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The Southeast Asian Region is one of the world's regions that has historically had poor air quality conditions due to excess fossil fuel usage, coal combustion, and intensive deforestation activities. As the hub of economic activity, Indonesia's Jakarta and Palembang cities have drawn significant attention from rural areas, leading to unrestrained urbanization in the past decade. Therefore, this study aimed to integrate the two urban centers of Indonesia, Jakarta and Palembang. It analyzed the variation of nitrogen dioxide (NO 2) concentration, vegetation cover, and land surface temperature (LST) across all seasons from 2021 to 2023. We retrieved the tropospheric NO 2 concentration data from the ozone monitoring instrument (OMI) aboard Aura Satellite, and obtained LST and the normalized difference vegetation index (NDVI) from Landsat 8 OLI images. We then used a Pearson correlation analysis to determine the relationship between the NO 2 concentration, NDVI, and LST. The findings showed that Jakarta had higher levels of air pollution than Palembang, with rising LST and NO 2 levels. During the study period, the mean NO 2 concentration in Jakarta and Palembang was 3.25 × 1015 mol/cm2 and 0.87 × 1015 mol/cm2, respectively. While, the mean LST values in Jakarta and Palembang were 33.97 °C and 27.17 °C, respectively. The correlation results indicated a negative relationship between NO 2 level and NDVI (r = −0.378, p < 0.01), while it obtained a positive association with LST (r = 0.421, p < 0.01). These results can be a chance for the authority to formulate a new strategy for mitigating air pollution, especially for NO 2 pollutants in urban areas. [ABSTRACT FROM AUTHOR]

Increasing emissions of aerosol and trace gases (e.g. nitrogen dioxide: NO2 and sulfur dioxide: SO2) have resulted in severe air pollution in China due to its rapid industrialization, economic growth, and urbanization. This resulted in numerous environmental and health problems, and poor air quality mainly in industrial areas and major cities. This study identifies long-term (2005‒2020) Ozone Monitoring Instrument (OMI) based NO2 and SO2 pollution hotspots across China by analyzing spatiotemporal distributions and variations, with characterization of polluted provinces, SO2/NO2 ratio, trend, and assessing how effective China's Air Pollution Control Policy (APCP) is on NO2 and SO2. Results show that NO2 and SO2 pollution hotspots were seen in China's central (Hubei), eastern (Anhui, Jiangsu, Shandong, Zhejiang), northern (Beijing, Hebei, Henan, Shanxi, Tianjin), northeast (Liaoning, Jilin), northwestern (Urumqi), southern (Guangdong, Hong Kong), and southwest (Chongqing, Sichuan). However, the pollution level was higher in winter, followed by autumn, spring, and summer. China's eight provinces (Tianjin, Shanghai, Shandong, Jiangsu, Beijing, Hebei, Hong Kong, and Henan) were identified as extremely polluted with high NO2 levels ranging from 16.86 − 9.75 (1015 molecules/cm2), whereas Shandong, Tianjin, Hebei, Beijing, Henan, Shanxi, Jiangsu, Shanghai, Anhui, and Liaoning were deemed to extremely polluted provinces with high SO2 levels ranging from 20.62 − 14.30 (1015 molecules/cm2). Moreover, the SO2/NO2 ratio for 27 Chinese provinces fluctuates between 1.02 to 4.98, indicating industries emit more SO2 than NO2. Finally, China's air pollution control policies (APCP) led to the largest annual reductions in NO2 during the 12th five-year plan (FYP) (6%‒94%) and SO2 during the 11th FYP (6%‒74%). The present study concludes, however, that China's APCP improved air quality by easing NO2 and SO2 emissions. This study recommends that the Chinese government may adopt a comprehensive strategy to reduce air pollution, including investing in clean energy, promoting electric vehicles, enforcing strict emission standards for industries, implementing green building practices, and raising public awareness about pollution reduction. [ABSTRACT FROM AUTHOR]

This study presents new glyoxal (CHOCHO) products from the Ozone Monitoring Instrument (OMI) by utilizing updated level 1B irradiance/radiance data (Collection 4) and an updated glyoxal retrieval algorithm. The adoption of Collection 4 contributes to the reduction of artificial signals in differential glyoxal slant column densities (dSCDs) and improved fitting root mean square, and the updated retrieval settings result in fewer negative values of glyoxal dSCDs over oceans and less noisy dSCDs in the South Atlantic Anomaly. On‐line calculations of air mass factors consider interactive physical processes between input parameters. To address persistent trends in glyoxal SCDs over the Pacific Ocean that remain despite these updates, a trend correction is implemented. We evaluate the updated OMI glyoxal products using inter‐comparisons with GOME‐2A/2B glyoxal products. OMI glyoxal products exhibit good spatial and temporal agreement with GOME‐2A/2B, with correlation coefficients of 0.75–0.78 globally and 0.84–0.85 over source regions. Small biases are observed in OMI glyoxal vertical column densities, ranging from −0.2 ± 5.7% to 9 ± 3% in low and high glyoxal conditions, respectively, against GOME‐2A/2B. These advancements contribute to the reliability and accuracy of OMI glyoxal products, enhancing their utility for atmospheric studies and enabling a 20‐year‐long data record suitable for climate studies. Plain Language Summary: This research introduces new glyoxal (CHOCHO) products obtained from a satellite instrument called the Ozone Monitoring Instrument (OMI). For new glyoxal products, we use the updated OMI irradiance/radiance data and update the way we analyze the radiance data. As a result, new OMI glyoxal products show the reduction of errors caused by the instrument and consider interactive physical processes between the surface and atmosphere. The new data matches well with similar data from other satellite instruments (GOME‐2A/B), showing that the improvements are effective. This better data set helps scientists study the air quality over a long period of time. Key Points: We improve Ozone Monitoring Instrument (OMI) glyoxal column measurements with the new radiance data (Collection 4) and updated retrieval algorithmThe new glyoxal measurements show the stable spectral fitting through OMI's lifetimeCompared to GOME‐2A/B, OMI glyoxal products show good spatial (temporal) correlation coefficients of 0.75–0.78 (0.84–0.85), respectively [ABSTRACT FROM AUTHOR]

Forty percent of patients with acute coronary occlusion myocardial infarction (OMI) do not present with STEMI criteria, which delays their treatment and increases morbidity and mortality. The need to identify these patients promptly is crucial, and this sets the stage for the proposed reclassification. Many of these patients can be identified by other ECG and clinical features. Background/Objectives: We sought to evaluate cases of STEMI and NSTEMI that result in OMI. Additionally, we focused on the consequences of delayed revascularization in NSTEMI patients with acute coronary occlusion (NSTEMI-OMI). Methods: The study is a retrospective analysis conducted on 334 patients who underwent coronary angiography for acute coronary syndrome at UHC "Mother Teresa", Tirana, Albania, during January–May 2023. "OMI was defined as an acute culprit lesion with TIMI 0–2 flow, or an acute culprit lesion with TIMI 3 flow intervened upon and with highly elevated troponin (cTnI > 10.0 ng/mL, hs-cTnI > 5000 ng/L)". The presence or absence of STEMI criteria were determined in the final diagnosis written on the chart by a cardiologist using the third universal definition of MI. Ejection fraction (EF), total ischemia time, length of stay, and complications were compared between groups. Mechanical complications include acute ventricular failure, cardiogenic shock, rupture of the interventricular septum, rupture of the free wall, rupture of the papillary muscle, and pericarditis. Electrical complications include ventricular arrhythmias, supraventricular arrhythmias, and atrioventricular and interventricular blocks. Results: There were 334 patients included, 98 (29.3%) of whom were NSTEMI-OMI patients. Ninety-six patients (40%) of OMI patients did not fulfill the STEMI criteria. Only 11 patients (11%) of STEMI(−)OMI had PCI performed within the first 12 h vs. 76 patients (77%) with STEMI(+)OMI, p < 0.001. There was no difference in the percent of patients requiring PCI between the STEMI(+)OMI 98 patients (93%) and STEMI(−)OMI 87 patients (89%) (p = 0.496). The overall in-hospital mortality was 19 patients (5.7%), with subgroup mortality of 14 patients (4.2%) with STEMI(+)OMI, 2 patients (0.6%) with STEMI(+) NOMI, and 3 patients (0.9%) with STEMI(−)OMI, 0% STEMI(−)NOMI, (p = 0.013). Patients with mechanical complications included 67 patients (46.8%) with STEMI(+)OMI and 45 patients (46.4%) with STEMI(−)OMI. In addition, 26 patients (18.5%) with STEMI(+)OMI and 13 patients (13.1%) with STEMI(−)OMI developed electrical complications. Conclusions: STEMI(−)OMI patients had significant delays in catheterization, yet had angiographic findings, rates of PCI, and complications similar to STEMI(+)OMI. These data add further support to refocusing the paradigm of acute MI to improve recognition and rapid reperfusion of all OMIs, rather than only those with STEMI criteria. [ABSTRACT FROM AUTHOR]

