Stratospheric Ozone Research Articles

Skin Lesions Identification and Analysis with Deep Learning Model Using Transfer Learning

Sunlight has beneficial as well as harmful rays. Environmental pollution occurs as a result of the depletion of the ozone layer caused by the damage caused by humans to the environment. As a result of these pollutants, skin diseases can be seen in areas exposed to direct sunlight, such as the head and neck. Early detection of actinic keratosis (akiec), basal cell carcinoma (bcc), bening keratosis (bkl), dermafibroma (df), melanoma (mel), melanocytic nevi (nv), and vascular (vasc) skin cancer types, which is one of the most common skin diseases, is important for medical intervention. Otherwise, severe spread, called metastasis, may occur as a result of aggressive growths. For the stated reasons, a deep learning model based on transfer learning, which can classify skin cancer types, has been proposed to assist the medical personnel who serve in this field. With this proposed model, the aim is to classify at high accuracy rates without any pre-processing. As a result of the experimental studies carried out as a result of the stated goals, an accuracy rate of 99,51% was achieved with the proposed model.

Observations and emission constraints of trichlorofluoromethane (CFC-11) in southeastern China: first-year results from a new AGAGE station

The recovery of the ozone layer relies on decreasing atmospheric mixing ratios of ozone-depleting substances (ODSs), including chlorofluorocarbons (CFCs). A significant decline in the mixing ratio of trichlorofluoromethane (CFC-11 or CCl3F ), the second most abundant CFC, has been observed since the mid-1990s. However, a slowdown in the decline after 2012 indicates a rise in emissions, particularly in Eastern Asia. Ground-based observations are lacking in southeastern China, limiting a thorough evaluation of CFC-11 levels and emissions in this region. A new Advanced Global Atmospheric Gases Experiment background station was established at Xichong (XCG), Shenzhen, China, to provide high-frequency continuous in situ observations. The annual mean CFC-11 mixing ratio, recorded from May 2022 to April 2023, is 221.64 ± 2.29 ppt. When compared with a monthly (MHD) or daily (MLO) observation, this value is found to be 0.45% to 5.36% higher than the northern hemispheric background. With the inverse modeling and interspecies correlation method, we estimate CFC-11 emissions in southeastern China between 1.23 ± 0.25 Gg yr−1 and 1.58 ± 0.21 Gg yr−1, in line with the bottom-up estimation of 1.50 Gg yr−1. Results indicate that CFC-11 emissions in the Pearl River Delta region have returned to levels before 2010, aligning with regional and global trends. Observations from XCG would compensate for the deficiency of CFC-11 measurements in southeastern China, paving the road for ODS studies in this region and beyond.

Roles of non‐visible light and temperature in the regulation of anthocyanin synthesis in fruits and vegetables

AbstractThe depletion of the ozone layer creates a gate for non‐visible spectra to impact the Earth's surface and interfere with fruit and vegetable growth and developments by affecting their morphology and physiology. The potential contribution of visible light to photosynthetic activity has received significant attention, particularly blue and red/far‐red light in the visible spectrum. However, plants are also inevitably exposed to relatively high doses of non‐visible spectra, including ultraviolet (UV) and infrared (IR) radiation. This review examines the literature on the impact of such non‐visible spectra on fruit and vegetable growth and development. The accumulation of radiation‐absorbing compounds is a primary mechanism of acclimation to changing radiation levels. Anthocyanins are compounds that exhibit high sensitivity to UV and IR radiation as well as temperature variations, playing a crucial protective role against detrimental radiation in plants. Current research helps to elucidate the involvement of low and high temperatures in the control of UVB‐induced anthocyanin accumulation. Different UV radiation types have been shown to affect fruit and vegetable growth and pigment content differentially. Recent studies have also revealed that IR radiation increases anthocyanin content. Furthermore, specific non‐visible spectra mitigate the inhibitory effect of high and low temperature stress on anthocyanin accumulation in fruits and vegetables. These findings have important implications for the horticultural industry, as they suggest that the application of specific of non‐visible light spectra could be a promising approach to increasing the nutritional value and marketability of fruits and vegetables.

