Found 2681 publications. Showing page 1 of 269:
Nitrogen dioxide (NO2) is a well-known air pollutant, mostly elevated by car traffic in cities. To date, small, reliable, cost-efficient multipollutant sensors with sufficient power and accuracy for community-based atmospheric studies are still lacking. The HAPADS (highly accurate and autonomous programmable platforms for providing air pollution data services) platforms, developed and tested in real conditions, can be a possible approach to solving this issue. The developed HAPADS platforms are equipped with three different NO2 sensors (7E4-NO2–5, SGX-7NO2, MICS-2711 MOS) and a combined ambient air temperature, humidity, and pressure sensor (BME280). The platforms were tested during the driving test, which was conducted across various roads, including highways, expressways, and national and regional routes, as well as major cities and the countryside, to analyse the environmental conditions as much as possible (Poland, 2024). The correlation coefficient r was more than 0.8, and RMSE (root mean squared error) was in the 3.3–4.3 μg/m3 range during the calibration process. The results obtained during the driving tests showed R2 of 0.9–1.0, which proves the ability of HAPADS platforms to work in the hard environmental conditions (including high rain and snow, as well as sun and a wide range of temperatures and humidity).
2026
Quantifying European SF6 emissions from 2005 to 2021 using a large inversion ensemble
Abstract. Sulfur hexafluoride (SF6) is a highly potent and long-lived greenhouse gas whose atmospheric concentrations are increasing due to human emissions. In this study, we determine European SF6 emissions from 2005 to 2021 using a large ensemble of atmospheric inversions. To assess uncertainty, we systematically vary key inversion parameters across 986 sensitivity tests and apply a Monte Carlo approach to randomly combine these parameters in 1003 additional inversions. Our analysis focuses on high-emitting countries with robust observational coverage – UK, Germany, France, and Italy – while also examining aggregated EU-27 emissions. SF6 emissions declined across all studied regions except Italy, largely attributed to EU F-gas regulations (2006, 2014), however, national reports underestimated emissions: (i) UK emissions dropped from 68 (47–77) t yr−1 in 2008 to 19 (15–26) t yr−1 in 2018, aligning with the reports from 2018 onward; (ii) French emissions fell from 78 (51–117) t yr−1 (2005) to 35 (19–54) t yr−1 (2021), exceeding reports by 88 %; (iii) Italian emissions fluctuated (25–48 t yr−1), surpassing reports by 107 %; (iv) German emissions declined from 182 (155–251) t yr−1 (2005) to 97 (88–104) t yr−1 (2021), aligning reasonably well with reports; (v) EU-27 emissions decreased from 403 (335–501) t yr−1 (2005) to 225 (191–260) t yr−1 (2021), exceeding reports by 20 %. A substantial drop from 2017 to 2018 mirrored the trend in southern Germany, suggesting regional actions were taken as the 2014 EU regulation took effect. Our sensitivity tests highlight the crucial role of dense monitoring networks in improving inversion reliability. The UK system expansions (2012, 2014) significantly enhanced result robustness, demonstrating the importance of comprehensive observational networks in refining emission estimates.
2025
Biomethanol as a Marine Fuel Within Land Use Sustainability Boundaries
Global shipping is an essential, energy-efficient enabler of trade, yet it remains a hard-to-abate sector. With shipping demand projected to continue to rise in the coming decades, identifying scalable and sustainable fuel alternatives is critical. Biofuels, and particularly biomethanol, offer a promising option due to their compatibility with existing infrastructure. However, their sustainability critically hinges on land use impacts. From this Perspective, we argue that biomethanol derived from a dedicated crop could contribute to maritime decarbonisation, with ~71–77% well-to-wake greenhouse gases (GHG) reductions under cropland-only constraints. We further point to the fact that a wider adoption faces challenges such as higher costs, limited availability, and lower energy density relative to fossil fuels. Continued research and monitoring are essential to ensure that biofuel production does not inadvertently contribute to deforestation or biodiversity loss. We underscore the need for spatially sensitive biofuel deployment strategies that align maritime decarbonisation with land-system sustainability and climate objectives.
