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The Arctic region is experiencing notable warming as well as more lightning. Lightning is the dominant source of upper tropospheric nitrogen oxides (NOx), which are precursors for ozone and hydroxyl radicals. In this study, we combine the nitrogen dioxide (NO2) observations from the TROPOspheric Monitoring Instrument (TROPOMI) with Vaisala Global Lightning Dataset 360 to evaluate lightning NO2 (LNO2) production in the Arctic. By analyzing consecutive TROPOMI NO2 observations, we determine the lifetime and production efficiency of LNO2 during the summers of 2019-2021. Our results show that the LNO2 production efficiency over the ocean is ∼6 times higher than over continental regions. Additionally, we find that a higher LNO2 production efficiency is often correlated with lower lightning rates. The summertime lightning NOx emission in the Arctic (north of 70° N) is estimated to be 219 ± 116 Mg of N, which is equal to 5% of anthropogenic NOx emissions. However, for the span of a few hours, the Arctic LNO2 density can even be comparable to anthropogenic NO2 emissions in the region. These new findings suggest that LNO2 can play an important role in the upper-troposphere/lower-stratosphere atmospheric chemical processes in the Arctic, particularly during the summer.

© Copyright 2022. Sociedad Meteorológica Estadounidense (AMS). Para obtener permiso para reutilizar cualquier parte de este Trabajo, comuníquese con permisos@ametsoc. org . Cualquier uso del material en este Trabajo que se determine como "uso justo" según la Sección 107 de la Ley de derechos de autor de EE. UU. (17 Código de EE. UU. § 107) o que cumpla las condiciones especificadas en la Sección 108 de la Ley de derechos de autor de EE. ) no requiere el permiso de la AMS. La republicación, la reproducción sistemática, la publicación en forma electrónica, como en un sitio web o en una base de datos de búsqueda, u otros usos de este material, excepto los exentos de la declaración anterior, requieren un permiso por escrito o una licencia de la AMS. Todas las publicaciones periódicas y monográficas de AMS están registradas en el Centro de Autorización de Derechos de Autor (https://www.copyright.com ). Se proporcionan detalles adicionales en la declaración de política de derechos de autor de AMS, disponible en el sitio web de AMS ( https://www.ametsoc.org/PUBSCopyrightPolicy ) ., In 2021, both social and economic activities began to return towards the levels preceding the COVID-19 pandemic for some parts of the globe, with others still experiencing restrictions. Meanwhile, the climate has continued to respond to the ongoing increase in greenhouse gases and resulting warming. La Niña, a phenomenon which tends to depress global temperatures while changing rainfall patterns in many regions, prevailed for all but two months of the year. Despite this, 2021 was one of the six-warmest years on record as measured by global mean surface temperature with an anomaly of between +0.21° and +0.28°C above the 1991–2020 climatology., Lake surface water temperatures from satellite data have been generated within the GloboLakes project funded by the UK National Environment Research Council (NE/J023345/2), with extensions funded by the EU Copernicus Climate Change Service (C3S) programme...

Despite the large number of domestic inland river vessels in China, information on inland ship emissions is very limited, since legislation for shipping emission control is limited and there is no monitoring infrastructure. Taking the Yangtze River in the region of Nanjing as a research area, we compiled a ship emission inventory based on real-time information received from automatic identification system (AIS) signals combined with ship-related data provided by the China Classification Society (CCS) database. The total ship emissions we derived for the Jiangsu section of the Yangtze River from September 2018 to August 2019 for NOx, SO2, PM10 and PM2.5 were 83.5, 0.04, 0.006 and 0.005 kt yr−1, respectively. This ship emission inventory we constructed was compared with the Multi-resolution Emission Inventory for China (MEIC), the Shipping Emission Inventory Model (SEIM) and the satellite-derived emissions using the Daily Emissions Constrained by Satellite Observations (DECSO) algorithm. The results show a consistent spatial distribution, with riverine cities having high NOx pollution. With this comparison we analyzed the relative impact of ship emissions on densely populated regions along the river. Inland ship emissions of NOx are shown to contribute significantly, accounting for at least 40 % of air pollution close to the river.

