Stratospheric Ozone Research Articles

Life cycle analysis of seawater biodesalination using algae

This study assesses environmental impacts of reverse osmosis and algae-based biodesalination in four scenarios using a life cycle assessment (LCA) approach. These scenarios encompass (1) a multistage conventional pre-treatment desalination system, (2) immobilized algae-based hybrid desalination system, (3) suspended algae pre-treatment hybrid system, and (4) an attached growth algae-based hybrid system with a low-pressure reverse osmosis (LPRO) system. The assessment integrates the ReCiPe and USEtox 2.0 methods, examining diverse phases such as construction, operation, waste treatment, and chemicals. The impact analysis unveils waste treatment as a significant contributor in Scenario 1. In Scenarios 2 and 3, the operational phase, driven by chemical consumption, emerges as a major factor by 60–70 %, causing environmental damage. Scenario 4 showcases superior environmental performance, notably in global warming potential, freshwater eutrophication, marine eutrophication, ozone layer depletion, and fossil resource scarcity. Results highlight that Scenario 2 and Scenario 3, utilizing immobilized and suspended growth biodesalination, do not align with favorable LCA outcomes. Overall, Scenario 4 displays the least environmental impact and a favorable carbon footprint. The study advocates pipeline brine disposal due to its greater convenience and lesser environmental damage. A sensitivity analysis emphasizes the advantages of shorter transportation distances for optimal brine disposal from the desalination plant to the sea.

Multiuse Polystyrene Plates for Phasing Out Single‐Use Plastics: Chemical Performances and Environmental Impact Assessment Through a Life Cycle Approach

European governments are addressing plastic pollution by implementing the Directive EU 2019/904 that bans single‐use items like cutlery, plates, straws, and beverage stirrers. One strategy proposed by several industries to continue their production is the conversion of single‐use items into multiuse items. Herein, the focus is on the production of polystyrene reusable plates and the suitability of this product for microwave and dishwasher use is assessed: in proper conditions, the structure is preserved without cuts or visible deformations, and the chemical stability is guaranteed. To get a full picture of the benefits and impacts of this new product, a life cycle assessment methodology is applied to compare the performances of one reusable plate with 20 single‐use plates. Results indicate that proper use is crucial: a reusable plate disposed after one use is more impactful than a single‐use plate. In contrast, the reuse of plates for 20 times allows to reduce carbon footprint and acidification potential. Eutrophication and ozone layer depletion, on the other hand, increase due to the washing phase. The solutions that can mitigate these issues and enhance the sustainability of the reusable plates include the improvement of the detergent compositions and the use of electricity from renewable sources.

Ozone Layer Depletion: Causes, Effects and Prevention

The purpose of this study was to review the Causes, effects and prevention of the ozone layer depletion. Ozone layer is a part of the stratosphere which absorbs the harmful ultraviolet (UV) rays of the sun and prevents it from reaching the earth surface. Industrial activities, release chemicals into the air that can destroy ozone layer, this process known as ozone layer depletion. The main causes of ozone layer depletion are Chlorofluorocarbons (CFCs), Halons (HCFCs) and NOX (nitrogen oxides), depletion of stratospheric ozone, led to increased ultraviolet radiation at the earth’s surface as well as spectral shifts to the more biologically damaging shorter wavelengths, which is harmful to the human, plants and ecosystem. An international environmental initiative to lessen ozone depletion is known as the Montreal Protocol. This agreement required all nations to impose legal obligations on the reduction of CFCs and other comparable chemical compounds. As a result, an international fund has been set up to assist in introducing these nations to new and environmentally friendly technologies and chemicals.

