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The article discusses ozone layer monitoring efforts by the U.S. National Aeronautics and Space Administration (NASA) using the ER-2 jet. Topics include the role of atmospheric chemist James Anderson in the research, the possible role of overshoot storms that reach the stratosphere in damaging the ozone layer, and aspects of the Dynamics of Chemistry of the Summer Stratosphere (DCOTSS) project.

Abstract Castor bean (Ricinus communis L.) an important non-edible oilseed crop, is a prominent feed stock towards the generation of renewable materials for industrial production which has multiple applications ranging from cosmetics to biofuels industry. India accounts for 76% of the total world production of castor oil seed. However, major concern for developing countries like India where expanding economy led to rapid increases in gases like NOx, CO and VOCs photochemically form ozone. Ozone is strong oxidant that damages agriculture, ecosystems, and materials with considerable reduction in crop yields and crop quality. One way to reduce ozone induced loss is to focus on the adapting crops to ozone exposure by selecting cultivars with demonstrated ozone resistance. An experiment was conducted for ozone risk assessment of castor cultivars to select cultivar with demonstrated resistance against ozone pollution. This study comprise an open top chamber experiment with three treatments viz. (i) control (ambient ozone concentration), (ii) enhanced ozone (average 75 ppb for 4 h daily throughout the growing season), and (iii) EDU application. Results suggested that the ozone pollution substantially affected growth and physiology of castor cultivars. Crop biomass and yield was also negatively influenced by ozone pollution. Developed defence provided strength to withstand against ozone pollution to the experimental crop cultivars. However, developed defence is cultivar specific and positively correlated with the resistance against ozone pollution. Study concluded that the damage to ozone is directly dependent on the antioxidative potential of plant species. However, ozone adaptability is based on the genetic makeup of the cultivar and yield related loss to ozone can be minimizing by selecting ozone tolerant variety as seen in cultivar Nidhi-999. Graphical abstract Image 1 Highlights • Tropospheric ozone is detrimental for castor crop and reduces growth and yield. • ROS scavenging provided adaptability to castor cultivars for ozone pollution. • Developed defence for ozone is based on the genetic makeup of the cultivars. • Yield related loss to ozone can be minimize by selecting ozone tolerant variety as in cultivar Nidhi-999. Tropospheric ozone is detrimental for crop yield and yield related loss to ozone can be minimize by selecting ozone tolerant variety. [ABSTRACT FROM AUTHOR]

The effects of elevated O3 (EO3) on greenhouse gas (GHG) emissions and global warming potential (GWP) from wheat systems with differential O3 sensitivity are not well understood. The nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions from cropping (CP) and bare soil or root-free (BS) plots, GWP, GWP per unit yield, and biomass and its allocation to belowground between O3-sensitive (cultivar YN19) and tolerant (cultivar Y15) wheat (Triticum aestivum L.) systems were investigated at EO3 and ambient O3 (AO3) with an openair O3 fumigation system. Results indicated that a 50% elevation above AO3 significantly reduced belowground biomass of the two cultivars. The EO3 significantly increased the cumulative emissions of CO2 and N2O but did not change that of CH4 in YN19 CP. For BS, it significantly increased the emission of CO2 but decreased that of CH4 and N2O. The EO3 significantly increased the GWP and GWP per unit yield in YN19 CP but reduced the GWP in BS. The O3 sensitivity of wheat cultivar affected the responses of gaseous C and N emission, GWP and GWP per unit yield to EO3. The O3-sensitive wheat cultivar would release more freshly assimilated C, increasing cumulative GHG emissions, GWP and GWP per unit yield in response to O3 stress, when compared to the O3 O3-tolerant wheat cultivar. Our results suggest that EO3 may impair soil C and N sequestration in an O3 O3-sensitive wheat-soil system in view of lower root biomass but higher CO2 and N2O emissions under EO3. [ABSTRACT FROM AUTHOR]

The article presents a report on the 29th Meeting of the Parties of the Montreal Protocol, held in conjunction with the 11th meeting of the Conference of the Parties of the Vienna Convention for the Protection of the Ozone Layer, on November 20-24, 2017 in Montreal, Canada. Topics of discussion included the implementation of the Kigali Amendment on hydrofluorocarbons, energy efficiency in the refrigeration, air-conditioning, and heat-pump sectors, and Multilateral Fund replenishment.

