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The aerosol particles serving as cloud condensation and ice nuclei contribute to key cloud processes associated with cold-air outbreak (CAO) events but are poorly constrained in climate models due to sparse observations. Here we retrieve aerosol number size distribution modes from measurements at Andenes, Norway, during the Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) and at Zeppelin Observatory, approximately 1000 km upwind from Andenes at Svalbard. During CAO events at Andenes, the sea-spray-mode number concentration is correlated with strong over-ocean winds with a mean of 8±4 cm−3 that is 71 % higher than during non-CAO conditions. Additionally, during CAO events at Andenes, the mean Hoppel minimum diameter is 6 nm smaller than during non-CAO conditions, though the estimated supersaturation is lower, and the mean number concentration of particles that likely activated in-cloud is 109±61 cm−3 with no statistically significant difference from the non-CAO mean of 99±66 cm−3. For CAO trajectories between Zeppelin Observatory and Andenes, the upwind-to-downwind change in number concentration is the largest for the accumulation mode with a mean decrease of 93±95 cm−3, likely attributable primarily to precipitation scavenging. These characteristic properties of aerosol number size distributions during CAO events provide guidance for evaluating CAO aerosol–cloud interaction processes in models. [ABSTRACT FROM AUTHOR]

Black carbon (BC) and brown carbon (BrC) both have a versatile nature, and they have an apparent role in climate variability and changes. As anthropogenic activity is surging, BC and BrC are also reportedly increasing. So, the monitoring of BC and BrC and observations of land use land cover change (LULCC) at a regional level are necessary for the changes in various interconnected meteorological phenomena. The current study investigates BC , BrC , CO2 , BC from fossil fuels (BCff), BC from biomass burning (BCbb), and LULCC and their relationship to the corresponding meteorological conditions over Gangtok in the Sikkim Himalayan region. The concentration of BC (BrC) was found to be highest during March 2022 (April 2021) at 43.5 µgm-3 (32.0 µgm-3)​​​​​​​. Surface pressure exhibits a significant positive correlation with BC , BCff , BCbb , and BrC. Higher surface pressure results in a calmer and more stable boundary layer, which effectively retains deposited contaminants. Conversely, the wind appears to facilitate the dispersion of pollutants, showing a strong negative correlation. The fact that all pollutants and precipitation have been shown to behave similarly points to moist scavenging of the pollutants. Despite the dense cloud cover, it is clear that the area is not receiving convective precipitation, implying that orographic precipitation is occurring over the region. Most of Sikkim receives convective rain from May to September, indicating that the region has significant convective activity contributed from the Bay of Bengal during the monsoon season. Furthermore, monsoon months have the lowest concentrations of BC , BCbb , BCff , and BrC , suggesting the potential of convective rain (as rainout scavenging) to remove most of the pollutants. [ABSTRACT FROM AUTHOR]

This study presents an improved wet scavenging process for particles in air quality modeling, focusing on the Korean Peninsula. New equations were incorporated into the air quality chemical transport model (CTM) to enhance the simulation of particulate matter (PM) concentrations. The modified air quality CTM module, utilizing size-dependent scavenging formulas, was applied to simulate air quality for April 2018, a month characterized by significant precipitation. Results showed that the modified model produced more accurate predictions of PM10 and PM2.5 concentrations compared to the original air quality CTM model. The maximum monthly average differences were 5.46 µg/m3 for PM10 and 2.87 µg/m3 for PM2.5, with pronounced improvements in high-concentration regions. Time-series analyses for Seoul and Busan demonstrated better agreement between modeled and observed values. Spatial distribution comparisons revealed enhanced accuracy, particularly in metropolitan areas. This study highlights the importance of incorporating region-specific, size-dependent wet scavenging processes in air quality models. The improved model shows promise for more accurate air quality predictions, potentially benefiting environmental management and policy-making in the region. Future research should focus on integrating more empirical data to further refine the wet scavenging process in air quality modeling. [ABSTRACT FROM AUTHOR]

Predaceous diving beetle adults scavenge for carrion in freshwater habitats. We identified two scavenging strategies used by adult Dytiscus sinensis Feng (Coleoptera: Dytiscidae) to locate and consume food at the bottom of water when needing to surface for air store renewal: dine‐in then relocate the food (dine‐in strategy) and carry the food to the surface (take‐away strategy). In 5‐cm‐deep water, a higher proportion of individuals successfully located food within an 8‐min test window than in 25‐cm‐deep water. Their latencies to locating food did not differ among depths. Dytiscus sinensis adults preferred the take‐away strategy in 5‐cm‐deep water and a higher proportion of them adopted the dine‐in strategy in 25‐cm‐deep water. Further, a 10‐cm‐deep test showed that the success rate or efficiency of relocating food did not increase with the experience of locating it the first time. This might explain why D. sinensis preferred the take‐away strategy in shallower water, in which it had lower risks of losing the food. The present study revealed a direct bottom‐up benefit for dytiscids foraging in shallower water where finding and securing food were easier. Our findings demonstrate that the surfacing requirement of dytiscid adults was reflected in foraging strategies with depth‐dependent preferences. [ABSTRACT FROM AUTHOR]

In the present study, the effect of chloride ions on the oxidative degradation of an alcohol ethoxylate (Brij 30) by persulfate (PS)/UV-C was experimentally explored using Brij 30 aqueous solution (BAS) and a domestic wastewater treatment plant effluent spiked with Brij 30. Brij 30 degradation occurred rapidly during the early stages of oxidation without affecting the water/wastewater matrix. Mineralization of intermediates of Brij 30 degradation markedly influenced by presence of chloride ions. Chloride ions at concentrations up to 50 mg/L accelerated the mineralization through reactions involving reactive chlorine species, which reduced the sink of SO4·− by Cl− scavenging at both initial pH of 6.0 and 3.0 in the case of BAS. The fastest mineralization was achieved under acidic conditions. The WWTP effluent matrix significantly influenced mineralization efficacy of the intermediates. Co-existence of HCO 3 - and Cl− anions accelerated the mineralization of degradation products. Organic matter originating from the WWTP effluent itself had an adverse effect on the mineralization rate. The positive effects of organic and inorganic components present in the WWTP effluent were ranked in the following order of increasing influence: (Organic matter originating from the effluent + Cl− + HCO 3 - ) < (Cl−) < (Cl− + HCO 3 - ). [ABSTRACT FROM AUTHOR]

