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The Kototabang (0.20°S, 100.3°E, 10.36°S dip latitude) Equatorial Atmosphere Radar (EAR) observations of valley region field-aligned irregularities (FAI) reveal maximum percentage of occurrence (PO) of high signal to noise ratio (greater than 3 dB) type-B 150-km echoes during boreal summer (June-August) and winter (December-January) of solar moderate to minimum years 2016–2019. The PO is anomalously high in the solar minimum year 2019 and particularly during the September equinox when a major austral sudden stratospheric warming (SSW) event has occurred. Its possible relation with mesospheric tides and stratospheric ozone is investigated. The space–time spectral analysis of upper mesospheric temperature information obtained from the spaceborne radiometer instrument Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) reveals that migrating semi-diurnal tide (SW2) is dominant during June-August, when the PO of the 150-km echoes maximizes, whereas migrating diurnal tide (DW1) is dominant during equinox months. It also reveals quasi-biennial variability of the DW1 tide probably due to similar variability of the stratospheric ozone. It is suggested that the DW1 tides generated due to solar radiation absorption by stratospheric ozone and tropospheric water vapour can have phases opposite to each other, leading to the suppression of DW1 tide during September 2017 and 2019 resulting in the relative dominance of SW2 tide over DW1 tide. The meridional wind shear associated with the relatively dominant SW2 tide results in an interchange instability developed on the gradient of daytime descending ion layer along with solar minimum conditions leads to plasma irregularities responsible for these echoes. The large eastward propagating diurnal tide with zonal wavenumber 3 (DE3) observed during June-September 2019 is unlikely to cause the instability, due to its weak meridional component.

There have been extensive studies on poleward expansion of the Hadley cells and the associated poleward shift of subtropical dry zones in the past decade. In the present study, we study the trends in the width and strength of the Hadley cells, using currently available simulation results of the Coupled Model Intercomparison Project Phase-6 (CMIP6), and compare the trends with that in CMIP5 simulations. Our results show that the total annual-mean trend in the width of the Hadley cells is 0.13° ± 0.02° per decade over 1970–2014 in CMIP6 historical All-forcing simulations. It is almost the same as that in CMIP5. The trend in the strength of the Northern-Hemisphere (NH) cell shows much greater weakening in CMIP6 than in CMIP5, while the strength trend in the Southern-Hemisphere (SH) cell shows slight strengthening. Single-forcing simulations demonstrate that increasing greenhouse gases cause widening and weakening of both the NH and SH Hadley cells, while anthropogenic aerosols and stratospheric ozone changes cause weak strengthening trends in the SH cell. CMIP6 projection simulation results show that both the widening and weakening trends increase with radiative forcing.

This study presents the continuation of our previous analysis of variations of atmospheric and space weather parameters above Iberian Peninsula along two years near the 24th solar cycle maximum. In the previous paper (Morozova et al., 2017) we mainly discussed the first mode of principal component analysis of tropospheric and lower stratospheric temperature and pressure fields, which was shown to be correlated with lower stratospheric ozone and anti-correlated with cosmic ray flux. Now we extend the investigation to the second mode, which suggests a coupling between the stratosphere and the ionosphere. This second mode, located in the low and middle stratosphere (and explaining ~7% of temperature and ~3% of geopotential height variations), showed to be statistically significantly correlated with variations of the middle stratosphere ozone content and anti-correlated with variations of ionospheric total electron content. Similar co-variability of these stratospheric and ionospheric parameters was also obtained with the wavelet cross-coherence analysis. To investigate the role of atmospheric circulation dynamics and the causal nature of the found correlations, we applied the convergent cross mapping (CCM) analysis to our series. Strong evidence for the stratosphere-ionosphere coupling were obtained for the winter 2012–2013 that is characterized by the easterly QBO phase (quasi-biennial oscillations of the direction of the stratospheric zonal winds) and a strong SSW (sudden stratospheric warming event). Further analysis (for the three-year time interval 2012–2015) hint that SSWs events play main role in emphasizing the stratosphere-ionosphere coupling.

The global climate change is related with greenhouse gas emission from cultivated soils – carbon dioxide, methane and nitrous oxide. The emissions of N2O also have negative influence on ozone layer of our planet. The major source of the nitrous oxide is denitrification process in soil, which controlled by specific soil microbe society. The pot experiment with flooding to accelerate the denitrification process and the application of the monosilicic acid as a source of soluble form of Si was carried out with barley. Several forms of nitrous oxide emission (unlimited carbon denitrification and potential denitrification with or without ethylene application) were measured. The obtained data showed that the application of monosilicic acid to brown soil when growing barley under conditions of soil flooding has a significant effect on nitrogen emission and can change the N2O:N2 ratio. The application of the monosilicic acid reduced the uC-D N2O emission, while increased the PD N emission. Generally the application of the water soluble Si decreased the N2O:N2 ratio. We suggested that the presence of monosilicic acid in the system provides a more complete denitrification process with the formation of N2 in the NO3− → NO2− → NO→N2O → N2 reaction sequence, while the deficiency of bioactive Si mainly provides the formation and emission of N2O. Considering that N2 is not a greenhouse gas, we can conclude that application of monosilicic acid to the soil can reduce greenhouse gas emissions and reduce the impact of global climate change on agricultural activity.

In construction industry, apart from cement, the aggregate type, mix design method and transport distance of raw materials also contribute significantly to the environment related issues. This paper compares environment impacts of recycled coarse aggregate (RCA) and Particle Packing Method (PPM) of mix design approach with the concrete proportioned using natural coarse aggregate (NCA) and IS code method. The system boundary is determined based on cradle-to-gate theory. The primary data regarding the preparation of NCA and RCA are collected from the respective production facilities and Ecoinvent 3.01 is used as background database. Abiotic depletion, abiotic depletion due to fossil fuels, global warming potential, depletion of ozone layer, formation of tropospheric ozone photochemical oxidants, acidification potential, and eutrophication potential are measured using CML baseline method with the help of SimaPro software. Lower environmental impacts are observed for PPM mix designed concrete owing to the requirement of lesser cement quantity. The combination of RCA and PPM mix design approach exhibits minimum environmental impacts. Transport activities are the second largest contributor after cement and hence, sensitivity analysis is carried out to evaluate the influence of different transport scenarios and distances in Indian context. For comparable environmental impact with natural aggregate concrete proportioned using IS code method, the maximum possible supply distance of RCA is determined for different collection distance of C&D waste. The collection distance of C&D waste can be incremented by 9–12 km for each 50 km increment in the supply distance of processed RCA to prepare recycled aggregate concrete.