The Evolutions and Large‐Scale Mechanisms of Summer Stratospheric Ozone Intrusion Across Global Hotspots

AbstractStratospheric ozone intrusions can have a significant impact on regional near‐surface ozone levels. Especially in summer, intrusions can contribute to extreme ozone events because of preexisting high ozone levels near the surface and cause serious health issues. Considering the increasing trend of surface ozone level, an understanding of stratospheric ozone intrusion is necessary. From a 19‐year Whole Atmosphere Community Climate Model, version 6 simulation and a stratospheric origin ozone tracer, we identify the global hotspots of stratospheric intrusions based on extreme tracer concentrations near the surface: North America, Africa, the Mediterranean, and the Middle East. We investigate the common underlying large‐scale mechanisms of the stratospheric intrusions over the identified hotspots from the lower stratosphere to the lower troposphere. From the trajectory analysis, we find that the upper‐level jet drives isentropic mixing near the jet axis and initiates stratospheric ozone intrusion. Subsequently, climatological descent at the lower troposphere brings the ozone down to the surface, which explains the spatial preference of summertime stratospheric intrusion events.

The Climate and Global Warming Responses to the Changing Greenhouse Gas Concentration in the Atmosphere

Increase of the World temperature throughout the Earth is called Global warming. Studies have shown that Temperature of the earth have risen, if do not stopped on time, it will rise further. The reason of this global warming are Greenhouse gases like, Nitrous Oxide, Carbon Dioxide, Methane, Sulphurehexafloride, Nitrogen Trifloride, Hydrofluorocarbon, Perfluorocarbon. Global warming of the Nitrous oxide is 265 and can stay up to 121 years in the atmosphere. It has 298 times more potential in the warming up of the glob than Carbon dioxide, which are being produced by human’s industrial activities. Therefore Carbon dioxide is being produced with the burning of the fossil fuels and the ability of the Carbon dioxide in global warming 1. Methane is a gas which is being produced by the burning of the organic materials. Sulphur Hexafluoride is also a strong gas of the greenhouse gases and is unburnable and is able to wipe out the infrared waves. It keeps the earth warm for a long time. Nitrogentrichloride is a gas which causes skin and eye’s disease. Therefore, every molecule of the Hydrofluorocarbon is much stronger as compare to the Carbon dioxide. It prevents the distraction of the Ozone layer. On the other side, perfluorocarbon is a gas which has the ability to wipe out the Ozone Layer. Greenhouse is a place which protects Plants from direct sunlight. Greenhouse gases cause many problems which can cause climate change, like melting of the glacier, rise in the sea water and Increase in storms. In the reduction of the greenhouse gases, a number of processes have been started like using renewable energy, using Bicycle, Using local transportations, protecting forests and using air filters.

Investigating the Impact of Nanotechnology in Reducing Air and Environmental Pollution: A Review

Environmental pollution has a great impact on human health, ecosystem and financial development. The direct and indirect effects of nanotechnology on the environment and air pollution can be investigated from different aspects. The prospect of using this new technology is very wide. Today, in the world, nanotechnology is known as a key and influential technology on science, technology and industry,Nanotechnology uses various sciences and technologies such as physics, chemistry, biology and engineering. Nanotechnology is the science of building new materials atom by atom with desired properties, which is still at the beginning of its journey in the world and a very bright future is predicted for it among the many achievements of this technology is its application in the production, transmission, consumption and storage of energy with high efficiency and reducing environmental pollution, which creates a tremendous transformation in this field. It is expected that in the next 55 years, the world population will grow by 55% and the consumption of energy and materials will grow by 255%. So far, rising levels of production and consumption have countered our achievements in more efficient and cleaner technologies. Among these things, we can mention the production of urban solid waste, environmental effects caused by vehicles and air pollution, nanotechnology can contribute to reducing pollution or energy consumption of products. Air pollution is a change in the natural characteristics of the atmosphere due to chemical substances, dust or biological factors. Depletion of stratospheric ozone layer due to Air pollution has long been recognized as a danger to people's health and the earth's ecosystems.

