Satellite Ozone Data Research Articles

Relations between cyclones and ozone changes in the Arctic using data from satellite instruments and the MOSAiC ship campaign

Abstract. Large-scale meteorological events (e.g. cyclones), referred to as synoptic events, strongly influence weather predictability but still cannot be fully characterised in the Arctic region because of the sparse coverage of measurements. Due to the fact that atmospheric dynamics in the lower stratosphere and troposphere influence the ozone field, one approach to analyse these events further is the use of space-borne measurements of ozone vertical distributions and total columns in addition to conventional parameters such as pressure or wind speed. In this study we investigate the link between cyclones and changes in stratospheric ozone by using a combination of unique measurements during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) ship expedition, ozone profile and total column observations by satellite instruments (OMPS-LP, TROPOMI), and ERA5 reanalysis data. The final goal of the study is to assess whether the satellite ozone data can be used to obtain information about cyclones and provide herewith an additional value in the assimilation by numerical weather prediction models. Three special cases during the MOSAiC expedition were selected and classified for the analysis. They are one “normal” cyclone, where a low surface pressure coincides with a minimum in tropopause height, and two “untypical” cyclones, where this is not observed. The influence of cyclone events on ozone in the upper-troposphere lower-stratosphere (UTLS) region was investigated, using the fact that both are correlated with tropopause height changes. The negative correlation between tropopause height from ERA5 and ozone columns was investigated in the Arctic region for the 3-month period from June to August 2020. This was done using total ozone columns and sub-columns from TROPOMI, OMPS-LP, and MOSAiC ozonesonde data. The greatest influence of tropopause height changes on ozone contour levels occurs at an altitude between 10 and 20 km. Moreover, the lowering of the 250 ppb ozonopause (at about 11 km altitude) below 9 km was used to detect cyclones using OMPS-LP ozone observations. The potential of this approach was demonstrated in two case studies where the boundaries of cyclones could be determined using ozone observations. The results of this study can help improve our understanding of the relationship between cyclones, tropopause height, and ozone in the Arctic and demonstrate the usability of satellite ozone data in addition to the conventional parameters for investigating cyclones in the Arctic.

The recovery of the Antarctic ozone layer and suggestions for addressing the global warming

The ozone layer is a critical shield for humanity, located in the Earths atmosphere with a high ozone concentration. Its primary role is to absorb and filter out the majority of harmful ultraviolet rays emitted by the sun, which pose a threat to all living beings. However, the ozone layer suffered from very severe depletion. To counteract this, the Montreal Convention was established in 1987, mandating a reduction in chlorofluorocarbon emissions by humans. Because of the environmental problem of ozone layer destruction for a long time, based on some existing research background at this stage, people find that the ozone layer is gradually recovering through observation of some data. In this essay, it explains the causal factors behind the depletion of the Antarctic ozone layer, as well as the various elements that contribute to its recovery and their respective levels of significance, through some research. Additionally, this essay explores how these models can be applied to address other environmental concerns. To achieve a more comprehensive understanding of this subject, this paper has conducted an intensive search through various academic references. In conclusion, through the use of balloon and satellite ozone data, a chemistry-climate model, and volcanic aerosol measurements, the healing of the Antarctic ozone layer is contributed by three factors: chemical reduction, kinetics, and temperature. Among these factors, chemical factors have the greatest contribution.

Research Progress and Trends in the Field of Satellite Ozone from 2005 to 2023: A Bibliometric Review

Ozone, an important atmospheric constituent, affects various processes in the troposphere–stratosphere region and significantly contributes to climate and environmental change. The advancement of meteorological satellite technology has enabled the deployment of ozone detection instruments in space, providing accurate and global satellite ozone data in all weather conditions. This study employs scientometric methods, such as collaboration analysis, co-citation analysis, and keyword co-occurrence analysis to investigate the current status, trends, and future directions of satellite ozone research, with a broader search scope and more objective results compared with a manual review. Analyzing a dataset of 5320 bibliographic records from the WoS core collection database reveals the key intellectual frameworks shaping this field during the period from 2005 to 2023. The findings indicate that leading nations, like the United States, Germany, France, and China, along with their respective institutions and authors, spearhead satellite ozone research. Collaborative partnerships between the United States and European countries play a crucial role in advancing research efforts. Moreover, 20 distinct co-citation clusters identify the knowledge framework within the field, demonstrating a consistent progression over time. The focus has expanded from satellite ozone observation instruments to encompass broader areas, such as atmospheric pollution and environmental conditions, with “air quality” emerging as a prominent research area and future trend. Based on these insights, four major research directions are proposed: understanding atmospheric pollution mechanisms, improving ozone detection technologies, utilizing satellite ozone data for weather, and climate phenomena. This study aims to assist scholars by providing a comprehensive understanding of the developmental trajectory of satellite ozone research. Its results can serve as a valuable reference for researchers to identify relevant publications and journals efficiently. Policymakers can also utilize this systematic review as a structured point of reference.