India is one of the largest contributors to anthropogenic emissions during the recent decade associated with its rapid economic growth in India. Trace gases are important components in the climate change process and due to that climate change, there will be a change in their atmospheric concentrations as the climate is sensitive to Earth’s; therefore, proper assessment of trace gases is necessary for ongoing sudden changes in climate. In this study, we used remote-sensing datasets from the Atmospheric Infrared Sounder (AIRS) and Ozone Monitoring Instrument (OMI) to analyze the spatio-temporal variations of four trace gases, like methane (CH4), ozone (O3), carbon monoxide (CO), and nitrogen dioxide (NO2) over India region during 2006–2015 and taken four seasons (i.e., winter, spring, summer, and winter) to interpret the seasonal variation. The project focuses on the temporal pattern of pollutant trace gases i.e., monthly, seasonal, and annual mean variations of trace gases, trend analysis of trace gases, and a comparison of the seasonal behavior of the trace gases by trend analysis was assessed. Higher concentrations of CO show east-to-west, CH4 show north-to-south, and O3 south-to-north gradient, indicating the variations in trace gases due to the impact of emissions and local meteorology. On the other hand, due to immense population density, huge traffic emissions, tremendous, polluted air, and overgrown industrial activities, total NO2 concentrations shoot up over Delhi, Lucknow, and Kolkata. Now as a result of seasonal variation in the long-range transport of air parcels and biomass burning activities, all trace gases shown significant seasonal variations in the spring season and substantially reduced in the summer season. However, in the winter season, O3 concentration evaluates minimum due to less amount of heat on cold days which leads to the reduction of O3 formation. Due to trace gases, all are significant to get regional climate variability. In this study by taking 2006 as a base year and investigate the behaviors of gases for 2007–2015 years to exhibit the increment and decrements in four seasons of all trace gases by taking the most populated 11 different cities of India.

The results of an analysis of long-term trends and interannual variations of the NO2 content in the atmosphere according to measurements with the Ozone Monitoring Instrument (OMI) aboard the EOS Aura satellite in 2004–2020 are compared to the results of a similar analysis of the NO2 content derived from independent spectrometric twilight NO2 measurements by zenith-scattered solar radiation at stations of the Network for the Detection of Atmospheric Composition Change (NDACC). According to both data, seasonally dependent estimates of linear NO2 trends and variations of the NO2 content under the influence of an 11-year cycle of solar activity and large-scale circulation factors such as the Arctic and Antarctic Oscillations, variations in ocean surface temperature in the Niño 3.4 zone, and the quasi-biennial oscillation in zonal wind in the equatorial stratosphere have been obtained. In general, a good qualitative and, in some cases, quantitative correspondence between estimates of interannual variations of NO2 has been obtained. For interannual variations of stratospheric NO2, the correspondence between estimates based on satellite and ground-based data on average for all stations is not bad, but the correspondence between trend estimates is noticeably worse. The best correspondence between the analysis results has been obtained for the Zvenigorod station. For stratospheric NO2, it was noted in 80–90% of cases, and the correspondence for tropospheric NO2 is practically 100%. [ABSTRACT FROM AUTHOR]

Aerosols have a significant impact on solar radiation, air quality deterioration, and climate change. To effectively assess the consequences of aerosols, we have to initially recognize the spatiotemporal distributions of their characteristics. This article uses OMI retrieved UVAI and Aqua MODIS retrieved AE data to analyze the spatiotemporal distributions and inter-annual trends of absorbing aerosol across Nigeria. Significant spatio-temporal variations in UVAI were observed high in northern and low in southern regions. The mean UVAI and AE over Nigeria shows an increasing and decreasing trend of 3.16% year−1 and − 1.62% year−1. Annually, UVAI showed an increasing trend of 7.59%, 9.79%, 5.19%, 6.27%, 7.65%, 4.87%, 7.17%, 4.99%, 4.10%, and 6.73% over Delta, Niger, Edo, Sokoto, Kwara, Osun, Kogi, Ondo, Oyo, and Ogun states respectively whereas AE is decreasing at the rate of − 0.53% year−1, − 2.50% year−1, − 0.84% year−1, − 1.18% year−1, − 2.12% year−1, − 1.19% year−1, − 1.12% year−1, − 0.85% year−1, − 1.77% year−1, and − 1.06% year−1 over Delta, Niger, Edo, Sokoto, Kwara, Osun, Kogi, Ondo, Oyo, and Ogun states respectively. UVAI was observed high during winter associated with dust storm activities. The HYSPLIT cluster analysis reveals the dominance of natural aerosols over northern and southern regions and Urban/industrial pollutants over the central regions of Nigeria. A strong positive correlation of UVAI with precipitation and temperature is observed in the northern regions of Nigeria. In accordance with the outcomes of this study, multiple methods such as planting more trees, improving fuel quality, etc. can be employed to lower the concentration of particle pollution. [ABSTRACT FROM AUTHOR]

To study air pollution in the North China Plain (NCP), the Air Chemistry Research in Asia (ARIAs) campaign conducted airborne measurements of air pollutants in spring 2016. High pollutant concentrations, with O3 > 100 ppbv, CO > 500 ppbv, and NO2 > 10 ppbv, were observed. CMAQ simulations with the 2010 EDGAR emissions capture the spatial and temporal variations in ozone and its major precursors such as NO2 and VOCs, with significant underestimation. Differences between CMAQ simulations and satellite observations reflect changes in anthropogenic emissions, decreased NOx emissions in megacities such as Beijing, but slight increases in other cities and rural areas. CMAQ also underestimates HCHO and CO, suggesting adjustments of the 2010 EDGAR emissions are necessary. HCHO/NO2 column ratios derived from OMI measurements and CMAQ simulations show that VOC-sensitive chemistry dominates the ozone photochemical production in eastern China, suggesting the importance of tightening regulations on anthropogenic VOC emissions. After adjusting emissions based on satellite observations, better model performance was achieved. Because of the VOC-sensitive environment in ozone chemistry over the NCP, the underestimation of anthropogenic emissions could be important for CMAQ simulations, while future study and regulations should focus on VOC emissions with continuous controls on NOx emissions in China. [ABSTRACT FROM AUTHOR]

Abstract This study presents new glyoxal (CHOCHO) products from the Ozone Monitoring Instrument (OMI) by utilizing updated level 1B irradiance/radiance data (Collection 4) and an updated glyoxal retrieval algorithm. The adoption of Collection 4 contributes to the reduction of artificial signals in differential glyoxal slant column densities (dSCDs) and improved fitting root mean square, and the updated retrieval settings result in fewer negative values of glyoxal dSCDs over oceans and less noisy dSCDs in the South Atlantic Anomaly. On‐line calculations of air mass factors consider interactive physical processes between input parameters. To address persistent trends in glyoxal SCDs over the Pacific Ocean that remain despite these updates, a trend correction is implemented. We evaluate the updated OMI glyoxal products using inter‐comparisons with GOME‐2A/2B glyoxal products. OMI glyoxal products exhibit good spatial and temporal agreement with GOME‐2A/2B, with correlation coefficients of 0.75–0.78 globally and 0.84–0.85 over source regions. Small biases are observed in OMI glyoxal vertical column densities, ranging from −0.2 ± 5.7% to 9 ± 3% in low and high glyoxal conditions, respectively, against GOME‐2A/2B. These advancements contribute to the reliability and accuracy of OMI glyoxal products, enhancing their utility for atmospheric studies and enabling a 20‐year‐long data record suitable for climate studies.