Oxygenation of Earth's atmosphere induced metabolic and ecologic transformations recorded in the Lomagundi-Jatuli carbon isotopic excursion.

The oxygenation of Earth's atmosphere represents the quintessential transformation of a planetary surface by microbial processes. In turn, atmospheric oxygenation transformed metabolic evolution; molecular clock models indicate the diversification and ecological expansion of respiratory metabolisms in the several hundred million years following atmospheric oxygenation. Across this same interval, the geological record preserves 13C enrichment in some carbonate rocks, called the Lomagundi-Jatuli excursion (LJE). By combining data from geologic and genomic records, a self-consistent metabolic evolution model emerges for the LJE. First, fermentation and methanogenesis were major processes remineralizing organic carbon before atmospheric oxygenation. Once an ozone layer formed, shallow water and exposed environments were shielded from UVB/C radiation, allowing the expansion of cyanobacterial primary productivity. High primary productivity and methanogenesis led to preferential removal of 12C into organic carbon and CH4. Extreme and variable 13C enrichments in carbonates were caused by 13C-depleted CH4 loss to the atmosphere. Through time, aerobic respiration diversified and became ecologically widespread, as did other new metabolisms. Respiration displaced fermentation and methanogenesis as the dominant organic matter remineralization processes. As CH4 loss slowed, dissolved inorganic carbon in shallow environments was no longer highly 13C enriched. Thus, the loss of extreme 13C enrichments in carbonates marks the establishment of a new microbial mat ecosystem structure, one dominated by respiratory processes distributed along steep redox gradients. These gradients allowed the exchange of metabolic by-products among metabolically diverse organisms, providing novel metabolic opportunities. Thus, the microbially induced oxygenation of Earth's atmosphere led to the transformation of microbial ecosystems, an archetypal example of planetary microbiology.IMPORTANCEThe oxygenation of Earth's atmosphere represents the most extensive known chemical transformation of a planetary surface by microbial processes. In turn, atmospheric oxygenation transformed metabolic evolution by providing oxidants independent of the sites of photosynthesis. Thus, the evolutionary changes during this interval and their effects on planetary-scale biogeochemical cycles are fundamental to our understanding of the interdependencies among genomes, organisms, ecosystems, elemental cycles, and Earth's surface chemistry through time.

What Happens in the Troposphere Doesn’t Stay in the Troposphere

A new study suggests that spillover of tropospheric ozone is affecting measurements of stratospheric ozone recovery more than previously realized.

Influence of Natural Tropical Oscillations on Ozone Content and Meridional Circulation in the Boreal Winter Stratosphere

The dependence of ozone content in the polar stratosphere upon different phases of the quasi-biennial oscillation (QBO) of the zonal wind and the El Niño–Southern Oscillation (ENSO) during winter was studied. The monthly (from November to January) mean residual meridional circulation (RMC) was calculated for four different combinations of the main phases of ENSO and QBO using MERRA2 reanalysis data. It has been demonstrated that the QBO phase manifests itself in different vertical distributions of ozone in the equatorial stratosphere, as well as in strengthening/weakening of the secondary meridional circulation in the tropics. The enhancement of the RMC from the tropical to the polar stratosphere is stronger at altitudes where ozone is higher in the tropics under El Niño conditions. The RMC modification and intensification are observed from ozone-depleted areas under La Niña conditions. A “cumulative” effect is observed by February under La Niña conditions and the easterly QBO, which is expressed in the lowest ozone content in the polar stratosphere. The numerical experiments carried out using the Middle and Upper Atmosphere Model (MUAM) confirmed tendencies in changes in the meridional transport detected from the reanalysis data for different combinations of QBO and ENSO.

Earth’s atmosphere protects the biosphere from nearby supernovae

Geological evidence indicates that a supernova within 100 parsecs of Earth occurs around once per million years. Such nearby supernovas can produce an intense gamma-ray burst and a 100-fold increase of cosmic rays, lasting several centuries. We find that the effect of a short burst of gamma rays is small since they are strongly attenuated before reaching the lower stratosphere. Intense cosmic radiation affects stratospheric ozone but, due to compensating effects in catalytic chemical cycles, ozone depletion is moderate and comparable to that from current anthropogenic emissions. This also holds for the low-oxygen atmosphere during early evolution of terrestrial life. We estimate the increase in aerosol and clouds from a 100-fold increase of cosmic rays exerts a radiative forcing comparable in magnitude but opposite in sign to current anthropogenic climate forcing. We conclude that Earth’s atmosphere is effective at shielding the biosphere from nearby supernovae.