The Stratosphere-to-Troposphere Transport Related to Rossby Wave Breaking and Its Impact on Summertime Ground-Level Ozone in Eastern China

In summertime, eastern China experiences severe ozone pollution. Stratosphere-to-troposphere transport (STT), as the primary natural source of tropospheric ozone, may have a non-negligible contribution to ground-level ozone. Rossby wave breaking (RWB) is a leading mechanism that triggers STT, which can be categorized as anticyclonic wave breakings (AWBs) and cyclonic wave breakings (CWBs). This study uses an objective method to diagnose AWBs and CWBs and to investigate their influence on the surface ozone in eastern China using ground-based ozone observations, satellite ozone data from AIRS, a stratospheric ozone tracer simulated by CAM-chem, and meteorological fields from MERRA-2. The results indicate that AWBs occur mainly and frequently over northeast China, while CWBs occur mostly over the northern Sea of Japan. STTs triggered by AWBs mainly have sinking areas over the North China Plain, increasing the ground-level ozone concentrations by 5–10 ppbv in eastern China. The downwelling zones in the CWBs extend from Mongolia to the East China Sea, potentially causing an elevation of 5–10 ppbv of ozone in both central and eastern China. This study gives an overview of the impacts of AWBs and CWBs on surface ozone in eastern China and helps to improve our understanding of summertime ozone pollution in eastern China.

A Hurricane Initialization Scheme with 4DEnVAR Satellite Ozone and Bogus Data Assimilation (SOBDA) and Its Application: Case Study

The aim of this study is to joint assimilate the ozone product from the satellite Atmospheric Infrared Sounder (AIRS) and bogus data using the four-dimensional ensemble-variational (4DEnVar) method, and demonstrate the potential benefits of this initialization technique in improving hurricane forecasting through a case study. Firstly, the quality control scheme is employed to enhance the ozone product quality from the satellite AIRS; a bogus sea level pressure (SLP) at the hurricane center is constructed simultaneously based on Fujita’s mathematical model for subsequent assimilation. Secondly, a 4DEnVar satellite ozone and bogus data assimilation (SOBDA) model is established, incorporating an observation operator of satellite ozone that utilizes the relationship between satellite ozone and potential vorticity (PV) from the lower level of 400 hPa to the upper level of 50 hPa. Finally, several comparative experiments are performed to assess the influence of assimilating satellite ozone and/or bogus data, the 4DEnVAR method and four-dimensional variational (4D-Var) method, and ensemble size on hurricane prediction. It is found that assimilating satellite ozone and bogus data with the 4DEnVar method concurrently brings about significant alterations to the initial conditions (ICs) of the hurricane vortex, resulting in a more homogeneous and deeper vortex with a larger, warmer, and more humid core as opposed to assimilating only one type of data. As the duration of integration increases, the initial perturbations in the upper levels gradually propagate downwards, giving rise to significant disparities in the hurricane prediction when satellite ozone and/or bogus information is incorporated. The results demonstrate that utilizing the 4DEnVar approach to assimilate both satellite ozone and bogus data leads to the maximum enhancement in reducing track error and central SLP error of hurricane simulation throughout the entire 72 h forecasting period, compared to assimilating a single dataset. Furthermore, comparative experiments have indicated that the performance of 4DEnVar SOBDA in hurricane forecasting is influenced by the ensemble size. Generally, selecting an appropriate number of ensemble members can not only effectively improve the accuracy of hurricane prediction but can also significantly reduce the demand for computational resources relative to the 4D-Var method. This study can also serve as an advantageous technical reference for numerical applications of ozone products from other satellites and hurricane initialization.