We consider physical mechanisms responsible for forming plain-layered jet streams in the winter stratosphere. Unlike the conventional notion about the balance between the energy of the solar UV radiation energy absorbed by the stratospheric ozone within the Hartley band and the energy of loss due to infrared emission from СО2, О3, and Н2О molecules, such a balance is shown not to persist. It is shown that the bias of these energies observed in satellite experiments can be explained by dynamic mechanism increasing the air gravity potential in the tropical stratosphere and forming equator/winter pole baroclinic instability, which generates the jet stream. Jet streams transport energy and pulse from equatorial to polar region and facilitate the descending part of the Brewer-Dobson global circulation. Potential energy release, when the stratospheric jet stream lowers, is ∼1018 W/day; the air mass transported by the jet stream to the winter tropopause region is estimated as being ∼1014 kg/day. Based on the ECMWF ERA-Interim reanalysis data, we analyzed the temporal characteristics of the stratospheric air motion from the region of gravity potential abundance generation in the summer tropical stratosphere to the polar winter tropopause altitudes, where the stratospheric air ends its motion, thus participating in cyclogenesis. Duration of the descending part of the Brewer-Dobson circulation in the winter stratosphere/troposphere averages 50–70 days.

The 2016 Group of Twenty (G20) Hangzhou Summit was concurrently accompanied by extratropical cyclogenesis. To investigate whether the extratropical cyclone exerts any impact on the near surface ozone concentration, the Weather Research Forecast with Chemistry (WRF-Chem) model, with stratospheric passive tracers turned on, was used to simulate the air quality from August 24 to September 06, 2016. It turns out the WRF-Chem model generally performed well when compared to the observed data from a large number of air quality monitoring sites and satellite measurements. During the period, an occurrence of stratospheric intrusion was observed, associated with tropopause fold and curved upper-level jet in East Asia. A fairly large number of stratospheric passive tracers that had quite positive correlation with O3 concentrations were also found over the southeast China. Besides, observed ground surface anomaly of high O3 and the accompanied low CO as well as humidity further implied the downward transport of O3 from the stratosphere. These results suggest that stratospheric ozone intrusion acts as an additional source of the near surface tropospheric ozone concentration, which deteriorates the O3 pollution in China. This helps to explain the difficulty of O3 control during the campaign period of the G20, and provides some insights into stratosphere-to-troposphere transport of O3.

Photosynthesis is the gateway of the Sun's energy into the biosphere and the source of the ozone layer; thus it is both provider and protector of life as we know it. Despite its pivotal role we know surprisingly little about the genetic basis of variation in photosynthesis and the selective pressures giving rise to or maintaining this variation. In this review, I will briefly summarise our current knowledge of intraspecific and interspecific variation in photosynthesis to understand the main selective constraints on photosynthesis and what this means for the future of nature and agriculture in a changing world.

The global ozone layer has been continuously depleted in the last few decades due to the anthropogenic emissions of the ozone depleting substances (ODSs). This has created major concern for the ecosystem as well as mankind. This points to the need to examine the influence of each individual ODS in order to estimate how this burden can change in the future. To that end, we have analysed 52 years (1965–2017) data of the ozone depleting substances using the Box-Jenkins model, and have predicted the future trend of the ODSs until the year 2030. On the basis of the relationship between the trend in variations of the ozone depleting substances and the total ozone column, we have established that how much of the recent ozone increment is attributable to the concentration of the ozone depleting substances. By using the above mentioned model, we have estimated that the present atmospheric abundance of chlorine and bromine is about 3325 and 14.3 parts per trillion (ppt) respectively and have calculated that the atmospheric abundance of these substances will reduce to values of 3217 ppt (∼3.2%) and 13.1 ppt (∼8.3%) respectively. We have also inferred that if the decreasing trend of ODSs continues with the same rate in the coming decades, the ozone column will increase by 9–10% and the ozone level will return to its pre-1980 level by the year 2030.

Increasing nitrous oxide (N2O) emissions and their potential impacts on the ozone layer are of worldwide concern. Hydrate-based sequestration technology is considered to be a promising method for N2O control. This study investigated the conditions required for N2O sequestration through forming hydrates. Magnetic resonance imagining (MRI) was used to capture and quantify N2O hydrate formation in porous media simulated by fine quartz sands. The effect of the sequestration conditions on hydrate formation were investigated, involving pressure (1.5, 2, and 2.5 MPa), temperature (275.15, 276.15, and 277.15 K) and initial water saturation (25.06, 33.23, 42.13, and 50.81%). The results indicated the inhomogeneous formation and distribution of N2O hydrates in pore spaces. Initial water saturation and pressure were found to significantly impact the hydrate distribution during the initial formation stage. Moreover, N2O hydrates formed more rapidly in sediments with a lower water saturation and temperature, indicating that sufficient contact between gas and water and a higher driving force are crucial for abundant hydrate formation. A higher initial water saturation could help improve the sequestration efficiency, which would play a crucial role in locating the sequestration site. This work could provide some insights of the mechanism of N2O sequestration via hydrate formation in sediments, making contributions to potential applications in field tests.

The total ozone (TO3) multi-sensor reanalysis data-base, on a global scale, is examined for trend variability during the period 1979–2017. A multiple regression model is applied to the seasonal and yearly time series for zonal belts and 2-D bins covering the entire globe. Piecewise linear trend and independent linear trend pattern consisting of three joined and separated lines, respectively, are used to disclose long-term TO3 variability. The first line is for the ozone decline period forced by the increase of ozone depleting substances (ODS) in the stratosphere, the second one stands for an initial recovery phase starting after the ODS overturning at the end of the 1990s, and the third one is for latest trends. Negative trends are estimated outside the tropics in the first segment, especially during spring and summer. Both trend models provide significant year-round declining trend over the entire globe of ∼2% per 10 yr before the ODS overturning. Afterwards, in most cases trends are insignificant. However, significant positive trends are found for some latitudinal bands and bins at least in one of two post-ODS overturning segments. The number of bins with the upward trend is much larger than the number concerning bins with the downward trend. Significant positive year-round trends (∼2–4% per 10 yr) by both models are found over the entire globe, in the tropics, and poleward of 30° parallel after the ODS overturning. All these results support the emergence of ozone recovery on a global scale following the decline in the 1980s and 1990s.

The consumption of takeaway food is increasing worldwide. Single-use containers used for takeaway food represent a significant source of waste and environmental impacts due to their low recyclability. Consequently, it is important to identify the best available alternatives and improvement opportunities to reduce the environmental impacts of fast-food containers. For these purposes, this study estimates and compares for the first time the life cycle impacts of three most widely-used types of takeaway container: aluminium, polypropylene and extruded polystyrene. These are also compared to reusable polypropylene containers. The findings suggest that single-use polypropylene containers are the worst option for seven out of 12 impacts considered, including global warming potential. They are followed by the aluminium alternative with five highest impacts, including depletion of ozone layer and human toxicity. Overall, extruded polystyrene containers have the lowest impacts due to the lower material and electricity requirements in their manufacture. They are also the best option when compared to reused takeaway polypropylene containers, unless the latter are reused 3–39 times. The number of uses needed for the reusable “Tupperware” polypropylene food savers is even higher, ranging from 16 to 208 times, with terrestrial ecotoxicity being always higher than for extruded polystyrene, regardless of the number of uses. However, extruded polystyrene containers are currently not recycled and cannot be considered a sustainable option. If they were recycled in accordance with the European Union 2025 policy on waste packaging, most of their impacts would be reduced by >18%, while also reducing littering and negative effects on marine organisms. Most of the impacts of the other two types of container would also be reduced (>20%) through increased recycling. Implementing the European Union 2025 policy on recycling of waste packaging would reduce all the impacts by 2%–60%, including a 33% reduction in global warming potential. Based on 2025 million takeaway containers used annually in the European Union, the latter would save 61,700 t CO2 eq./yr, equivalent to the emissions of 55,000 light-duty vehicles. The outcomes of this study will be of interest to packaging manufacturers, food outlets, policy makers and consumers.