Understsanding the Effects of UV Radiation on Climate Change: A Comprehensive Review

‌This review paper explores the intricate relationship between ultraviolet (UV) radiation and climate change, delving into its multifaceted effects on atmospheric processes, global temperature dynamics, biological entities, and the intricate feedback mechanisms that shape the Earth's climate. Beginning with an examination of UV radiation's interaction with the atmosphere, we uncover its role in ozone layer dynamics and its potential to influence atmospheric circulation patterns.The discussion extends to the impact of UV radiation on global temperature patterns, emphasizing its contribution to the Earth's energy balance and its interaction with greenhouse gases. Moving beyond climatic elements, we explore the biological impacts of UV radiation, encompassing its effects on human health, plant productivity, and aquatic ecosystems. We unveil the intricate feedback loops, revealing how changes induced by UV radiation can cascade through the atmosphere, ecosystems, and human societies.The technological and policy implications are scrutinized, highlighting innovations in monitoring and mitigation strategies alongside international policies crafted to address UV radiation's impact on climate change. Looking toward the future, the paper offers insights into potential advancements, challenges, and opportunities, emphasizing the need for ongoing research, global collaboration, and sustainable practices to navigate the evolving dynamics of UV radiation and climate change. In conclusion, this review consolidates a comprehensive understanding of UV radiation's pivotal role in shaping our climate, offering a foundation for informed decision-making and sustainable stewardship of our planet

Predicting Ozone Depletion using BIn2O3 With RH based Solid Conductometric Sensor

<p>Ozone depletion arises due to the presence of gases like chlorofluorocarbons and halons which are liberated into the atmosphere. The region of earth’s atmosphere named as ozone shield, in which absorbs the ultra violet radiations of the sun. Although, its thickness varies periodically, this layer is primarily located in the lower stratosphere between 15 to 35 kms above the earth. Due to this, the ultraviolet rays directly enter into the earth causes harmful effects little by little on both living and non-living organisms. In this paper, BIn2O3 with rh sensor in co precipitation method is used to detect the ozone depletion and it is based on the solid-state gas sensors. To achieve the excellent performance of an ozone depletion detecting branch like BIn2O3 with rh, this was designed using a simple precipitation method. The coprecipitation method had deposited in BIn2O3 with a thickness of 45 to 50 nanometer. The detection limit of ozone reduced as 30 parts per billion. Further, the gas detector demonstrated high sensitivity and selectivity of the device. The rhodium covers the surface areas ranges from 0 to 0.1. It reaches the accuracy of 96%. According to the degree of rhodium coverage, the sensors will be response to the ozone gas. The oxygen chemisorbed ability and a coverage of a great surface area of BIn2O3 with rhodium highly related to the excellent sensing behavior. This study paves the way for an exact sensing and ppb level detection ozone gas.</p>

The ratio of denitrification end-products were influenced by soil pH and clay content across different texture classes in Oklahoma soils

Nitrous oxide (N2O) is a potent greenhouse gas that contributes to stratospheric ozone depletion and global climate change. Soil denitrification has two potential end-products, N2O and dinitrogen (N2), and the ratio of these end-products (N2O:(N2O+N2) or the N2O ratio) is controlled by various factors. This study aims to quantify the influence of soil pH on the ratio of denitrification end-products in Oklahoma soils with different soil textures. Six natural grassland soils encompassing three distinct soil textures were incubated in the laboratory under natural and modified pH with an overall tested pH ranging from 2 to 10. Denitrification end-products were measured in the laboratory using the acetylene inhibition technique and further estimated using a process-based biogeochemical model. Both the laboratory and model results showed that soil pH and texture influenced the ratio of the denitrification end-products. Generally, as soil pH increased the N2O ratio decreased, although both lab and model results indicated that this relationship was not linear. Soil texture may have an indirect effect on the N2O ratio, as two soils of the same texture could have different N2O ratios. However, clay percentage of the soil did show a linear positive correlation with the N2O ratio, suggesting components of soil texture may be more influential than others. Overall, soil pH was a controlling factor in the ratio of denitrification end-products and the newly observed nonlinear relationship warrants further study, particularly when considering its effects in different soil textures.

Foliar N2 O emissions constitute a significant source to atmosphere.