Annual solar spectral energy distributions in North America

Predicting outdoor service life of polymers and coatings requires knowledge of the spectral power distribution (SPD) of the sunlight and the amount of radiant energy they receive. Standard solar SPDs such as ASTM G173 and ASTM G177 are snapshots of the SPD at a single moment under model conditions. A better measure would be average annual spectral energy distributions (SED) for specific locations, especially benchmark outdoor weathering sites. The annual SED is the energy received at each wavelength over the course of a year. A Smithsonian/NIST collaboration placed SR-18 UV spectroradiometers in Miami, FL, Phoenix, AZ, and Madison, WI during the period 1997-2012, collecting data at ca. 2 nm intervals between 290 and 324 nm. Similar data have been collected at Edgewater, MD for many years. The data are not complete for any year, but gaps could be patched using data from other years. These data sets were compared to data available on-line from ongoing U.S Department of Agriculture (USDA)/Colorado State University outdoor spectroradiometer measurements, after similar patching. The USDA data have fewer points in the UV but extend into the visible portion of the spectrum. The data sets give consistent results and show that the SEDs can be fit by SPDs calculated using the SMARTS 2.9.5 model and satellite ozone data. The annual standard deviations are < 5% for wavelengths > 310 nm. SEDs for average annual radiant energy received by horizontal and 45° south exposures are reported for benchmark sites near Miami and Phoenix. The paper provides a general approach for determining an SED for a location based on SMARTS modeling of the autumnal equinox and subsequent scaling based on reported annual total solar radiant energy.

Toward a Reanalysis of Stratospheric Ozone for Trend Studies: Assimilation of the Aura Microwave Limb Sounder and Ozone Mapping and Profiler Suite Limb Profiler Data

AbstractCompatibility of the stratospheric ozone profile data from the Ozone Mapping and Profiler Suite Limb Profiler (OMPS‐LP) and the Microwave Limb Sounder (MLS) is assessed in the context of a continuity requirement for future reanalyses. A methodology for the assimilation of OMPS‐LP data into the Goddard Earth Observing System data assimilation system with a stratospheric chemistry module is developed. It is demonstrated that a simple homogenization technique significantly reduces the bias between OMPS‐LP and MLS analyses. With the homogenization applied, the mean difference between the two analyses is within 3% and the difference standard deviation within 10%, consistent with the estimated uncertainties of the satellite ozone data. Larger differences are seen in the tropical lower stratosphere. The MLS and OMPS‐LP assimilation experiments agree very well with independent data from ozonesondes and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer. Heterogeneous ozone depletion during polar spring in both hemispheres as well as ozone transport during the 2016 quasi‐biennial oscillation disruption event are realistically represented in both analyses. This work establishes a step toward achieving continuity of the post‐2004 ozone record in future reanalyses, necessary for trend and long‐term ozone variability studies, although further development is needed to address a drift in the OMPS‐LP ozone data.

Total Ozone over Vernadsky Antarctic Station: Ground-based and Satellite Measurements

Objective. Provide an analysis of the total ozone variations over Vernadsky Antarctic station (Faraday Base until 1996) from long-term ground-based and satellite series. Study the discrepancies between the data of different instruments. Methods. Data visualization followed by analysis, statistical treatment of the Vernadsky Dobson spectrophotometer observations and satellite total ozone series. Results. Satellite and ground-based measurements of total ozone over Vernadsky station have confirmed the stabilization in the ozone layer in the stratosphere over Antarctica from the early 2000s. British Faraday Base observations have retrieved an ozone spring maximum during the 1950s–1970s with a sharp decrease in the August–October values in the 1980s–1990s. That changed substantially total ozone seasonal cycle. Satellite overpasses and model data based on satellite measurements have been analyzed. It is shown that typical discrepancies between the Ozone Monitoring Instrument (OMI) model and the Vernadsky Dobson daily means are mainly in the range of 20 DU. Larger deviations are rare and are observed predominantly on the beginning and at the end of the observational season. Seasonal means and standard deviations for the model–Dobson differences were calculated that demonstrates worse correspondence of the OMI model with Vernadsky Dobson data during separate years, in particular 2009–2010. Conclusions. Both Dobson and satellite ozone data over Faraday/Vernadsky station have shown the total ozone decrease during the 1980s–1990s (mainly in spring) with a following stabilization since year 2000. Comparison between the ground-based data and models calculated from satellite measurements indicates better correspondence of the Dobson and GOME2 results relatively the OMI ones. There are evidences that individual Dobson measurements underestimate to some degree total ozone on the beginning of observational season at high solar zenith angles and the low total ozone values.