This paper reports investigation data on the temporal variability of total ozone content (TOC) in the Central Asian and Tibet Plateau mountain regions obtained by conventional methods, as well as by spectral, cross-wavelet, and composite analyses. The data of ground-based observation stations located at Huang He, Kunming, and Lake Issyk-Kul, along with the satellite data obtained at SBUV/SBUV2 (SBUV merged total and profile ozone data, Version 8.6) for 1980-2013 and OMI (Ozone Monitoring Instrument) and TOU (Total Ozone Unit) for 2009-2013 have been used. The average relative deviation from the SBUV/SBUV2 data is less than 1% in Kunming and Issyk-Kul for the period of 1980-2013, while the Huang He Station is characterized by an excess of the satellite data over the ground-based information at an average deviation of 2%. According to the Fourier analysis results, the distribution of amplitudes and the periods of TOC oscillations within a range of over 14 months is similar for all series analyzed. Meanwhile, according to the cross-wavelet and composite analyses results, the phase relationships between the series may considerably differ, especially in the periods of 5-7 years. The phase of quasi-decennial oscillations in the Kunming Station is close to the 11-year oscillations of the solar cycle, while in the Huang He and Issyk-Kul stations the TOC variations go ahead of the solar cycle. [ABSTRACT FROM AUTHOR]

This paper investigates the relationship between ground-level ozone (O 3 ) and temperature in the Midwestern U.S. during the period 1990–2015. From 1990 to 2015, the overall trend of 95th percentile temperature showed an increase of 0.04 K yr −1 , while summertime 95th percentile O 3 concentrations in the Midwest decreased at an average rate of 0.7 ppb yr −1 largely because NO 2 concentrations decreased by more than 50%. The ozone-climate penalty, defined as the slope of O 3 change with increasing temperature (Δ O 3 /Δ T ), was by average 0.43 ppb K −1 less in 1999–2007 than in 1990–1998, indicating the early success of NO x emission controls. However, the slope did not continue to decrease in 2008–2015 despite further NO x emission reductions, and it increased more rapidly with increasing temperature (Δ 2 O 3 /Δ T 2 ) by 0.03–0.09 ppb K −2 in most urban areas of the Midwest. This was accompanied by more frequent dry tropical (DT) weather in the Midwest since 2008. We find that O 3 in DT weather was 12 ppb and 17 ppb higher than in non-DT weather in rural and urban areas, respectively. Furthermore, the 2008–2015 period experienced 8% more surface air stagnation days than in 1990–1998. This demonstrates that, in addition to the impact of warmer temperatures, the ozone-climate penalty could be aggravated by altered weather conditions under climate change. It will be challenging for Midwestern cities to attain the National Ambient Air Quality Standard for O 3 if such conditions persist in the future, and future air quality improvements may require even greater efforts to reduce both NO x and VOC emissions in the Midwest. [ABSTRACT FROM AUTHOR]

The Limb Profiler (LP) is a part of the Ozone Mapping and Profiler Suite launched on board of the Suomi NPP satellite in October 2011. The LP measures solar radiation scattered from the atmospheric limb in ultraviolet and visible spectral ranges between the surface and 80 km. These measurements of scattered solar radiances allow for the retrieval of ozone profiles from cloud tops up to 55 km. The LP started operational observations in April 2012. In this study we evaluate more than 5.5 years of ozone profile measurements from the OMPS LP processed with the new NASA GSFC version 2.5 retrieval algorithm. We provide a brief description of the key changes that had been implemented in this new algorithm, including a pointing correction, new cloud height detection, explicit aerosol correction, and a reduction of the number of wavelengths used in the retrievals. The OMPS LP ozone retrievals have been compared with independent satellite profile measurements obtained from the Aura Microwave Limb Sounder (MLS), Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) and Odin Optical Spectrograph and InfraRed Imaging System (OSIRIS). We document observed biases, seasonal differences and evaluate the stability of the version 2.5 ozone record over 5.5 years. Our analysis indicates that the mean differences between LP and correlative measurements are well within required ±10 % between 18 and 42 km. In the upper stratosphere and lower mesosphere (> 43 km) LP tends to have a negative bias. We find larger biases in the lower stratosphere and upper troposphere, but LP ozone retrievals has significantly improved in version 2.5 compared to version 2 due to the implemented aerosol correction. In the northern high latitudes we observe larger biases between 20 and 32 km due to the remaining thermal sensitivity issue. Our analysis shows that LP ozone retrievals agree well with the correlative satellite observations in characterizing vertical, spatial and temporal ozone distribution associated with natural processes, like the seasonal cycle and Quasi Biennial Oscillations. We found a small positive drift ~ 0.5 %/yr in the LP ozone record against MLS and OSIRIS that is more pronounced at altitudes above 35 km. This pattern in the relative drift is consistent with a possible 100-meter drift in the LP sensor pointing detected by one of our altitude resolving methods. [ABSTRACT FROM AUTHOR]