Abstract Nowadays, environmental problems have gradually become the focus of world attention. In recent years, heat waves in many parts of Europe have increased ozone concentrations, fuelling ozone pollution. Therefore, this paper investigates the spatial and temporal distribution of tropospheric column ozone concentrations in South-western Europe, future trend changes, influencing factors, and potential source regions based on remotely sensed monitoring data from the OMI (Ozone Monitoring Instrument) from 2011 to 2021. The results show that the areas of high tropospheric column ozone concentrations are mainly concentrated in the northwest, Poland, and southeast coastal areas. At the same time, the monthly variation curve of column ozone concentration is bimodal. Trend change analyses indicate an upward trend in future column ozone concentrations in the southeastern part of the study area. The potential for increases also exists in parts of Germany, France, and Poland, which will need to be monitored. Random forest model projections found a slight decrease in column ozone concentrations in 2022 and 2023 of about 1–4 DU compared to tropospheric column ozone concentrations in 2021. The health risk assessment found that the number of all-cause premature deaths due to exposure to ozone was the highest in Germany. During the summer, when ozone pollution is high, the potential source area in the southeastern part of the study area is located at the border of the three countries, and synergistic management is recommended. In exploring the correlation between the influencing factors and ozone, it was found that there is a significant difference between the long-time and short-time series. In addition, the pathway analysis shows that the population size, distribution density, and forested area in southwestern Europe may be more sensitive to the production of tropospheric ozone.

Nowadays, environmental problems have gradually become the focus of world attention. In recent years, heat waves in many parts of Europe have increased ozone concentrations, fuelling ozone pollution. Therefore, this paper investigates the spatial and temporal distribution of tropospheric column ozone concentrations in South-western Europe, future trend changes, influencing factors, and potential source regions based on remotely sensed monitoring data from the OMI (Ozone Monitoring Instrument) from 2011 to 2021. The results show that the areas of high tropospheric column ozone concentrations are mainly concentrated in the northwest, Poland, and southeast coastal areas. At the same time, the monthly variation curve of column ozone concentration is bimodal. Trend change analyses indicate an upward trend in future column ozone concentrations in the southeastern part of the study area. The potential for increases also exists in parts of Germany, France, and Poland, which will need to be monitored. Random forest model projections found a slight decrease in column ozone concentrations in 2022 and 2023 of about 1–4 DU compared to tropospheric column ozone concentrations in 2021. The health risk assessment found that the number of all-cause premature deaths due to exposure to ozone was the highest in Germany. During the summer, when ozone pollution is high, the potential source area in the southeastern part of the study area is located at the border of the three countries, and synergistic management is recommended. In exploring the correlation between the influencing factors and ozone, it was found that there is a significant difference between the long-time and short-time series. In addition, the pathway analysis shows that the population size, distribution density, and forested area in southwestern Europe may be more sensitive to the production of tropospheric ozone. [ABSTRACT FROM AUTHOR]

The Outer Continental Shelf of the Gulf of Mexico (GOM) is populated with numerous oil and natural gas (ONG) platforms which produce NOx (NOx = NO + NO2), a major component of air pollution. The Bureau of Ocean Energy Management (BOEM) is mandated to ensure that the air quality of coastal states is not degraded by these emissions. As part of a NASA‐BOEM collaboration, we conducted a satellite data‐based analysis of nitrogen dioxide (NO2) patterns and trends in the GOM. Data from the OMI and TROPOMI sensors were used to obtain 18+ year records of tropospheric column (TrC) NO2 in three GOM regions: (a) Houston urban area, (b) near shore area off the Louisiana coast, and a (c) deepwater area off the Louisiana coast. The 2004–2022 time series show a decreasing trend for the urban (−0.027 DU/decade) and near shore (−0.0022 DU/decade) areas, and an increasing trend (0.0019 DU/decade) for the deepwater area. MERRA‐2 wind and TROPOMI NO2 data were used to reveal several NO2 hotspots (up to 25% above background values) under calm wind conditions near individual platforms. The NO2 signals from these deepwater platforms and the high density of shallow water platforms closer to shore were confirmed by TrC NO2 anomalies of up to 10%, taking into account the monthly TrC NO2 climatology over the GOM. The results presented in this study establish a baseline for future estimates of emissions from the ONG hotspots and provide a methodology for analyzing NO2 measurements from the new geostationary TEMPO instrument. Plain Language Summary: Oil and natural gas operations emit nitrogen oxides (NOx), which are major air pollutants and precursors to ground‐level ozone. The Bureau of Ocean Energy Management (BOEM) agency is responsible for managing planned oil and natural gas (ONG) activity on the outer continental shelf, and is mandated to ensure related emissions do not degrade air quality of coastal states. In collaboration with BOEM, we used satellite data from the OMI and TROPOMI sensors to construct an 18+ year record of tropospheric nitrogen dioxide (NO2), a proxy for NOx, in the Gulf Coast region. These time series focused on three areas: (a) Houston urban, (b) off the Louisiana coast, and (c) deepwater Gulf off Louisiana. These regions experienced changes in tropospheric column NO2 of −13.7%, −5.8%, and +5.4% per decade, respectively. We also identified NO2 hotspots from ONG platforms using TROPOMI NO2 averages under calm wind conditions. The ONG deepwater platforms enhance NO2 background amounts by 7%–13% on average, and up to 25% for the Mars and Olympus platforms combined. The results presented here will facilitate our work on emissions estimates from these sources and on applications to the recently launched TEMPO instrument. Key Points: Satellite NO2 records and trends of urban, coastal and deep water areas from 2005 to 2022, are presentedClassifying NO2 over the Gulf of Mexico (GOM) under various wind conditions highlights typical patterns in average NO2 valuesGOM NO2 hotspots from deepwater platforms were identified by TROPOMI under calm wind conditions, the largest of which is over Mars/Olympus [ABSTRACT FROM AUTHOR]

This study aims to generate a satellite-based qualitative emission source characterization for the heavily polluted eastern part of China in the 2010–2016 time period. The applied source identification technique relies on satellite-based NOx and SO2 emission estimates by OMI, their SO2:NOx ratio, and the MIX anthropogenic emission inventory to distinguish emissions from different emission categories (urban, industrial, natural) and characterize the dominant source per 0.25° × 0.25° grid cell in East China. Overall, we find good agreement between the satellite- and emission inventory–based spatiotemporal distribution and characterization of the dominant emission sources in East China in 2010–2016. In 2010, the satellite measurements suggest an emission distribution less dominated by industrial areas, a somewhat larger role for urban/transportation areas and agricultural activities, and more natural emissions in the southern part compared to the bottom-up emission categorization. In 2016, more than half of the classified emission categories over East China have remained the same. At the same time, there is a notable increase of agricultural lands and decrease of areas dominated by industry/transportation in 2016, suggestive of an overall decrease in heavy air pollution in East China over the course of 7 years. This is likely attributed to the sustained efforts of the Chinese government to drastically improve the air quality, especially since 2013 when the National Air Pollution Prevention and Control Action Plan was enacted. However, signs of urban expansion (urbanization) and rural–urban migration ("Go West" motion) stemmed from China's rapid economic growth and labour demand are evident; escalating industrialization (even with cleaner means) and the urban population growth in East China resulted in stronger emissions from sources representing consumption and transportation which are strongly related to NO2 and PM10 pollution (rather than SO2) and are directly influenced by the population size. This resulted to a shift of the emissions from the east mainly to the north and northwest of East China. Overall, although the effectiveness of the Chinese environmental control policies has been successful, the air pollution problem remains an important concern. [ABSTRACT FROM AUTHOR]

Tropospheric and ground-level levels of nitrogen dioxide (NO2) may have changed due to environmental policies and technological changes. Here, multiyear ground-based measurement (2014–2022) and satellite-derived retrieval (October 2004 to May 2023) datasets of NO2 concentrations are used to study the long-term ground-level and tropospheric NO2 patterns and trends at four time scales (interannual, quarterly, monthly, and hourly) over the three regions with the highest global NO2 concentrations. Several tropospheric NO2 hotspots are observed over industrialized and highly populated coastal zone areas. Over the past 18 years, these hotpots have generally decreased due to the implementation of strong and effective environmental protection policies. A significant trend reversal was observed in 2011 in East-central China. The maximum values of tropospheric NO2 occurred in winter over East-central China, Western Europe and East-central USA, with concentrations of 13.010, 4.243 and 4.149 × 1015 molecules cm−2, respectively. The Bohai Sea exhibited disproportionately high tropospheric NO2 levels, suggesting it as a significant contributor to regional nitrogen pollution. Ground-level NO2 shows similar temporal patterns to tropospheric concentrations, with over 82.8 % of sites in East-central China exceeding 30 μg m−3, compared to 12.8 % in Western Europe and 3.8 % in East-central USA. The analysis of diurnal variations in ground-level NO2 concentrations shows a significantly decrease during the daytime compared to nighttime, reflecting that the peak occurs at approximately 08:00 and 20:00 LT, while the lowest concentrations at around 12:00 LT. These insights clarify the impacts of environmental policies on NO2 levels and identify critical areas for targeted pollution control, enhancing our understanding of NO2 dynamics in high-pollution regions globally.