The global diabatic circulation of the stratosphere as a metric for the Brewer–Dobson circulation

Abstract. The circulation of the stratosphere, also known as the Brewer–Dobson circulation, transports water vapor and ozone, with implications for radiative forcing and climate. This circulation is typically quantified from model output by calculating the tropical upwelling vertical velocity in the residual circulation framework, and it is estimated from observations by using time series of tropical water vapor to infer a vertical velocity. Recent theory has introduced a method to calculate the strength of the global mean diabatic circulation through isentropes from satellite measurements of long-lived tracers. In this paper, we explore this global diabatic circulation as it relates to the residual circulation vertical velocity, stratospheric water vapor, and ozone at interannual timescales. We use a comprehensive climate model, three reanalysis data products, and satellite ozone data. The different metrics for the circulation have different properties, especially with regards to the vertical autocorrelation. In the model, the different residual circulation metrics agree closely and are well correlated with the global diabatic circulation, except in the lowermost stratosphere. In the reanalysis products, however, there are more differences throughout, indicating the dynamical inconsistencies of these products. The vertical velocity derived from the time series of water vapor in the tropics is significantly correlated with the global diabatic circulation, but this relationship is not as strong as that between the global diabatic circulation and the residual circulation vertical velocity. We find that the global diabatic circulation in the lower to middle stratosphere (up to 500 K) is correlated with the total column ozone in the high latitudes and in the tropics. The upper-level circulation is also correlated with the total column ozone, primarily in the subtropics, and we show that this is due to the correlation of both the circulation and the ozone with upper-level temperatures.

Assessment of total columnar ozone climatological trends over the Indian sub-continent

ABSTRACTIn the present study, long term satellite and Dobson spectrophotometer Total Column Ozone (TCO) data have been used to study the interannual variability and also to assess climatological trends in TCO over different geographical locations of Indian sub-continent. TCO data were analyzed for the period 1957 to 2015 over New Delhi (28.63° N, 77.18° E), Varanasi (25.30° N, 83.02° E), Pune (18.53° N, 73.84° E) and Kodaikanal (10.0° N, 77.47° E). An extensive validation was performed for Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) retrieved TCO data independently with Dobson Spectrophotometer TCO measurements over New Delhi, Varanasi, Pune and Kodaikanal. The results of this exercise showed good correlation coefficient (r) of 0.87 (0.88), 0.84 (0.82), 0.91 (0.80) and 0.84 (Data not available) respectively. Climatological mean TCO over New Delhi, Varanasi, Pune and Kodaikanal are 275.02 ± 6.44 DU, 269.03 ± 7.34 DU, 260.78 ± 5.07 DU and 258.71 ± 6.36 DU respectively for the period 1957 to 2015. An increasing trend over New Delhi (0.20 DU year–1), Pune (0.18 DU year–1), Kodaikanal (0.14 DU year–1) and decreasing trend over Varanasi (0.01 DU year–1) were observed. High significance of TCO trend was found at New Delhi (p-value < 0.0001), Pune (p-value = 0.002) and Kodaikanal (p-value = 0.003) with negligible trend over Varanasi with p-value of 0.84. The TCO variations at different geographical locations associated with upper atmospheric meteorological parameters such as lower Stratospheric Temperature (ST) at 65 hPa and Tropopause Height (TH) were also addressed. Annual lower stratospheric temperature shows positive relationship with TCO and Stratospheric ozone over the study sites. Further, decadal variability in TCO with respect to solar activity at New Delhi was also analyzed.

An update on ozone profile trends for the period 2000 to 2016

Abstract. Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and from ground-based data measured by four techniques at stations of the Network for the Detection of Atmospheric Composition Change indicate significant ozone increases in the upper stratosphere, between 35 and 48 km altitude (5 and 1 hPa). Near 2 hPa (42 km), ozone has been increasing by about 1.5 % per decade in the tropics (20° S to 20° N), and by 2 to 2.5 % per decade in the 35 to 60° latitude bands of both hemispheres. At levels below 35 km (5 hPa), 2000 to 2016 ozone trends are smaller and not statistically significant. The observed trend profiles are consistent with expectations from chemistry climate model simulations. This study confirms positive trends of upper stratospheric ozone already reported, e.g., in the WMO/UNEP Ozone Assessment 2014 or by Harris et al. (2015). Compared to those studies, three to four additional years of observations, updated and improved data sets with reduced drift, and the fact that nearly all individual data sets indicate ozone increase in the upper stratosphere, all give enhanced confidence. Uncertainties have been reduced, for example for the trend near 2 hPa in the 35 to 60° latitude bands from about ±5 % (2σ) in Harris et al. (2015) to less than ±2 % (2σ). Nevertheless, a thorough analysis of possible drifts and differences between various data sources is still required, as is a detailed attribution of the observed increases to declining ozone-depleting substances and to stratospheric cooling. Ongoing quality observations from multiple independent platforms are key for verifying that recovery of the ozone layer continues as expected.