Historically, the Environmental Protection Agency (EPA) has sidestepped prescribing modeling procedures for secondarily formed ozone and PM2.5 (particles with a size below 2.5 microns) because refined modeling tools for such analyses were not available. In recent years, the availability of Eulerian models, also known as photochemical grid models (PGMs), and advanced Lagrangian (puff) models with chemistry has made it more feasible to conduct such modeling. [ABSTRACT FROM AUTHOR]

An ozone mini-hole is a synoptic-scale region with strongly decreased total column ozone resulting from dynamical processes. Using total column measurements from the Ozone Monitoring Instrument and ozone profile measurements from the Microwave Limb Sounder, we evaluate the accuracy of mini-hole representation in five reanalyses. This study provides a metric of the reanalyses' ability to capture dynamically driven ozone variability. The reanalyses and the measurements show similar seasonal variability and geographical distributions of mini-holes; however, all of the reanalyses underestimate the number of mini-holes and their area, and in many reanalyses their location displays an eastward bias. The reanalyses' underestimation of mini-hole number ranges from about 34 to about 83%. The mini-hole vertical representation in the reanalyses agrees well with that in the MLS measurements and, furthermore, is consistent with previously reported mechanisms for mini-hole formation. The skill of the reanalyses is not closely tied to the ozone fields assimilated, suggesting that the dynamics of the reanalysis models are more important than the assimilated ozone fields to reproducing ozone mini-holes. [ABSTRACT FROM AUTHOR]

Despite the Montreal protocol and the eventual recovery of the ozone layer over Antarctica, there are still concerns about increased levels of ultraviolet-B ( UV-B) radiation in the Southern Hemisphere. UV-B induces physiological, biochemical and morphological stress responses in plants, which are species-specific and different even for closely related cultivars. In woody plant species, understanding of long-term mechanisms to cope with UV-B-induced stress is limited. Therefore, a greenhouse UV-B daily course simulation was performed for 21 days with two blueberry cultivars (Legacy and Bluegold) under UV-BBE irradiance doses of 0, 0.07 and 0.19 W m−2. Morphological changes, photosynthetic performance, antioxidants, lipid peroxidation and metabolic features were evaluated. We found that both cultivars behaved differently under UV-B exposure, with Legacy being a UV-B-resistant cultivar. Interestingly, Legacy used a combined strategy: initially, in the first week of exposure its photoprotective compounds increased, coping with the intake of UV-B radiation (avoidance strategy), and then, increasing its antioxidant capacity. These strategies proved to be UV-B radiation dose dependent. The avoidance strategy is triggered early under high UV-B radiation in Legacy. Moreover, the rapid metabolic reprogramming capacity of this cultivar, in contrast to Bluegold, seems to be the most relevant contribution to its UV-B stress-coping strategy. [ABSTRACT FROM AUTHOR]

The article offers information on the 2016 Quadrennial Ozone Symposium (QOS-2016) organized by the International Ozone Commission (IO3C) in Edinburgh, Scotland on September 4-9, 2016

Profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European satellite Envisat have been retrieved from versions MIPAS/4.61 to MIPAS/4.62 and MIPAS/5.02 to MIPAS/5.06 level-1b data using the scientific level-2 processor run by Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Astrofísica de Andalucía (IAA). These profiles have been compared to measurements taken by the balloon-borne cryosampler, Mark IV (MkIV) and MIPAS-Balloon (MIPAS-B), the airborne MIPAS-STRatospheric aircraft (MIPAS-STR), the satellite-borne Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the High Resolution Dynamic Limb Sounder (HIRDLS), as well as the ground-based Halocarbon and other Atmospheric Trace Species (HATS) network for the reduced spectral resolution period (RR: January 2005–April 2012) of MIPAS. ACE-FTS, MkIV and HATS also provide measurements during the high spectral resolution period (full resolution, FR: July 2002–March 2004) and were used to validate MIPAS CFC-11 and CFC-12 products during that time, as well as profiles from the Improved Limb Atmospheric Spectrometer, ILAS-II. In general, we find that MIPAS shows slightly higher values for CFC-11 at the lower end of the profiles (below  ∼  15 km) and in a comparison of HATS ground-based data and MIPAS measurements at 3 km below the tropopause. Differences range from approximately 10 to 50 pptv ( ∼  5–20 %) during the RR period. In general, differences are slightly smaller for the FR period. An indication of a slight high bias at the lower end of the profile exists for CFC-12 as well, but this bias is far less pronounced than for CFC-11 and is not as obvious in the relative differences between MIPAS and any of the comparison instruments. Differences at the lower end of the profile (below  ∼  15 km) and in the comparison of HATS and MIPAS measurements taken at 3 km below the tropopause mainly stay within 10–50 pptv (corresponding to  ∼  2–10 % for CFC-12) for the RR and the FR period. Between  ∼  15 and 30 km, most comparisons agree within 10–20 pptv (10–20 %), apart from ILAS-II, which shows large differences above  ∼  17 km. Overall, relative differences are usually smaller for CFC-12 than for CFC-11. For both species – CFC-11 and CFC-12 – we find that differences at the lower end of the profile tend to be larger at higher latitudes than in tropical and subtropical regions. In addition, MIPAS profiles have a maximum in their mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Comparisons of the standard deviation in a quiescent atmosphere (polar summer) show that only the CFC-12 FR error budget can fully explain the observed variability, while for the other products (CFC-11 FR and RR and CFC-12 RR) only two-thirds to three-quarters can be explained. Investigations regarding the temporal stability show very small negative drifts in MIPAS CFC-11 measurements. These instrument drifts vary between  ∼  1 and 3 % decade−1. For CFC-12, the drifts are also negative and close to zero up to  ∼  30 km. Above that altitude, larger drifts of up to  ∼  50 % decade−1 appear which are negative up to  ∼  35 km and positive, but of a similar magnitude, above. [ABSTRACT FROM AUTHOR]