Here we focused on the co-occurrence pattern on regional and local scales, and on the niche differences of two species of congeneric beetles (Ochthebius quadricollis and O. lejolisii, Hydraenidae) exclusive of supratidal rockpools. Abundances of adults and larval stages from both species and environmental variables were obtained in 10 pools from 12 localities along the Iberian Mediterranean coast. To determine the local co-existence pattern, we monthly sampled two localities in an annual cycle. On regional and local scales, we found negative correlations between both species' pool abundances, which suggest spatio-temporal segregation based on their different environmental responses. The OMI analysis detected interspecific niche differences, larger in larvae than adults. The best regression models obtained for O. quadricollis larvae included depth, conductivity, and fine sediments as the main explanatory variables with a positive effect, and distance to sea and CPOM with a negative effect. For O. lejolisii larvae, the best models included CPOM and periphyton with positive effects, while pool area, depth and conductivity negatively affected. Our results suggest that subtle interspecific differences in ecological niches, mainly those related to pool hydroperiod and salinity, could determine spatio-temporal storage effects as the principal mechanisms of co-existence on local and regional scales. [ABSTRACT FROM AUTHOR]

Air quality has been one of the main concerns among Tehran residents for at least two decades. In this study, we investigated air quality in the metropolitan area of Tehran utilizing TROPOMI and OMI data based on the Google Earth Engine platform. Long-term analysis indicated slight negative trends in NO2, SO2, and HCHO over the last two decades, which are due to the development of urban transportation systems. Air quality parameters were classified based on spatiotemporal similarities. Urban pollutants include CO1, NO2, and HCHO, which were concentrated over the eastern part of Tehran and decreased radially towards the city border. Among the pollutants, CO1 showed a dependency with altitude. SO2 was controlled by both urban vehicles and nonurban industrial activities. SO2 was thus classified as an urban-industrial pollutant. The exterior parameters almost entirely controlled by external factors include O3, aerosols, and clouds. The spatial variations of the pollutants highly differed from a fraction to several times. All pollutants exhibited seasonality associated with fuel consumption and air conditions. However, the seasonality in the exterior parameters was associated with regional air masses. The Iranian New Year holiday significantly impacts air pollution. NO2, CO1, and SO2 experienced their annual minimum levels during this holiday period. COVID-19–related closures also led to negative trends in NO2, CO1, and SO2 after March 2020. However, the exterior parameters were not affected by these events. The results agreed with in situ measurements. As the final objective, we aimed to support urban management to reduce atmospheric pollution in Tehran. [ABSTRACT FROM AUTHOR]

The paper analyzes the trends in the average monthly concentrations of nitrogen dioxide in the period from 2005 to 2021 in 18 large cities in different geographical areas: St. Petersburg, Moscow, Kyiv, Donetsk, Helsinki, Warsaw, Istanbul, Athens, Rome, Milan, Barcelona, Madrid, Paris, London, and Amsterdam. It was found that, in all cities, the concentration of this gas decreases, but at different rates. The highest rate of change was recorded in cities with the highest gas content at the time of the initial stage—2005. A linear dependence of the average nitrogen dioxide concentration on the population and anthropogenic emissions was revealed according to HTAPv3 data. Approximately every 1 million people of the population of large cities is responsible for the formation of a gas concentration of ∼200 × 1015 molecules/cm2, regardless of the geographical location of the city. Every ∼10 000 t/month of nitrogen dioxide emissions based on HTAPv3 generate gas concentrations of ∼500 × 1015 molecules/cm2. Using these dependences, it is possible to estimate anthropogenic emissions of NO2 sources throughout the country, based on remote sensing data. The results of the study also indicate the possibility of verifying and correcting inventory databases of gas emissions based on satellite observations of the nitrogen dioxide content in the atmosphere. [ABSTRACT FROM AUTHOR]

Abstract The Outer Continental Shelf of the Gulf of Mexico (GOM) is populated with numerous oil and natural gas (ONG) platforms which produce NOx (NOx = NO + NO2), a major component of air pollution. The Bureau of Ocean Energy Management (BOEM) is mandated to ensure that the air quality of coastal states is not degraded by these emissions. As part of a NASA‐BOEM collaboration, we conducted a satellite data‐based analysis of nitrogen dioxide (NO2) patterns and trends in the GOM. Data from the OMI and TROPOMI sensors were used to obtain 18+ year records of tropospheric column (TrC) NO2 in three GOM regions: (a) Houston urban area, (b) near shore area off the Louisiana coast, and a (c) deepwater area off the Louisiana coast. The 2004–2022 time series show a decreasing trend for the urban (−0.027 DU/decade) and near shore (−0.0022 DU/decade) areas, and an increasing trend (0.0019 DU/decade) for the deepwater area. MERRA‐2 wind and TROPOMI NO2 data were used to reveal several NO2 hotspots (up to 25% above background values) under calm wind conditions near individual platforms. The NO2 signals from these deepwater platforms and the high density of shallow water platforms closer to shore were confirmed by TrC NO2 anomalies of up to 10%, taking into account the monthly TrC NO2 climatology over the GOM. The results presented in this study establish a baseline for future estimates of emissions from the ONG hotspots and provide a methodology for analyzing NO2 measurements from the new geostationary TEMPO instrument.

The variation of tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) indirectly reflects the difference in pollution emissions from industrial production and transportation. Accurately analyzing its pollution sources and driving factors plays an important role in energy conservation, emission reduction, and air pollution reduction. NO2 concentration products of Sentinel-5P (Sentinel-5 Precursor) TROPOMI (TROPOspheric Monitoring Instrument) from 2019 to 2021 and Aura OMI (Ozone Monitoring Instrument) from 2009 to 2021, combined with China’s main energy consumption, the growth value of the industry, Gross Domestic Product (GDP), and other data were used to analyze the influencing factors of NO2 variations. Firstly, NO2 tropospheric vertical column densities (NO2 TVCDs) of China increased by 14.72% and 3.26% in 2021 and 2020 compared with the 2019. The secondary and tertiary industry and the national energy consumption increased synchronously, which was highly related to the increase in NO2 TVCDs. Secondly, the impact of COVID-19 (coronavirus disease 2019) on China’s industrial production and residents was mainly concentrated in the first quarter of 2020, which leading to a decline in the annual average NO2 concentration in densely populated areas in 2020 compared to the same period in 2019. The industrial production scale and production capacity has gradually recovered since April 2020, and the NO2 concentration has gradually reached or exceeded the level of the same period of 2019. Finally, atmospheric pollution prevention and control measures played a positive role in the decline of NO2 of China.