Bursting bubbles transport bacteria, viruses, and other marine particles across the air‐sea interface. This effect is enhanced when particles are hydrophobic and cling to the bubbles as they rise. Recent studies suggest that plastic particles, a major ocean pollutant, can also be transported by sea spray. However, estimates of plastic transport via this pathway have large uncertainties due to limited size detection techniques in field studies and few lab studies. An understanding of the number and size of particles carried in the smallest drops, which have the longest residence time in the atmosphere, is missing from current literature. Here, we develop a modeling framework to provide bounds on the number, area, and volume transport of non‐scavenged hydrophilic and fully‐scavenged hydrophobic particles of radii between 0.1 and 100 μm for a range of jet and film drops. For droplets containing plastic particulates, we predict particle enrichment is significantly higher in jet drops than film drops. For particles in these jet drops, our results suggest that in the absence of bubble scavenging, the number distribution is dominated by smaller plastics, the mass/volume distribution by larger plastics, and surface area distribution is balanced across plastic size. Whereas for hydrophobic particles, scavenging dramatically modifies these distributions, enhancing certain particle–droplet size combinations by over four orders of magnitude. Our predictions suggest critical effects of enrichment in air‐sea particle transport and highlight the variable dependencies on bubble and particle size, improving our theoretical understanding of plastic and marine particle transport and identifying modeling assumptions to refine with experimental measurements. Plain Language Summary: Plastic particles in the oceans are a topic of growing concern due to their spread throughout the environment. The oceans are a reservoir of plastics, however recent studies have found that bursting bubbles can eject the plastic into the atmosphere, where it has the potential to be transported much further. We create a first‐principles modeling framework to estimate the expected effects of particle and bubble size on the transport of hydrophobic and hydrophilic particles. We predict bounds on the extent that hydrophobic particles, like some plastics, may be highly selected to become airborne compared to hydrophilic particles. Selectivity effects are especially significant for the small airborne drops, which is important if it is the size of the drops rather than the size of the particle that influences the time they remain suspended in the atmosphere. This model provides a means to untangle the effects of bubble and particle size, as well as provide theoretical predictions to test against experimental data. This generic framework can be applied to the air‐sea transport of particles beyond plastics, with important implications to the selective aerosolization of other particles such as viruses or bacteria. Key Points: Modeling reveals how the air‐sea transfer of hydrophilic/phobic particles between 0.1 and 100 μm in radius varies with particle and bubble sizeParticle hydrophobicity may be key to air‐sea transport as particles are selectively aerosolized up to 300,000x under the conditions modeledFor drops containing plastic particulates, model predicts particle enrichment is significantly higher in jet drops than film drops [ABSTRACT FROM AUTHOR]

Sustainable water management is very important for industries with high water consumption and wastewater generation, such as the textile industry. This study aims to investigate the treatment of textile wastewater with ultraviolet (UV) assisted and Fe2+ catalyzed sodium percarbonate (SPC) oxidation, which is an eco-friendly treatment method in terms of both added oxidant and activation methods. Based on the removal efficiencies and reaction rates, a sorting was made as UV/SPC/Fe2+ > SPC/Fe2+ > UV/Fe2+ > UV/SPC > SPC > UV. It was observed that the removal efficiencies increased as the SPC dose increased, and decreased due to the scavenging effect with the 5 g/L oxidant dose, and the optimum SPC dose was determined as 2.5 g/L. It was determined that the removal efficiencies were higher in acidic conditions and high UV power applications. Under optimum operating conditions (pH:3, SPC dose: 2.5 g/L, Fe2+ dose: 1 g/L, UV lamps: 4), 68% COD, 80.9% UV254, and 92% color removal were achieved. Under optimum conditions energy cost, chemical cost, and operational cost were calculated as 11.9 $/m3, 0.20 $/m3, and 12.1 $/m3, respectively. By reducing the process COD concentration to 236.2 mg/L, discharge standards have been achieved, and the applicability of the UV/SPC/Fe2+ process was proven. [ABSTRACT FROM AUTHOR]

The fabrication of environmentally friendly materials for wastewater remediation represents a promising approach. Thus, we present the fabrication of nanostructured CoFe2O4 (CF) particles entangled within a hydrogel-based matrix composed of carboxy methyl cellulose-psyllium-RGO (CPRHG/CF). The functionality, composition, and nature of the fabricated composite were characterized using FTIR, XRD, and XPS techniques. Furthermore, the internal and surface morphology was analyzed through FE-SEM and HR-TEM imaging. To assess the photo activity, UV-Vis and photoluminescence (PL) spectroscopy were employed, confirming that CPRHG/CF exhibits significant potential for light absorption in the visible spectrum while minimizing the charge recombination rate. The fabricated CPR/CFHG composite hydrogel was employed for the removal of pharmaceutical effluent, tramadol (TMD), via both adsorption and photocatalysis processes. In batch adsorption experiments lasting 2 hours, the composite hydrogel demonstrated impressive adsorption efficiency of 92.93% and a maximum adsorption capacity of 89.97 mg g-1. Subsequently, during photocatalytic treatment under 1 h of solar illumination, approximately 90.36% of the TMD was successfully degraded. The degradation process followed a pseudo-firstorder kinetics model with a rate constant (k1) of 0.0380 min-1. Furthermore, the investigation of reactive oxygen species (ROS) has identified superoxide radicals (O2 -) as the major species responsible for the degradation process, which was confirmed through radical scavenging experiments. [ABSTRACT FROM AUTHOR]

Hydrothermal vents serve as a primary interface between the cold deep ocean and the warm oceanic crust. While early research showed that seawater-rock interactions add to or remove elements from seawater during the generation of hydro-thermal fluids, consideration of these fluid fluxes alone does not relay the total impact that hydrothermal systems have on seawater geochemistry. In addition, hydrothermal plumes, areas where hydrothermal fluids mix with ocean waters, are host to a range of particle precipitation and scavenging reactions that further modify gross hydro-thermal fluid fluxes to define the total "net" hydrothermal impact on oceanic inventories. Here, we review the major discoveries made by the international GEOTRACES program regarding the geochemical transformations occurring within hydrothermal plumes. We classify each element into one of five categories based on its behavior in hydrothermal plumes, a spectrum spanning the geochemical mass balance between net hydrothermal source fluxes and net hydrothermal plume scavenging sinks. Overall, we celebrate the role that GEOTRACES has played in defining the extent and dynamics of hydrothermal plume geochemistry, which is a crucial lever for determining global hydrothermal impacts. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS), which are key cellular signalling molecules, are reactive chemicals containing oxygen. Cell survival or death is a critical issue in the inflammatory response. Accumulation of ROS involves ROS generation and scavenging, which determine ROS homeostasis. Understanding the roles of ROS in modulating the inflammatory response in fish is vital for helping protect fish from the damage of water pollutants in harsh environmental conditions. ROS‐related key genes and signalling pathways are relatively conserved in fish but vary among different species. Recent frequent incidences of fish diseases have posed a considerable challenge to large‐scale aquaculture. ROS is important in stress perception, integration of diverse stress‐responsive signalling networks, and activation of animal defence mechanisms, which frequently occur during inflammation in fish. This review summarises recent studies on ROS signalling pathways during inflammation in fish. Furthermore, it examines the relationship between ROS and inflammation in fish. This review may contribute to the understanding of the underlying mechanisms by which ROS regulate inflammation in fish and provide suggestions for sustainable development in aquaculture. [ABSTRACT FROM AUTHOR]