In a series of 10-day campaigns in Ontario and Quebec, Canada, between 2005 and 2007, ozonesondes were launched twice daily in conjunction with continuous high-resolution wind-profiling radar measurements. Windprofilers can measure rapid changes in the height of the tropopause, and in some cases follow stratospheric intrusions. Observed stratospheric intrusions were studied with the aid of a Lagrangian particle dispersion model and the Canadian operational weather forecast system. Definite stratosphere-troposphere transport (STT) events occurred approximately every 2–3 days during the spring and summer campaigns, whereas during autumn and winter, the frequency was reduced to every 4–5 days. Although most events reached the lower troposphere, only three events appear to have significantly contributed to ozone amounts in the surface boundary layer. Detailed calculations find that STT, while highly variable, is responsible for an average, over the seven campaigns, of 3.1% of boundary layer ozone (1.2 ppb), but 13% (5.4 ppb) in the lower troposphere and 34% (22 ppb) in the middle and upper troposphere, where these layers are defined as 0–1 km, 1–3 km, and 3–8 km respectively. Estimates based on counting laminae in ozonesonde profiles, with judicious choices of ozone and relative humidity thresholds, compare moderately well, on average, with these values. The lamina detection algorithm is then applied to a large dataset from four summer ozonesonde campaigns at 18 North American sites between 2006 and 2011. The results show some site-to-site and year-to-year variability, but stratospheric ozone contributions average 4.6% (boundary layer), 15% (lower troposphere) and 26% (middle/upper troposphere). Calculations were also performed based on the TOST global 3D trajectory-mapped ozone data product. Maps of STT in the same three layers of the troposphere suggest that the STT ozone flux is greater over the North American continent than Europe, and much greater in winter and spring than in summer or fall. When averaged over all seasons, magnitudes over North America show similar ratios between levels to the previous calculations, but are overall 3–4 times smaller. This may be because of limitations (trajectory length and vertical resolution) to the current TOST-based calculation.

Due to the contributions of nitrous oxide (N2O) to global climate change and stratospheric ozone destruction, it is important to understand how climate and agricultural management affect N2O emissions. Although the process-based Denitrification Decomposition (DNDC) model is often used for quantifying emissions of N2O, the accuracy of these predictions remains in question, and it is not clear which input variables, environmental or field management, have the greatest effect on model performance. In this study, DNDC was evaluated for prediction of N2O fluxes from two climatically-different corn-field sites in the United States (a Colorado irrigated field and a Minnesota rainfed field). Besides climate, these sites offer the additional advantage that measurements are available for multiple field management practices, including fertilizer application, tillage, and crop rotation. This evaluation found that DNDC did not consistently, correctly predict daily-scale N2O fluxes. Cumulative growing season N2O fluxes were significantly under-predicted in Colorado and were both under- and over-predicted in Minnesota. Model calibration of four soil input parameters did not significantly improve N2O emission predictions at either site or time scale. Modeled and measured N2O fluxes and model error were all strongly correlated with precipitation. Over-predictions of N2O fluxes were associated with heavy precipitation and high modeled denitrification. Based on our results, model improvements to decrease model error for corn cropping systems in temperate climate zones should focus on better accounting for the effects of precipitation on denitrification. Despite discrepancies in daily and cumulative growing season N2O fluxes, DNDC correctly identified the only field management (fertilizer application rate) that significantly influenced the measured N2O fluxes.

A human being causes extensive destruction to the environment, water, land, various elements of the environment, and the ecosystem itself. There are so much human-made pollution and environmental degradation that the nightmare that awaits us is enough to shake us all. Looking at the overall scenario, there are a few trends underway. Earth atmosphere is excessively polluted at the global and regional levels. The accumulation of greenhouse gases will lead to significant changes in weather patterns in the near future leading to global warming. The destruction of the ozone layer and the further warming of the earth's surface leading to a tragic consequences such as outbreaks of cancerous and tropical diseases, disruption of the ocean food chain, sea level rise, the submersion of many islands and the melting of small landmasses. In Iraq, there are many environmental violations that threaten human life, which leads to making Iraq an inappropriate country to live in the near future due to outbreaks of incurable diseases and the difficulty of environmental adaptation to massive environmental disasters. In this paper, we are aiming to present a case study about Wasit-Iraq regarding environmental violations and environmental pollution threatening human life.

High ambient temperature is well known to have an adverse impact on air conditioners; it lowers their cooling capacity along with their coefficient of performance. Moreover, air conditioning plays a significant role in damaging the environment as it contributes to both global warming and ozone depletion. In the past few decades, the Montreal agreement was introduced to protect the ozone layer from substances that contribute to its depletion. Developing countries are now facing the challenges of phasing out HCFCs such as R22 in the air conditioning sector. The aim of this study is to find an alternative refrigerant that can replace R22 after its phase out. The new refrigerant must have low environmental impacts and should be able to withstand operation in high ambient temperature countries. In this study, the hydrocarbon refrigerant R290 and the hydrofluorocarbon R410A were selected as alternatives. Furthermore, experimental testing was carried out on the baseline refrigerant R22 and R410A using a 7kW ducted split unit at three outdoor conditions: 35oC, 48oC, and 52oC. From the experimental results, a model based on R22 and R410A was developed using Engineering Equation Solver (EES). The model was successful in verifying the experimental results within a 15% error range and was tested again with external data from (Eltalouny & Nielsen, 2016) [10]. After confirming its validity, the model was simulated to predict the performance of the alternative refrigerant R290 under the same experimental conditions and input data. To test the model’s validity on R290, results from Eltalouny & Nielsen (2016) were used. The model succeeded in predicting the COP and power consumption. The refrigerants demonstrated deterioration in their performance at elevated temperatures compared to their performance at a typical operating regime. With proper safety measures, and enhancement to the compressor efficiency, R290 can be considered as a promising alternative.