Sub-Saharan Africa (SSA) is one of the regions most affected by climate change and health problems caused by atmospheric pollution are becoming increasingly serious. Based on the daily data of OMI/AURA UVAI from 2010 to 2021, this study derived the spatial and temporal distribution patterns of UVAI levels in SSA over a long time series. By using big data, slope, and GTWR analysis methods, the influencing factors are explored and discussed. Studies have shown the following: (1) year-to-year UVAI levels values in SSA are high in the north and low in the south. The average annual variation of UVAI displayed a wave-like structure with a gradually increasing minimum over time. (2) The monthly UVAI column volume pattern in the study area is distinct, with a peak in June and an inverted "V" shape. (3) The correlations of each variable with UVAI levels in the study area are negative for NDVI> precipitation> water content> 10m wind speed, positive for correlation on u-directional wind> v-directional wind> air temperature, and almost independent for barometric pressure. (4) During the study, the dynamic UVAI change pattern in SSA has shown a substantial drop in the north, and a significant increase in the south. Finally, the authors concluded that air pollution in the region is closely related to climate change; moreover, the strengthening of composite studies in regard of air pollution and climate change will be the main work to be conducted in the future. [ABSTRACT FROM AUTHOR]

This study uses ozone in the atmosphere column collected by the Aura satellite's ozone monitoring instrument (OMI), to evaluate the ozone pollution status of Japan. Mann–Kendall and slope trend analysis, Hurst index analysis, the potential source contribution factor algorithm, GTWR (geographically and temporally weighted regression model), and the random forest regression model were used in this paper to investigate ozone column concentrations in Japan from 2010 through 2021. The results showed that ozone column concentrations had a significant latitudinal trend over the past 12 years, i.e., concentrations increased with increasing latitude. And the slope has showed a small upward trend over the years (slope = 0.01). The interannual maximum and minimum ozone column concentrations are in 2021 (387.57 DU) and 2015 (241.27 DU), respectively. The monthly maximum and minimum values occur in March (361.60 DU) and October (286.96 DU), with seasonal concentrations in the order of Spring (352.94 DU) > Winter (336.01 DU) > Summer (306.78 DU) > Autumn (296.30 DU). Column ozone concentrations have increased in 69.82% of Japan over the past 12 years. In 2022, the maximum, minimum, and mean ozone column concentrations based on random forest forecasts are 372DU, 278DU, and 334DU, respectively. Pollution sources in Japan are largely derived from pollutants that are transported across borders from the seas around the country or from other countries in the world, with the largest potential source areas being located in the Kanto region. Relative humidity, lift index, and air temperature (in all three seasons except winter) have a negative effect on ozone column concentrations. The positive effects of precipitable water and nitrogen dioxide on ozone column concentrations in the Hokkaido locality and southern Japan were more significant. The contribution of population density and GDP to ozone is small. [ABSTRACT FROM AUTHOR]

La regulación de los buques autónomos marítimos de superficie (MASS) hará necesario redefinir algunas categorías jurídicas y conceptuales tradicionales del derecho del mar, cuyas normas fueron adoptadas sobre la base de que las naves contaban con un capitán y una tripulación a bordo. Una interpretación evolutiva de la Convemar permite sustentar que la OMI asuma los trabajos para regular la operación de los MASS. En ese marco, la OMI ha completado un estudio exploratorio en el que adoptó una definición preliminar de los MASS e identificó tres asuntos que deben ser abordados prioritariamente: el significado de los términos capitán, tripulación o persona responsable; el tratamiento del centro o puesto de control a distancia; y la posibilidad de designar a los operadores remotos como gente de mar. La OMI también estableció una hoja de ruta para la adopción de un código sobre los MASS no obligatorio basado en objetivos para 2024 y de un código obligatorio para 2025. En seguimiento al estudio exploratorio y a la hoja de ruta, en 2022 se iniciaron las negociaciones para la regulación de los MASS en la OMI. En dichos trabajos en curso se viene contemplando cómo adaptar la regulación existente para que los Estados puedan operar los MASS conforme a las obligaciones y derechos previstos en la Convemar y los instrumentos de la OMI, garantizando la seguridad marítima.

This research report investigated the impacts of the COVID-19 lockdown restrictions on CO, SO2, and NO2 trends in Durban from 2019 to 2021. The COVID-19 lockdown restrictions proved to decrease greenhouse gas (GHG) emissions globally; however, the decrease in GHG emissions was for a short period only. Space-borne technology has been used by researchers to understand the spatial and temporal trends of GHGs. This study used Sentinel-5P to map the spatial distribution of CO, SO2, and NO2. Use was also made of the Atmospheric Infrared Sounder (AIRS), Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2), and the Ozone Monitoring Instrument (OMI) to understand the temporal trends of CO, SO2, and NO2, respectively. To validate the results of this study, we used the Sequential Mann–Kendall (SQMK) test. This study indicated that there were no significant changes in all the investigated gases. Therefore, this study failed to reject the null hypothesis of the SQMK test that there was no significant trend for all investigated gasses. Increasing trends were observed for CO, SO2, and NO2 trends during winter months throughout the study period, whereas a decreasing trend was observed in all investigated gases during the spring months. This shows that meteorological factors play a significant role in the accumulation of air pollutants in the atmosphere. Most importantly, this study has noted that there was an inverse relationship between the trends of all investigated gases and the COVID-19 lockdown restrictions. [ABSTRACT FROM AUTHOR]

Agung, Bromo, and Sinabung Volcanoes have high volcanic activity over the last decade, and have different eruption characteristics. Hence, it would be fascinating to study the characteristics of their volcanic activity patterns based on SO2 emission rates and thermal anomaly correlated with the seismicity data. The SO2 emission rate measurement was carried out using the Differential Optical Absorption Spectroscopy (DOAS), and calculated based on SO2 column density, distance of measurement, wind speed, and wind direction. In addition, SO2 emission was detected using Ozone Monitoring Instrument (OMI) images with daily global coverage. Thermal anomaly detection was performed using Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER) of Thermal Infrared (TIR) subsystem with high spatial resolution (90x90 m). ASTER TIR images were corrected for radiometric and thermal atmospheric. The emissivity and brightness temperature separation algorithm was applied to obtain surface temperature of Agung, Bromo, and Sinabung Volcanoes. All the data were correlated with the seismicity of each volcano. The SO2 emission rates correlate with the magma ascent to the shallow depth in an open system volcano (Bromo Volcano). In the closed-system volcanoes (early phase of Agung and Sinabung), SO2 emission was detected after the transition of closed to open system. Magmatic injection from the reservoir to the shallow depth was detected as thermal anomalies, such as in Agung Volcano. Whereas in Bromo Volcano, the thermal anomaly was insignificant since Bromo Volcano has an explosive eruption at a short period, so the ASTER image could not observe the thermal anomaly on the eruption time. Thermal anomaly pattern in Sinabung Volcano was the manifestation of new magmatic injection to the shallow depth. Therefore, their increase serves as indicators for the increasing magmatic activity prior to the eruptions. [ABSTRACT FROM AUTHOR]

The research on formaldehyde is of great significance to preventing ozone pollution under high temperatures in the future and protecting people's health. Brazil is the largest economy and trading power in South America, in recent years, air pollution, especially the emission of volatile organic compounds (VOCs), has increased. This paper takes formaldehyde (HCHO) as an example to monitor its pollution distribution and provide a basis for its treatment. Based on this, the temporal and spatial distribution characteristics and influencing factors of formaldehyde in Brazil from 2012 to 2021 were analyzed, and the future trend of formaldehyde was discussed. The results showed that the formaldehyde column concentration (31.1 × 1015 molec/cm2) was the highest in August and the lowest in December was 6.8 × 1015 molec/cm2. The formaldehyde column concentration in dry season was higher than that in rainy season. Formaldehyde showed a decreasing trend from southwest to northeast. The correlation coefficients between HCHO and the normalized vegetation index (NDVI) and leaf area index (LAI) were − 0.84 ~ 0.84 and − 0.86 ~ 0.82, respectively. In addition, the mean annual water content (MAWC) and mean annual temperature (MAT) also had some effects. The path coefficient was used to analyze the influence of human activities on HCHO, and it was found that the contribution rates of total energy consumption (1.3592), GDP (1.1499), and electricity consumption (− 1.1113) were high, while the impact of coal consumption was relatively small (0.6425). It is expected that formaldehyde in Brazil may continue to show a weak persistence reduction trend in the future. [ABSTRACT FROM AUTHOR]

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This study investigated the impact of Octomodal Mental Imagery (OMI) and management dimensions on shoppers' experiences and mall loyalty. The study was collected through "Questionnaire Star," and 358 valid data points were obtained. The data were analyzed using SPSS27 and AMOS28. The results showed that sensory attributes such as visual, tactile, gustatory, and olfactory attributes positively influenced shoppers' experiences in OMI, while the auditory attribute had no significant effect. Spatial, a structural attribute of OMI, positively influenced shoppers' experiences, whereas autonomy and kinesthetics did not have a considerable effect. Tenant mix and entertainment positively impacted shoppers' experiences in management, while accessibility had no significant effect. The study also found that shoppers' experiences positively impacted mall loyalty, while hedonistic motivation had a more substantial effect than utilitarian motivation. This study is the first to examine the impact of OMI on shoppers' experiences. It fills a gap in the literature on this relationship. It also examines the combined impact of management dimensions (accessibility, tenant mix, and entertainment) on the overall shopper's experience, filling a gap in the Chinese shopping mall literature and extending the generalizability of the theory. The study further explores the relationship between shoppers' experiences and mall loyalty and the moderating effect of incentive orientation. The results of this study have critical implications for mall managers. Strengthening the mental image and management dimensions of the shopping mall will enhance shoppers' experiences and build loyalty, allowing brick-and-mortar malls to remain competitive and sustainable in today's highly competitive and popular e-commerce environment. [ABSTRACT FROM AUTHOR]