2025
Fine particulate matter (PM) poses a major threat to public health, with organic aerosol (OA) being a key component. Major OA sources, hydrocarbon-like OA (HOA), biomass burning OA (BBOA), and oxygenated OA (OOA), have distinct health and environmental impacts. However, OA source apportionment via positive matrix factorization (PMF) applied to aerosol mass spectrometry (AMS) or aerosol chemical speciation monitoring (ACSM) data is costly and limited to a few supersites, leaving over 80% of OA data uncategorized in global monitoring networks. To address this gap, we trained machine learning models to predict HOA, BBOA, and OOA using limited OA source apportionment data and widely available organic carbon (OC) measurements across Europe (2010–2019). Our best performing model expanded the OA source data set 4-fold, yielding 85 000 daily apportionment values across 180 sites. Results show that HOA and BBOA peak in winter, particularly in urban areas, while OOA, consistently the dominant fraction, is more regionally distributed with less seasonal variability. This study provides a significantly expanded OA source data set, enabling better identification of pollution hotspots and supporting high-resolution exposure assessments.
2025
2025
Reliable quantification of polychlorinated alkanes (PCAs) remains a major challenge, hindering environmental research across diverse matrices. Each sample can contain over 500 homologue groups, collectively producing >1000 m/z ratios that require interference checks. High-resolution mass spectrometry methods vary in ionization signals and data formats and require specialized algorithms for quantification. CPxplorer streamlines data processing through the integration of three modules: (1) CPions generates target ion sets and isotopic thresholds for compound identification into the next module; (2) Skyline performs instrument-independent data integration, interference evaluation, and homologue profiling; and (3) CPquant deconvolves homologues and reports concentrations using reference standards and homologue profiles from Skyline. Evaluation of the workflow with NIST-SRM-2585 dust and ERM-CE100 fish tissue material yielded comparable results across raw data formats from different instruments. Further applications of CPxplorer across diverse matrices, including indoor dust, organic films, silicone wrist bands, and food samples, demonstrated the usefulness in biological and environmental monitoring. Compared to existing tools limited to qualitative detection, CPxplorer enables quantitative outputs, reduces processing time, and expands functionality to PCA-like substances (e.g., BCAs) and PCA degradation products (e.g., OH-PCAs). CPxplorer reduces learning barriers, empowers users to quantify PCAs across various analytical instruments, and contributes to generating comparable results in the field.
2025
Tidal Amplification in the Lower Thermosphere During the 2003 October–November Solar Storms
Abstract Using the National Center for Atmospheric Research's vertically extended version of the Whole Atmosphere Community Climate Model nudged with reanalyses, we examine the impact of the 2003 Halloween solar storms on atmospheric tides and planetary waves in the lower thermosphere (LT). One of the largest solar flares and fastest coronal mass ejections on record occurred on 30 October, resulting in significant energy transfer via Joule heating and auroral particle precipitation in the Earth's higher latitude thermosphere. In the simulation, that occurrence creates large zonally asymmetric heating perturbations, amplifying the diurnal migrating tide (DW1), semidiurnal migrating tide (SW2), as well as non‐migrating westward and eastward tides between 120 and 200 km. Large‐amplitude bursts of DW1 in the Northern Hemisphere and non‐migrating westward tides in the Southern Hemisphere lead to westward wave forcings, which strengthen the thermospheric wind. Planetary waves are also amplified, but their forcing is much weaker than the forcing exerted by tides in the LT. Non‐migrating tides are generated by nonlinear interactions between tides, or between tides and quasi‐stationary planetary waves, and in situ processes in the LT linked to Joule heating and auroral particle precipitation. The induced disruptions of the thermospheric mean meridional circulation reinforce the Spring thermospheric branch in the Southern Hemisphere at high latitudes and oppose the Fall branch in the Northern Hemisphere. Our examination could be relevant to understand the dynamical impact of recent geomagnetic storms that occurred in May 2024 and October 2024.