臭氧观测的全球四维变分资料同化技术

针对平流层大气观测资料稀少的问题，提出利用同化卫星臭氧观测改进全球数值天气预报效果的方法。将复杂的臭氧资料同化问题转换为一个以大气运动控制方程为约束条件的大规模最优化问题，并实现了SCIAMACHY卫星臭氧观测的全球四维变分资料同化。试验结果表明:由于卫星臭氧观测资料同化的引入，一定程度上提高了地面报和探空报的同化利用率，总气柱臭氧含量预报场的分布具有明显变化，对南北半球形势场预报技巧评分具有一定幅度的提高。 In order to solve the problems of being short of stratospheric atmospheric observations, a method of improving the global numerical weather prediction (NWP) qualities is proposed by assimilating satellite ozone data. The complex problem of ozone data assimilation is transformed into a large-scale optimization problem constrained by the governing equations of atmospheric motion, and the global four-dimensional variational data assimilation of ozone from SCIAMACHY remote sensor is implemented to produce initial fields for global NWP model. The numerical experimental results show that the utilization rates of surface and sounding observations have been upgraded to a certain extent due to the introduction of satellite ozone data assimilation, and the distribution of the ozone prediction field changes obviously. Furthermore, the forecast skills in the northern and southern hemispheres are improved a lot by carrying out the statistical verification.

A modeling study of effective radiative forcing and climate response due to tropospheric ozone

This study simulates the effective radiative forcing (ERF) of tropospheric ozone from 1850 to 2013 and its effects on global climate using an aerosol–climate coupled model, BCC AGCM2.0.1 CUACE/Aero, in combination with OMI (Ozone Monitoring Instrument) satellite ozone data. According to the OMI observations, the global annual mean tropospheric column ozone (TCO) was 33.9 DU in 2013, and the largest TCO was distributed in the belts between 30°N and 45°N and at approximately 30°S; the annual mean TCO was higher in the Northern Hemisphere than that in the Southern Hemisphere; and in boreal summer and autumn, the global mean TCO was higher than in winter and spring. The simulated ERF due to the change in tropospheric ozone concentration from 1850 to 2013 was 0.46 W m−2, thereby causing an increase in the global annual mean surface temperature by 0.36°C, and precipitation by 0.02 mm d−1 (the increase of surface temperature had a significance level above 95%). The surface temperature was increased more obviously over the high latitudes in both hemispheres, with the maximum exceeding 1.4°C in Siberia. There were opposite changes in precipitation near the equator, with an increase of 0.5 mm d−1 near the Hawaiian Islands and a decrease of about −0.6 mm d−1 near the middle of the Indian Ocean.

Intercomparison of vertically resolved merged satellite ozone data sets: interannual variability and long-term trends

Abstract. In the framework of the SI2N (SPARC (Stratosphere-troposphere Processes And their Role in Climate)/IO3C (International Ozone Commission)/IGACO-O3 (Integrated Global Atmospheric Chemistry Observations – Ozone)/NDACC (Network for the Detection of Atmospheric Composition Change)) initiative, several long-term vertically resolved merged ozone data sets produced from satellite measurements have been analysed and compared. This paper presents an overview of the methods, assumptions, and challenges involved in constructing such merged data sets, as well as the first thorough intercomparison of seven new long-term satellite data sets. The analysis focuses on the representation of the annual cycle, interannual variability, and long-term trends for the period 1984–2011, which is common to all data sets. Overall, the best agreement amongst data sets is seen in the mid-latitude lower and middle stratosphere, with larger differences in the equatorial lower stratosphere and the upper stratosphere globally. In most cases, differences in the choice of underlying instrument records that were merged produced larger differences between data sets than the use of different merging techniques. Long-term ozone trends were calculated for the period 1984–2011 using a piecewise linear regression with a change in trend prescribed at the end of 1997. For the 1984–1997 period, trends tend to be most similar between data sets (with largest negative trends ranging from −4 to −8% decade−1 in the mid-latitude upper stratosphere), in large part due to the fact that most data sets are predominantly (or only) based on the SAGE-II record. Trends in the middle and lower stratosphere are much smaller, and, particularly for the lower stratosphere, large uncertainties remain. For the later period (1998–2011), trends vary to a greater extent, ranging from approximately −1 to +5% decade−1 in the upper stratosphere. Again, middle and lower stratospheric trends are smaller and for most data sets not significantly different from zero. Overall, however, there is a clear shift from mostly negative to mostly positive trends between the two periods over much of the profile.