Lignanoids are an active ingredient exerting powerful antioxidant and anti-inflammatory effects in the treatment of many diseases. In order to improve the efficiency of the resource utilization of traditional Chinese medicine waste, Magnolia officinalis Rehder & E.H.Wilson residue (MOR) waste biomass was used as raw material in this study, and a series of deep eutectic solvents (ChUre, ChAce, ChPro, ChCit, ChOxa, ChMal, ChLac, ChLev, ChGly and ChEG) were selected to evaluate the extraction efficiency of lignanoids from MORs. The results showed that the best conditions for lignanoid extraction were a liquid–solid ratio of 40.50 mL/g, an HBD-HBA ratio of 2.06, a water percentage of 29.3%, an extract temperature of 337.65 K, and a time of 107 min. Under these conditions, the maximum lignanoid amount was 39.18 mg/g. In addition, the kinetics of the extraction process were investigated by mathematic modeling. In our antioxidant activity study, high antioxidant activity of the lignanoid extract was shown in scavenging four different types of free radicals (DPPH, ·OH, ABTS, and superoxide anions). At a concentration of 3 mg/mL, the total antioxidant capacity of the lignanoid extract was 1.795 U/mL, which was equal to 0.12 mg/mL of Vc solution. Furthermore, the antibacterial activity study found that the lignanoid extract exhibited good antibacterial effects against six tested pathogens. Among them, Staphylococcus aureus exerted the strongest antibacterial activity. Eventually, the correlation of the lignanoid extract with the biological activity and physicochemical properties of DESs is described using a heatmap, along with the evaluation of the in vitro hypoglycemic, in vitro hypolipidemic, immunomodulatory, and anti-inflammatory activity of the lignanoid extract. These findings can provide a theoretical foundation for the extraction of high-value components from waste biomass by deep eutectic solvents, as well as highlighting its specific significance in natural product development and utilization. [ABSTRACT FROM AUTHOR]

In this paper measurements are presented of the observed properties of aerosols and microphysics of clouds associated with the characteristics of precipitation in convective clouds that formed off the east coast of Barbados during EUREC4A. Most data were gathered by the instrumented British Antarctic Survey Twin Otter aircraft supported by detailed in-situ aerosol measurements at the Ragged Point observatory on Barbados as well as HALO and PoldiRad radars, dropsonde and satellite data. The development of precipitation was studied in the three aerosol regimes previously reported, i.e. one low aerosol regime and two containing desert dust that had been advected across the Atlantic Ocean. The later dust event also contained evidence of biomass burning aerosol. Results showed that the maximum intensity of rain was similar for all the aerosol regimes. Clouds that developed in an environment with high aerosol loading tended to be deeper than those that developed in the clean environment. It was also found that the greatest intensities occurred in clouds that had aggregated, in agreement with previous work. [ABSTRACT FROM AUTHOR]

In the North Pacific Subtropical Gyre, which is one of the largest oligotrophic regions, there is a lack of information regarding the sources and transport of trace metals through water mass mixing. Rare earth elements (REEs) are essential for tracing lithogenic sources and water mass transport. In this study, we present dissolved REE concentrations and the factors controlling their distributions in the northwest Pacific during a GEOTRACES cruise (GP09). In the surface water along 11°N, we observed input signals from the Philippine and the Hawaiian Islands, characterized by positive Eu anomalies and slightly elevated REE concentrations. By incorporating our data and published REE data from the northwest Pacific to the southeast Pacific (40°N–40°S), we demonstrated that the REE concentrations and Yb/Nd ratios can distinguish North Pacific Intermediate Water (NPIW), Antarctic Intermediate Water (AAIW), and modified AAIW. By estimating the ratio of water mass mixing, we suggest that heavy REEs are predominantly contributed by water mass mixing (e.g., 93 % ± 4% for Yb) and can be used as semi-conservative tracers to quantify the mixing of NPIW and modified AAIW at the potential density of 27.2 kg/m3. At ∼800 m depth at stations K12, K13, and K14, weak negative Ce anomalies (>0.1) were observed, indicating the lateral transport of water masses imprinted with sediment signals from the Philippine Islands. In the deep waters (>1500 m) at the Luzon Strait (station K1), we propose that the weak Ce negative anomalies (>0.08) and low Yb/Nd ratios (<5), combined with the low beam transmission, are the result of particle resuspension and release. In deep water (>2000 m), combining high-resolution REE measurements with water mass analysis, our research reveals that dissolved REEs (except Ce) are dominantly controlled by water mass mixing (e.g., 80 %∼100 % for Yb and 70 %∼100 % for Nd). For the non-conservative behavior, which is not explained by water mass mixing, the residual fraction of heavy REEs (<20 % for Yb) originates from release of sinking particles (organic matter and siliceous particles), while the remaining concentrations of light REEs (<30 % for Nd) may be influenced by a combination of particle release and scavenging processes. These findings highlight valuable information about lithogenic sources and the proportions of REE distributions that are controlled by physical and biogeochemical processes. Moreover, it emphasizes the applicability of heavy REEs as effective tracers for understanding basin-scale water mass mixing in the northwest Pacific. [ABSTRACT FROM AUTHOR]