This paper presents our new formaldehyde (H2CO) retrievals, obtained from spectra recorded by the nadir instrument of the Ozone Mapping and Profiler Suite (OMPS) flown on board NASA's Suomi National Polar-orbiting Partnership (SUOMI-NPP) satellite. Our algorithm is similar to the one currently in place for the production of NASA's Ozone Monitoring Instrument (OMI) operational H2CO product. We are now able to produce a set of long-term data from two different instruments that share a similar concept and a similar retrieval approach. The ongoing overlap period between OMI and OMPS offers a perfect opportunity to study the consistency between both data sets. The different spatial and spectral resolution of the instruments is a source of discrepancy in the retrievals despite the similarity of the physic assumptions of the algorithm. We have concluded that the reduced spectral resolution of OMPS in comparison with OMI is not a significant obstacle in obtaining good-quality retrievals. Indeed, the improved signal-to-noise ratio of OMPS with respect to OMI helps to reduce the noise of the retrievals performed using OMPS spectra. However, the size of OMPS spatial pixels imposes a limitation in the capability to distinguish particular features of H2CO that are discernible with OMI. With root mean square (RMS) residuals  ∼ 5 × 10−4 for individual pixels we estimate the detection limit to be about 7.5 × 1015 molecules cm−2. Total vertical column density (VCD) errors for individual pixels range between 40 % for pixels with high concentrations to 100 % or more for pixels with concentrations at or below the detection limit. We compare different OMI products (SAO OMI v3.0.2 and BIRA OMI v14) with our OMPS product using 1 year of data, between September 2012 and September 2013. The seasonality of the retrieved slant columns is captured similarly by all products but there are discrepancies in the values of the VCDs. The mean biases among the two OMI products and our OMPS product are 23 % between OMI SAO and OMPS SAO and 28 % between OMI BIRA and OMPS SAO for eight selected regions. [ABSTRACT FROM AUTHOR]

The STRatospheric Estimation Algorithm from Mainz (STREAM) determines stratospheric columns of NO2  which are needed for the retrieval of tropospheric columns from satellite observations. It is based on the total column measurements over clean, remote regions as well as over clouded scenes where the tropospheric column is effectively shielded. The contribution of individual satellite measurements to the stratospheric estimate is controlled by various weighting factors. STREAM is a flexible and robust algorithm and does not require input from chemical transport models. It was developed as a verification algorithm for the upcoming satellite instrument TROPOMI, as a complement to the operational stratospheric correction based on data assimilation. STREAM was successfully applied to the UV/vis satellite instruments GOME 1/2, SCIAMACHY, and OMI. It overcomes some of the artifacts of previous algorithms, as it is capable of reproducing gradients of stratospheric NO2, e.g., related to the polar vortex, and reduces interpolation errors over continents. Based on synthetic input data, the uncertainty of STREAM was quantified as about 0.1–0.2 × 1015 molecules cm−2, in accordance with the typical deviations between stratospheric estimates from different algorithms compared in this study. [ABSTRACT FROM AUTHOR]

The review is compiled on the basis of the results provided by the system of total ozone (TO) monitoring in the CIS and Baltic countries that functions in the operational regime at the Central Aerological Observatory (CAO). The monitoring system uses data from the national network of M-124 filter ozonometers being under the methodological supervision ofthe Main Geophysical Observatory. The functioning of the entire system is under operational control based on the observations obtained from the OMI satellite equipment (NASA, USA). Basic TO observation data are generalized for each month of the fourth quarter of 2015, for the fourth quarter, and for the year as a whole. The results of regul ar observations of surface ozone content carried out in the Moscow region and Crimea are also provided. [ABSTRACT FROM AUTHOR]

The article offers global environmental and industry news briefs as of November 2015 including a study on air quality in Rangiora, New Zealand, the phase out of ozone layer-damaging chemicals in the European Union and the celebration of the International Day for the Preservation of the Ozone Layer.