Today's refrigeration and air-conditioning industry is adopting chlorine- and fluorine-free working fluids, because chlorine is the cause of depleting the ozone layer, and fluorine is the cause of global warming. CFC12 is a more suitable refrigerant recognized in vapor compression refrigeration systems. It was phased out in developed countries in 1996. It is recommended to use HFC134a for replacing CFC12 in vapor compression refrigeration systems. But HFCs have a high global warming potential. The "Kyoto Protocol" aims to reduce the whole GHG emissions by at least 5-times over the 1990 level during the commitment period from 2008 to 2012. Therefore, in the near future, the production and utilization of HFC134a will be ended. There are millions of heat pumps and air-conditioners in refrigeration systems that use CFC12 and HFC134a in the world that must be properly retrofitted under the aforementioned phase-out. However, there are few studies on the replacement of HFC134a refrigerant. This motivates the use of some available environmentally friendly fluids to replace the new product lines of CFC12 and HFC134a to study the performance of the new product line of vapor compression refrigeration systems. But none of them are environmentally acceptable substitutes. In the work of this project, refrigerant R290/R600a (68/32% by weight), R290/R600 (79/21% by weight) is used for the performance of vapor compression refrigeration system), LPG (R290/R600/R600a-33/53)/14 wt.%) and LPG/R134a (60/40 wt.%) have been experimentally studied as modifications of CFC12 and HFC134a. Finally try to predict system performance under the action of a magnetic field. Six magnets are placed on the full liquid pipeline at the outlet of the condenser, and each magnet has a level of 4000 Gauss. Due to the magnetic field, the power consumption of the compressor is decreased by 2.5%, and the COP is reduced by 2.4%. The results of this study prove that the new alternative refrigerants R290/R600a (68/32 wt.%) and R290/R600 (79/21 wt.%) mixtures can well replace CFC12 and HFC134a, and can be used without any modification. It can be used to transform the old system. The refrigerants LPG and LPG/R134a (60/40% by weight) can be used for higher evaporation temperature applications.

The coronavirus 2019 (COVID 19, or SARS-CoV-2) pandemic that started in December 2019 has caused an unprecedented impact in most countries globally and continues to threaten human lives worldwide. The COVID-19 and strict lockdown measures have had adverse effects on human health and national economies. These lockdown measures have played a critical role in improving air quality, water quality, and the ozone layer and reducing greenhouse gas emissions. Using Soil Moisture Active Passive (SMAP) Level 4 carbon (SMAP LC4) satellite products, this study investigated the impacts of COVID-19 lockdown measures on annual carbon emissions globally, focusing on 47 greatly affected countries and their 105 cities by December 2020. It is shown that while the lockdown measures significantly reduced carbon emissions globally, several countries and cities observed this reduction as temporary because strict lockdown measures were not imposed for extended periods in 2020. Overall, the total carbon emissions of select 184 countries reduced by 438 Mt in 2020 than in 2019. Since the global economic activities are slowly expected to return to the non-COVID-19 state, the reduction in carbon emissions during the pandemic will not be sustainable in the long run. For sustainability, concerned authorities have to put significant efforts to change transportation, climate, and environmental policies globally that fuel carbon emissions. Overall, the presented results provide directions to the stakeholders and policymakers to develop and implement measures to control carbon emissions for a sustainable environment., Graphical abstract Unlabelled Image

Nitrous oxide is one of the most powerful greenhouse gases and can destroy the ozone layer through photochemical reactions. In 2019, we conducted three cruises to study the spatial and temporal variability of N2O distribution and emissions in the Bohai Sea (BS) and North Yellow Sea (NYS), and analyzed the regional sources and sinks. The maximum average N2O concentrations were observed in the summer, followed by autumn, while the minimum was observed in the spring. The N2O concentration decreased in a gradient from the estuary to the continental shelf, particularly in summer, which indicated that the riverine input from the estuary was a strong source of N2O in the Bohai Sea. Due to the vertical mixing of the water column, the vertical distribution of N2O was moderate in autumn, while the bottom remained a hotspot for N2O emissions in spring and summer. The generalized additive model (GAM) showed that the temperature, salinity, DO and pH were strong predictors of N2O in the BS and NYS. Excess N2O concentrations were positively linearly correlated with the apparent oxygen utilization and NO3- concentrations, which suggested that nitrification was the dominant process of in situ N2O production in the BS and NYS. The mixing of water masses, especially DW (diluted water) and BCW (Bohai Sea coastal water), provided a significant amount of N2O to the entire shelf area of the BS. In addition, the coastal input was a dominate pusher of N2O emissions in the estuarine region. Overall, the annual N2O emissions from BS and NYS were approximately 1.72 × 10-2 Tg yr-1, which accounted for 0.51% of the annual global marine N2O emissions, but only 0.04% of the total area of the world's oceans. Hence, both the BS and NYS acted as N2O sources to the atmosphere.

This paper suggests that some of the common policies and decrees made by many countries to curb the spread of the Coronavirus (a global pandemic) may also be adoptable to mitigate climate change or reduce greenhouse gas emissions and invariably contribute to the world’s ozone layer repair, considering that both issues are global in nature. However, the article pinpoints some adjustments that may have to be made to some of these rules for them to be transposable for climate change mitigation. Distinctively the paper encourages that although some of these changes imposed by the law may seem extraneous, however, they are vital sacrifices that must be made if the projected climate change effects shall not overcome the human race. According to Antonio Guterres (UN general Secretary): the challenge is a global one and the world must remain resilient in resolving it.

The Kyoto Protocol was agreed upon at the end of 1997 with the main goal of combating global warming by the reduction of the emissions of six greenhouse gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexachloride (SH6). Like the Montreal Protocol (1987) – which was negotiated on the back of solid scientific evidence that the ozone layer is thinning dangerously, the grounds for the Kyoto Protocol were laid by solid scientific evidence about the negative side effects of global warming (rising sea levels, extreme weather, etc.) and the causal links with the above mentioned six gases. Back in the 1980s and 1990s the scientists correctly predicted that if greenhouse gas (GHG) emissions were left unchecked, our planet will continue to warm and humanity will have to face the consequences. Whereas the Montreal Protocol so far has turned out to be a moderate success – NASA projects ozone recovery in the Arctic by 2025, and global averages and the Antarctic recovering by 2040, the success of the Kyoto Protocol is quite limited. Only the Annex I countries – as a group – have managed to achieve reductions of GHG emissions compared to 1990 (the base year) levels. Globally however, territorial CO2 emissions have increased from 22.7 Gt in 1990 to 36.6 Gt in 2018 – or about 60%. Therefore, the Kyoto Protocol’s main achievement seems to be playing the role of a limiting factor in a context of growing emissions. This paper examines the reasons behind the Protocol’s puny success and suggests that for all its limitations and shortcomings it has played an important role in the organized response to the challenge of global warming.

Although catalytic chemistry involving ozone-depleting substances (ODSs) is currently a primary driver impacting the abundance of stratospheric ozone, water vapor and aerosols are constituents that also affect stratospheric ozone. Variability in both water vapor and aerosols can induce variability in ozone, and although small relative to that due to trends in ODSs, in the future may become a much more important source of ozone variability.

The Montreal Protocol has halted 99% of global production of chemical substances that deplete stratospheric ozone, which protects life on earth from the harmful effects of ultraviolet (UVB) radiation. UVB causes skin cancer and cataracts, suppresses the human immune system, destroys plastics, and damages agricultural crops and natural ecosystems. Because ozone-depleting substances (ODSs) are powerful greenhouse gases, the Montreal Protocol also protects climate. From the authors’ perspectives in multiple roles as environmental entrepreneurs, practitioners, and authorities, this paper explains how individuals, companies, and military organizations researched, developed, commercialized and implemented alternatives to ODSs that are also safer for climate. With the benefit of hindsight, the authors reflect on what was neglected or done badly under the Montreal Protocol and present lessons learned on how Montreal Protocol institutions can be renewed and revitalized to phase down hydrofluorocarbons (HFCs).