Aerosols significantly affect cloud microphysics and energy budget in different ways. The contribution of the direct, semi‐direct, and indirect effects of aerosols on radiation are here investigated over the North Atlantic tropical ocean under different aerosol loadings. The Weather Research and Forecasting Model is used to perform a set of numerical idealized experiments, which are forced with prescribed aerosol profiles. We evaluate the effects of aerosols on modeled shallow clouds and surface radiative budget. The results indicate that large aerosol loadings are associated with enhanced cloudiness and reduced precipitation. While the change in rainfall is mainly due to the larger number of smaller droplets, the change in cloudiness is attributed to the effects of absorbing aerosols, mainly dust particles, which are responsible for a rise of temperature that feeds back onto specific humidity. As in the boundary layer the increase of moisture dominates, the net effect is a higher relative humidity, which favors the formation of thin low non‐precipitating clouds. The feedback accounts for a dynamical change in the lower troposphere: shortwave radiation absorption increases temperature at the top of the marine atmospheric boundary‐layer and reduces entrainment of warm and dry air, increasing low level moisture content. Despite the overall increase in cloudiness, daytime cloud cover is reduced. The semi‐direct effect of aerosols on clouds results in a warming of the surface, opposite to the indirect effect. [ABSTRACT FROM AUTHOR]

The response of the oceanic surface layer to atmospheric shallow convection is explored using realistic atmospheric large eddy simulations coupled with an oceanic 1D model with high vertical resolution. The effects of cloud shading, rain, and enhanced heat loss due to gust fronts on the edge of cold pools and their interactions are investigated in a case study of the Cooperative Indian Ocean Experiment on Intraseasonal Variability/Dynamics of the Madden–Julian Oscillation experiment in the tropical Indian Ocean, during a suppressed phase of the Madden–Julian Oscillation. Conditions of low surface wind and strong solar heating result in diurnal warming of the oceanic surface of 2 °C over a depth of 1 m. Analysis of specific periods covering the diurnal cycle shows the contrasting effects of cloud shading, rain, and turbulent heat fluxes under the cold pools on the sea temperature at the surface and below. On the one hand, decreasing the solar radiation (cloud shading) results in slight cooling extended horizontally and penetrating down to 1–2 m depth, depending on the time of the day. On the other hand, turbulent heat fluxes enhanced up to 300 W·$$ \cdotp $$m −2$$ {}^{-2} $$ by gusts and freshwater lenses due to rain act together and more locally. They isolate and strongly cool a thin inner layer at the surface, which eventually destabilizes the surface layer and propagates the cooling downward. The exact relative part and efficiency of these processes depend on the time evolution of the thermal stratification and vertical turbulent mixing in the oceanic upper layer. Surface cooling of up to −$$ - $$0.5 °C may occur in a few tens of minutes and last for several hours, significantly mitigating the effects of diurnal warming over large extents. [ABSTRACT FROM AUTHOR]

Estuarine processes are key in modulating the riverine input of particle-reactive trace elements to the ocean. An important, but still under-utilized member of these elements is beryllium-9 (9Be) that together with cosmogenic 10Be has been suggested to serve as a quantitative tracer of present and past continental weathering flux. This study investigates different pathways of terrigenous 9Be through coastal areas into the ocean, based on dissolved 9Be concentrations in surface and bottom waters together with corresponding particulate 9Be concentrations along the salinity gradient in the Changjiang Estuary. Dissolved 9Be in the Changjiang Estuary shows a non-conservative behavior: At low to mid-salinity where water is well-mixed, 9Be is removed from both surface and bottom waters at low salinity and then released back into the water column at mid-salinity. At high salinity where water is stratified, dissolved 9Be is removed from surface waters, but is released back into bottom waters. In combination with hydrochemical (e.g., dissolved oxygen) and particulate 9Be data obtained from different extracted phases, we attribute the removal of dissolved 9Be at low salinity to salt-induced colloidal flocculation, whereas in surface waters at high salinity, we ascribe the removal to biological scavenging facilitated by phytoplankton blooms. The release of 9Be into mid- and high-salinity bottom waters is likely dominated by benthic processes, including porewater diffusion and/or submarine groundwater discharge. The contribution from desorption of 9Be from suspended particulate matter is negligible throughout the entire estuary. We propose that the release of 9Be through benthic processes potentially presents the most important contributor to the marine 9Be budget, where this benthic flux of 9Be is likely enhanced by hypoxic conditions in coastal bottom waters. [ABSTRACT FROM AUTHOR]

Over the years, there have been discussions about the possibility of air pollution affecting the process of rain formation. In this study, we have developed a simplified model that represents the atmospheric dynamics and cloud microphysics to explore the impact of pollution on rain formation. We used an existing three-dimensional minimal model consisting of five equations, for which we added a simple bulk parametrization that represents the role of cloud condensation nuclei (CCN) in cloud formation processes. We conducted numerical tests using two CCN profiles, with either one or two accumulation layers and modified their abundance to explore the effects of different CCN concentrations and distributions. We conducted four numerical tests corresponding to the two aforementioned profiles with polluted and low-polluted scenarios. The numerical simulations suggested that a layer with high CCN concentration close to the surface tends to suppress precipitation, while the same concentration distributed over two layers tends to enhance the efficiency of rain formation. The simulations also showed that CCN particles far from the surface produced higher cloud tops and longer events, consistent with previous research. Although the model includes a stable representation of precipitating turbulent convection with bulk cloud microphysics, we expect its simplicity and conservation properties to allow for deeper theoretical analyses that can help us better understand the physical processes involved in the studied phenomenon. We hope this model will serve as a tool to explore different aerosol-related scenarios within the context of minimal models. [ABSTRACT FROM AUTHOR]

The aerosol particles that provide cloud condensation and ice nuclei contribute to key cloud processes associated with cold-air outbreak (CAO) events but are poorly constrained in climate models due to sparse observations. Here we retrieve aerosol size distribution modes from measurements at Andenes, Norway during the Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) and at Zeppelin Observatory, approximately 1000 km upwind in Svalbard. During CAO events at Andenes, the sea spray mode number concentration is correlated to strong over-ocean winds with a mean of 8±4 cm-3 that is 71 % higher than during non-CAO conditions. Additionally during CAO events at Andenes, the mean Hoppel minimum diameter is 6 nm smaller than during non-CAO conditions though the estimated supersaturation is lower and the number concentration of particles that likely activated in-cloud is 109±61 cm-3 (similar to non-CAO conditions). For CAO trajectories between Zeppelin Observatory and Andenes, the upwind-to-downwind change in number concentration is largest for the accumulation mode with a mean decrease of 93±95 cm-3, likely attributable primarily to precipitation scavenging. These characteristic properties of aerosol size distributions during CAO events provide guidance for evaluating CAO aerosol-cloud interaction processes in models. [ABSTRACT FROM AUTHOR]