Nitrous oxide (N2 O) is a potent greenhouse gas and causes stratospheric ozone depletion. While the emissions of N2 O from soil are widely recognized, recent research has shown that terrestrial plants may also emit N2 O from their leaves under controlled laboratory conditions. However, it is unclear whether foliar N2 O emissions are universal across varying plant taxa, what the global significance of foliar N2 O emissions is, and how the foliage produces N2 O insitu. Here we investigated the abilities of 25 common plant taxa, including trees, shrubs and herbs, to emit N2 O under insitu conditions. Using 15 N isotopic labeling, we demonstrated that the foliage-emitted N2 O was predominantly derived from nitrate. Moreover, by selectively injecting biocide in conjunction with the isolating and back-inoculating of endophytes, we demonstrated that the foliar N2 O emissions were driven by endophytic bacteria. The seasonal N2 O emission rates ranged from 3.2 to 9.2 ng N2 O-N g-1 dried foliage h-1 . Extrapolating these emission rates to global foliar biomass and plant N uptake, we estimated global foliar N2 O emission to be 1.21 and 1.01 Tg N2 O-N year-1 , respectively. These estimates account for 6%-7% of the current global annual N2 O emission of 17 Tg N2 O-N year-1 , indicating that insitu foliar N2 O emission is a universal process for terrestrial plants and contributes significantly to the global N2 O inventory. This finding highlights the importance of measuring foliar N2 O emissions in future studies to enable the accurate assigning of mechanisms and the development of effective mitigation.

The effect of UV radiation on the frequency of crossing over in Drosophila melanogaster

The increasing ozone layer depletion due to exposure to high environmental pollutants may contribute to the high probability of cells being exposed to UV radiation, causing various cellular responses, such as genomic instability. This study aimed to determine the effect of UV on the frequency of crossing over in a cross between the wild-type and the black vestigial strain of Drosophila melanogaster, using four variations of duration UV exposure as follows: 0’, 3’, 6’, and 9’. Recombinant progeny were calculated and analyzed using single-factor ANOVA. The results showed that: (1) The longer the duration of the UV exposure, the higher the percentage of recombinant progeny. (2) The body size of the D. melanogaster progeny exposed to UV light was more petite, and their movements were slower. (3) The single factor ANOVA showed that the length of UV had not affected the frequency of crossing over; but there was a phenomenon of crossing over, which has been showed that UV exposure made higher the percentage of recombinant progeny and affected to the body size of D. melanogaster. Therefore, further research is needed to examine the effect of UV radiation with longer periods of crossing over frequency and molecular analysis needs to be considered.

Wind speed and wind power forecasting models

Sustainable energy resources have proved to be the best alternative in the wake of environmental degradation, depletion of ozone layer and ever-increasing demand for energy. Though wind energy is a promising resource, the non-linear nature and non-stationary characteristics of wind have remained a formidable challenge. Variability in wind power has posed numerous challenges in managing the power systems, especially in grid evacuation, penetration and integration. Forecasting wind is one of the powerful solutions to solve this problem. As the penetration of renewable energy sources is poised to increase in future, an accurate prediction can go a long way in helping the electricity grid to perform well. This article presents a review of existing research and recent trends in the forecasting of wind power and speed with a critical analysis of the contribution of every researcher. A review of forecasting technologies, data, time horizons, various forecasting approaches and error metrics has been presented in detail. The plethora of research issues that continue to challenge power system operators, wind farm owners and other stakeholders has been highlighted. The development of models for wind power or wind speed forecasting with excellent reliability and outstanding accuracy is the need of the hour.

«Green» logistics in the business of logistics transportation: prospects and features of the development of «green» logistics in business for Ukraine