On the regional distinctions in annual cycle of total ozone in the northern midlatitudes

To better attribute the total ozone column (TOC) anomalies observed from the ozone measurements in Ukraine, the climatologies of annual ozone cycle along the latitudinal band 40–60° N with the 30° step in longitude have been analysed. Gridded satellite ozone data based on the merged ozone dataset over the period 1979–2011 are used. The results show that, similar to the known longitudinal dependences of both the total ozone itself and its decadal trends, the annual TOC cycle in the northern midlatitudes is also longitudinally dependent. The higher (lower) regional TOC level is associated with the leading (lagging) development of the annual cycle relative to the zonal mean climatology. Particularly, a 2- to 3-month lead of annual cycle in eastern Asia (120–150° E) in comparison with that in eastern Atlantic (0–30° W) exists. Revealed coupling between regionality and seasonality of the TOC in the northern midlatitudes may be involved in the regional climate variability and deserves further studies with higher temporal and spatial resolution.

Summertime free-tropospheric ozone pool over the eastern Mediterranean/Middle East

Abstract. Observations show that the Mediterranean troposphere is characterized by a marked enhancement in summertime ozone, with a maximum over the eastern Mediterranean. This has been linked to enhanced photochemical ozone production and subsidence under cloud-free anticyclonic conditions. The eastern Mediterranean is among the regions with the highest levels of background tropospheric ozone worldwide. A 12 yr climatological analysis (1998–2009) of free-tropospheric ozone was carried out over the region based on the ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-Interim reanalysis data and simulations with the EMAC (ECHAM5–MESSy) atmospheric chemistry–climate model. EMAC is nudged towards the ECMWF analysis data and includes a stratospheric ozone tracer. A characteristic summertime pool with high ozone concentrations is found in the middle troposphere over the eastern Mediterranean–Middle East (EMME) in the ERA-Interim ozone data, Tropospheric Emission Spectrometer (TES) satellite ozone data and simulations with EMAC. The enhanced ozone over the EMME during summer is a robust feature, extending down to lower free-tropospheric levels. The investigation of ozone in relation to potential vorticity and water vapour and the stratospheric ozone tracer indicates that the dominant mechanism causing the free-tropospheric ozone pool is the downward transport from the upper troposphere and lower stratosphere, in association with the enhanced subsidence and the limited horizontal divergence observed over the region. The implications of these high free-tropospheric ozone levels on the seasonal cycle of near-surface ozone over the Mediterranean are discussed.

On the inclusion of Limb Infrared Monitor of the Stratosphere version 6 ozone in a data assimilation system

AbstractVersion 6 ozone profiles for 1978–1979 from the Limb Infrared Monitor of the Stratosphere experiment on the NIMBUS 7 satellite (or LIMS v6) are assimilated into an updated version of the GEOS‐5 model of NASA. First, an assimilation study is carried out using GEOS‐5 version 7.2 (v7.2) and solar backscatter ultraviolet (SBUV) version 8.6 ozone profiles. Then, a second study is conducted that ingests both the LIMS and SBUV ozone, as weighted by their estimated absolute error vectors. Ozone from this second study compares well with independent observations from the Stratospheric Aerosol and Gas Experiment (SAGE I) and from the time series of ozonesonde data at Hohenpeissenberg and at Wallops Island. Assimilation of the LIMS data gives improved ozone distributions in the upper stratosphere (pressure &lt; 5 hPa) and in the polar night region—the latter where solar backscatter ultraviolet (SBUV) is not observed. The LIMS ozone leads to improved total column ozone analyses in winter/spring outside of the tropics, based on independent comparisons with total ozone from the Total Ozone Mapping Spectrometer. The LIMS ozone also adds information in the tropics on coherent structural features at 20–30 hPa, related to the phase transition of the quasi‐biennial oscillation wind field. It is affirmed that the process of data assimilation represents a cost‐effective way of characterizing new and/or reprocessed satellite ozone data sets. It is concluded that the GEOS‐5 v7.2 model with the addition of the LIMS data can improve analyses of ozone in 1978–1979.