Turbulence in clouds is known to enhance particle collision rates, as widely demonstrated for warm rain formation. A similar impact on ice growth processes is expected but a solid observational basis is missing. A statistical analysis of a 15‐month data set of cloud radar observations allows for the first time to quantify the impact of turbulence on ice aggregation and riming in Arctic low‐level mixed‐phase clouds. Increasing eddy dissipation rate (EDR), from below 10−4 to above 10−3 m2 s−3, yields larger ice aggregates, and higher particle concentration, likely caused by increasing fragmentation. In conditions more favorable to riming, higher EDR is associated with dramatically higher particle fall velocities (by up to 125%), under similar liquid water paths, indicative of markedly higher degrees of riming. Our findings thus reveal the key role of turbulence for cold precipitation formation, and highlight the need for an improved understanding of turbulence‐hydrometeor interactions in cold clouds. Plain Language Summary: Liquid and frozen precipitation mainly forms by collision and subsequent aggregation of small particles. Collisions between cloud particles, such as droplets and ice crystals, are thought to be increased by turbulence. While this effect has been intensively studied for liquid‐only clouds, the impact of turbulence on ice‐ice collisional growth (aggregation) and ice‐liquid collisional growth (riming) is expected but has so far been poorly quantified. We study the effect of turbulence on aggregation and riming based on a long‐term remote‐sensing data set of low‐level clouds containing both ice and liquid particles, recorded at the Arctic site of Ny‐Ålesund, Svalbard. Cloud radar observations are used to retrieve the dissipation rate of turbulent kinetic energy (i.e., the eddy dissipation rate; EDR), which is the relevant quantity driving increases in collision rates, and to characterize ice particle properties. We find evidence that higher EDR regimes enhance the aggregation of particles, and are associated with signatures of increased ice particle concentration, possibly caused by the production of particle fragments upon collision. In temperature regimes more favorable to riming, turbulence dramatically enhances the particles' fall velocity, denoting higher degrees of riming. Our findings thus highlight a key role of turbulence for the formation of precipitable ice. Key Points: Relation between turbulence and ice growth investigated based on long‐term remote sensing data set of Arctic low‐level mixed‐phase cloudsHigher eddy dissipation rate (EDR) correlates with larger ice aggregates, and possibly higher degrees of fragmentationHigh EDR is an essential component needed for the formation of rimed particles [ABSTRACT FROM AUTHOR]

Precipitation plays an important role in cloud and aerosol processes over the Southern Ocean (SO). The main objective of this study is to characterize SO precipitation properties associated with SO stratocumulus clouds. We use data from the Southern Ocean Clouds Radiation Aerosol Transport Experimental Study (SOCRATES), and leverage observations from airborne radar, lidar, and in situ probes. We find that for the cold‐topped clouds (cloud‐top‐temperature <0°C), the phase of precipitation with reflectivity >0 dBZ is predominantly ice, while reflectivity < −10 dBZ is predominantly liquid. Liquid‐phase precipitation properties are retrieved where radar and lidar are zenith‐pointing. Power‐law relationships between reflectivity (Z) and rain rate (R) are developed, and the derived Z–R relationships show vertical dependence and sensitivity to the presence of droplets with diameters between 10 and 40 μm. Using derived Z–R relationships, a reflectivity‐velocity (ZV) retrieval method, and a radar‐lidar retrieval method, we derive rain rate and other precipitation properties. The retrieved rain rate from all three methods shows good agreement with in‐situ aircraft estimates, with rain rates typically being quite light (<0.1 mm hr−1). We examine the vertical distribution of precipitation properties, and find that rain rate, precipitation number concentration, and precipitation liquid water all decrease as one gets closer to the surface, while precipitation size and distribution width increases. We also examine how cloud base rain rate (RCB) depends on cloud depth (H) and aerosol concentration (Na) for particles with a diameter greater than 70 nm, and find that RCB is proportional to H3.1Na−0.8 ${H}^{3.1}\,{N}_{a}^{-0.8}$. Plain Language Summary: Precipitation plays an important role over the Southern Ocean (SO), such as transferring water from the atmosphere to the ocean, and affecting clouds and aerosols (tiny airborne particles). This study aims to characterize SO precipitation properties using aircraft data that can count the number and size of cloud and precipitation droplets, as well as lidar and radar that measure light and microwaves respectively reflected by droplets. Using information from lidar, we can distinguish the precipitation phase, and we find that ice precipitation is more frequent when the amount of reflected energy measured by the radar (radar reflectivity) is larger than a certain threshold. We derived relationships between rain rate and radar reflectivity. We also find the precipitation properties inferred from radar and lidar data compare well with direct measurements from the aircraft, and the precipitation tends to be very light. We study how precipitation properties vary vertically, and find that as one gets closer to the surface, there is a decrease in precipitation droplet number and water, while there is an increase in the average size of droplets. We also find that rain rate depends on how thick the clouds are and the number of aerosols, consistent with theoretical expectations. Key Points: Liquid‐phase precipitation retrievals show good agreement with in situ observations and feature the prevalence of light rainReflectivity to rain rate relationships are developed, showing vertical dependence and sensitivity to the intermediate‐sized dropsThe below‐cloud precipitation phase with radar reflectivity >0 dBZ is mostly ice, while radar reflectivity <−10 dBZ is mostly liquid [ABSTRACT FROM AUTHOR]

Surface radiative cooling in polar regions can generate persistent stability in the atmospheric boundary layer. Stable layers below clouds can decouple the cloud layer from the near-surface environment. Under these conditions, surface aerosol measurements are not necessarily representative of the near-cloud or intra-cloud aerosol populations. To better understand the variability in the vertical structure of aerosol properties over the central Greenland Ice Sheet, in-situ measurements of aerosol particle size distributions up to cloud base were made at Summit Station in July and August 2023. These measurements identified distinct vertical aerosol layers between the surface and cloud base associated thermodynamic decoupling layers. Such decoupling layers occur 49 % of the time during the summer in central Greenland, suggesting that surface aerosol measurements are insufficient to describe the cloud-relevant aerosol population half of the time. Experience during this first measurement season demonstrated the ability of a tethered balloon platform to operate effectively under icing conditions and at low surface pressure (< 680 hPa). The results presented here illustrate the value of vertically resolved in-situ measurements of aerosol properties to develop a nuanced understanding of the aerosol effects on cloud properties in polar regions. [ABSTRACT FROM AUTHOR]

