A5058895036- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Climate variability and models
- Vehicle emissions and performance
- Atmospheric Ozone and Climate
- Aeolian processes and effects
- Meteorological Phenomena and Simulations
- Water Systems and Optimization
- Ship Hydrodynamics and Maneuverability
- Fluid Dynamics Simulations and Interactions
- Icing and De-icing Technologies
- Magnetic properties of thin films
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Air Quality Monitoring and Forecasting
- Statistical Methods and Inference
- Magneto-Optical Properties and Applications
- Precipitation Measurement and Analysis
- Multiferroics and related materials
- Advanced Image Fusion Techniques
- Energy Load and Power Forecasting
- Infrared Target Detection Methodologies
- Advanced Causal Inference Techniques
- Characterization and Applications of Magnetic Nanoparticles
University of Oxford
2020-2024
Institut de Ciència de Materials de Barcelona
2020
Abstract Ships brighten low marine clouds from emissions of sulfur and aerosols, resulting in visible “ship tracks”. In 2020, new shipping regulations mandated an ∼80% reduction the allowed fuel content. Recent observations indicate that ship tracks have decreased. Model simulations since 2020 induced a net radiative forcing +0.12 Wm −2 . Analysis recent temperature anomalies indicates Northern Hemisphere surface 2022–2023 are correlated with observed cloud is spatially simulated emission...
Abstract Cloud reflectivity is sensitive to atmospheric aerosol concentrations because aerosols provide the condensation nuclei on which water condenses 1 . Increased due human activity affect droplet number concentration, liquid and cloud fraction 2 , but these changes are subject large uncertainties 3 Ship tracks, long lines of polluted clouds that visible in satellite images, one main tools for quantifying aerosol–cloud interactions 4 However, only a small by shipping show ship tracks 5,6...
Abstract Many different emission pathways exist that are compatible with the Paris climate agreement, and many more possible miss target. While some of most complex Earth System Models have simulated a small selection Shared Socioeconomic Pathways, it is impractical to use these expensive models fully explore space possibilities. Such explorations therefore mostly rely on one‐dimensional impulse response models, or simple pattern scaling approaches approximate physical given scenario. Here...
Using hybrid piezoelectric-magnetic systems we have generated large amplitude magnetization waves mediated by magnetoelasticity with up to 25 degrees variation in the orientation. We present direct imaging and quantification of both standing propagating acoustomagnetic different wavelengths, over distances several millimeters a nickel thin film.Received 2 January 2020Accepted 5 March 2020DOI:https://doi.org/10.1103/PhysRevLett.124.137202© 2020 American Physical SocietyPhysics Subject...
Data assimilation of observational data into full atmospheric states is essential for weather forecast model initialization. Recently, methods deep generative have been proposed which allow using new input without retraining the model. They could also dramatically accelerate costly process used in operational regional models. Here, a central US testbed, we demonstrate viability score-based context realistically complex km-scale weather. We train an unconditional diffusion to generate...
The idea of invisible ship tracks for the study aerosol-cloud interactions sounds promising: We have been studying effects aerosols on clouds many years, among others by investigating bright lines left in low marine ships. However, only a small fraction ships leaves behind visible tracks. This means we can under certain meteorological conditions, biasing our understanding. Instead, all polluted ('invisible tracks') with methodology developed, should be able to get full picture interactions....
Abstract. Human aerosol emissions change cloud properties by providing additional condensation nuclei. This increases droplet numbers, which in turn affects other like liquid-water content and ultimately albedo. These adjustments are poorly constrained, making effects the most uncertain part of anthropogenic climate forcing. Here we show that number water react differently to changing emission amounts shipping exhausts. We use information about ship positions modeled together with reanalysis...
Abstract. The assessment of aerosol-cloud interactions remains a major source uncertainty in understanding climate change, partly due to the difficulty making accurate observations aerosol impacts on clouds. Ships can release large numbers aerosols that serve as cloud condensation nuclei, which create artificially brightened clouds known ship tracks. These emissions offer "natural'', or "opportunistic'', experiment explore effects while disentangling meteorological influences. Utilising...
Many different emission pathways exist that are compatible with the Paris climate agreement, and many more possible miss target. While some of most complex Earth System Models have simulated a small selection Shared Socioeconomic Pathways, it is impractical to use these expensive models fully explore space possibilities. Such explorations therefore mostly rely on one-dimensional impulse response models, or simple pattern scaling approaches approximate physical given scenario. Here we present...