Chest pain is a common presentation to the Emergency Department (ED) with roughly 6 million visits a year. The primary diagnostic modality for the identification of acute coronary syndrome (ACS) is the electrocardiogram (ECG), which is used to screen for electrocardiographic findings representing acute coronary occlusion. It is known that the ischemia generated by an acutely occluded coronary vessel generates a wall motion abnormality which can be visualized by echocardiogram; however, emergency physician-performed focused cardiac ultrasound (FOCUS) currently does not have a formal role in the diagnosis of OMI within the emergency department. We sought to define the characteristics of FOCUS performed by emergency physicians of variable training levels in the identification of RWMA in patients presenting to the emergency department with high suspicion for ACS before undergoing cardiac catheterization or formal echocardiography. We also explored whether RWMA was associated with OMI in these patients. We performed a structured, retrospective review of adult patients presenting to a large, academic, tertiary care center with suspected ACS from July 1st, 2019, and October 24th, 2020. Patients were included if they underwent FOCUS in the ED during the time-period above for suspected ACS looking for RWMA and FOCUS images were stored and reviewable in our middleware software. The primary outcome was the accuracy, sensitivity, and specificity of FOCUS compared to formal echocardiography for the detection of RWMA. Secondary outcomes were sensitivity of FOCUS compared to formal echocardiography for detection of RWMA in patients with and without cardiac catheterization proven OMI and sensitivity and specificity of FOCUS operators based on training. FOCUS for RWMA performed by emergency physicians had a sensitivity of 94% (95% CI, 82–98), specificity 35% (95% CI, 15–61), and overall accuracy of 78% (95% CI, 66–87). Of all subjects, 82% underwent urgent or emergency coronary angiography, of which 71% had OMI at the time of coronary angiography of the procedure. FOCUS identified RWMA in 87% of patients with coronary angiography proven OMI. Residents (PGY-1 - PGY-3) (n = 31) were able to detect RWMA with a sensitivity of 86% (95% CI, 64–96), a specificity of 56% (95% CI, 23–85%), and an accuracy of 77 (95% CI, 58–90%). Emergency ultrasound fellows and attendings (n = 34) were able to detect RWMA with a sensitivity of 85% (95% CI, 64–95%), a specificity of 75% (95% CI, 36–96%), and an accuracy of 82% (95% CI, 65–93%). Our retrospective study concludes FOCUS performed by emergency physicians may be used to detect RWMA in patients with high concern for acute coronary syndrome. This may have its greatest utility in patients presenting without STEMI where the ECG is felt to be equivocal, but the clinician has high concern for OMI, in which the presence of RWMA might result in emergent cath lab activation, though this requires further study. The presence of RWMA in such cases may help to rule in OMI as a cause; however, the absence of RWMA should exclude OMI. Further research is necessary to confirm these findings. [ABSTRACT FROM AUTHOR]

COVID-19 lockdown has given us an opportunity to investigate the pollutant concentrations in response to the restricted anthropogenic activities. The atmospheric concentration levels of nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3) have been analysed for the periods during the first wave of COVID-19 lockdown in 2020 (25th March–31st May 2020) and during the partial lockdowns due to second wave in 2021 (25th March–15th June 2021) across India. The trace gas measurements from Ozone Monitoring Instrument (OMI) and Atmosphere InfraRed Sounder (AIRS) satellites have been used. An overall decrease in the concentration of O3 (5–10%) and NO2 (20–40%) have been observed during the 2020 lockdown when compared with business as usual (BAU) period in 2019, 2018 and 2017. However, the CO concentration increased up to 10–25% especially in the central-west region. O3 and NO2 slightly increased or had no change in 2021 lockdown when compared with the BAU period, but CO showed a mixed variation prominently influenced by the biomass burning/forest fire activities. The changes in trace gas levels during 2020 lockdown have been predominantly due to the reduction in the anthropogenic activities, whereas in 2021, the changes have been mostly due to natural factors like meteorology and long-range transport, as the emission levels have been similar to that of BAU. Later phases of 2021 lockdown saw the dominant effect of rainfall events resulting in washout of pollutants. This study reveals that partial or local lockdowns have very less impact on reducing pollution levels on a regional scale as natural factors like atmospheric long-range transport and meteorology play deciding roles on their concentration levels. [ABSTRACT FROM AUTHOR]

Air pollution has become one of the factors that most affect the quality of life, human health, and the environment. Gaseous pollutants from motor vehicles have a significantly harmful effect on air quality in the Metropolitan Area of São Paulo (MASP)—Brazil. Motor vehicles emit large amounts of particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOCs), the last three acting as the main tropospheric ozone (O3) precursors. In this study, we evaluated the effects of these pollutants on air quality in the MASP during the partial lockdown that was imposed to ensure the social distancing necessitated by the COVID-19 pandemic. We compared the monthly data for nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI) and CO, SO2, and BC from MERRA-2 for the period between April and May 2020 (during the pandemic) with the average for the same period for the (pre-pandemic) years 2017 to 2019 in the southeast region of Brazil. The meteorological and pollutant concentration data from the CETESB air quality monitoring stations for the MASP were compared with the diurnal cycle of three previous years, with regard to the monthly averages of April and May (2017, 2018, and 2019) and the same period in 2020, when the partial lockdown was first imposed in southeast Brazil. Our findings showed that there was a decrease in NO2 concentrations ranging from 10% to more than 60% in the MASP and the Metropolitan Area of Rio de Janeiro (MARJ), whereas in the Metropolitan Area of Belo Horizonte and Vitoria (MABH and MAV, respectively), there was a reduction of around 10%. In the case of the concentrations of CO and BC from MERRA-2, there was a considerable decrease (approx. 10%) during the period of partial lockdown caused by COVID-19 throughout almost the entire state of São Paulo, particularly in the region bordering the state of Rio de Janeiro. The concentration of SO2 from MERRA-2 was 5 to 10% lower in the MASP and MARJ and the west of the MABH, and there was a decrease of 30 to 50% on the border between the states of São Paulo and Rio de Janeiro, while in the MAV region, there was an increase in pollutant levels, as this region was not significantly affected by the COVID-19 pandemic. Sharp reductions in the average hourly concentrations of CO (38.8%), NO (44.9%), NO2 (38.7%), and PM2.5 (6%) were noted at the CETESB air quality monitoring stations in the MASP during the partial lockdown in 2020 compared with the hourly average rate in the pre-pandemic period. In contrast, there was an increase of approximately 16.0% in O3 concentrations in urban areas that are seriously affected by vehicular emissions, which is probably related to a decrease in NOx. [ABSTRACT FROM AUTHOR]

The response of tropospheric column nitrogen dioxide (NO2) variations under the background of Major Function Oriented Zones (MFOZs) over eastern China is analyzed in this study. There is an increasing and then decreasing trend in the average annual value of NO2 in eastern China, with the highest values in 2011 and the lowest in 2017. As serious polluted regions, three regions (Jing-Jin-Ji, Yangtze River Delta, and Pearl River Delta) all show decrease trend, the average concentration of NO2 in the Jing-Jin-Ji region is the highest, and the decrease rate is also the highest. By analyzing the variation characteristics of NO2 concentration in MFOZs, there is a maximum in optimized zones and a minimum is the key ecological safety zones, each region shows a downward trend, and the optimized zones has the highest decrease rate. Population and gross domestic product (GDP) distribution are the key factors affecting NO2 concentration, changes of NO2 concentration are consistent with the population and GDP density, the regions with higher population and GDP density also have higher NO2 concentration (like the optimized zones and the prioritized zones), and the regions with lower population and GDP density also have lower NO2 concentration (like the ecological safety zones). [ABSTRACT FROM AUTHOR]

In this study, the aim was to create daily ground-level NO2 maps for Vietnam spanning from 2019 to 2021. To achieve this, various machine learning models (including the Mixed Effect Model, Neural Network, and LightGBM) were utilized to process satellite NO2 tropospheric columns from Ozone Monitoring Instrument (OMI) and TROPOMI, as well as meteorological and land use maps and ground measurement NO2 data. The LightGBM model was found to be the most effective, producing results with a Pearson r of 0.77, RMSE of 7.93 μg/m³, and Mean Relative Error (MRE) of 42.6% compared to ground truth measurements. The annual average NO2 maps from 2019–2021 obtained by the LightGBM model for Vietnam were compared to a global product and ground stations, and it was found to have superior quality with Pearson r of 0.95, RMSE of 2.27 μg/m³, MRE of 9.79%, based on 81 samples.