Based on the TRMM dataset, this paper compares the applicability of the improved MCE (minimum circumscribed ellipse), MBR (minimum bounding rectangle), and DIA (direct indexing area) methods for rain cell fitting. These three methods can reflect the geometric characteristics of clouds and apply geometric parameters to estimate the real dimensions of rain cells. The MCE method shows a major advantage in identifying the circumference of rain cells. The circumference of rain cells identified by MCE in most samples is smaller than that identified by DIA and MBR, and more similar to the observed rain cells. The area of rain cells identified by MBR is relatively robust. For rain cells composed of many pixels (N > 20), the overall performance is better than that of MCE, but the contribution of MBR to the best identification results, which have the shortest circumference and the smallest area, is less than that of MCE. The DIA method is best suited to small rain cells with a circumference of less than 100 km and an area of less than 120 km2, but the overall performance is mediocre. The MCE method tends to achieve the highest success at any angle, whereas there are fewer "best identification" results from DIA or MBR and more of the worst ones in the along-track direction and cross-track direction. Through this comprehensive comparison, we conclude that MCE can obtain the best fitting results with the shortest circumference and the smallest area on behalf of the high filling effect for all sizes of rain cells. [ABSTRACT FROM AUTHOR]

Stratiform rain and the overlying ice play crucial roles in Earth's climate system. From a microphysics standpoint, water mass flux primarily depends on two variables: particles' concentration and their mass. The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement mission core satellite is a spaceborne instrument capable of estimating these two quantities through dual-wavelength measurements. In this study, we evaluate bulk statistics on the ice particle properties derived from dual-wavelength radar data in relation to the properties of rain underneath. Specifically, we focus on DPR observations over stratiform precipitation, characterized by columns exhibiting a prominent bright band, where the melting layer can be easily detected. Our analysis reveals a large increase in the retrieved mass flux as we transition from the ice to the rain phase in the official DPR product. This observation is in disagreement with our expectation that mass flux should remain relatively stable across the bright band in cold-rain conditions. To address these discrepancies, we propose an alternative retrieval algorithm that ensures a gradual transition of Dm (mean mass-weighted particle melted-equivalent diameter) and the precipitation rate across the melting zone. This approach also helps in estimating bulk ice density above the melting level. These findings demonstrate that DPR observations can not only quantify ice particle content and their size above stratiform rain regions but also estimate bulk density, provided uniform conditions that minimize uncertainties related to partial beam filling. [ABSTRACT FROM AUTHOR]

A direct-reverse flotation process of the refractory siliceous collophane from Guizhou was studied. Using GC-4 as collector, the raw ore was treated by a direct desilication flotation process, consisting of one roughing, two cleanings, one scavenging, combined with a demagging reverse flotation process. The phosphate concentrate assayed 34.65% P2O5, with 92.39% P2O5 recovery and 7.18% MER (ratio of MgO and R2O3 to P2O5) could be produced. This concentrate was subjected directly to phosphoric-acid and production by wet process. Meanwhile, the middlings contained 19.80% P2O5, 23.29% SiO2, 1.23% MgO and 12.52% R2O3 (Al2O3 + Fe2O3), which were used for mid to low end nutrition compound phosphate fertilizer. The experimental results showed that GC-4 was a multi-functional collector with stable forth, liquidity and good index. It can be used as single collector in direct-reserve flotation, which avoided the consequence that various collectors interact with each other due to different pH, and also facilitated the reuse of backwater from direct-reserve flotation. WFS was an acidic waste water of phosphorus chemical industry, which had a good effect in the reverse flotation of collophane. WFS can replace H2SO4 as an inhibitor by the reverse flotation, which can save production cost and improve social benefits. The successful application of GC-4 and WFS in this experiment provided a technical reference for the large-scale utilization of refractory collophanite. [ABSTRACT FROM AUTHOR]

While modeling efforts have furthered our understanding of marine iron biogeochemistry and its influence on carbon sequestration, observations of dissolved iron (dFe) and its relationship to physical, chemical and biological processes in the ocean are needed to both validate and inform model parameterization. Where iron comes from, how it is transported and recycled, and where iron removal takes place are critical mechanisms that need to be understood to assess the relationship between iron availability and primary production. To this end, hydrographic and trace metal observations across the GO‐SHIP section SR3, south of Tasmania, Australia, have been analyzed in tandem with the novel application of an optimum multiparameter analysis. From the trace‐metal distribution south of Australia, key differences in the drivers of dFe between oceanographic zones of the Southern Ocean were identified. In the subtropical zone, sources of dFe were attributed to waters advected off the continental shelf, and to recirculated modified mode and intermediate water‐masses of the Tasman Outflow. In the subantarctic zone, the seasonal replenishment of dFe in Antarctic surface and mode waters appears to be sustained by iron recycling in the underlying mode and intermediate waters. In the southern zone, the dFe distribution is likely driven by dissolution and scavenging by high concentrations of particles along the Antarctic continental shelf and slope entrained in high salinity shelf water. This approach to trace metal analysis may prove useful in future transects for identifying key mechanisms driving marine dissolved trace metal distributions. Plain Language Summary: Iron is an essential nutrient for the growth of phytoplankton, marine plants that are an integral part of the marine carbon cycle. The Southern Ocean has very low amounts of iron, which largely limits phytoplankton growth. To better understand carbon and iron cycles, investigating the supply and distribution of iron throughout the Southern Ocean is needed to see how phytoplankton responds to current iron sources and into the future as our climate changes. Shipboard observations from a transect south of Tasmania, Australia, to the Antarctic continental margin have been used to assess how iron distributions are influenced by ocean circulation, chemical processes, biological activity, and new sources of iron to the ocean. Different processes were found to influence and control the iron distribution between distinct regions of the Southern Ocean. In the north of the transect, iron was sourced from sediments and the continental shelf around Tasmania, and was also delivered to the study area by local ocean currents around Tasmania. Further south, biological activity within a single water‐mass layer appears to be responsible for maintaining a subsurface iron pool. Closer to Antarctica, ocean currents and biological processes are less important, with high particle concentrations likely driving the iron distribution. Key Points: Application of optimum multiparameter analysis to Southern Ocean dissolved iron as a new approach to trace metal distribution analysisClear differences in the dominant mechanisms that distribute dissolved iron were found between oceanographic zonesObservational evidence for key dissolved iron distribution mechanisms can be used for model validation and optimization at the basin scale [ABSTRACT FROM AUTHOR]