Stability requirements of satellites to detect long-term stratospheric ozone trends based upon Monte Carlo simulations

Stability requirements of satellites to detect long-term stratospheric ozone trends based upon Monte Carlo simulations

A decrease in radiative forcing and equivalent effective chlorine from hydrochlorofluorocarbons

The Montreal Protocol and its successive amendments have been successful in curbing emissions of ozone-depleting substances and potent greenhouse gases via production/consumption controls. Here we show that the radiative forcing and equivalent effective chlorine from hydrochlorofluorocarbons has decreased from 61.75 mW m−2 and 321.69 ppt, respectively, since 2021, 5 years before the most recent projected decrease. This important milestone demonstrates the benefits of the Protocol for mitigating climate change and stratospheric ozone layer loss.

New insights and reaction mechanisms on ZrO2 (110) surface enhanced catalytic hydrolysis of CFC-12: a density functional theory study.

Freon, a greenhouse gas that contributes to the depletion of the ozone layer, has been the subject of investigation in this study. The catalytic hydrolysis enhancement of CFC-12 by ZrO2 was examined using a density functional theory approach. A detailed reaction mechanism and a new reaction pathway were proposed. The study found that CFC-12 is more likely to be adsorbed on the ZrO2 surface in the CFC-12-TO(F) configuration, while H2O is more likely to be adsorbed on the ZrO2 surface in the H2O-TO(H) configuration. Additionally, H2O replaces CFC-12 on the surface of ZrO2. The hydrolysis of CFC-12 is primarily determined by the first dechlorination process, while the defluorination process is comparatively easier. ZrO2 has a catalytic effect on both dechlorination and defluorination processes, with a more pronounced effect on the former. The production of C-OH bonds is inhibited, which facilitates the dechlorination and defluoridation processes. This work was carried out in the Dmol3 program in the Material Studio 2017, including the geometric structure optimization and energy calculations. The GGA/PBE method was used in this work, along with the DNP basis, spin-polarized set, and DFT-D correction. The possible TSs were guessed based on the linear synchronous transit/quadratic synchronous transit/conjugate gradient (LST/QST/CG) method, and they were further confirmed and reoptimized to ensure that the only one imaginary frequency exists in the TSs.

More to offer from the Montreal protocol: how the ozone treaty can secure further significant greenhouse gas emission reductions in the future

ABSTRACT Action under the Montreal Protocol has contributed to climate change mitigation for almost 35 years. The phase-out of ozone-depleting substances (ODS) has set the ozone layer on a path to recovery, protecting the world’s biosphere from harmful ultraviolet radiation. The 2016 Kigali Amendment to the Montreal Protocol is expected to avoid 5.6–8.7 gigatonnes of carbon-dioxide equivalent (GtCO2e) emissions of hydrofluorocarbons (HFC) per year by 2100, reducing the impact of HFCs on global average warming by up to 0.4°C. Despite its successes, unexpected emissions of phased out ODS – notably the chlorofluorocarbon, CFC-11 - have brought attention to shortcomings in the Protocol’s monitoring, reporting, verification and enforcement (MRV+E) which must be addressed to guarantee its controls are sustained. Meanwhile, additional significant mitigation could be achieved by accelerating the phase-down of HFCs under the Kigali Amendment, by tackling ODS and HFC emissions from leaking banks of equipment and products and by controlling feedstocks, which are not subject to Montreal Protocol phase-out controls. Recent scientific papers have linked almost 870 million tCO2 per year of greenhouse gases (GHG) and ODS to fluorochemical industrial processes and illegal fluorochemical production. Expanding the scope of the Montreal Protocol to address nitrous oxide (N2O), itself an ODS and GHG, would also contribute substantial ozone and climate benefits. This perspective essay discusses new and strengthened policy measures that governments can consider under the Montreal Protocol in order to maximize early, cost-effective reductions in emissions of non-CO2 greenhouse gases and ensure future implementation.