The tropospheric NO2 column from Sentinel-5P/TROPOMI (2018–2020) and Aura/OMI (2010–2020) over Poland, notably for 7 major Polish cities, was used to assess the annual variability and the COVID-19 lockdown effect. On a national scale, during lockdown (March–June 2020), strong sources of pollution were found in Katowice and Warszawa, as well as at the power plant in Bełchatów. A gradual drop in OMI NO2 values between March and June was found for all cities and the entire domain of Poland, this being a part of the annual NO2 cycle derived for every year from 2010 to 2020. In fact, the gradual drop of NO2 in the lockdown year was within the typical monthly and annual variability. In March 2020, Kraków showed the highest NO2 reduction rate. A reduction of NO2 was observed in Gdańsk, Wrocław, and Warszawa during every month of the lock-down period. Several factors, including wind speed and direction, temperature, and increased emission sources, can limit the dispersion and removal of NO2. Although meteorological conditions have a significant impact on the annual cycle of NO2 in Poland, it is important to note that anthropogenic emissions remain the primary driver of NO2 concentrations. Therefore, the study concludes that the effect of COVID-19 restrictions on NO2 pollution was negligible and clarifies the current understanding of the COVID-19 effect over Poland, with an emphasis on hotspots in the major Polish cities and their vicinity. This is consistent with our understanding that the reduction of NO2 pollution is seen in cities due to reduced traffic (domestic, municipal, and airborne).

NO2 is one of the main pollutants in the atmospheric environment, which can directly or indirectly cause harm to human health. Jiangsu province is economically developed and densely populated, and the conflict between economic development and ecological environment protection is more prominent, which causes its mean annual NO2 concentration to be higher than other neighboring provinces. The study takes the formation mechanism of NO2 concentration distribution heterogeneity at different spatial scales as the research object. By using OMI satellite remote sensing data and NO2 concentration ground monitoring data in Jiangsu Province from 2015 to 2020, the paper studies NO2 concentration distribution heterogeneity at macroscopic and microscopic scales, respectively, to analyze the formation mechanism. The results show that: (1) The spatial distribution characteristics of NO2 concentration obtained based on the analysis of two data sources have good consistency, with the overall performance of high NO2 concentration in the south of Jiangsu where the concentration of NO2 column reached 16.3 × 1015 molec/cm 2 and the monitoring concentration reached 46.3μg/m3, while the concentration of NO2 in central Jiangsu is relatively low, with average concentrations of 6 × 1015 molec/cm 2 and 26μg/m3. (2) Under the macroscopic spatial scale, the average NO2 column concentration in the south of Jiangsu is 9 × 1015 molec/cm 2 higher and the monitoring concentration is 15μg/m3 than that in the north of Jiangsu; natural factors such as temperature are the important influencing factors for the heterogeneity of NO2 concentration distribution under this scale. (3) At the microscopic spatial scale, NO2 concentration is 5–10% higher in industrial concentrations in southern Jiangsu, some heating cities in northern Jiangsu, and industrial parks in northern Jiangsu. In addition, NO2 concentration decreases gradually with distance from this area; anthropogenic factors such as population density, GDP, and car ownership are important factors to influence the heterogeneity of NO2 concentration distribution at this scale. Based on the above findings, the paper proposes to adjust the industrial structure, limit the number of high energy-consuming and high-emission enterprises, and develop seasonal emission reduction measures.

Arid urban areas are pivotal in the global landscape, and their air quality issues are highlighted by the complexities of tropospheric ozone production. Here, we use recent satellite observations from TROPOMI and a longer record of data from OMI to investigate the levels of ozone precursors (NO _2 and CH _2 O) in 12 major cities in arid regions. Using a space-based CH _2 O/NO _2 indicator, we identified the dominant chemical regime influencing ozone formation, revealing a clear temporal trend that aligns with previously reported economic trajectories as well as variation in emission control strategies implemented in these cities. Our results show that, NO _2 concentrations decreased in cities with proactive regulatory policies, such as Madrid and Los Angeles in semi-arid and arid regions. A contrasting increase was observed in rapidly developing cities within arid and hyper-arid regions, such as Tehran and Cairo, where emission controls are less strict. An increase in CH _2 O levels was also apparent, requiring more attention to VOCs control. Furthermore, our analysis clearly shows that the interactions between ozone production and climatic factors such as temperature exhibit a nonlinear relationship, especially in arid climates. These findings highlight the importance of emission reduction strategies that consider the meteorological and chemical drivers of dry regions, particularly in light of the rising global aridity.

Air pollution is a global issue causing major health hazards. By proper monitoring of air quality, actions can be taken to control air pollution. Satellite remote sensing is an effective way to monitor global atmosphere. Various sensors and instruments fitted to satellites and airplanes are used to obtain the radar images. These images are quite complex with various wavelength differentiated by very close color differences. Clustering of such images based on its wavelengths can provide the much-needed relief in better understanding of these complex images. Such task related to image segmentation is a universal optimization issue that can be resolved with evolutionary techniques. Differential Evolution (DE) is a fairly fast and operative parallel search algorithm. Though classical DE algorithm is popular, there is a need for varying the mutation strategy for enhancing the performance for varied applications. Several alternatives of classical DE are considered by altering the trial vector and control parameter. In this work, a new alteration of DE technique labeled as DiDE (Divergent Differential Evolution Algorithm) is anticipated. The outcomes of this algorithm were tested and verified with the traditional DE techniques using fifteen benchmark functions. The new variant DiDE exhibited much superior outcomes compared to traditional approaches. The novel approach was then applied on remote sensing imagery collected form TEMIS, a web based service for atmospheric satellite images and the image was segmented. Fuzzy Tsallis entropy method of multi-level thresholding technique is applied over DiDE to develop image segmentation. The outcomes obtained were related with the segmented results using traditional DE and the outcome attained was found to be improved profoundly. Experimental results illustrate that by acquainting DiDE in multilevel thresholding, the computational delay was greatly condensed and the image quality was significantly improved. [ABSTRACT FROM AUTHOR]

The results of measuring the NO2 content in vertical columns of the stratosphere and troposphere using the Ozone Monitoring Instrument (OMI) on board the EOS Aura satellite in 2004–2020 are compared with the results of ground-based measurements at stations of the Network for the Detection of Atmospheric Composition Change (NDACC), first and foremost, with the results of measurements at the Zvenigorod Scientific Station (ZSS) of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The comparison between the satellite data and the ZSS data is performed using the two products of satellite measurements: the NO2 contents in stratospheric and tropospheric columns. When comparing the OMI data with ground-based measurements at other stations, satellite values of the NO2 content in the stratospheric column are compared to values of the total content (TC) of NO2 obtained from ground-based measurements. The correspondence between the results of satellite and ground-based measurements is characterized by the magnitude of difference between them, the linear correlation coefficients, and regression coefficients. The difference has a noticeable seasonal variation. The correlation and regression coefficients depend significantly on the season. Characteristic patterns of correlation coefficient changes with latitude, as well as specific features of correlation between satellite and ground-based data in the polar and middle latitudes of the Southern Hemisphere in spring, have been revealed. For some stations, the dependence of quantitative characteristics of the correspondence between the results of satellite and ground-based measurements on cloudiness has been found. Under cloudless conditions at the ZSS, a weakening of the correlation between the satellite and ground-based values of the stratospheric NO2 content and an increase in the correlation between the values of the tropospheric NO2 content is observed. The dependence of the correspondence characteristics between the data of satellite and ground-based measurements on the level of pollution of the lower troposphere by nitrogen oxides is revealed. The correlation between the values of the tropospheric NO2 content in the vicinity of ZSS under strong pollution increases, while the correlation between the values of the stratospheric NO2 content decreases. Based on the results of the comparison of satellite and ground-based data, estimates of the upper threshold values of the tropospheric NO2 content at different stations are found. The lowest values are obtained for polar stations, and the highest value are obtained for the ZSS, which is most susceptible to anthropogenic pollution due to its proximity to the Moscow megapolis. [ABSTRACT FROM AUTHOR]