The stratospheric ozone layer is expected to recover as a result of the regulations of the Montreal Protocol on chlorine and bromine containing ozone-depleting substances (ODSs). Model simulations project a return of global annually averaged total column ozone to 1980 levels before the middle of the 21st century, well before the ODSs will return to 1980 levels. This earlier ozone return date is due to the effects of rising greenhouse gas (GHG) concentrations. GHGs influence ozone directly by chemical reactions, but also indirectly by changing stratospheric temperature and the Brewer–Dobson circulation. Based on projections of chemistry–climate models, this article summarizes the effects of GHGs on stratospheric and total column ozone in the mid-latitude upper stratosphere, Arctic and Antarctic spring, and the tropics. The sensitivity of future ozone change to the GHG scenario is discussed, as well as the specific role of a future increase in nitrous oxide and methane.

The Montreal Protocol has controlled the production and consumption of ozone depleting substances (ODSs) since its signing in 1987. The levels of most of these ODSs are now declining in the atmosphere, and there are now initial signs that ozone levels are increasing in the stratosphere. Scientific challenges remain for the Montreal Protocol. The science community projected large ozone losses if ODSs continued to increase, and that ozone levels would increase if ODSs were controlled and their levels declined. Scientists remain accountable for these projections, while they continue to refine their scientific basis. The science community remains vigilant for emerging threats to the ozone layer and seeks scientific evidence that demonstrates compliance with Montreal Protocol. As ODSs decrease, the largest impact on stratospheric ozone by the end of the 21st century will be increases in greenhouse gases. The associated climate forcings, and the human responses to these forcings, represent major uncertainties for the future of the stratospheric ozone layer.

The comprehensive investigation of polar ozone photochemistry and dynamics has required data obtained from as full a complement of available platforms as possible (ground-based, balloon, aircraft, and satellites). Perhaps the most detailed process studies have been conducted using measurements from aircraft, taking advantage of their targeting capabilities coupled with the potential for enabling measurements at high spatial and temporal resolution. The US National Aeronautics and Space Administration (NASA) conducted the first airborne science investigation of polar ozone in an effort to establish the causes of the recurring seasonal depletion of the Earth's stratospheric ozone layer over Antarctica that was identified in the mid-1980s. Subsequent airborne studies in the polar regions of both hemispheres benefitted from extensive successful collaborations among international scientists and the integration of the aircraft measurements with those obtained using ground-based, balloon-borne, and satellite instruments. This article provides an historical perspective of NASA's utilization of its airborne assets to advance our understanding of the chemical and physical processes that control the abundance of stratospheric ozone in both the Antarctic and Arctic.

We examine the variation of stratospheric ozone over northern Finland using ozonesonde observations from 1845 stratospheric balloon flights launched between 1989 and 2015 from near Sodankylä. The annual variation of the ozone partial pressure is examined and seasonal variations are explored and quantified. Direct links between the measured ozone partial pressure and common solar-wind parameters are also examined. A superposed-epoch analysis of the observations based on 191 solar proton events (SPEs) reveals a clear drop in the ozone partial pressure that commences following SPE-arrival at Earth. This analysis shows a reduction in stratospheric ozone in the winter/early-spring months (when the polar vortex is active over northern Finland), in contrast to summer/early-autumn months where no decrease is detected. By subtracting the natural seasonal variations in ozone partial pressure the SPE-driven reduction in ozone between 16 km and 24 km altitude is quantified. Analysis indicates that the ozone partial pressure during winter/early-spring is reduced, with a minimum reached ∼8 days following the SPE arrival. On average, the ozone partial pressure is reduced by ∼10% between 16 and 24 km altitude and takes ∼40 days to return to its previous level. To the best of our knowledge, this is the first comprehensive statistical study, on a regional basis, that provides direct, and long-term in-situ evidence for ozone depletion by SPEs in the northern hemisphere.

Off late, the continuously depletion of the ozone layer and global warming issue have increased the awareness of the construction industries in using more eco-friendly construction materials. Against this background, geopolymer concrete has started to gain significant attention from the research scholars and construction practitioners, due to its advantageous in using by-product waste to replace cement and reducing greenhouse gas emission during its production. It also possesses better mechanical properties and durability compared to conventional concrete. Despite its advantageous, the use of geopolymer concrete in practical is considerably limited. This is mainly due to the lacking in the studies in terms of structural elements, design and application studies. This paper reviewed the material and structural performances of geopolymer concrete to identify the research gaps in this area for future research development. Analysis shown that geopolymer concrete can replace conventional concrete as they presented better mechanical properties, higher durability and more desirable structural performances compared with conventional counterparts. More studies are still needed for practical design standards and finally, the full scale studies on the structural elements should be established to ensure its feasibility in practical.

The Montreal Protocol has banned the production of long-lived chlorine-containing gases such as chlorofluorocarbons (CFCs) that deplete stratospheric ozone. These halogenated compounds ultimately form HCl in the upper atmosphere; the effectiveness of the Montreal Protocol can therefore be monitored by measuring stratospheric HCl. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) measures infrared solar occultation spectra of the Earth's atmosphere from which altitude profiles of HCl volume mixing ratios (VMRs) are determined. The upper stratospheric HCl VMR time series has a linear trend of −4.8 ± 0.2%/decade for 2004–2017, highlighting the continuing success of the Montreal Protocol.

It has been shown that the short-lived halogenated hydrocarbons, such as dichloromethane (DCM), which are not regulated by the Montreal Protocol, have the potential to impact stratospheric ozone. DCM with increasing atmospheric mixing ratios in recent years, is widely used in solvent, foam-blowing and methyl fluoride production sectors in China, which is a large producer as well as consumer of DCM. This study develops a comprehensive emission inventory of anthropogenic DCM in China using a bottom-up method based on the industrial consumption of DCM in China from 2005 to 2016 and makes a projection to 2030. The inventory considered solvent use, polyurethane (PU) foam manufacturing, the chemical industry, and other end uses. Anthropogenic emissions of DCM increased from 101 (80–122) Gg/yr to 318 (254–384) Gg/yr between 2005 and 2016, a increase of 215% over the last 11 years. Solvent use and the manufacture of PU foam agents are the major contributors to total DCM emissions. Under a business as usual (BAU) scenario future Chinese emissions of DCM are predicted to increase to 708 (588–831) Gg/yr by 2030, more than twice the emission IHS, 2016. Chinese emission account for approximately 25%–37% of the 515 Gg/yr estimates by the WMO as average annual global emissions in 2008.