Ocean surface rain layers (RLs) form when relatively colder, fresher, less dense rain water stably stratifies the upper ocean. RLs cool sea surface temperature (SST) by confining surface evaporative cooling to a thin near‐surface layer, and generate sharp SST gradients between the cool RL and the surrounding ocean. In this study, ocean‐atmosphere coupled simulations of the November 2011 Madden‐Julian Oscillation (MJO) event are conducted with and without RLs to evaluate two pathways for RLs to influence the atmosphere. The first, termed the "SST gradient effect," arises from the hydrostatic adjustment of the boundary layer to RL‐enhanced SST gradients. The second, termed the "SST effect," arises from RL‐induced SST reductions impeding the development of deep atmospheric convection. RLs are found to sharpen SST gradients throughout the MJO suppressed and suppressed‐to‐enhanced convection transition phases, but their effect on convection is only detected during the MJO suppressed phase when RL‐induced SST gradients enhance low‐level convergence/divergence and broaden the atmospheric vertical velocity probability distribution below 5 km. The SST effect is more evident than the SST gradient effect during the MJO transition phase, as RLs reduce domain average SST by 0.03 K and narrow vertical velocity distribution, thus delaying onset of deep convection. A delayed SST effect is also identified, wherein frequent RLs during the MJO transition phase isolate accumulated subsurface ocean heat from the atmosphere. The arrival of strong winds at the onset of the MJO active phase erodes RLs and releases subsurface ocean heat to the atmosphere, supporting the development of deep convection. Plain Language Summary: Rain water is less dense than near‐surface ocean water. For this reason, rain water can float on the ocean surface following rain events and form a "rain layer" in the upper ocean. Rain layers that form in the tropical Indian Ocean reduce sea surface temperature (SST) and shield the subsurface ocean below the rain layer from the atmosphere, thus altering heat exchange between the ocean and atmosphere. In this study, we conduct model experiments over the tropical Indian Ocean to investigate rain layer feedbacks to the atmosphere. We identify two potential rain layer feedback mechanisms, one in which rain‐enhancement of SST gradients contributes to the formation of clouds and precipitation in the atmosphere, and a second in which rain‐driven SST reduction suppresses the development of clouds and precipitation. Our results indicate that rain‐driven SST reduction is the dominant immediate feedback, as clouds and precipitation are reduced in the presence of rain layers. A delayed rain layer feedback is also identified, wherein rain layers insulate subsurface ocean heat from the atmosphere. When rain layers are destroyed by wind‐driven mixing, the stored ocean heat is released to the atmosphere, and supports the development of clouds and precipitation. Key Points: Cold and statically stable freshwater rain layers (RLs) warm the subsurface ocean by reducing nocturnal vertical mixingRL‐induced surface cooling and sub‐surface warming first delay, but then enhance the development of deep convection within the Madden‐Julian Oscillation (MJO)RL regulation of convective intensity may thus play a role in setting MJO period and propagation speed [ABSTRACT FROM AUTHOR]

We investigated long-term changes using a harmonised 22-year data set of aerosol light absorption measurements, in conjunction with air mass history and aerosol source analysis. The measurements were performed at Zeppelin Observatory, Svalbard, from 2002 to 2023. We report a statistically significant decreasing long-term trend for the light absorption coefficient. However, the last 8 years of 2016–2023 showed a slight increase in the magnitude of the light absorption coefficient for the Arctic haze season. In addition, we observed an increasing trend in the single-scattering albedo from 2002 to 2023. Five distinct source regions, representing different transport pathways, were identified. The trends involving air masses from the five regions showed decreasing absorption coefficients, except for the air masses from Eurasia. We show that the changes in the occurrences of each transport pathway cannot explain the reductions in the absorption coefficient observed at the Zeppelin station. An increase in contributions of air masses from more marine regions, with lower absorption coefficients, is compensated for by an influence from high-emission regions. The proportion of air masses en route to Zeppelin, which have been influenced by active fires, has undergone a noticeable increase starting in 2015. However, this increase has not impacted the long-term trends in the concentration of light-absorbing aerosol. Along with aerosol optical properties, we also show an increasing trend in accumulated surface precipitation experienced by air masses en route to the Zeppelin Observatory. We argue that the increase in precipitation, as experienced by air masses arriving at the station, can explain a quarter of the long-term reduction in the light absorption coefficient. We emphasise that meteorological conditions en route to the Zeppelin Observatory are critical for understanding the observed trends. [ABSTRACT FROM AUTHOR]

Summary: After abalone muscle hot water extract (AHE) was digested in‐vitro, three components (F1, F2, and F3) were separated using the Sephadex G‐15 column, and the antioxidant activity and absorption across Caco‐2 cells were analysed. The result showed that the half‐maximal inhibitory concentrations of F2 for scavenging hydroxyl and ABTS radicals were 0.763 and 0.028 mg mL−1, respectively, which were lower than those of F1 and F3. Moreover, the Trolox equivalent antioxidant capacity was increased after the F2 was transported through the Caco‐2 cell‐monolayered Transwell chamber. The mass spectrometry analysis revealed that the transported samples contained oligopeptides (Leu‐Tyr, Gly‐Ala‐Ala, and His‐Gly‐Ser‐Ala), and the Leu‐Tyr displayed the highest antioxidant activity and transport rate. Overall, these results suggest that oligopeptides with high antioxidant capacities can be produced from AHE through a combination of in‐vitro digestion and absorption across Caco‐2 cells. [ABSTRACT FROM AUTHOR]

A mathematical model is constructed for the dynamics of a raindrop moving in a gravity field through an atmosphere containing fine particles, taking into account the processes of relaxation of its velocity and the capture of fine particles. It has been established that the equation of motion of a drop in the problem being posed belongs to the class of singularly perturbed equations, for the integration of which it is necessary to involve special algorithms. In the limiting modes of droplet motion, analytical solutions of the problem are obtained that describe the dependence of the droplet velocity and coordinate on time. In the complete formulation, the solutions of the problem are obtained numerically for different values of the defining parameters. The influence of the droplet size on the parameters of its motion in a concentrated aerodispersed mixture has been studied. The dependences of the limiting volume fraction of the solid component in the composition of the drop and the intensity of the precipitation of particles (washed out by the drop) on the earth's surface on the size of the drop are obtained. A comparison of the calculated, approximate–analytical and experimental dependences of the steady-state rate of fall of a drop on its size has been carried out, and it shows their good agreement. [ABSTRACT FROM AUTHOR]