Trend of Antarctic Ozone Hole and Its Influencing Factors

Influencing factors, and variations and trends of Antarctic ozone hole in recent decades are analyzed, and sudden change processes of ozone at Zhongshan station and the effect of atmospheric dynamic processes on ozone changes are also discussed by using the satellite ozone data and the ground-measured ozone data at two Antarctic stations as well as the NCEP/NCAR reanalysis data. The results show that equivalent effective stratospheric chlorine (EESC) and stratospheric temperature are two important factors influencing the ozone hole. The column ozone at Zhongshan and Syowa stations is significantly related with EESC and stratospheric temperature, which means that even though the two stations are both located on the edge of the ozone hole, EESC and stratospheric temperature still played a very important role in column ozone changes, and mean while verifies that EESC is applicable on the coast of east Antarctic continent. Decadal changes in EESC are similar with those of the ozone hole, and inter-annual variations of ozone are closely related with stratospheric temperature. Based on the relation of EESC and ozone hole size, it can be projected that the ozone hole size will gradually reduce to the 1980’s level from 2010 to around 2070. Of course there might exist many uncertainties in the projection, which therefore needs to be further studied. CitationBian, L.-G., Z. Lin, X.-D. Zheng, et al., 2012: Trend of Antarctic ozone hole and its influencing factors. Adv. Clim. Change Res.,3(2), doi: 10.3724/SP.J.1248.2012.00068.

Climatology 2011: An MLS and sonde derived ozone climatology for satellite retrieval algorithms

The ozone climatology used as the a priori for the version 8 Solar Backscatter Ultraviolet (SBUV) retrieval algorithms has been updated. The climatology was formed by combining data from Aura MLS (2004–2010) with data from balloon sondes (1988–2010). The Microwave Limb Sounder (MLS) instrument on Aura has excellent latitude coverage and measures ozone daily from the upper troposphere to the lower mesosphere. The new climatology consists of monthly average ozone profiles for ten degree latitude zones covering pressure altitudes from 0 to 65 km. Ozone below 8 km (below 12 km at high latitudes) is based on balloons sondes, while ozone above 16 km (21 km at high latitudes) is based on MLS measurements. Sonde and MLS data are blended in the transition region. Ozone accuracy in the upper troposphere is greatly improved because of the near uniform coverage by Aura MLS, while the addition of a large number of balloon sonde measurements improves the accuracy in the lower troposphere, in the tropics and southern hemisphere in particular. The addition of MLS data also improves the accuracy of the climatology in the upper stratosphere and lower mesosphere. The revised climatology has been used for the latest reprocessing of SBUV and TOMS satellite ozone data.

Extreme ozone loss over the Northern Hemisphere high latitudes in the early 2011

ABSTRACTThe satellite ozone data comprising The New Zealand National Institute of Water and Atmospheric Research (NIWA) total ozone database version 2.7, total ozone by the Ozone Monitoring Instrument (OMI) spectrophotometer on the Aura platform, and the ozone mixing ratios by SBUV/2 measurements on The National Oceanic and Atmospheric Administration (NOAA) platforms are analysed for ozone variability over the sunlit part of the Northern Hemisphere polar region. An extended area, with unusually low ozone values, is observed in a two-month period beginning in mid February 2011. The total area with extremely depleted total ozone reached the maximum at the end of March 2011, equal to ~11×106 km2. The area is even larger in the lower/mid stratosphere. A multiple regression model is proposed to attribute the polar total ozone variability to various chemical and dynamical ozone forcings. The model reproduces the ozone loss in early 2011 and the overall picture of the ozone long-term changes. The extreme ozone decline in 2011 could be attributed to the long-lasting period with low stratospheric temperature (<195 K), weaker than the normal Brewer-Dobson circulation, and the Arctic Oscillation in a strong positive phase. A deficit of total ozone in the following summer months (June–July–August), after the total ozone decline in March, was predicted and supported by later OMI observations.