Found 10456 publications. Showing page 410 of 419:
Unprecedented shifts in aerosol pollution sources in China under a decade of clean air actions
China is a major hotspot of black carbon (BC) emissions, contributing to climate warming and risk to public health. Here, our dual-isotope-constrained observations indicate stringent air pollution controls have drastically reduced coal-burning in North China over the past decade, marking a transition to a “post-coal” era compared to earlier 2012–2014. However, biomass-burning fraction (fbb) for north/central/east winter hazes has doubled from earlier (north/east) ~20%, with significantly higher fbb during polluted winters. Comparisons between observation and transport modelling show good alignment in BC concentrations but substantial discrepancies in source attribution (i.e., fbb). Leveraging radiocarbon measurements, advanced atmospheric modelling, and a Bayesian approach, our study identifies biases stemming from misallocated residential fuel types in emission inventories. These findings underscore the untapped potential to mitigate BC emissions by targeting rural biomass burning, while providing critical insights into BC source evolution to refine emission inventories and formulate effective air quality policies for China and other nations facing severe air pollution.
2025
Divergent impacts of climate interventions on China’s north-south water divide
Abstract Solar radiation modification-based climate interventions may cause uneven regional hydrological changes while mitigating warming. Here, we investigate the effects of climate interventions on China’s North Drought-South Flood pattern using the Norwegian Earth System Model supplemented by volcanic data. Our results indicate that equatorial stratospheric aerosol injection could mitigate the north-south water divide by reducing inter-hemispheric and equator-to-North-pole temperature gradients, thereby modifying atmospheric circulation and the East Asian monsoon to increase precipitation and surface runoff in northern China while reducing them in the south, compared to the high emissions scenario. This mechanism is supported by observed precipitation changes following the Mount Pinatubo volcanic eruption. In contrast, marine cloud brightening may intensify southern flood risks, while cirrus cloud thinning and moderate emissions reduction might exacerbate northern droughts. Our findings reveal distinct regional hydroclimatic impacts of different climate interventions, highlighting potential synergies and trade-offs between their global intervention efficacy and regional water security.
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 semi-annual oscillation (SAO) dominates seasonal variability in the equatorial stratosphere and mesosphere. However, the seasonally dependent modulation of the SAO in the stratosphere (SSAO) and mesosphere (MSAO) by sudden stratospheric warmings (SSWs) in the Arctic has not been investigated in detail. In this study, we examine the seasonal evolution of the SAO during 16 major SSW events spanning 2004 to 2024 using the Japanese Atmospheric General Circulation Model for Upper Atmosphere Research Data Assimilation System Whole Neutral Atmosphere Re-analysis (JAWARA). Basic features of the SAO are well captured by JAWARA, as evidenced by the SSAO and MSAO appearing at around 50 km and 85 km, respectively. The different responses of the SAO to early and late winter SSWs are particularly strong during the Northern Hemisphere winter of 2023/24. Early winter SSWs tend to significantly intensify the westward SSAO, while late winter SSWs tend to weaken the eastward SSAO. Similarly, the eastward MSAO is amplified during early winter SSWs, whereas the westward MSAO is slightly weakened during late winter SSWs. The weak MSAO response is probably due to its smaller climatological magnitude. Modulation of the SAO by SSWs is related to meridional temperature changes during SSWs through the thermal wind balance. Our findings contribute to the understanding of coupling between the tropics and high latitudes, as well as interhemispheric coupling.
2025
2025
Tore har 52 flyreiser på ett år: – Flaut
Tore Christian Sævold lever et dobbeltliv. I ti år har han pendlet fra Stockholm til Bergen for å holde liv i skuespillerkarrieren.
2025
2025
2025
Anthropogenic particles in surface waters from Adventfjorden (Svalbard)
The ubiquitous presence of microplastics and other anthropogenic compounds in the marine environment are unfortunately not surprising anymore. Recent publications are revealing the occurrence of those synthesized particles in even remote and/or pristine areas in different marine matrices like biota, water and sediment. Nevertheless, the knowledge about sources and transport mechanisms of those anthropogenic particles (APs) is still lacking, especially in the Arctic. In this study we investigated surface waters from Isfjorden and the branching Adventfjorden, where Longyearbyen the largest settlement of Svalbard is located. Here, untreated wastewater is released into the fjord system. At two sample sites upstream and two sample sites downstream, three replicates at each location have been collected in June 2021. APs larger than <50μm were investigated regarding size, shape, and polymer type via μFTIR spectroscopy. At each sampling station, APs were present. The highest concentration of APs was found upstream and downstream Isfjorden; whereas lower concentrations were found within Adventfjorden, closest to the wastewater outlet. Additives and polypropylene showed the highest frequencies. Besides local sources like the untreated wastewater, freshwater inputs, ship traffic or the northwards long-range transport from the south into the Arctic needs to be considered.
2025
Suspect screening helps detect chemicals in environmental samples without predefined target lists which can facilitate isolation of a larger number of substances. This study shows however that no single extraction method or analytical platform (LC-HRMS or GC-HRMS) can capture all relevant pollutants—at least half are missed. The technique works best for chemically similar families, where optimized methods can target specific classes or broader families of similar substances (e.g. PFAS). Effective grouping of similar substances is therefore essential. A broad coverage of substances can however be achieved if multiple sample extractions are performed and each extract is analysed on both LC- and GC-HRMS. Strategies where comparisons can be made over time or across locations will also help to isolate pollutant-related signals from the background. Such considerations must be integrated into programme design and budgeting for retrospective analysis. This will maximize likelihood of detection for the largest diversity of substances.