Nitrous oxide (N2O) is a potent greenhouse gas that contributes to climate change and stratospheric ozone destruction. Nitrogen-enriched rivers are significant sources of atmospheric N2O. This study conducted a one-year field campaign in seven N-enriched rivers draining urban, rural, and agricultural land to determine the link between the production, concentrations, and emissions of N2O and land use. Estimated N2O fluxes varied between 1.30 and 1164.38 μg N2O-N m−2 h−1 with a mean value of 154.90 μg N2O-N m−2 h−1, indicating that rivers were the net sources of atmospheric N2O. Concentrations of N2O ranged between 0.23 and 29.21 μg N2O-N L−1 with an overall mean value of 3.81 μg N2O-N L−1. Concentrations of ammonium and nitrate in urban and rural rivers were high in the cold season. The concentrations were also high in agricultural rivers in the wet season. N2O concentrations and emissions in rural and urban rivers followed a similar pattern to ammonium and a similar pattern to nitrate in agricultural rivers. A strong link between the concentrations and emissions of N2O and land use was observed. N2O concentrations in and emissions from the rivers draining the urban and rural areas were significantly higher than the rivers draining the agricultural areas (P

Halogenated hydrocarbons with high ozone depletion potential (ODP) were banned under Montreal Protocol (1987) due to their detrimental effects on ozone layer that shields the planet against ultraviolet radiations. The greenhouse gases (GHG) used in modern refrigeration, air conditioning, and heat pumping systems, are under Kyoto Protocol (1997)’s time-barred permission period. In order to reduce the depletion of ozone and reverse the climate change effects, the European Union legislation (2014) and Paris Accord (2016) are strongly emphasizing the phasing out of the use of harmful synthetic refrigerants. Choice of natural refrigerants makes no net addition of the greenhouse gases (GHG) in the environment. To retrofit and modify existing cooling and heating systems using natural refrigerants, extensive investigations are in progress worldwide. This work reviews timeworn, current and the next-generation refrigerants using Refrigerant Qualitative Parametric (RQP) quantification model to assist the refrigerant choice decision process. It is based on the ratio of arithmetic sums of actual parametric values of refrigerants normalized to equivalent ideal values. This model can help in choosing alternative refrigerants to replace CFCs by HCFCs or HFCs provisionally and finally replacing HCFCs or HFC to low GWP and ODP synthetic and natural refrigerants. A set of 16 refrigerants, both natural and synthetic, as an example, is computed for the standard Vapour Compression Cycle (VCC) based on the proposed model using REFPROP (NIST- 23 standard). The techno-economic parametric values of chosen refrigerants are taken from cited literature, ASHREA safety standards and international environmental legislations, laws and protocols. This paper reports the environment benign natural (CO2, NH3, HCs) and a few synthetic (R-152a, R-1234yf) refrigerants to be the optimal options.

This study aims to conduct the multi-criteria analysis of a self-consumption strategy for building sectors focused on ground source heat pump (GSHP) systems that simultaneously considers the energy generation, economic, and environmental effects of the system in the planning and design phases. In this study, an education facility, a sports facility, and a residential facility are selected as the target facilities. The GSHP system is analyzed at all the target facilities considering the self-consumption of 0–100%, with 25% intervals. The results of this study are as follows. The energy generation rate is increased with increasing self-consumptions in all the target facilities. In terms of the economic effects, the higher self-consumption is, the higher net present value is in all target facilities. However, the savings-to-investment ratio differs by building types due to the energy policy (i.e., the education facility: from 2.68 to 2.39. and the sports facility: from 2.33 to 1.95), however, SIR increased in a residential facility (i.e., the education facility: from 2.65 to 3.32). In terms of the environmental effects, the abiotic depletion, global warming, acidification, and eutrophication potentials decrease in all the target facilities, but the ozone layer depletion potential increases. The proposed model may be useful for decision makers (i.e., architects, owners, construction managers, etc.) or policymakers to determine the percentage of self-consumption when introducing the GSHP system to buildings.

Using a 3-dimensional global atmospheric chemistry and transport model we investigated the atmospheric degradation of HCFO-1233zd(E), E-CF3CH=CHCl, a commercially important, new hydrofluorocarbon replacement compound. Atmospheric degradation of E-CF3CH=CHCl is initiated by reaction with OH radicals, which leads to several chemical oxidation products. Dissemination of these oxidation products to the environment is of concern due to the possible formation of trifluoroacetic acid (TFA) as a degradation product. The model indicates that the average global yield of TFA from atmospheric processing of E-CF3CH=CHCl is approximately 2%. The annually averaged atmospheric lifetime of E-CF3CH=CHCl was found to be approximately 36 days (12 days for Z-CF3CH=CHCl). As E-CF3CH=CHCl is short lived, by far the majority of its Cl atoms will be released and deposited in the lower atmosphere, and the impact on stratospheric ozone is insignificant. An Ozone Depletion Potential of 0.00030 was determined. The Photochemical Ozone Creation Potential was evaluated and a value of 3.6 determined. Finally, we derive a Global Warming Potential for E-CF3CH=CHCl for a 100 year time horizon of

This study investigates the nonlinear dynamics of the stratospheric ozone layer at Pakistan atmospheric region. Ozone considered now the most important issue in the world because of its diverse effects on earth biosphere, including human health, ecosystem, marine life, agriculture yield and climate change. Therefore, this paper deals with total monthly time series data of stratospheric ozone over the Pakistan atmospheric region from 1970 to 2013. Two approaches, basic statistical analysis and Fractal dimension (D) have adapted to study the nature of nonlinear dynamics of stratospheric ozone level. Results obtained from this research have shown that the Hurst exponent values of both methods of fractal dimension revealed an anti-persistent behavior (negatively correlated), i.e. decreasing trend for all lags and Rescaled range analysis is more appropriate as compared to Detrended fluctuation analysis. For seasonal time series all month follows an anti-persistent behavior except in the month of November which shown persistence behavior i.e. time series is an independent and increasing trend. The normality test statistics also confirmed the nonlinear behavior of ozone and the rejection of hypothesis indicates the strong evidence of the complexity of data. This study will be useful to the researchers working in the same field in the future to verify the complex nature of stratospheric ozone.

International audience; Ecological, signaling, metabolic, and chemical processes in plant-microorganism systems and in plant-derived material may link the use of chlorinated pesticides in the environment with plant chloromethane emission. This neglected factor should be taken into account to assess global planetary budgets of chloromethane and impacts on atmospheric ozone depletion.

Recent publications are reviewed in the context of urban health issues possibly resulting from global climate change. The most important phenomena having an impact on health discussed in the paper include increased ultraviolet radiation due to stratospheric ozone, temperature-related effects, precipitation-related effects (both excessive precipitation and drought), vector-borne diseases, and finally air quality, smog-related effects. Among the above, those most directly linked to climate change may be associated with temperature-related and precipitation-related effects. The paper points out that even with 1.5°C warming major health impacts can be expected. Among the most important are respiratory problems (such as asthma) and increase in vector-borne diseases especially through ticks. In addition, urban expansion due to population increase projects urban heat island intensity increase superimposed on global warming.

The history of refrigerants is elaborated and the international agreements concerning protection of the ozone layer and climate change are presented. We have to learn from mistakes in the past. There are countries with successful policies. The most used natural refrigerants are presented: ammonia, CO2 and hydrocarbons. Their advantages and disadvantages are described and their applications. The fourth generation of fluorine-based gases is elaborated: hydrofluoroolefins. The most used are R1234yf and R1234ze(E), and their blends with HFCs. A vision for the future with environmental refrigerants is described. Innovations such as new types of components, new concepts of low charge ammonia systems and their expansion in many applications. There are improvements of CO2 systems installing parallel compressors, ejectors as an expansion device and usage of evaporative condenser. There is a big potential of R290 to be a refrigerant no. 1 for split air conditioning units. Finally, a new approach is recommended.