The urgency of researching the directions of logistics transformation determines the growth of the social responsibility of business. This article examines the goals, tasks, and principles of ecological logistics and the factors of the concept of responsibility during the implementation of logistics operations. Now, significant results of applying new technologies and strategies in the activities of Ukrainian entrepreneurs, state institutions, and commercial and non-commercial organizations are being monitored. Today, logistics technologies reach a new level of organization and management, and innovative solutions, technologies, and strategies are used. This determines the high level of environmental protection. The business implements modern trends to preserve the environment. For example, factories and transport companies create their environmental plans. The majority of customers and companies prefer rail transport for international transportation. Thanks to this, the achievement of quantitative and qualitative goals of logistics activity is created. Through the cooperation of economic, social, and environmental components. This forms the image of «green logistics». The article considers the goals, tasks, and principles of «green» logistics, factors that contribute to the formation of the concept of general responsibility during logistics operations, and conditions of its implementation. It was determined that the possibility of achieving quantitative and qualitative goals of logistics activity is provided by synthesizing economic, social, and ecological components that form the outline of «green logistics»; the unity of the interaction of these components provides resource-saving technologies. The cooperation of these components creates conditions for the development of resource-saving technologies. Logistics has a significant impact on most components of the environment. For example, atmospheric air and water pollution, ozone layer destruction, etc. It has been studied that the impact of various vehicles on the environment has become an incentive for countries' governments to develop «green» technologies. It is important to note that state support is a significant factor in implementing ecological strategies and innovations for implementing approaches and methods of managing material, technical, production-economic, and transport-distribution operations. Keywords: logistics, «green» logistics, environment, logistics processes, «green» technologies.

Detecting Relationship between the North–South Difference in Extreme Precipitation and Solar Cycle in China

The sun plays a crucial role as the primary source of energy for the Earth’s climate system and the issue of the influence of solar activity on the climate has been actively discussed recently. However, the precise impact of solar activity on extreme precipitation on the decadal timescale remains insufficiently confirmed. In this study, we investigate the relationship between summer extreme precipitation events exceeding 20 mm (R20mm) in China and the 11-year sunspot number (SSN) cycle from 1951 to 2018. Results showed that the first mode of June–July R20mm, a “south-drought and north-flooding (SDNF)” distribution, exhibited a significant correlation with the SSN cycle (p = 0.02). The fundamental driver is likely the pronounced periodic response of stratospheric ozone to solar forcing. During summer of the high-solar-activity years (HSY), there is a notable increase in ozone concentration and high temperatures in the stratosphere, particularly in the Southern Hemisphere. This phenomenon leads to a layer of anomalous temperature inversion, suppressing convection at the subtropics. This induced downward anomalous airflow toward the north stimulates convective activity in the equatorial region and generates northward wave activities. These wave activities produce rising and sinking anomalies at different latitudes in the Northern Hemisphere troposphere, finally causing the “SDNF” pattern in China.

Integrasi Bioenergi dalam Desain Taman Kota

Bioenergy is a renewable energy source that can be renewed naturally and has a good environmental impact on air quality in urban environments. Urban parks have the potential to integrate bioenergy into an urban context. Design environmentally friendly city parks to be able to produce bioenergy, so that public spaces can double as both open recreation spaces and sources of green energy. The air condition in Lhokseumawe City experiences CO2 pollution and high air temperatures. The aim is to implement bioenergy in gardens through application to plants and trees. Climate change is characterized by extreme rainfall and temperatures. Apart from that, the depletion of the ozone layer is the impact of global warming which is indicated by high air temperatures a global issue. In essence, climate change occurs in all cities. Apart from that, rapid urban development is the influence of the activity and density of the city center which triggers an increase in global warnings and has an impact on thermal comfort. good air quality and thermal conditions in outdoor spaces in urban areas are difficult to find. The presence of public space plays a role as a green open space and a source of green energy and renewable energy and can increase absorption areas. However, the existence of environmentally friendly green open spaces that are capable of reducing global warming cannot be integrated with bioenergy, which is still less familiar and not yet optimal for application, so it is the basic fundamental phenomenon in this research. This research aims to identify thermal quality (CO2, temperature, and wind speed); identify softcape elements, namely plants in RTH, and contribute through integration with the bioenergy approach in RTH as a solution to reduce global warming, especially CO2. This type of research is descriptive using a quantitative approach. The research results show that CO2 levels have exceeded the threshold, resulting in air pollution with high air temperatures. This condition has a very negative impact on the survival of an urban environmental climate. The presence of plant elements as softcap elements has yet to be fulfilled, so certain plants are needed as a solution in producing bioenergy applications.