Nitrogen oxides (NOx) emissions play an important role in air quality, the nitrogen cycle, and as precursor for climate gasses. The most important sources of NOx emissions are fossil fuel burning (industry and traffic) and the release from soil.With the inversion algorithm DECSO (Daily Emissions Constrained by Satellite Observations) we derive quantitative NOx emissions on a 5 to 20 km resolution from TROPOMI (on Sentinel 5p) observations of NO2, taking advantage of the fine spatial resolution (5 x 3.5 km) of the TROPOMI instrument. DECSO is a full inversion algorithm based on data assimilation of satellite observation and the Chemical-transport model CHIMERE. For the data assimilation a Kalman Filter technique is used. For the inversion no apriori information of the NOx emissions is needed and for this reason new sources can be detected. In the postprocessing we use the seasonal cycle to distinct between soil emissions (having strong seasonal cycle with summer peak) and anthropogenic emissions (having low variability over the year).To assess the quality of satellite-derived NOx emissions on various scales, i.e. national, regional, city and points-sources, they are compared to various bottom-up inventories. For bottom-up emissions we selected NEC (National Emission Ceilings Directive inventory), LRTAP (LRTAP convention data), the CAMS (Copernicus Atmosphere Monitoring Service) regional anthropogenic emission database and the high-resolution emission inventory HERMES (High-Elective Resolution Modelling Emission System) for Catalonia. Detailed results will be shown, including the spatial and temporal variation per emission category.

In the coming decades, a large increase in population is expected to occur on the African continent, leading to a doubling of the current population, which will reach 2.5 billion by 2050. At the same time, the African continent is experiencing substantial economic growth. As a result, air pollution and greenhouse gas emissions will increase considerably with expected health impacts on the African population. The impact of wildfires also needs to be carefully assessed. Will the frequency of fire episodes increase? And how will this perturbation compare with anthropogenic emissions in urban areas? In the decades ahead, Africa’s contribution to climate change and air pollution will become increasingly important. Time has come to address the changing role of Africa in understanding and quantifying global environmental change. What can we learn from the new TROPOMI satellite data for Africa, in combination with emerging modelling efforts including the MUSICA development at NCAR and the development of inverse modelling techniques? How can we deal with the lack of surface observations in many areas of Africa?We will show several recent achievements related to Africa, using space observations and modeling approaches as a contribution towards the development of an integrated community effort to better characterize air quality and climate-related processes in this continent. This presentation will mainly focus on the potential of the use of TROPOMI data for Africa Research.

Over the past century ammonia (NH3) emissions have increased with human population growth and fertilizer usage. The abundant NH3 emissions lead to climate change, reduction in biodiversity and affect the human health. Up-to-date information of NH3emissions are essential to better understand the impact of NH3. In this study we adapted the existing DECSO (Daily Emissions Constrained by Satellite Observations) algorithm for use of NH3 observations from the Cross-track Infrared Sounder (CrIS) to estimate NH3 emissions. By considering the interaction between NH3 and NOx, we implemented DECSO to estimate NOx and NH3 emissions simultaneously on 20 km resolution over European domain. NH3 and NOx emissions over Europe are derived for 2020 on a daily basis from CrIS and TROPOMI (on Sentinel 5p). Due to the sparseness of daily satellite observations of NH3, monthly emissions of NH3 are constructed and analysed. The comparison of these emissions with other existing emission inventories will be presented.

Methane (CH4) is the second most important greenhouse gas after CO2. The TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel 5 Precursor (S5-P) satellite measures CH4 at a high horizontal resolution of 7 × 7 km2, showing the capability on identifying and quantifying the sources at a local to regional scale. The Middle East is one of the strong CH4-emitting regions in the world. However, it is difficult to estimate the emissions here because of the uncertainties caused by bright surfaces and high aerosol loadings. Furthermore, several sources are located near the coast or in places with complex topography, where satellite observations are often of reduced quality. We use the product from the University of Bremen, WMF-DOAS XCH4 v1.8 product, which has good spatial coverage over the ocean and mountains, to estimate the emissions in the Middle East. The Aerosol Optical Depth (AOD) data from the MODIS/Aqua satellite instrument, which has a similar overpass time as TROPOMI, was adopted to filter potential unreliable XCH4 in the product.For the inversion, we use the divergence method of Liu et al., (2021), which has been proven to be a fast and efficient way to estimate CH4 emissions from satellite observations. We have improved our method by comparing the fluxes in different directions for better background corrections over areas with complicated topographies. The temporal filter was established to further filter false emissions caused by surface albedos. We derived CH4 emissions on a grid of 0.2° from 2018 to 2021 and compared them to the latest bottom-up inventory EDGAR v7.0 in the same years. We found significantly lower emissions than EDGAR for the locations that are mainly determined by observed gas-flaring from satellites. Apart from sources of oil/gas production, the emissions from livestock in Saudi Arabia's irrigation zones, which have been reported neither in EDGAR nor other previous studies, are identified and quantified by using our divergence method. Another unexpected finding is that emissions from landfills are fairly stable and strong in some cities like Tehran.