Over the past few decades, development of nanotechnology has been made its mark in the various fields of research. Further, the energy consumption has seen an increment with the increasing refrigeration and air conditioning systems in numbers. However, to overcome the energy crisis globally the need of highly efficient systems becomes a necessity. At the same time, preventing the environment by these technological leaps becomes challenging. In view of environmental impacts of these technologies Montreal Protocol Treaty was signed in 1987 to restrict the use of substances such as chlorofluorocarbons damaging the ozone layer and was enforced from January 1989. Whereas, Kyoto Protocol Treaty signed in 1997 to restrict usage of high valued Global Warming Potential substances such as hydrofluorocarbons and was enforced on February 2005 onwards. Therefore, using low ozone depletion potential and low global warming valued refrigerants such as R-600a, R-290, etc. becomes an effective substitute. In this study, the thermophysical properties of mixed nano-refrigerants made from mixing R-290 and R-600a with nanoparticles has been estimated using fluid data available in NIST database standard 4 (SUPERTRAP®) versions 3.2.1. Further, the effect of volume concentration of nanoparticles in mixed refrigerant (R-290 and R-600a) on density, thermal conductivity, viscosity and specific heat is investigated. In addition, the effect of pressure on these properties is also investigated

The Montreal Protocol is regarded as an example of effective environmental governance—setting the stratospheric ozone hole on the road to recovery by coordinating science, multilateral funding, and private-sector innovation. How robust is the Protocol to emerging threats, and what lessons can it offer for climate governance?

Chloromethane (CH3Cl), currently the most abundant chlorinated organic compound in the atmosphere at around ~ 550 parts per trillion by volume (pptv), is considered responsible for approximately 16% of halogen-catalyzed stratospheric ozone destruction. Although emissions of CH3Cl are known to occur from animals such as cattle, formation and release of CH3Cl from humans has not yet been reported. In this study a pre-concentration unit coupled with a gas chromatograph directly linked to a mass spectrometer was used to precisely measure concentrations of CH3Cl at the pptv level in exhaled breath from 31 human subjects with ages ranging from 3 to 87 years. We provide analytical evidence that all subjects exhaled CH3Cl in the range of 2.5 to 33 parts per billion by volume, levels which significantly exceed those of inhaled air by a factor of up to 60. If the mean of these emissions was typical for the world's population, then the global source of atmospheric CH3Cl from humans would be around 0.66 Gg yr− 1 (0.33 to 1.48 Gg yr− 1), which is less than 0.03% of the total annual global atmospheric source strength. The observed endogenous formation of a chlorinated methyl group in humans might be of interest to biochemists and medical scientists as CH3Cl is also known to be a potent methylating agent and thus, could be an important target compound in future medical research diagnostic programs.

Ultraviolet-B (280−320 nm wavelength; UV-B) is one of the important reactive oxygen species (ROS) production factors in plants. The use of chlorofluorocarbons (CFCs) as refrigerants or propellants caused a serious depletion of ozone in the 1980s, which led to an increase of UV-B. Although the emissions of CFCs have decreased significantly in recent years, the ozone layer will not recover soon. The slow recovery of the ozone causes the slow decrease of UV-B intensity, and the intensity of UV-B varies with time and weather throughout the day. In the present study, typical intertidal macroalgae Ulva prolifera was exposed to moderate and extreme UV-B radiation (1 W m-2 and 5 W m-2), and the production and roles of ROS in U. prolifera under UV-B are discussed. The results are as follows: 1) ROS were mainly produced in the chloroplast under moderate UV-B radiation (1 W m-2). ROS played the signaling molecule function and led the secondary signaling pathways during this process. 2) Excessive ROS were produced in both the chloroplast and peroxisome. OH caused irreversible damage to the thalli exposed to 5 W m−2 radiation. Overall, these novel results support the idea of dual roles of ROS in U. prolifera under UV-B radiation (signaling molecules and oxidative damage). Moreover, they further highlight the role of photosynthesis in the production of ROS under UV-B.

Long-term ozone lidar routine measurements are sparse in China. In this study, we used one year of continuous ozone lidar measurements to systematically investigate the effects of synoptic patterns on the vertical structure of ozone during high ozone episodes in Hong Kong. The height of the near-surface ozone layer was identified and compared with that of the mixing layer. The results showed that Hong Kong was greatly affected by ozone transport from the Pearl River Delta region when a tropical cyclone (“C” pattern) or a trough (“T” pattern) existed. When a high-pressure center was located to the north (“H” pattern) or when both a high-pressure system and a tropical cyclone existed (“CH” pattern), Hong Kong was affected by ozone transport from southeastern or southern China. Substantial amounts of ozone were transported within a layer near the ground with an average height of 0.83, 0.75, 0.94, and 0.85 km under the C, H, CH, and T synoptic patterns, respectively. Variation in the near-surface ozone layer height was consistent with that of the mixing layer height. Weak vertical mixing resulted in a shallow near-surface ozone layer under the C and H synoptic patterns. Due to the combined effect of near-surface transport and suppressed vertical mixing, the ozone concentrations were extremely high near the ground but rapidly declined with height under the C synoptic pattern. Our investigations of the vertical structure of ozone contribute to filling the knowledge gap between synoptic patterns and the evolution of high surface ozone episodes.

Free cooling based on loop thermosyphon is ideal energy-saving method for data centers. Most working fluids presently used in this field will cause greenhouse effect or destroy the ozone layer. It is necessary to investigate the applicability of environment friendly fluids. A distributed-parameter model of a CO2 loop thermosyphon in an integrated air conditioning system for free cooling is built and validated. The performance is compared with traditional working fluids and the effects of some key geometric parameters are evaluated. The results show that the optimal filling ratios for CO2, R22 and R134a are 120%, 100% and 90%, respectively. The circulation flow rate of CO2 is much smaller than those of R22 and R134a. For CO2 loop thermosyphon, the heat transfer rate decreases with the increase of pipe length, while increases with the increase of riser diameter and height difference. The heat transfer rate increases with the increase of tube number and length of the evaporator, while the increasing rate decreases gradually. The optimal tube number and length are 80 and 0.6 m, respectively. The relationships between the above phenomenon and the internal flow state are also analyzed.

The installed capacity of stationary batteries is expected to grow rapidly in the coming years. This deployment will have impacts on the environment that must be investigated to guide our policy and technology choices. A large variety of stationary battery technologies exists, however previous studies have failed to assess the environmental implications of several of them. In this study, the environmental performance of Lithium Metal Polymer (LMP) stationary batteries is quantified through the life cycle assessment methodology and compared to Lithium-ion (Li-ion) units. LMP is a promising technology which is advocated as more stable, safe and simple to manufacture than batteries with liquid electrolytes. Models with a storage capacity of 6 MWh and 75 kWh are examined, corresponding respectively to batteries designed for a centralized and a distributed grid configuration. The assessments cover the entire life cycle of the batteries and evaluate their impacts in fifteen different environmental categories. The results show that the battery manufacturing stage drives the majority of environmental impacts in the different investigated batteries. Li-ion batteries cause significantly more impacts than LMP units in terms of global warming and ozone depletion. The effects on global warming come mainly from the production of components in countries where fossil fuel dominates electricity mixes. The production of polytetrafluoroethylene, used only in Li-ion batteries, is the main contributor to the ozone layer depletion category and also an important source of global warming emissions. Conversely, LMP batteries are responsible for a bigger impact in terms of aquatic eutrophication originating from sulfidic tailings linked to mining activities. An additional finding of this study is that centralized battery system configurations bring smaller environmental impacts than distributed systems with more but smaller storage units.