2025
The role of the tropical carbon balance in determining the large atmospheric CO2 growth rate in 2023
Abstract. The global annual mean atmospheric CO2 growth rate in 2023 was one of the highest since records began in 1958, comparable to values recorded during previous major El Niño events. We do not fully understand this anomalous growth rate, although a recent study highlighted the role of boreal North American forest fires. We use a Bayesian inverse method to interpret global-scale atmospheric CO2 data from NASA's Orbiting Carbon Observatory (OCO-2). The resulting a posteriori CO2 flux estimates reveal that from 2022 to 2023, the biggest changes in CO2 fluxes of net biosphere exchange (NBE) – for which positive values denote a flux to the atmosphere – were over the land tropics. We find that the largest NBE increase is over eastern Brazil, with small increases over southern Africa and Southeast Asia. We also find significant increases over southeastern Australia, Alaska, and western Russia. A large NBE increase over boreal North America, due to fires, is driven by our a priori inventory, informed by independent data. The largest NBE reductions are over western Europe, the USA, and central Canada. Our NBE estimates are consistent with gross primary production estimates inferred from satellite observations of solar-induced fluorescence and from satellite observations of vegetation greenness. We find that warmer temperatures in 2023 explain most of the NBE change over eastern Brazil, with hydrological changes more important elsewhere across the tropics. Our results suggest that the ongoing environmental degradation of the Amazon is now playing a substantial role in increasing the global atmospheric CO2 growth rate.
2025
Satellite instruments for measuring atmospheric column mixing ratios have improved significantly over the past couple of decades, with increases in pixel resolution and accuracy. As a result, satellite observations are being increasingly used in atmospheric inversions to improve estimates of emissions of greenhouse gases (GHGs), particularly CO2 and CH4, and to constrain regional and national emission budgets. However, in order to make use of the increasing resolution in inversions, the atmospheric transport models used need to be able to represent the observations at these finer resolutions. Here, we present a new and computationally efficient methodology to model satellite column average mixing ratios with a Lagrangian particle dispersion model (LPDM) and calculate the Jacobian matrices describing the relationship between surface fluxes of GHGs and atmospheric column average mixing ratios, as needed in inversions. The development will enable a more accurate representation of satellite observations (especially high-resolution ones) via the use of LPDMs and, thus, help improve the accuracy of emission estimates obtained by atmospheric inversions. We present a case study using this methodology in the FLEXPART (FLEXible PARTicle dispersion model) LPDM and the FLEXINVERT inversion framework to estimate CH4 fluxes over Siberia using column average mixing ratios of CH4 (XCH4) from the TROPOMI (TROPOspheric Monitoring Instrument) instrument aboard the Sentinel-5P satellite. The results of the inversion using TROPOMI XCH4 are evaluated against results using ground-based observations.
2025
Removal Processes of the Stratospheric SO2 Volcanic Plume From the 2015 Calbuco Eruption
Abstract We analyze the volcanic plume from the April 2015 Calbuco eruption over a 35‐day period using simulations from Meso‐NH, a non‐hydrostatic mesoscale atmospheric model. A dedicated parameterization of the deep injection of the plume into the stratosphere ensures a realistic representation when compared to Infrared Atmospheric Sounding Interferometer satellite observations. During the first 12 hr of the eruption, on 22 April 2015, SO 2 mixing ratio reached 29 ppmv between 15 and 18 km for the first eruption pulse, and 38 ppmv between 12 and 16 km for the second. Most SO 2 was injected directly into the stratosphere, with a stratospheric load reaching 308 ktS (kilotons of atomic sulfur, i.e. 616 kilotons of SO 2 ) after the eruption. After 1 month, both stratospheric and tropospheric SO 2 loads returned to near‐background levels. During analysis, the chemical conversion of SO 2 into H 2 SO 4 removed a part of SO 2 from the stratosphere. During the long‐range advection, the co‐location between the subtropical jet stream and the Calbuco plume led to three significant stratospheric intrusions on 24, 26 and 28 April 2015. These events transferred stratospheric SO 2 into the troposphere, SO 2 mixing ratios in the upper troposphere reaching 15 ppmv, 26 and 15 ppbv, respectively. SO 2 is gradually oxidized into H 2 SO 4 , with up to 5 ktS of gaseous H 2 SO 4 in the stratosphere on 30 April, but dynamical processes dominate the SO 2 atmospheric budget over chemical transformations. This study demonstrates that stratospheric intrusions can play a critical role in the removal of volcanic material from the stratosphere following a major eruption.
2025