The article reports on the Montreal Protocol (MP) 26th Meeting of Parties (MoP-26) in Paris, France and mentions MoP-27 to be held in Dubai United Arab Emirates in November 2015. Topics discussed include replenishing of Multilateral Fund (MLF) to control the use of ozone depleting substances (ODSs), need of hydrochlorofluorocarbons (HCFCs) alternatives, ODSs issues like its byproduct release, critical and essential exceptions use of ODS and sovereign rights impact in MP activities.

The article offers information on the Quadrennial Ozone Symposium (QOS) that was held in Toronto, Ontario in August 2012. Topics discussed include discovery of the first Arctic ozone hole, use of brewer ozone spectrophotometers, and release of protocol related to reducing of ozone layer depleting substances such as chlorofluorocarbons. It discusses the need of monitoring the ozone layer.

The article offers information on the Montreal Protocol on Ozone (MP) which entered into force on January 1, 1989. Topics discussed include circumstances that has led to the establishment of the Montreal Protocol Implementation Committee (MPIC) in 1990, the non-compliance procedures under Article 8 of the MP, and the most recent meeting of the MPIC under the guidance of MPIC President Brian Ruddie.

We review what is presently known about the climate system response to stratospheric ozone depletion and its projected recovery, focusing on the responses of the atmosphere, ocean and cryosphere. Compared with well-mixed greenhouse gases (GHGs), the radiative forcing of climate due to observed stratospheric ozone loss is very small: in spite of this, recent trends in stratospheric ozone have caused profound changes in the Southern Hemisphere (SH) climate system, primarily by altering the tropospheric midlatitude jet, which is commonly described as a change in the Southern Annular Mode. Ozone depletion in the late twentieth century was the primary driver of the observed poleward shift of the jet during summer, which has been linked to changes in tropospheric and surface temperatures, clouds and cloud radiative effects, and precipitation at both middle and low latitudes. It is emphasized, however, that not all aspects of the SH climate response to stratospheric ozone forcing can be understood in terms of changes in the midlatitude jet. The response of the Southern Ocean and sea ice to ozone depletion is currently a matter of debate. For the former, the debate is centred on the role of ocean eddies in possibly opposing wind-driven changes in the mean circulation. For the latter, the issue is reconciling the observed expansion of Antarctic sea-ice extent during the satellite era with robust modelling evidence that the ice should melt as a result of stratospheric ozone depletion (and increases in GHGs). Despite lingering uncertainties, it has become clear that ozone depletion has been instrumental in driving SH climate change in recent decades. Similarly, ozone recovery will figure prominently in future climate change, with its impacts expected to largely cancel the impacts of increasing GHGs during the next half-century. [ABSTRACT FROM AUTHOR]

Measurement assurance in the identification of ozone-depleting substances is considered. It is indicated thatozone-depleting halogenated hydrocarbons must be monitored, and portable devices for detecting counterfeits in customs border control are needed. [ABSTRACT FROM AUTHOR]

Satellite remote sensing provides important observational constraints for monitoring dust life cycle and improving the understanding of its effects on local to global scales. The present work analyzes the dust aerosol patterns over the arid environment of the Sistan region in southeastern Iran, by means of multiple satellite platforms aiming to reveal the spatio-temporal distribution and trends. The dataset includes records of Aerosol Index (AI) from Total Ozone Mapping Spectrometer (TOMS) (1978-2001) and 6-year AI records from the Ozone Monitoring Instrument (OMI) aboard Aura. Moreover, the aerosol optical depth is analyzed through 11-year records from Multi-angle Imaging Spectroradiometer (MISR) aboard Terra (2000-2010) and from Moderate-resolution Imaging Spectroradiometer (MODIS) onboard Terra (2000-2007) and Aqua (2002-2011). The main focus is to determine the similarities and differences in dust variability over southwest Asia, in general, and the Sistan region, in particular. The results show a marked seasonal cycle with high aerosol loading during summer and lower in winter, while MISR, MODIS, and TOMS/OMI observations agree in both terms of monthly and seasonally mean spatial and temporal patterns. The higher aerosol concentrations during summer are interpreted as a result of the combined effect of the seasonal drying of the Hamoun lakes and the strong northerly Levar winds favoring dust erosion from the alluvial deposits in Sistan. After prolonged drought period, the dust aerosol load over the area has increased in the beginning of the 2000 s and decreased after 2004, thereby leading to an overall declining trend during the last decade. Such a trend is absent during the winter period when dust emission over the region is minimal. [ABSTRACT FROM AUTHOR]