Thunderstorms can significantly influence the air composition via strong updraft and lightning nitrogen oxides (LNOx). In this study, the ozonesondes and TROPOMI (TROPOspheric Monitoring Instrument) nitrogen dioxide (NO2) observations for two cases are combined with a model to investigate the effects of typical strong convection on vertical redistribution of air pollutants in Nanjing, southeastern China. The ozonesonde observations show higher O3 and water vapor mixing ratios in the upper troposphere (UT) after convection, indicating the strong updraft transporting lower-level air masses into the UT and the possible downward O3-rich air near the top of UT over the convective period. During the whole convection life cycle, the UT O3 production is driven by the chemistry (5–10 times the magnitude of dynamic contribution) and reduced by the LNOx (−40 %). Sensitivity tests demonstrate that neglecting LNOx in standard TROPOMI NO2 products causes overestimated air mass factors over fresh lightning regions and the opposite for outflow and aged lightning areas. Therefore, a new high-resolution retrieval algorithm is applied to estimate the LNOx production efficiency. Our work shows the demand for high-resolution modeling and satellite observations on LNOx emissions of both active and dissipated convection, especially small-scale storms.

Human kidney organoids possess early glomerular and tubular function. However, little is known about their hormone producing ability. In this report, we show that kidney organoids take up and metabolize inactive 25(OH) vitamin D (25(OH)D3). Uptake of 25(OH)D3 led to a significant upregulation of vitamin D metabolizing CYP24A1 mRNA levels, indicating that kidney organoids possess a feedback mechanism to control active vitamin D (1,25(OH)2D3) levels. They therefore resemble the kidney in its regulation of vitamin D and illustrate the presence of the kidney endocrine system in organoids. These findings underscore the value of kidney organoids for research into the hormonal function of the kidney.

Patients presenting to spine surgeons for lumbar radiculopathy often undergo initial conservative treatment including medications, therapy, and lumbar transforaminal epidural steroid injections. Despite a growing number of spinal injections performed, there is a lack of available data regarding the occurrence of wrong-site injections. However, when examined, the discrepancies between ordering level and level of epidural steroid injection performed are immense. To aid with this issue, we propose that instead of ordering a lumbar transforaminal epidural steroid injections at a given level, it should be ordered to address a specific nerve root with laterality. This has the potential to reduce wrong-site procedures and improve patient outcomes.Retrospective chart review of 60 patients at a private orthopaedic spine practice under the care of spine surgeons or physician assistants over a 1-year period. The progress note, injection order form, procedure note, and procedural fluoroscopy were reviewed. If there were inconsistencies between one or more of these steps, it was deemed a failure. Results were analyzed to assess for any differences in outcomes between the two groups. We calculated our sample size prior to the study and powered it at 90%; descriptive statistics, Chi-square, Fisher's exact test, Student'sThirty-seven patients (37/60, 61.6%) were considered a failure. There were no failures when ordering an S1 nerve root injection. We identified one wrong-site procedure and one wrong-level order that was identified and corrected by the interventionalist.There were multiple inconsistencies identified at various steps in the injection ordering process. This indicates a need to standardize the language used in this process to avoid wrong-site procedures. There were no inconsistencies in ordering an S1 injection, likely because this injection could only be ordered at the nerve root. It is also critical to utilize and save a localization film to ensure accuracy and accountability. We propose indicating the affected nerve root in all cases rather than the level of disc pathology would avoid confusion.