Norwegian Environment Agency, M-3038|2025
NILU
2026
2026
Franzefoss Husøya Kristiansund. Målinger av ammoniakk NH3 og flyktige organiske forbindelser VOC
NILU
2026
Global Atmospheric Microplastics Emissions Estimated Using Constrained Bayesian Inverse Modeling
We present an analysis of global atmospheric microplastics (MPs) concentration and deposition measurements using constrained Bayesian inverse modeling to estimate global MPs emissions. The proposed Bayesian framework explicitly accounts for unknown ratios between size fractions inherent to MPs measurements and incorporates prior emission information to stabilize the inversion. The coupling between observations and unknown emissions is established using the atmospheric transport model FLEXPART version 11 operated in backward mode for each measurement. Model parameters are inferred using a variational Bayes approach, resulting in an iterative estimation scheme that updates both model parameters and the effective spatial structure of the computational domain. This methodology reduces the need for manual intervention during the inversion process and limits potential bias in the results. The resulting global MPs emission estimates are evaluated against previously published ones. Acknowledgment:This research has been supported by the Czech Science Foundation (grant no. GA24-10400S). N.E. was funded by the Norwegian Research Council (NFR) project MAGIC (No.: 334086). FLEXPART model simulations are cross-atmospheric research infrastructure services provided by ATMO-ACCESS (EU grant agreement No 101008004). The computations were performed on resources provided by Sigma2 - the National Infrastructure for High Performance Computing and Data Storage in Norway.
2026
Exposures in Indoor Air Affecting Health
Indoor air quality (IAQ) is influenced by a wide range of chemical, biological and physical agents that can negatively impact physical, immunological and mental health. Adverse health effects depend on the type and concentration of pollutants, duration of exposure, and individual susceptibility. The availability of data on IAQ is limited, as are standardized approaches for evaluating its health impact. This expert review aims to describe the most important indoor air determinants affecting health, and present the IDEAL cluster, which comprises seven EU‐funded scientific projects on the topic of IAQ and human health. Across the IDEAL projects, knowledge is generated on exposure to a wide range of indoor air pollutants, including well‐known hazards and more explorative chemical and microbiological determinants. The projects will also contribute to the implementation of low‐cost and/or real‐time sensors on IAQ, as well as advanced chemical and microbiological analyses, and evaluate various interventions to improve IAQ. Several of them focus on particularly vulnerable groups. Raising public awareness and implementing measures to reduce pollutant levels are essential for safeguarding health, particularly in urban areas with elevated pollution levels.
2026
Marine Carbon Removal Gains Momentum But Can It Scale Responsibly?
As mCDR gains global traction, we discuss the current state of this sector with leading mCDR representatives.
2026
Large aerosol particles within the coarse mode affect the environment, climate, and human health in ways that strongly depend on particle type. Although this size range is dominated by mineral dust and sea spray aerosol (SSA), less abundant biological particles can exert disproportionate effects, such as triggering ice formation at comparatively warm temperatures. Accurate, type-resolved characterization of coarse-mode aerosols is therefore critical for understanding their environmental and climatic roles. Here, we present a new laboratory-based reference dataset for common coarse-mode aerosol sources, including pollen, dust, bacteria, and microplastics, based on laboratory measurements of single-particle ultraviolet light-induced fluorescence (UV-LIF) spectroscopy and particle morphology. Comparison with existing datasets reveals source-specific fluorescence signatures, but also demonstrates substantial overlap between biological and non-biological particles, which can lead to misclassification when fluorescence information is used alone.Building on this dataset, we introduce a new machine-learning classification framework that combines fluorescence and morphological features. The algorithm is trained using laboratory data and evaluated with field observations from Zeppelin Observatory, Svalbard. To improve discrimination of combustion-related particles and to better separate dust from SSA, we apply domain adaptation using in situ measurements. The updated classifier successfully reproduces the previously reported annual bioaerosol cycle, yields higher bioaerosol concentrations than a fluorescence-only method, and maintains similar correlations with established biological and combustion tracers. Our open-source code enables more robust quantification of bioaerosols across a range of environments, allows reassessment of prior observations, and can be further improved as new particle characterization data become available.
2026
Heritable mutations in male germ cells pose a critical risk to human health and future generations, however standardized methods for assessing germ cell genotoxicity remain limited. We refined the in vivo alkaline comet assay (proof-of-concept (Dirven et al. 2023); protocol (Olsen et al. 2024)) to detect DNA damage in testicular germ cells, with selective addressment of haploid spermatids and primary spermatocytes. Measurements of DNA damage (% Tail DNA) and DNA content (total fluorescence intensity) in individual comets were combined with visual comet identification to distinguish testicular comet populations based on differences in DNA content and appearance. To verify the method’s functionality and reliability, DNA damage was assessed in rats exposed to the direct-acting, well-characterized genotoxicants X-rays and ethyl methanesulfonate across distinct testicular cell populations, alongside liver and blood. To minimize experimental variation, the protocol included stringent standardization of animal handling, tissue processing, and comet assay procedures. Both X-rays and EMS induced significant DNA damage in testicular germ cells, with comparable responses across testicular cell types and similar (X-rays) or higher levels observed in somatic tissues. The low inter-animal variability observed supports the robustness of the method. Importantly, inclusion of testicular germ cells in OECD test guideline 489 would provide a valuable tool for hazard identification and mutagenicity classification of chemicals under the Globally Harmonized System of Classification and Labelling of Chemicals. This versatile, sensitive, and resource-efficient assay enhances the assessment of male-mediated genetic risks and supports regulatory efforts to protect reproductive health and safeguard the genetic integrity of future generations through the use of safer chemicals.
2026
2026