All activities are part of the release of gases in the atmosphere that affect the quality of air we breathe (air environment) and also the upper layer of the atmosphere, which can influence in the global climate, or in the ozone layer which protects us from some of the harmful effects of sun rays. Activities that cause most pollution are transport, industry, energy sector (production and processing of oil and gas and thermal energy production) and urban development. Releases in the atmosphere also come from agricultural activities, dumping of wastes and other human activities. Currently the main sources of air pollution are oil extraction, mobile sources, heating of houses, production of cement. The main source of urban air pollution is transport. The number of vehicles continues to grow from year to year. Emission of gases from vehicles (PM10) contribute to a large extent in air pollution causing problems in breathing, especially to minors and the elderly. Systematic measuring of emissions of basic polluting substances in the air of Albania includes continuous 24 hour measuring of: sulfur dioxides (SO2), total nitrogen oxides (NOx), troposphere ozone (O3), the overall content of suspended particles(PM10) and in it the content of lead (Pb) in 8 stations of 5 cities of Albania. [ABSTRACT FROM AUTHOR]

Since 1970 after scientific discoveries about the ozone hole humanity began to reconsider the environment. Environmental messages had different intensities depending on their sources. Scientific messages proved the harshest, the political ones had a powerful declarative impact, but the administrative apparatus, both worldwide and local didn't turn very perceptive. Towards the implementation of actions to protect the environment and sustainable development economic and social factors intervened and hindered the processus. [ABSTRACT FROM AUTHOR]

The Montreal Protocol was signed 25 years ago. As a result, the irreversible destruction of the ozone layer was prevented. However, stratospheric ozone will not recover completely until 2060 and the consequent epidemic in skin cancer cases will persist until 2100. Many millions of patients with asthma and chronic obstructive pulmonary disease have safely switched from chlorofluorocarbon (CFC)- powered metered-dose inhalers (MDIs) to either hydrofluorocarbon (HFC) or DPIs. China will be the last country to phase out CFCs by 2016. HFCs are global warming gases which will be controlled in the near future. HFCs in MDIs may be phased out over the next 10-20 years. [ABSTRACT FROM AUTHOR]

Record-low ozone column densities (with a minimum of 212 DU) persisted over three weeks at the Río Gallegos NDACC (Network for the Detection of Atmospheric Composition Change) station (51.5° S, 69.3° W) in November 2009. Total ozone remained two standard deviations below the climatological mean for five consecutive days during this period. The statistical analysis of 30 years of satellite data from the Multi Sensor Reanalysis (MSR) database for Río Gallegos revealed that such a long-lasting low-ozone episode is a rare occurrence. The event is examined using height-resolved ozone lidar measurements at Río Gallegos, and observations from satellite and groundbased instruments. The computed relative difference between the measured total ozone and the climatological monthly mean shows reductions varying between 10 and 30% with an average decrease of 25 %. The mean absolute difference of total ozone column with respect to climatological monthly mean ozone column is around 75 DU. Extreme values of the UV index (UVI) were measured at the ground for this period, with the daily maximum UVI of around 13 on 15 and 28 November. The high-resolution MIMOSACHIM (Modélisation Isentrope du transport Méso-échelle de l'Ozone Stratosphérique par Advection) model was used to interpret the ozone depletion event. An ozone decrease of about 2 ppmv was observed in mid-November at the 550K isentropic level (∼22 km). The position of Río Gallegos relative to the polar vortex was classified using equivalent latitude maps. During the second week of November, the vortex was over the station at all isentropic levels, but after 20 November and until the end of the month, only the 10 lower levels in the stratosphere were affected by vortex overpasses with ozone poor air masses. A rapid recovery of the ozone column density was observed later, due to an ozone rich filament moving over Río Gallegos between 18 and 24 km in the first two weeks of December 2009. [ABSTRACT FROM AUTHOR]

The article presents information on the provision of international public goods for the efficient of international health with respect to the risk of governance. The international public goods are required for the mitigation of climatic change, vaccination of diseases, preservation of the ozone layer and the reduction in acid rain. Information on the international governance for generating international cooperation for the public goods is also presented.

The article discusses U.S. and international delegation efforts regarding international trade, transportation, and environmental issues as of February 2012. The adoption of the Montreal Protocol on Substances that Deplete the Ozone Layer by nations such as the U.S. is also mentioned. The U.S. Environmental Protection Agency (EPA) is reportedly authorized to enforce the Montreal Protocol's provisions.