Despite the large number of domestic inland river vessels in China, information on inland river vessel emissions is very limited, because limited legislation exists for emission control and there is no monitoring infrastructure. Taking the Yangtze River in the region of Nanjing as research area, we compiled a ship emission inventory based on real-time information received from Automatic Identification System (AIS) signals and ship-related basic data provided by China Classification Society (CCS) database. The total estimated ship emissions in the Jiangsu section of the Yangtze River from September 2018 to August 2019 for NOx, SO2, PM10 and PM2.5 were 83.5, 41.8, 3.8 and 3.3 kton, respectively. These ship emissions were highest in the summer. From these estimates an inventory was constructed for ship emissions in the Yangtze River Delta (YRD) in Jiangsu. This ship emission inventory was compared with the Multi-resolution Emission Inventory for China (MEIC), the Shipping Emission Inventory Model (SEIM) and the satellite-derived emissions using the Daily Emissions Constrained by Satellite Observations (DECSO) algorithm. The result shows a consistent spatial distribution with riverine cities having higher NOx pollution than non-riverine cities. With this comparison we analyzed the relative impact of ship emissions on densely populated regions along the river. Inland ship emissions of NOx and SO2 are shown to contribute significantly, with each accounting for at least 40 %, to air pollution along the river.

Context Patients with mutations in thyroid hormone transporter MCT8 have developmental delay and chronic thyrotoxicosis associated with being underweight and having cardiovascular dysfunction. Objective Our previous trial showed improvement of key clinical and biochemical features during 1-year treatment with the T3 analogue Triac, but long-term follow-up data are needed. Methods In this real-life retrospective cohort study, we investigated the efficacy of Triac in MCT8-deficient patients in 33 sites. The primary endpoint was change in serum T3 concentrations from baseline to last available measurement. Secondary endpoints were changes in other thyroid parameters, anthropometric parameters, heart rate, and biochemical markers of thyroid hormone action. Results From October 15, 2014 to January 1, 2021, 67 patients (median baseline age 4.6 years; range, 0.5-66) were treated up to 6 years (median 2.2 years; range, 0.2-6.2). Mean T3 concentrations decreased from 4.58 (SD 1.11) to 1.66 (0.69) nmol/L (mean decrease 2.92 nmol/L; 95% CI, 2.61-3.23; P < 0.0001; target 1.4-2.5 nmol/L). Body-weight-for-age exceeded that of untreated historical controls (mean difference 0.72 SD; 95% CI, 0.36-1.09; P = 0.0002). Heart-rate-for-age decreased (mean difference 0.64 SD; 95% CI, 0.29-0.98; P = 0.0005). SHBG concentrations decreased from 245 (99) to 209 (92) nmol/L (mean decrease 36 nmol/L; 95% CI, 16-57; P = 0.0008). Mean creatinine concentrations increased from 32 (11) to 39 (13) µmol/L (mean increase 7 µmol/L; 95% CI, 6-9; P < 0.0001). Mean creatine kinase concentrations did not significantly change. No drug-related severe adverse events were reported. Conclusions Key features were sustainably alleviated in patients with MCT8 deficiency across all ages, highlighting the real-life potential of Triac for MCT8 deficiency.

Global Climate is one chapter from the State of the Climate in 2019 annual report and is avail- able from https://doi.org/10.1175/BAMS-D-20-0104.1 Compiled by NOAA’s National Centers for Environmental Information, State of the Climate in 2019 is based on contributions from scien- tists from around the world. It provides a detailed update on global climate indicators, notable weather events, and other data collected by environmental monitoring stations and instru- ments located on land, water, ice, and in space. The full report is available from https://doi.org/10.1175/2020BAMSStateoftheClimate.1.

The variation of NO2 concentrations in mainland China is analyzed on different timescales, from decadal to weekly, using both satellite data and data from ground-based monitoring networks. TROPOMI (TROPOspheric Monitoring Instrument) data were used to study the spatial variations of tropospheric NO2 vertical column densities (TVCDs) over the study area during 16–20 weeks after the Chinese Spring Festival (25 January 2020). These data were used to select 11 regions for more detailed analysis of the variation of NO2 TVCDs on a decadal timescale. In this analysis, monthly and annual averaged NO2 TVCDs derived from OMI (Ozone Monitoring Instrument) observations were used for the years 2011 to 2019. The results show the NO2 TVCD trends for different regions, all decreasing in response to emission reduction policies but with a different onset and a possible halt of the decrease in recent years; trends and period in the south of the study area are different from those in the north. Variations of NO2 TVCDs on shorter timescales, monthly and weekly, were analyzed using TROPOMI data. In addition, the variations of weekly-averaged ground-based NO2 concentrations in 11 major cities were analyzed together with those for O3 and PM2.5. In particular these data were used to determine their effect on the air quality as expressed by the air quality index (AQI). For quantitative estimates, the use of weekly concentrations is more accurate than the use of monthly values, and the effects of long-term trends and their reversal needs to be taken into account for the separation of effects of the lockdown and the Spring Festival. Neglecting the possible reversal of the trends leads to overestimation of the lockdown effect in the south and underestimation in the north. The ground-based data confirm earlier reports, based on satellite observations, that the expected improvement of air quality due to the reduction of NO2 concentrations was offset by the increase of the concentrations of O3 and the different effects of the lockdown measures on PM2.5, as well as effects of meteorological influences and heterogeneous chemistry. The AQI seems to be mostly influenced by PM2.5 rather than NO2. A qualitative comparison between time series of satellite and ground-based NO2 observations shows both similarities and differences. The study further shows the different behaviors in city clusters in the north and south of China, as well as inland in the Sichuan and Guanzhong basins. Effects of other holidays and events are small, except in Beijing where the air quality in 2020 was notably better than in previous years. This study was undertaken for China, but the methodology and results have consequences for air quality studies in other areas, and part of the conclusions are generally applicable.