Plum blossom low molecular weight polypeptide protects HaCaT cells against UVB-induced oxidative damage in vitro and underlying mechanism.

Increasing amounts of ultraviolet radiation occur as ozone depletion causes the earth's ozone layer to be destroyed, making antioxidant efficacy a research hotspot. Previous studies on plum blossom have mostly focused on Volatile Oils, Flavonoids, Phenylpropanoids, and other compounds, whereas few studies have focused on low molecular weight polypeptide (LMWP) of plum blossom. This research provides a reference for the deep processing and utilization of plum blossom. (a) Plum blossom low molecular weight polypeptides protect HaCaT cells against UVB-induced oxidative damage in vitro and the underlying mechanism. (b) Improve the theoretical basis for the intense processing and utilization of plum blossom. The safe concentration of LMWP and the survival rate of HaCaT cells were determined using the CCK-8 experiment. The fluorescence intensity of reactive oxygen species (ROS) was identified using the dichlorofluorescin diacetate (DCFH-DA) method; Superoxide dismutase (SOD) and malondialdehyde (MDA) concentrations were measured in ruptured cells; Western blot analysis was used to examine the expression levels of three proteins: nuclear factor E2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and benzoquinone oxidoreductase 1 (NQO-1). It was noted that a certain concentration of LMWP could promote cell proliferation. In oxidatively damaged HaCaT cells, SOD levels and survival rates were markedly reduced, but ROS and MDA levels were elevated. However, after treatment with LMWP, the survival rate of the cells and SOD levels were markedly increased, and the levels of ROS and MDA were markedly decreased. As shown by Western blotting, the model group exhibited lower levels of Nrf2, HO-1, and NQO-1 expression than the control group, whereas LMWP-treated cells had significantly higher levels of Nrf2, HO-1, and NQO-1 expression than their model-treated counterparts. LMMP can effectively protect HaCaT cells against oxidative damage in vitro induced by UVB, and the underlying mechanism is linked to the activation of the transcription factor Nrf2.

The Impact of the Tropical Sea Surface Temperature Variability on the Dynamical Processes and Ozone Layer in the Arctic Atmosphere

Tropical sea surface temperature (SST) variability, mainly driven by the El Niño–Southern Oscillation (ENSO), influences the atmospheric circulation and hence the transport of heat and chemical species in both the troposphere and stratosphere. This paper uses Met Office, ERA5 and MERRA2 reanalysis data to examine the impact of SST variability on the dynamics of the polar stratosphere and ozone layer over the period from 1980 to 2020. Particular attention is paid to studying the differences in the influence of different types of ENSO (East Pacific (EP) and Central Pacific (CP)) for the El Niño and La Niña phases. It is shown that during the CP El Niño, the zonal wind weakens more strongly and changes direction more often than during the EP El Niño, and the CP El Niño leads to a more rapid decay of the polar vortex (PV), an increase in stratospheric air temperature and an increase in the concentration and total column ozone than during EP El Niño. For the CP La Niña, the PV is more stable, which often leads to a significant decrease in Arctic ozone. During EP La Niña, powerful sudden stratospheric warming events are often observed, which lead to the destruction of PV and an increase in column ozone.

Measurements and Modeling of the Interhemispheric Differences of Atmospheric Chlorinated Very Short‐Lived Substances