The article discusses the importance of global environmental governance in the context of environmental regulatory policies needed to support a green economy. Topics such as the United Nations Environment Programme (UNEP), which is credited with reducing harm to the ozone layer, are discussed, and the relevance of scientific committees to the formation of international environmental agreements is noted. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is also discussed.

Abstract: A new Model of Ozone Deposition and Detoxification (MODD) is presented. This model describes stomatal ozone uptake and deposition on external plant surfaces and soil; it accounts for diurnal variability of detoxification processes and reactive ozone uptake on cuticular waxes and soil surface. The mechanistic modelling of plant defense reactions is based on the detoxification model in which the dynamics of apoplast chemistry are considered. To estimate ozone deposition fluxes on cuticular waxes and soil surface, we use a revised version of the model developed to account for ozone uptake on material surfaces. This model which has been fully integrated with a soil–plant–atmosphere continuum model ensures a complete coupling between stomatal conductance and O3 exchanges between leaves and the atmosphere. The observed diurnal variations in stomatal conductance which largely control the influx of O3 into the leaf are well reproduced. Model simulations point out that the pool of ascorbate located in the mesophyll cell wall plays a significant role in the detoxification of O3. Besides stomatal conductance, it is the key process involved in the control of ozone flux to the cell wall. A decrease in the pool of ascorbate lengthens the chemical lifetime of O3 in the cell wall then the virtual apoplastic resistance is found to increase with decreasing ascorbate. Although the atmospheric ozone concentration increases as the weather becomes hot and dry, the virtual apoplastic resistance follows the same trend, indicating a decrease of the ascorbate pool in the mesophyll cell wall. Results also indicate that for the pre-senescence period 57% of the ozone is deposited onto the cuticular surfaces, 4% on soil and only 37% is absorbed by stomata. The comparison of modelled and measured data reported in this study indicates that the model is capable of predicting the major features of the patterns of total ozone flux. [Copyright &y& Elsevier]

Abstract: Various dynamical, chemical and radiative processes control the thermal structure of the middle atmosphere. The middle atmosphere plays an important role in the radiative budget of the Earth and contains the stratospheric ozone layer protecting us against harmful solar UV radiation. Observations are thus fundamental to have a good knowledge of this region and to predict correctly its future evolution in relation with global climate changes. In situ and remote sensing ground-based measurements provide a detailed but localized description of the state of the atmosphere. On the contrary, space borne instruments allow the observation of atmospheric parameters on a global scale. The goal of this article is to describe the available space instruments for the study of the temperature and dynamics of the stratosphere and the mesosphere and to show how ground-based and satellite observations complement each other. [Copyright &y& Elsevier]

Abstract: This article provides an overview of the various satellite instruments, which have been used to observe stratospheric ozone and other chemical compounds playing a key role in stratospheric chemistry. It describes the various instruments that have been launched since the late 1970s for the measurement of total ozone column and ozone vertical profile, as well as the major satellite missions designed for the study of stratospheric chemistry. Since the discovery of the ozone hole in the early 1980s, spatial ozone measurements have been widely used to evaluate and quantify the spatial extension of polar ozone depletion and global ozone decreasing trends as a function of latitude and height. Validation and evaluation of satellite ozone data have been the subject of intense scientific activity, which was reported in the various ozone assessments of the state of the ozone layer published after the signature of the Montreal protocol. Major results, based on satellite observations for the study of ozone depletion at the global scale and chemical polar ozone loss, are provided. The use of satellite observations for the validation of chemistry climate models that simulate the recovery of the ozone layer and in data assimilation is also described. [Copyright &y& Elsevier]

The article focuses on the efforts being made to develop a new climate change agreement protocol. It mentions the problems being faced by international environmental law due to increasing greenhouse gases (GHG) and chlorofluorocarbons (CFC) and discusses the Kyoto Protocol on climatic changes and the Montreal Protocol, which is an international treaty aiming to protect the depleting ozone layer.