The new platforms for Earth observation from space are characterized by measurements made at great spatial and temporal resolutions. While this abundance of information makes it possible to detect and study localized phenomena, it may be difficult to manage this large amount of data for the study of global and large-scale phenomena. A particularly significant example is the use by assimilation systems of Level 2 products that represent gas profiles in the atmosphere. The models on which assimilation systems are based are discretized on spatial grids with horizontal dimensions of the order of tens of kilometres in which tens or hundreds of measurements may fall in the future. A simple procedure to overcome this problem is to extract a subset of the original measurements, but this involves a loss of information. Another option is the use of simple averages of the profiles, but this approach also has some limitations that we will discuss in the paper. A more advanced solution is to resort to the so-called fusion algorithms, capable of compressing the size of the dataset while limiting the information loss. A novel data fusion method, the Complete Data Fusion algorithm, was recently developed to merge a set of retrieved products in a single product a posteriori. In the present paper, we apply the Complete Data Fusion method to ozone profile measurements simulated in the thermal infrared and ultraviolet bands in a realistic scenario. Following this, the fused products are compared with the input profiles; comparisons show that the output products of data fusion have smaller total errors and higher information contents in general. The comparisons of the fused products with the fusing products are presented both at single fusion grid box scale and with a statistical analysis of the results obtained on large sets of fusion grid boxes of the same size. We also evaluate the grid box size impact, showing that the Complete Data Fusion method can be used with different grid box sizes even if this possibility is connected to the natural variability of the considered atmospheric molecule.

INTRODUCTION: Immune checkpoint inhibitor (ICI) associated diabetes is a harmful adverse event (AE) in patients with cancer following anti-programmed (cell) death protein-1 (PD-1) treatment. There are no available biomarkers able to predict this AE. The primary aim of this study was to investigate C-peptide levels as potential predictor for the occurrence of ICI-related diabetes. The secondary aim was to describe the presence of islet autoantibodies and course of pancreatic enzymes in patients with and without ICI-related diabetes.METHODS: From a total of 1318 patients with cancer who started anti-PD-1 treatment 8 cases and 16 controls were studied in this nested case-control study. C-peptide levels, islet autoantibodies, and pancreatic enzymes were measured in prospectively collected blood serum.RESULTS: In cases versus controls, median C-peptide levels were comparable at baseline and before toxicity or at the corresponding time point in controls. No patient had C-peptide levels below reference range before toxicity onset. Two out of eight patients in the ICI-related diabetes group had positive islet autoantibodies, whereas one out of 16 patients in the control group had positive islet autoantibodies. Pancreatic enzymes were elevated before diabetes onset in one patient (13%) and in one control (6%) at the corresponding time point.CONCLUSIONS: In patients developing ICI-related diabetes, changes in C-peptide levels, islet autoantibody positivity, and pancreatic enzymes before ICI-related diabetes onset seem comparable to patients without ICI-related diabetes. (NTR: NL6828).