Nano Technolgy Application to Enhance the Emission Control by Using Activated Carbons Modified by Magnesium Oxide

One of the fundamental processes for planet safety is the catalytic conversion of carbon monoxide (CO). CO has even been named one of the unseen toxins of this century. Inhaling CO can lead to hypoxic damage, neurological break, and even death. CO poisoning decays greenery life and accumulations in global warming and ozone layer depletion. CO is created in the atmosphere by the partial oxidation of carbon-containing mixtures. The primary origin of CO emissions is vehicles. Therefore, oxidizing contaminated CO to nonpoisonous CO2 under ambient conditions is essential for life protection in multiple applications. Additionally, low-temperature CO oxidation is crucial in reducing emissions at the cold start of an internal explosion in the engine. For controlling pollution, the available methods are pre-pollution control and post-pollution. This project depends on the post-pollution control method in Peugeot ROA automobiles using Activated Carbons Modified by Magnesium Oxide as a catalyst. An innovative catalytic converter design activated carbons modified by magnesium oxide nanoparticles as a catalyst to control pollution with different NPs lodgings and carbon structures. This proposed method aims for the reduction environmental pollution contributed by automobiles. It involves using more affordable materials than the existing rhodium nanoparticles, platinum, and palladium technique. The dispersion states of the grafted nanoparticles were examined with scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD), confirming the correlation between high grafted ratio states and improved properties. The nanocomposites' desired properties were significantly enhanced when the graft density was high.

In vitro and in vivo antimicrobial activity of the fumigant, ethyl formate, against bacteria and fungi of date fruits in postharvest phase

The search is on for safer alternatives to fumigants like methyl bromide and phosphine, which harm the ozone layer and pose other risks. Ethyl formate is a promising candidate due to its potential antimicrobial and insecticidal action in stored products like date fruits. The susceptibility of date fruits to microbial spoilage is significantly influenced by factors such as moisture content, storage practices, and environmental conditions. In the present study, the in vitro antimicrobial effect of ethyl formate against three microbial species, namely Aspergillus niger F4, Mucor circinelloides YMM22, and Pseudomonas aeruginosa B1 was tested under laboratory conditions. In addition, two common date fruit varieties, semi-dry El-Wady I and the dry Frehi, were fumigated with ethyl formate alone in a laboratory-scale prototype and with a mixture of ethyl formate and CO2 at a semi-industrial scale prototype. Both varieties had an initial moisture content of around 13.40 and 12.48% for El-Wady I and Frehi, respectively. The fumigation was conducted using the optimal concentration of 70 mg/L air for 24 h incubation period. Fumigation with ethyl formate alone or in combination with CO2 significantly reduced the number of viable bacteria and fungi (CFU/g), but the potential for a combined effect with CO2 was not investigated. The percentages of reduction in the fungal count were 78.18 and 90.76% for Frehi and El-Wady I varieties, respectively in a semi-industrial scale prototype. Moreover, the percentages of reduction in the bacterial count were 53.31 and 65.20%, respectively for Frehi and El-Wady I varieties. Ethyl formate showed promise as a natural alternative to control microbial contamination of stored date fruits. Further research suggests that increasing fumigation duration or concentration could provide comprehensive control of microbial pathogens at all stages of development.

Global agricultural N2O emission reduction strategies deliver climate benefits with minimal impact on stratospheric O3 recovery

Agricultural nitrous oxide (N2O) emission reduction strategies are required given the potency of N2O as a greenhouse gas. However, the growing influence of N2O on stratospheric ozone (O3) with declining stratospheric chlorine means the wider atmospheric impact of N2O reductions requires investigation. We calculate a N2O emission reduction of 1.35 TgN2O yr-1 (~5% of 2020 emissions) using spatially separate deployment of nitrification inhibitors ($70–113 tCO2e−1) and crushed basalt (no-cost co-benefit) which also sequesters CO2. In Earth System model simulations for 2025–2075 under high (SSP3-7.0) and low (SSP1-2.6) surface warming scenarios, this N2O mitigation reduces NOx-driven O3 destruction, driving regional stratospheric O3 increases but with minimal impact on total O3 column recovery. By 2075, the radiative forcing of the combined N2O and CO2 reductions equates to a beneficial 9–11 ppm CO2 removal. Our results support targeted agricultural N2O emission reductions for helping nations reach net-zero without hindering O3 recovery.