The United Nations Convention on the Law of the Sea of 1982 (UNCLOS) and the International Maritime Organization (IMO) are working on the regulation of autonomous surface maritime vessels (MASS). The IMO has adopted a preliminary definition of MASS and has established a roadmap for the adoption of a non-binding code in 2024 and a binding code in 2025. Negotiations began in 2022 to adapt existing regulations and ensure maritime safety. The development of a new instrument, a MASS Code, is proposed to address common issues and potential gaps in the regulation of autonomous vessels. [Extracted from the article]

The Chinese government introduced regulations to control emissions and reduce the level of NOx pollutants for the first time with the 12th Five-Year Plan in 2011. Since then, the changes in NOx emissions have been assessed using various approaches to evaluate the impact of the regulations. Complementary to the previous studies, this study estimates anthropogenic NOx emissions in 2015 and 2019 over Eastern China using as a reference the Hemispheric Transport of Air Pollution (HTAP) v2.2 emission inventory for 2010 and the new variational inversion system the Community Inversion Framework (CIF) interfaced with the CHIMERE regional chemistry transport model and OMI satellite observations. We also compared the estimated NOx emissions with the independent Multi-resolution Emission Inventory for China (MEIC) v1.3, from 2015. The inversions show a slight global decrease in NOx emissions (in 2015 and 2019 compared to 2010), mainly limited to the most urbanized and industrialized locations. In the locations such as Baotou, Pearl River Delta, and Wuhan, the estimations in 2015 compared to 2010 are consistent with the target reduction (10%) of the 12th Five-Year Plan. Comparisons between our emission estimates and MEIC emissions in 2015 suggest that our estimates likely underestimate the emission reductions between 2010 and 2015 in the most polluted locations of Eastern China. However, our estimates suggest that the MEIC inventory overestimates emissions in regions where MEIC indicates an increase of the emissions compared to 2010. [ABSTRACT FROM AUTHOR]

In the troposphere, ozone (O 3) formation can be limited by NOx, VOCs, or both, complicating efforts to reduce O 3 by controlling its precursors. This study used formaldehyde (HCHO) data and nitrogen dioxide (NO 2) data from the Ozone Monitoring Instrument (OMI) to analyze O 3 formation sensitivity in Fujian from 2012 to 2021. Over the past decade, an 8.7% reduction in NO 2 VCDs and a 9.91% increase in HCHO VCDs were observed. Due to differences in the primary driving factors, HCHO VCDs exhibit a characteristic seasonal pattern with higher in summer and lower in winter, whereas NO 2 VCDs show the opposite trend. O 3 formation chemistry was accurately diagnosed by combining satellite-based data and ground-based O 3 data. A new threshold value (3.3–4.6) was derived to determine the transition from VOC-limited to NOx-limited O 3 formation regimes. Results showed that O 3 sensitivity exhibited pronounced seasonal variations. The VOC-limited regime predominates throughout the entire Fujian region in winter, whereas it occupies only 5% of the area in summer. A VOC-limited region was found widely across Fujian on an annual average, but it decreased by 24% over 10 years. Transitional areas experienced a 19% increase. In two natural emission reduction cases (reductions during the Chinese Lunar New Year holiday and reductions in weekend traffic emissions compared to weekdays), ground-level O 3 effectively captured the impacts of sensitivity changes. The impact suggests that when Fujian is in the VOC control region, a significant reduction in NO x , without effective VOC control, might lead to an O 3 increase. The importance of controlling VOC emissions is highlighted in Fujian. This study enhances the understanding of O 3 formation regimes in southeastern China, which is crucial for developing O 3 prevention and control strategies. [Display omitted] • A threshold value of HCHO/NO 2 was derived to delineate O 3 formation regimes. • O 3 formation regimes exhibit significant variations across different cities and seasons. • Emission strategies need to focus on reducing VOC emissions. • Ground O3 captured the impact of sensitivity changes based on the threshold values. [ABSTRACT FROM AUTHOR]

Absorbing aerosols, consisting of smoke (black carbon (BC) and other organics) and dust (from windblown sources), can have a strong warming effect on the climate and impact atmospheric circulation due to localized heating. To investigate the spatiotemporal and vertical changes of absorbing aerosols across Asia, collocation data from OMI, MODIS, and CALIPSO were used to compare two periods: 2006–2013 and 2014–2021. This study revealed a significant temporal and spatial contrast of aerosol loading over the study region, with a drop in total aerosol concentration and anthropogenic smoke concentration recorded across the Eastern China region (all seasons) and a concurrent increase in the Indian sub-continent region (especially in autumn). The range of aerosol diffusion is affected by the height of the smoke and aerosol plumes, as well as the wind force, and is dispersed eastwards because of the Hadley circulation patterns in the Northern Hemisphere. Smoke from Southeast Asia typically rises to a height of 3 km and affects the largest area in contrast to other popular anthropogenic zones, where it is found to be around 1.5–2 km. The dust in Inner Mongolia had the lowest plume height of 2 km (typically in spring) compared to other locations across the study region where it reached 2–5 km in the summer. This study showed, by comparison with AERONET measurements, that combining data from MODIS and OMI generates more accuracy in detecting aerosol AOD from smoke than using the instruments singularly. This study has provided a comprehensive assessment of absorbing aerosol in Asia by utilizing multiplatform remote-sensed data and has summarized long-term changes in the spatiotemporal distribution and vertical structure of absorbing aerosols. [ABSTRACT FROM AUTHOR]

Using a series of characteristic analyses of HCHO, SO2, NO2, O3, and absorptive aerosols (ultraviolet aerosol index—UVAI) in the atmosphere of the study area from 2011 to 2021, this paper reviews the pollutants present in Jiangsu, Shandong, Henan, and Anhui provinces, which are the key regions for air pollution control in China. Furthermore, the correlation between various air pollutants and O3 is also examined. The results obtained show the following: (1) Within the research areas, temporal pollutant variations can be observed from 2011 to 2021. NO2 and HCHO only modestly decrease, SO2 sharply declines, while UVAI remains stable. During the study period, HCHO and O3 first increase and subsequently decline, whereas the other three pollutants exhibit the opposite behavior. (2) Among the examined pollutants, SO2 is the most unstable. (3) Our research discovered that the atmospheric transport paths at high-value points significantly vary between seasons using the public backward trajectory model. (4) Through the correlation analysis we performed, this research reveals the different degrees of spatial correlations between O3 and other pollutants. (5) Using the FNR index method, the sensitivity of O3 to its precursors (NOx and VOCs) is investigated. Based on the results, we provide some suggestions concerning the primary control pollutants and relative control strategies in different seasons and regions. [ABSTRACT FROM AUTHOR]

Ozone (O3) pollution is one of the predominant environmental problems, and exposure to high O3 concentrations has a significant negative influence on both human health and ecosystems. Therefore, it is essential to analyze spatio-temporal characteristics of O3 distribution and to evaluate O3 exposure levels. In this study, O3 monitoring and satellite data were used to estimate O3 daily, seasonal and one-year exposure levels based on the Bayesian maximum entropy (BME) model with a spatial resolution of 1 km × 1 km in the Beijing-Tianjin-Hebei (BTH) region, China. Leave-one-out cross-validation (LOOCV) results showed that R2 for daily and one-year exposure levels were 0.81 and 0.69, respectively, and the corresponding values for RMSE were 19.58 μg/m3 and 4.40 μg/m3, respectively. The simulation results showed that the heavily polluted areas included Tianjin, Cangzhou, Hengshui, Xingtai, and Handan, while the clean areas were mainly located in Chengde, Qinhuangdao, Baoding, and Zhangjiakou. O3 pollution in summer was the most severe with an average concentration of 134.5 μg/m3. In summer, O3 concentrations in 87.7% of the grids were more than 100 μg/m3. In contrast, winter was the cleanest season in the BTH region, with an average concentration of 51.1 μg/m3. [ABSTRACT FROM AUTHOR]