Lightning serves as the dominant source of nitrogen oxides ( NO x = NO + NO 2 ) in the upper troposphere (UT), with a strong impact on ozone chemistry and the hydroxyl radical production. However, the production efficiency (PE) of lightning nitrogen oxides (L NOx ) is still quite uncertain (32–1100 mol NO per flash). Satellite measurements are a powerful tool to estimate L NOx directly compared to conventional platforms. To apply satellite data in both clean and polluted regions, a new algorithm for calculating L NOx has been developed that uses the Berkeley High-Resolution (BEHR) v3.0B NO2 retrieval algorithm and the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). L NOx PE over the continental US is estimated using the NO2 product of the Ozone Monitoring Instrument (OMI) data and the Earth Networks Total Lightning Network (ENTLN) data. Focusing on the summer season during 2014, we find that the lightning NO2 (L NO2 ) PE is 32±15 mol NO2 per flash and 6±3 mol NO2 per stroke while L NOx PE is 90±50 mol NOx per flash and 17±10 mol NOx per stroke. Results reveal that our method reduces the sensitivity to the background NO2 and includes much of the below-cloud L NO2 . As the L NOx parameterization varies in studies, the sensitivity of our calculations to the setting of the amount of lightning NO (LNO) is evaluated. Careful consideration of the ratio of L NO2 to NO2 is also needed, given its large influence on the estimation of L NO2 PE.

The Solar-Terrestrial Centre of Excellence brings together and supports sun-space-earth research and services present at the federal level in Belgium. In 2019, the STCE was a founding member of a European network, PECASUS, that provides space weather services for civil aviation. Our expertise in solar observations and research combined with the experience of our Global Navigation Satellite System and solar particle radiation group proved to be crucial. The STCE also strongly invests in education and training as these are a backbone of quality research and services, and therefore created the Space Weather Education Centre. This centre offers the Space Weather Introductory Course covering the Sun, solar storms, heliosphere, ionosphere, magnetosphere, instruments and methods to observe solar and space weather activity, as well as reading and interpreting our space weather bulletins. This course is taught to future space weather advisory staff, both military and civilian. It is based upon the STCE’s expertise gained through scientific research, involvement in space missions and space weather monitoring, and on its forecasting capabilities. The course is given by qualified staff. In addition to the Space Weather Introductory Course, the STCE has been and remains involved in a wide range of outreach activities, from public lectures, over dedicated classes and workshops at schools, organization of public events like open doors, publications in popular journals and on online media, scientific newsletters and press releases, to the participation in science festivals and the organization of events for the scientific community. In this paper, we present more details of our educational programme, reflect on the methodologies used, and provide an overview of the obtained results

With the inversion algorithm DECSO (Daily Emissions Constrained by Satellite Observations) we derive quantitative NOx emissions on a 5 to 20 km resolution from TROPOMI (on Sentinel 5p) observations of NO2, taking advantage of the fine spatial resolution (5 x 3.5 km) of the TROPOMI instrument. The emissions are split into 3 categories: fossil-fuel, soil and maritime emissions using detailed land use information and signatures of the seasonal cycle in the emissions. DECSO is a full inversion algorithm based on data assimilation of satellite observation and the Chemical-transport model CHIMERE. For the data assimilation a Kalman Filter technique is used. For the inversion no apriori information of the NOx emissions is needed and for this reason new sources can be detected. To assess the quality of satellite-derived NOx emissions, they are compared to satellite-derived emissions calculated with the divergence method and compared to NOx emissions of various bottom-up inventories. The divergence method has been applied on TROPOMI data for a 3 month period to derive average emissions over Europe. For bottom-up emissions we selected both the CAMS (Copernicus Atmosphere Monitoring Service) regional anthropogenic emission database and the regional emission inventory HERMES (High-Elective Resolution Modelling Emission System) for Catalonia for the intercomparison. The analysis has been done for regional totals but also focussing on specific cities and factories. Detailed results will be shown, including the spatial and temporal variation per emission category. The intercomparison of DECSO with bottom-up inventories show good agreement for regional emission totals and its spatial distribution, but at a city-scale or focussing on individual sources (factories or power plants) interesting differences are found.