On account of the scarcity of fossil fuels and the environmental problems arising from its use and exploitation, countries are opting for developing technologies based on renewable sources as alternatives to achieve the growing energy demand. Among the renewable energy technologies, solar energy seems to be an attractive solution. Usually solar power plants are located in sunny environments due to requirements for power generation. Meanwhile, as the ozone layer damage has been exceeding its natural restoration, a growing level of UV radiation reaches the surface of the earth where the solar industry working public will be facing new risks; among them skin risks. The present paper, focusing on the proper usage of the renewable source, aims to assess skin exposures to solar radiation within solar industry. The assessment was based on direct solar radiation measurements carried out in an experimental solar facility in Mexico. The maximum time to stay unprotected without receiving a noticeable impact on skin is calculated and security measures for solar industry workers are suggested. This research may be seen as a basic evidence of an area within solar industry with improvement opportunities and assist the development of security procedures applicable to solar energy plants' working environments.

Using data from the AIRS satellite instrument (V6, L3), ozone, water vapor (WV), and temperature anomalies associated with the relatively short spring atmospheric blocking event and anomalously prolonged summer block over European Russia (ER) in 2010 are analyzed. Within the domain of the blocking anticyclones, negative total column ozone (TCO) anomalies and positive total column water vapor (TCWV) anomalies reaching the values of −25 and −32 Dobson Units (DU) and 10 and 11 kg m −2 during the spring and summer blocks are observed, respectively. Conversely, within the regions adjacent to the anticyclones to the west and east, positive TCO anomalies (77 and 45 DU) and negative TCWV anomalies (−3 and −4 kg m −2 ) are found. These TCO and TCWV anomalies are conditioned by the regional atmospheric circulation associated with the strong omega-type blocking. The TCO deficit and TCWV surplus within the atmospheric blocking domain are explained primarily by the poleward advection of subtropical air with low TCO and high TCWV content and tropopause uplift. The TCO and TCWV anomalies are also associated with quasi-stationary Rossby wave trains that accompanied these blocking events. An analysis of the anomaly vertical structure shows that the marked TCO decrease is primarily due to the lower stratospheric ozone decrease, while the strong TCWV increase is mainly the result of an increase of lower tropospheric WV content. The possible role of photochemical ozone destruction in the lower stratosphere due to WV advection within the blocked regions is also discussed. Vertical profiles of the thermal anomalies during both atmospheric blocking events reveal dipole-like structures characterized by positive temperature anomalies in the troposphere and negative anomalies in the lower stratosphere.

In this study, we investigate the causative processes responsible for the observed enhancement in the tropospheric and surface ozone during December 09–11, 2008 orography induced gravity wave event over Himalayan region. The analysis is done using surface ozone measurements and satellite datasets from Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A (AIRS/AMSU-A), COSMIC, TES and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). Observations depict a two fold increase in surface and tropospheric ozone during the event as compared to normal days in both AIRS and TES ozone measurements. COSMIC temperature perturbations show generation of shorter vertical wavelengths efficient for the sub-tropical tropopause folding due to orography induced gravity waves. Moreover, the intense tropopause folding as evidenced by upward-downward vertical velocities couplet could trigger the intrusion of stratospheric ozone rich air into upper tropospheric ozone poor air as also confirmed by high values of potential vorticity during the observational period. Hence, present study reemphasizes the importance of wave induced atmospheric dynamics on atmospheric constituents' especially tropospheric ozone over Himalayan region.

Nitrous oxide (N 2 O) has a high global warming potential and depletes stratospheric ozone. The U. S. Corn Belt plays an important role in the global anthropogenic N 2 O budget. To date, studies on local surface N 2 O emissions and the atmospheric N 2 O budget have commonly used Lagrangian models. In the present study, we used an Eulerian model - Weather Research and Forecasting Chemistry (WRF-Chem) model to investigate the relationships between N 2 O emissions in the Corn Belt and observed atmospheric N 2 O mixing ratios. We derived a simple equation to relate the emission strengths to atmospheric N 2 O mixing ratios, and used the derived equation and hourly atmospheric N 2 O measurements at the KCMP tall tower in Minnesota to constrain agricultural N 2 O emissions. The modeled spatial patterns of atmospheric N 2 O were evaluated against discrete observations at multiple tall towers in the NOAA flask network. After optimization of the surface flux, the model reproduced reasonably well the hourly N 2 O mixing ratios monitored at the KCMP tower. Agricultural N 2 O emissions in the EDGAR42 database needed to be scaled up by 19.0 to 28.1 fold to represent the true emissions in the Corn Belt for June 1–20, 2010 - a peak emission period. Optimized mean N 2 O emissions were 3.00–4.38, 1.52–2.08, 0.61–0.81 and 0.56–0.75 nmol m − 2 s − 1 for June 1–20, August 1–20, October 1–20 and December 1–20, 2010, respectively. The simulated spatial patterns of atmospheric N 2 O mixing ratios after optimization were in good agreement with the NOAA discrete observations during the strong emission peak in June. Such spatial patterns suggest that the underestimate of emissions using IPCC (Inter-governmental Panel on Climate Change) inventory methodology is not dependent on tower measurement location.

Noctilucent clouds (NLC) are measured by the Rayleigh/Mie/Raman-lidar at the ALOMAR research facility in Northern Norway (69°N, 16°E) since 1994. The data set contains about 2860 h of NLC detections and is investigated for the first time regarding trends. NLC properties depend on cloud brightness which is taken into account by the use of several cloud classes, related to brightness ranges. For NLC brighter than the long-term detection limit and strong NLC, respectively, the trend terms show increasing occurrence frequency (+9%/dec and+5%/dec) and brightness (+1.7×10−10 m−1 sr−1/dec and +1.5×−10 m−1 sr−1/dec) from 1998 to 2015. In the same period the altitude of faint and long-term limit clouds decreases (−66 m/dec and −108 m/dec). Over the entire time period of 22 years strong clouds show an increasing altitude by +76 m/dec. NLC properties are affected differently by solar and atmospheric parameters. In general, Lyman-α and stratospheric ozone impact all three NLC parameters, temperature at 83 km impacts mainly the NLC altitude. Time series of RMR lidar and SBUV satellite instruments match best for NLC occurrence frequency and brightness when restricting SBUV to the morning data at longitudes around ALOMAR (64–74°N, 8–24°E/0–9 LT). This suggests longitudinal dependent trends, which is confirmed by trend investigations of longitudinal subsets of the SBUV data set.