Enhancing Global Environmental Cooperation Through Information Exchange: A Comparative Analysis of International Treaties

This article explores how information exchange is key to global cooperation to protect our environment. The article focuses on organizations that have an impact on the international environment, such as the United Nations Declaration on the Human Environment, the Vienna Convention for the Protection of the Ozone Layer, the United Nations Convention on the Law of the Sea, and the Antarctic Treaty. These platforms ensure that all members will be able to keep pace and lead an agreement on the global environment. Surprisingly, this information exchange is win-win. For scientists, it is necessary to obtain the data necessary for solving environmental problems. It is very important for each country to fulfill international environmental obligations. In this paper, this paper investigate how these mechanisms are developed, especially in order to form more specific consensus forms. Clearly, by comparing different treaties that regulate how to exchange and provide information, their specific goals may be different, but their main goals are consistent: enhancing our information exchange and cooperation by enhancing environmental protection

Testing a novel life cycle assessment based framework for produced water management from offshore oilfield operations

As worldwide reliance on the petroleum industry persists, environmental concerns associated with offshore oilfield operations continue to present a critical challenge for sustainable management. This study develops and tests a novel life cycle assessment (LCA)-based framework to examine strategies for produced water (PW) management from offshore oilfield operations. The framework encompasses experimental designs under a dynamic modelling system coupled with stepwise linear regression, multi-criteria decision analysis (MCDA), and fluctuating scenarios in Enhanced Oil Recovery (EOR) and other internal reuse options including cooling systems, drilling operations, and utility services. Two strategies for treatment train technologies were tested with various PW compositions, sludge management options, and variable EOR demands. When comparing conventional (corrugated plate interceptor, hydrocylone and nutshell filter) with recent treatment/disposal technologies (tubular separation, combined fiber coalescence and mechanical vapor compression), the LCA revealed that the latter increased operational efficiency (14%), reduced cost (6.5%) and the overall environmental impact categories (66%). The scenario that exhibited the lowest emissions incorporated recent treatment technologies and land application for sludge management. This configuration demonstrated considerable environmental advantages, evidenced by significant reductions in key impact indicators including freshwater eutrophication (74%), global warming (64%), marine ecotoxicity (58%), and stratospheric ozone depletion (44%) when compared to the baseline scenario with conventional treatment-disposal methods. The system dynamics model revealed that the internal reuse options exploited 23%–47% of PW inflow, indicating a significant annual surplus of unused PW that presents an opportunity for external applications to enhance sustainability. In closure, we argue that the proposed framework offers a valuable tool for waste management practitioners, facilitating the identification and selection of strategies with minimal environmental impacts for PW management.

Regional Sea Level Response to External Forcings from the Twentieth to the Twenty-First Century

Abstract Using a range of Detection and Attribution Model Intercomparison Project (DAMIP) simulations from phase 6 of Coupled Model Intercomparison Project (CMIP6), we study the response of dynamic sea level (DSL) to external anthropogenic climate forcing [greenhouse gases (GHGs), aerosols, and stratospheric ozone] with a focus on the differences over the twentieth and twenty-first century. In the second half of the twentieth century, the DSL nonuniformity in the Northern Hemisphere (NH) was relatively small due to a cancellation between the effects of increasing GHGs and aerosols. In contrast, the DSL signal in the Southern Hemisphere (SH) over this period was large because stratospheric ozone depletion reinforced the effects of increasing GHGs. In the twenty-first century, the DSL response has been intensified in the NH because the warming effects of diminishing aerosols have acted to reinforce the effects of increasing GHGs. Meanwhile, the distribution of SH DSL has also become uneven although stratospheric ozone recovery has partially offset the effects of rising GHGs. Using a global ocean circulation model, we decompose the changes in the twenty-first century DSL into distinct responses to surface forcings including sea surface temperature, salinity, and wind stress. Our results show that the dipole-like pattern of DSL in the North Pacific can be attributed largely to sea surface warming, while the dipole-like pattern in the North Atlantic is attributed to subpolar surface salinity freshening. The belted pattern of DSL changes in the Southern Ocean is induced by both surface warming and intensifying/poleward-shifting westerly winds.