The Arctic is experiencing rapid climate change. The increasing temperature not only reduces the sea-ice extent but will also have doubled the number of lightning flashes by the end of the century. The unlocked Arctic ocean can also lead to increased human activities such as shipping and expanded oil and gas production. In addition, the increase of lightning will cause more wildfires. All of these above will give rise to emissions of nitrogen oxides (NOx).In this study, we track and estimate three-year (2019-2021) Arctic NOx emissions by combing the TROPOspheric Monitoring Instrument (TROPOMI) observations, Visible Infrared Imaging Radiometer Suite (VIIRS) data, and the Vaisala’s Global Lightning Dataset (GLD360). The NOx emissions are divided into two different categories and estimated separately: 1) NOx emissions from lighting; 2) surface NOx emissions from all other sources.The continuous overlapping orbits of TROPOMI passing over the Arctic provide unique opportunities for tracking the lightning NOx (LNOx) and calculating both LNOx lifetime and production efficiency. Previous studies focused on the LNOx emissions in the tropical and mid-latitude regions and estimated the global LNOx within the range of 2 to 8 T N yr-1. This study can add the missing LNOx productions in high latitudes.Besides, a Cloud-Snow Differentiation (CSD) method is applied to get more high-precision TROPOMI observations over large boreal snow-covered areas by discriminating snow-covered surfaces from clouds. The derived NOx emissions from power plants, natural gas industries, and soil will play an important role in updating the present-day NOx inventories which have a limited number of data sets. This study highlights the potential of TROPOMI as well as future satellite missions for monitoring Arctic NOx emissions.

The Permian basin is the largest oil and gas production region in the U.S.A. Because of the non-conventional exploration of the basin, the region is covered with hundreds of small production facilities. Observations from the surface and from aircrafts have shown that there are continuous emissions of amongst others CH4 and NOx. Although they come from the same facilities, the sources of CH4 and NOx differ: NOx is predominantly produced by engines and generators used for drilling and to run the facilities, whereas CH4 is produced from planned and accidental releases from the production, storage and transportation of oil and gas. The TROPOMI satellite instrument allows continuous monitoring of CH4 and NO2 and has confirmed the large contribution of the oil and gas industry to the CH4 and NO2 concentrations in the Permian basin.Using the divergence method, we have derived emissions for both CH4 and NO2 from the TROPOMI data, with a high spatial resolution of better than 5x5 km2 for NO2 and better than 10x10 km2 for CH4. The results show that the Permian CH4 emissions in the basin are not dominated by a few large emission events, but are also impacted by many smaller releases across the basin. The basin can therefore be seen as a large area source that varies in space and time. Mitigation of these releases is challenging, rather than solving a few large leaks in a few facilities, the equipment and management of many small sites have to be improved to reduce emissions.In this contribution we present results of the emission retrievals. Using CAMS model data, we show the potential of the divergence method and its sensitivity. Analyses will be presented of the TROPOMI derived emissions, showing the spatial variability of CH4 and NOx emissions over the region and their relation to the underlying oil and gas production and drilling activities.

Thunderstorms can significantly influence the air composition via strong updraft and lightning nitrogen oxides (LNOx). In this study, the ozonesondes and TROPOMI nitrogen dioxide (NO2) observations for two cases are combined with model to investigate the effects of typical strong convection on vertical redistribution of air pollutants in Nanjing, southeastern China. The ozonesonde observations show higher O3 and water vapor mixing ratios in the upper troposphere (UT) after convection, indicating the strong updraft transporting lower-level airmass into the UT, and the possible downward O3-rich air near the top of UT over the convective period. During the whole convection life cycle, the UT O3 production is driven by the chemistry (> 87 %) and reduced by the LNOx (−40 %). Sensitivity tests demonstrate that neglecting LNOx in standard TROPOMI NO2 products causes overestimated air mass factors over fresh lightning regions and the opposite for outflow and aged lightning areas. Therefore, a new high-resolution retrieval algorithm is applied to estimate the LNOx production efficiency. Our work shows the demand for high-resolution modeling and satellite observations on LNOx emissions of both active and dissipated convection, especially small-scale storms.

We present a new divergence method to estimated methane (CH4) emissions from satellite observed mean mixing ratio of methane (XCH4) by deriving the regional enhancement of XCH4 in the Planetary Boundary Layer (PBL). The applicability is proven by comparing the estimated emissions with its known emission inventory from a 3-month GEOS-Chem simulation. When applied to TROPOspheric Monitoring Instrument observations, sources from well-known oil/gas production areas, livestock farms and wetlands in Texas become clearly visible in the emission maps. The calculated yearly averaged total CH4 emission over the Permian Basin is 3.06 (2.82, 3.78) Tg a−1 for 2019, which is consistent with previous studies and double that of EDGAR v4.3.2 for 2012. Sensitivity tests on PBL heights, on the derived regional background and on wind speeds suggest our divergence method is quite robust. It is also a fast and simple method to estimate the CH4 emissions globally.