AbstractChlorinated very short‐lived substances (Cl‐VSLS) are ubiquitous in the troposphere and can contribute to the stratospheric chlorine budget. In this study, we present measurements of atmospheric dichloromethane (CH2Cl2), tetrachloroethene (C2Cl4), chloroform (CHCl3), and 1,2‐dichloroethane (1,2‐DCA) obtained during the National Aeronautics and Space Administration (NASA) Atmospheric Tomography (ATom) global‐scale aircraft mission (2016–2018), and use the Community Earth System Model (CESM) updated with recent chlorine chemistry to further investigate their global tropospheric distribution. The measured global average Cl‐VSLS mixing ratios, from 0.2 to 13 km altitude, were 46.6 ppt (CH2Cl2), 9.6 ppt (CHCl3), 7.8 ppt (1,2‐DCA), and 0.84 ppt (C2Cl4) measured by the NSF NCAR Trace Organic Analyzer (TOGA) during ATom. Both measurements and model show distinct hemispheric gradients with the mean measured Northern to Southern Hemisphere (NH/SH) ratio of 2 or greater for all four Cl‐VSLS. In addition, the TOGA profiles over the NH mid‐latitudes showed general enhancements in the Pacific basin compared to the Atlantic basin, with up to ∼18 ppt difference for CH2Cl2 in the mid troposphere. We tagged regional source emissions of CH2Cl2 and C2Cl4 in the model and found that Asian emissions dominate the global distributions of these species both at the surface (950 hPa) and at high altitudes (150 hPa). Overall, our results confirm relatively high mixing ratios of Cl‐VSLS in the UTLS region and show that the CESM model does a reasonable job of simulating their global abundance but we also note the uncertainties with Cl‐VSLS emissions and active chlorine sources in the model. These findings will be used to validate future emission inventories and to investigate the fast convective transport of Cl‐VSLS to the UTLS region and their impact on stratospheric ozone.

Preconditioned Stratospheric Modulation on the Occurrence of Stratospheric Final Warmings

AbstractStratospheric Final Warmings (SFWs) are considered to have a distinct impact on the surface weather and stratospheric ozone. Most SFWs are predominantly wave‐driven, while previous studies generally focused on the effects of tropospheric anomalous wave forcing on stratospheric wave amplification. This study demonstrates the crucial role of preconditioned stratospheric modulation on the occurrence of wave‐driven SFWs in the Northern Hemisphere, using ERA5 reanalysis. In most cases, the preconditioned stratospheric state is the key factor in determining the occurrence of both early and late SFWs. The tropospheric anomalous wave forcing cannot independently trigger most SFWs without stratospheric modulation. The proportion of anomalous stratospheric signals followed by SFWs is much higher than that of anomalous tropospheric forcing, even if the proportions of SFWs preceded by anomalous stratospheric signals and tropospheric wave forcing are similar. Additionally, about 25% of SFWs are only preceded by stratospheric modulation without anomalously strong tropospheric wave amplification.

Impact of a gravity wave process on the upper stratospheric ozone valley on the Qinghai-Tibetan Plateau

Atmospheric gravity waves are essential meso-small-scale oscillations that facilitate material exchange within the atmosphere. These waves can significantly affect the ozone layer in the Upper Troposphere and Lower Stratosphere (UTLS) on the Qinghai-Tibetan Plateau. However, the influence of gravity wave dynamic processes on upper stratospheric ozone has rarely been studied. This paper identifies the gravity waves on the Tibetan Plateau based on ECMWF Reanalysis 5 (ERA5) data, analyzes the response of the upper stratospheric ozone to the event, and simulates the dynamic propagation mechanism of gravity waves by the Weather Research and Forecasting (WRF) model. This analysis reveals that between 15:00 and 21:00 UTC on July 29, 2015, gravity waves propagated from the surface of Tibetan Plateau (450 hPa) up to the upper stratosphere (20 − 3 hPa) in an arc-shaped structure and tilted to the east with height. The gravity wave signals started to weaken at 21:00 UTC on the same day. Influenced by the easterly rapids, gravity waves partially broke near 3 hPa at 02:30 UTC on July 30, but gravity wave signals were still present, and gravity waves completely broke and released energy at 04:00 UTC. During this process, ozone in the 20–3 hPa region (upper stratosphere) on the Qinghai-Tibetan Plateau responds well to gravity waves, and the ozone mixing ratio began to drop in ozone concentration 30 min after the partial breakup (03:00 UTC). The ozone dropped drastically by about 0.014 ppmv from 04:00 to 05:00 UTC. The WRF simulation results agree well with ERA5 and accurately capture the intricate characteristics of gravity waves. Furthermore, the breakup of gravity waves caused a total drop in ozone of 0.024 ppmv.