Observations from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) were analysed with the two-dimensional GMTR retrieval system in order to obtain fields of ozone and several molecular species related to ozone chemistry: HNO3, N2O, NO2, N2O5, ClONO2, COF2, CFC-11 and CFC-12. MIPAS measures mid-infrared emission of the atmosphere both during the day and at night time with global coverage. Observing the atmosphere with limb viewing geometries, the instrument is able to resolve finer vertical structures than with nadir instruments, thus enabling the investigation of ozone height-dependent processes. With the currently planned mission extended up to 2014, MIPAS can provide both short-term resolution and long-term trends needed for studying ozone. The adopted GMTR algorithm permits us to resolve the horizontal inhomogeneities of the atmosphere that are modelled using a two-dimensional discretization of the atmosphere. It is therefore especially suitable for analysing portions of the atmosphere where strong gradients such as at the ozone hole may be poorly reproduced by common horizontal homogeneous one-dimensional retrievals. The adopted strategy is well suited for a refined analysis and a correct monitoring of the ozone recovery, as required by the Montreal Protocol and successive amendments. [ABSTRACT FROM AUTHOR]

The Montreal Protocol on Substances that Deplete the Ozone Layer, a multilateral environmental agreement, has successfully eliminated the use of most ozone-depleting chlorofluorocarbons. As a result, a number of observers have pointed to the possibility of transferring successes-and even linking regulations-between the Montreal Protocol and Kyoto Protocol, the international but stalled climate-change agreement. We argue that there is need for caution on this issue. The Montreal and Kyoto protocols are the outcomes of vastly different political contexts, from public civil society approaches to what we call 'the private turn': the current loss of faith in state sovereignty, the rejection of multilateralism, and an embrace of private knowledge about economic damage over public knowledge about the protection of citizens and natural resources. From this broader perspective we show that the differences between the Montreal and Kyoto protocols are therefore more than `command-and-control' versus `market-based' solutions. These differences also reflect an even deeper divide over what `counts' as knowledge in political decision-making processes. We illustrate these points through a case study of the current knowledge controversies around the phase-out of methyl bromide under the Montreal Protocol. We explain how the methyl bromide phase-out has stalled because the phase-out approach is incompatible with the current political regime, thus supporting the argument that neoliberal forms of governance cannot solve global environmental problems. This case, therefore, shows us that the challenges we face are more than atmospheric: to save the Earth we must create new ways to govern ourselves. [ABSTRACT FROM AUTHOR]

The present study is concerned with the total ozone variation in Ankara, Turkey (39°57' N; 32°53' E) and developing a total ozone prediction model by Total Ozone Mapping Spectrometer (TOMS) and single-site aerological data (1984-2006). The daily averages of the total column ozone over Ankara show a seasonal variation, with larger values in spring/winter and lower in autumn/summer and a large day-to-day variability. In this study, in order to forecast the total column ozone over Ankara, a multi-linear regression equation was performed. Predictors are selected by stepwise regression method. The ozone value on the previous day, temperature at the 100 hPa pressure level, previous day's temperature for the 700 hPa pressure level and temperature difference for 50 hPa and 500 hPa are the most important predictors. The success of monthly prognostic total column ozone models built up for Ankara is tested by using Brewer MK III Spectrophotometer data and satellite (OMI) data with the upper-air data in 2007. The Brewer MKIII has been in operation since November 2006 in Ankara. The ground-based one-year data show good agreement with the satellite OMI data. [ABSTRACT FROM AUTHOR]

The article discusses the efforts of several countries to repair and prevent the further depletion of the ozone layer and how changes could affect climate conditions. It discusses the Montreal Protocol, an agreement signed by several countries in 1987 to phase out the production of ozone destroying compounds. It projects that the recovery of the ozone layer will take effect in 2050 but certain factors such as greenhouse gases have created uncertainty in the estimates. Moreover, it also looks how the climate act upon the ozone and how changes to the ozone will, in turn, contribute to changes in the climate. Other issues such as the continued use of pollutants like methyl bromide are also explored.

Although the Montreal Protocol now controls the production and emission of ozone depleting substances, the timing of ozone recovery is unclear. There are many other factors affecting the ozone layer, in particular climate change is expected to modify the speed of re-creation of the ozone layer. Therefore, long-term observations are needed to monitor the further evolution of the stratospheric ozone layer. Measurements from satellite instruments provide global coverage and are supplementary to selective ground-based observations. The combination of data derived from different space-borne instruments is needed to produce homogeneous and consistent long-term data records. They are required for robust investigations including trend analysis. For the first time global total ozone columns from three European satellite sensors GOME (ERS-2), SCIAMACHY (ENVISAT), and GOME-2 (METOP-A) are combined and added up to a continuous time series starting in June 1995. On the one hand it is important to monitor the consequences of the Montreal Protocol and its amendments; on the other hand multi-year observations provide the basis for the evaluation of numerical models describing atmospheric processes, which are also used for prognostic studies to assess the future development. This paper gives some examples of how to use satellite data products to evaluate model results with respective data derived from observations, and to disclose the abilities and deficiencies of atmospheric models. In particular, multi-year mean values derived from the Chemistry-Climate Model E39C-A are used to check climatological values and the respective standard deviations. [ABSTRACT FROM AUTHOR]