Abstract. Human aerosol emissions change cloud properties by providing additional condensation nuclei. This increases droplet numbers, which in turn affects other like liquid water content, and ultimately albedo. These adjustments are poorly constrained, making effects the most uncertain part of anthropogenic climate forcing. Here we show that number content react differently to changing emission amounts shipping exhausts. We use information about ship positions modelled together with...
1 Null experiment with uncorrelated winds and satellite data Figure S1.The 3 cases investigated in this study: the 2018 ship tracks case, first null (with both MODIS from 2019), second 2019).The has significantly different response to correlated experiment, recovering more of a response.We consider an analogy Manshausen et al. ( 2023), as seen Tab. 1, where locations ERA5 are year before overpass.These that used predict track will be essentially cloud properties retrieved, therefore...
Aerosol-cloud interactions continue to resist reliable quantification, partly owing their strong dependence on cloud and weather regimes. For a long time, opportunistic experiments such as ship tracks have been used overcome issues of confounding. Recent advances leverage (i) Machine Learning (ML) drastically enlarge track data bases, (ii) ‘invisible tracks’, found by advecting emissions, selection biases in studies. Here, we combine both approaches, advance our...
Data assimilation of observational data into full atmospheric states is essential for weather forecast model initialization. Recently, methods deep generative have been proposed which allow using new input without retraining the model. They could also dramatically accelerate costly process used in operational regional models. Here, a central US testbed, we demonstrate viability score-based context realistically complex km-scale weather. We train an unconditional diffusion to generate...
The ability of anthropogenic aerosols to freeze supercooled cloud droplets remains debated. In this work, we present observational evidence for the glaciation liquid-water clouds at industrial aerosol hot spots temperatures between -10° and -24°C. Compared with nearby clouds, shortwave reflectance was reduced by 14% longwave radiance increased 4% in glaciation-affected regions. There an 8% reduction cover 18% optical thickness. Additionally, daily glaciation-induced snowfall accumulations...
Abstract. The assessment of aerosol–cloud interactions remains a major source uncertainty in understanding climate change, partly due to the difficulty making accurate observations aerosol impacts on clouds. Ships can release large numbers aerosols that serve as cloud condensation nuclei, which create artificially brightened clouds known ship tracks. These emissions offer “natural”, or “opportunistic”, experiment explore effects clouds, while also disentangling meteorological influences....
The recent explosion in applications of machine learning to satellite imagery often rely on visible images and therefore suffer from a lack data during the night. gap can be filled by employing available infra-red observations generate images. This work presents how deep applied successfully create those using U-Net based architectures. proposed methods show promising results, achieving structural similarity index (SSIM) up 86\% an independent test set providing visually convincing output...
Estimating the effects of continuous-valued interventions from observational data is a critically important task for climate science, healthcare, and economics. Recent work focuses on designing neural network architectures regularization functions to allow scalable estimation average individual-level dose-response curves high-dimensional, large-sample data. Such methodologies assume ignorability (observation all confounding variables) positivity treatment levels every covariate value...
Aerosol-cloud interactions include a myriad of effects that all begin when aerosol enters cloud and acts as condensation nuclei (CCN). An increase in CCN results decrease the mean droplet size (r$_{e}$). The smaller leads to brighter, more expansive, longer lasting clouds reflect incoming sunlight, thus cooling earth. Globally, aerosol-cloud cool Earth, however strength effect is heterogeneous over different meteorological regimes. Understanding how evolve function local environment can help...
Living downwind of a cement-producing or metallurgical plant could mean you get more snow, fewer clouds and sunshine compared to nearby areas. We use satellite observations reveal the glaciation supercooled stratiform liquid-phase by anthropogenic aerosols acting as ice-nucleating particles. There are strong indications that is caused emitted from oil refineries, coal-fired power plants, cement, metal smelting processing, chemical other air pollution sources in Europe, Asia, North America...
Aerosol-cloud interactions remain a large source of uncertainty in anthropogenic climate forcing. One the reasons for this is confounding role meteorology, influencing both aerosols and cloud properties. To untangle these variables, ship tracks, clouds polluted by shipping emissions, have been widely studied. Recently, use emissions locations amounts, combined with reanalysis winds, has allowed us to study following they are advected time satellite measurement clouds. This possible even when...
Abstract The effects of anthropogenic aerosol, solid or liquid particles suspended in the air, are biggest contributor to uncertainty current climate perturbations. Heavy industry sites, such as coal power plants and steel manufacturers, large sources greenhouse gases, also emit amounts aerosol a small area. This makes them ideal places study interactions with radiation clouds. However, existing data sets heavy locations either not public, suffer from reporting gaps. Here, we develop...