Crisis of Humanism, Failure of American Dream, and Quest for Global Harmony in Fitzgerald’s The Great Gatsby

This paper explores the crisis of humanism, the quest for global harmony and honesty, and the failure of the American Dream in Fitzgerald’s novel ‘The Great Gatsby’. The American dream means prioritizing money, whereas the failure of American dream means becoming unsuccessful in making money, and inhumanity has increased. It is Jay Gatsby whose financial condition was alarming, but because of his excellent earnings, his present life has become prosperous. The society regards him as a person of high status. None investigates his past life. Therefore, the study prioritizes global harmony, humanity, and honesty rather than money. There are nominal research works on this site. Because of money and a money-minded mentality, human relations have deteriorated. Modern man, like Gatsby, just accounts for the money. He has a mindset of no benefit of being honest and humane. The loss and profit game has mechanicalized modern life. It has become too much calculative. One man does not contact another man, as the ozone layer has depleted his friendship environment. The study’s findings show that the more dishonest and inhumane you become, the more benefits you get. The new generation after two great wars is a kind of lost generation. So, this research sheds light on how to amend the humanitarian ground. The study analyzes the novel using Gertrude Stein’s lost generation theory and explanatory methods. The research focuses on why modern men have become over-money-minded. Why have harmony, honesty, and humanity been in crisis?

Rice husk biochar for carbon sequestration, soil fertility and plant health improvement: A review

Carbon dioxide (CO2) is considered one of the ozone layer gases that contribute to climate change. As the area under agricultural use expands, the level of CO2 from soil as an agricultural by-product increases in the atmosphere. Burning rice husks in open air, decomposing plant materials among other activities release CO2 directly to the atmosphere. Rice husks as a by-product of rice production in Kenya has both the potential to be a source of greenhouse gas (GHG) and production of biochar. Production and deposition of rice husk biochar (RHB) into soil is thought to be one of the viable options for permanent carbon storage with related benefits to soil fertility. This review seeks to consolidate information from various studies that highlight the innovative way of using RHB in combating climate change, improving soil fertility, plant health and crop yields. Studies that have demonstrated beneficial use of RHB were evaluated to prepare this review. When RHB is used as a soil amendment, it has the ability to increase soil carbon storage, mitigate 10% of the current anthropogenic carbon emissions, improve pH and raise Cation Exchange Capacity (CEC), increase available plant nutrients, enhance inherent plant immunity, increase crop yields and improve water quality by increasing retention of nutrients and agrochemicals for plant utilization. A review of the benefits of RHB use in agriculture and climate change mitigation will enhance its adoption. The review further emphasizes the usefulness of pyrolysis in turning organic waste into bioenergy, compost and other beneficial products while protecting the environment. Key Words: Carbon dioxide, climate change, global warming, innovation, ozone layer, temperature.

The Spillover of Tropospheric Ozone Increases Has Hidden the Extent of Stratospheric Ozone Depletion by Halogens

AbstractStratospheric ozone depletion from halocarbons is partly countered by pollution‐driven increases in tropospheric ozone, with transport connecting the two. While recognizing this connection, the ozone assessment's evaluation of observations and processes have often split the chapters at the tropopause boundary. Using a chemistry‐transport model we find that air‐pollution ozone enhancements in the troposphere spill over into the stratosphere at significant rates, that is, 13%–34% of the excess tropospheric burden appears in the lowermost extra‐tropical stratosphere. As we track the anticipated recovery of the observed ozone depletion, we should recognize that two tenths of that recovery may come from the transport of increasing tropospheric ozone into the stratosphere.