Author(s):

Guanyu Huang ◽

Xiong Liu ◽

Kelly Chance ◽

Kai Yang ◽

Zhaonan Cai

Keyword(s):

Stratospheric Ozone ◽

Radiometric Calibration ◽

High Altitudes ◽

Ozone Monitoring Instrument ◽

Data Set ◽

Spatial Consistency ◽

Ozone Profile ◽

Microwave Limb Sound ◽

Before And After ◽

Global Mean

Abstract. We validate the Ozone Monitoring Instrument (OMI) ozone profile (PROFOZ v0.9.3) product including ozone profiles between 0.22 and 261 hPa and stratospheric ozone columns (SOCs) down to 100, 215, and 261 hPa from October 2004 through December 2014 retrieved by the Smithsonian Astrophysical Observatory (SAO) algorithm against the latest Microwave Limb Sound (MLS) v4.2x data. We also evaluate the effects of OMI row anomaly (RA) on the retrieval by dividing the data set into before and after the occurrence of serious RA, i.e., pre-RA (2004–2008) and post-RA (2009–2014). During the pre-RA period, OMI ozone profiles agree very well with MLS data. After applying OMI averaging kernels to MLS data, the global mean biases (MBs) are within 3 % between 0.22 and 100 hPa, negative biases are within 3–9 % for lower layers, and the standard deviations (SDs) are 3.5–5 % from 1 to 40 hPa, 6–10 % for upper layers, and 5–20 % for lower layers. OMI shows biases dependent on latitude and solar zenith angle (SZA), but MBs and SDs are mostly within 10 % except for low and high altitudes of high latitudes and SZAs. Compared to the retrievals during the pre-RA period, OMI retrievals during the post-RA period degrade slightly between 5 and 261 hPa with MBs and SDs typically larger by 2–5 %, and degrade much more for pressure less than ∼ 5 hPa, with larger MBs by up to 8 % and SDs by up to 15 %, where the MBs are larger by 10–15 % south of 40∘ N due to the blockage effect of RA and smaller by 15–20 % north of 40∘ N due to the solar contamination effect of RA. The much worse comparisons at high altitudes indicate the UV1 channel of pixels that are not flagged as RA is still affected by the RA. During the pre-RA period, OMI SOCs show very good agreement with MLS data with global mean MBs within 0.6 % and SDs of 1.9 % for SOCs down to 215 and 261 hPa and of 2.30 % for SOC down to 100 hPa. Despite clearly worse ozone profile comparisons during the post-RA period, OMI SOCs only slightly degrade, with SDs larger by 0.4–0.6 % mostly due to looser spatial coincidence criteria as a result of missing data from RA and MBs larger by 0.4–0.7 %. Our retrieval comparisons indicate significant bias trends, especially during the post-RA period. The spatiotemporal variation of our retrieval performance suggests the need to improve OMI's radiometric calibration to maintain the long-term stability and spatial consistency of the PROFOZ product.

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Past changes in the vertical distribution of ozone – Part 1: Measurement techniques, uncertainties and availability

Atmospheric Measurement Techniques ◽

10.5194/amt-7-1395-2014 ◽

2014 ◽

Vol 7 (5) ◽

pp. 1395-1427 ◽

Cited By ~ 43

Author(s):

B. Hassler ◽

I. Petropavlovskikh ◽

J. Staehelin ◽

T. August ◽

P. K. Bhartia ◽

...

Keyword(s):

Stratospheric Ozone ◽

Measurement Techniques ◽

United Nations Environment Programme ◽

Critical Examination ◽

Profile Measurement ◽

Data Sets ◽

Data Set ◽

Ozone Profile ◽

Measurement Uncertainties

Abstract. Peak stratospheric chlorofluorocarbon (CFC) and other ozone depleting substance (ODS) concentrations were reached in the mid- to late 1990s. Detection and attribution of the expected recovery of the stratospheric ozone layer in an atmosphere with reduced ODSs as well as efforts to understand the evolution of stratospheric ozone in the presence of increasing greenhouse gases are key current research topics. These require a critical examination of the ozone changes with an accurate knowledge of the spatial (geographical and vertical) and temporal ozone response. For such an examination, it is vital that the quality of the measurements used be as high as possible and measurement uncertainties well quantified. In preparation for the 2014 United Nations Environment Programme (UNEP)/World Meteorological Organization (WMO) Scientific Assessment of Ozone Depletion, the SPARC/IO3C/IGACO-O3/NDACC (SI2N) Initiative was designed to study and document changes in the global ozone profile distribution. This requires assessing long-term ozone profile data sets in regards to measurement stability and uncertainty characteristics. The ultimate goal is to establish suitability for estimating long-term ozone trends to contribute to ozone recovery studies. Some of the data sets have been improved as part of this initiative with updated versions now available. This summary presents an overview of stratospheric ozone profile measurement data sets (ground and satellite based) available for ozone recovery studies. Here we document measurement techniques, spatial and temporal coverage, vertical resolution, native units and measurement uncertainties. In addition, the latest data versions are briefly described (including data version updates as well as detailing multiple retrievals when available for a given satellite instrument). Archive location information for each data set is also given.

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Ozone trends derived from the total column and vertical profiles at a northern mid-latitude station

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-10373-2013 ◽

2013 ◽

Vol 13 (20) ◽

pp. 10373-10384 ◽

Cited By ~ 37

Author(s):

P. J. Nair ◽

S. Godin-Beekmann ◽

J. Kuttippurath ◽

G. Ancellet ◽

F. Goutail ◽

...

Keyword(s):

Heat Flux ◽

Stratospheric Ozone ◽

Solar Flux ◽

Quasi Biennial Oscillation ◽

Data Set ◽

Total Column Ozone ◽

Latitude Station ◽

Ozone Trends ◽

Column Ozone ◽

Total Column

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.

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