Mixed-phase clouds contain both supercooled cloud liquid and ice crystals. In principle, precipitation may be initiated either by the liquid phase or by the ice phase. Ice crystals may grow by vapor diffusion to become snow ("ice crystal process"), forming "cold" precipitation. Equally, cloud droplets, when large enough, coalesce to form "warm" precipitation by the "warm rain process." Warm rain could be supercooled and freeze as "warm" graupel. In the present paper, a new simplified theoretical analysis is provided to examine the microphysical system consisting of three species of hydrometeor, namely, cloud liquid, "cold ice" (crystals, snow), and "warm rain" (frozen or supercooled). This is obtained by nondimensionalizing and simplifying the evolution equations for the mass of each species. Analytical formulas are given for equilibria. Feedback analysis shows that the sign of the feedback is linked to the abundance of precipitation, with a neutral surface in the 3D phase space. The system's precipitation amount explodes while in the initial unstable regime, crossing the neutral surface and approaching the equilibrium point that is a stable attractor. Positive and negative feedbacks are elucidated. In a standard case, the cold ice mass is about 1000 times larger than the warm rain mass. To illustrate the physical behavior of the theory, sensitivity tests are performed with respect to environmental conditions (e.g., aerosol, updraft speed) and microphysical parameters (e.g., riming and sedimentation rates for cold ice). Cold ice prevails, especially in fast ascent, due to its low bulk density, favoring slow sedimentation and a wide cross-sectional area for riming. Significance Statement: The theory elucidates how the ice phase can prevail in the precipitation from any mixed-phase clouds with supercooled cloud liquid and crystals. The ice phase radically suppresses cloud liquid by riming when active and "wins" the competition against coalescence. This prevalence of ice is shown to arise from the low bulk density of snow. The cloud is viewed as a system of negative and positive feedbacks that prevail in realms of stability and instability in a 3D phase space. [ABSTRACT FROM AUTHOR]

This study introduces a new chemistry option in the Weather Research and Forecasting model data assimilation (WRFDA) system, coupled with the WRF‐Chem model (Version 4.4.1), to incorporate aqueous chemistry (AQCHEM) in the assimilation of ground‐level chemical measurements. The new DA capability includes the integration of aqueous‐phase aerosols from the Regional Atmospheric Chemistry Mechanism (RACM) gas chemistry, the Modal Aerosol Dynamics Model for Europe (MADE) aerosol chemistry, and the Volatility Basis Set (VBS) for secondary organic aerosol production. The RACM‐MADE‐VBS‐AQCHEM scheme facilitates aerosol‐cloud‐precipitation interactions by activating aerosol particles in cloud water during the model simulation. With the goal of enhancing air quality forecasting in cloudy conditions, this new implementation is demonstrated in the weakly coupled three‐dimensional variational data assimilation (3D‐Var) system through regional air quality cycling over East Asia. Surface particulate matter (PM) concentrations and four gas species (SO2, NO2, O3, and CO) are assimilated every 6 hr for the month of March 2019. The results show that including aqueous‐phase aerosols in both the analysis and forecast can represent aerosol wet removal processes associated with cloud development and rainfall production. During a pollution event with high cloud cover, simulations without aerosols defined in cloud water exhibit significantly higher values for liquid water path, and surface PM10 (PM2.5) concentrations are overestimated by a factor of 10 (3) when wet scavenging processes dominate. On the contrary, AQCHEM proves to be helpful in simulating the wet deposition of aerosols, accurately predicting the evolution of surface PM concentrations without such overestimation. Plain Language Summary: Major air pollution events over the Korean peninsula are often observed in association with significant cloud cover, especially over the Yellow Sea to the west of the peninsula. Cloudy conditions pose challenges for both remote sensing observations and model predictions, but the inclusion of aqueous‐phase (or cloud‐borne) aerosols in the WRF‐Chem/Weather Research and Forecasting model data assimilation system improves the simulation of aerosol wet scavenging, leading to improved predictions of surface particulate matter concentrations that were otherwise substantially overestimated. Key Points: The Weather Research and Forecasting (WRF)‐Chem/WRF model data assimilation 3D‐Var system (V4.4.1) is extended for chemical data assimilation with aqueous chemistry using the Regional Atmospheric Chemistry Mechanism‐Modal Aerosol Dynamics Model for Europe‐Volatility Basis Set schemeSurface PM2.5, PM10, SO2, NO2, O3, and CO concentrations are assimilated in the coupled systemThe inclusion of aqueous‐phase aerosols in air quality cycling enhances the simulation of aerosol wet deposition in cloudy conditions [ABSTRACT FROM AUTHOR]

Atmospheric aerosols have important impacts on air quality and the Earth–atmospheric energy balance. However, as computing power is limited, Earth system models generally use coarse spatial grids and parameterize finer-scale atmospheric processes. These parameterizations and the simulation of atmospheric aerosols are often sensitive to model horizontal resolutions. Understanding the sensitivities is necessary for the development of Earth system models at higher resolutions with the deployment of more powerful supercomputers. Using the Energy Exascale Earth System Model (E3SM) version 1, this study investigates the impact of horizontal grid spacing on the simulated aerosol mass budget, aerosol–cloud interactions, and the effective radiative forcing of anthropogenic aerosols (ERF aer) over the contiguous United States. We examine the resolution sensitivity by comparing the nudged simulation results for 2016 from the low-resolution model (LR) and the regional refinement model (RRM). As expected, the simulated emissions of natural dust, sea salt, and marine organic matter are substantially higher in the RRM than in the LR. In addition, RRM simulates stronger aqueous-phase production of sulfate through the enhanced oxidation of sulfur dioxide by hydrogen peroxide due to increased cloud liquid water content. In contrast, the gas-phase chemical production of sulfate is slightly suppressed. The RRM resolves more large-scale precipitation and produces less convective precipitation than the LR, leading to increased (decreased) aerosol wet scavenging by large-scale (convective) precipitation. Regarding aerosol effects on clouds, RRM produces larger temporal variabilities in the large-scale liquid cloud fractions than LR, resulting in increased microphysical cloud processing of aerosols (more interstitial aerosols are converted to cloud-borne aerosols via aerosol activation) in RRM. Water vapor condensation is also enhanced in RRM compared to LR. Consequently, the RRM simulation produces more cloud droplets, a larger cloud droplet radius, a higher liquid water path, and a larger cloud optical depth than the LR simulation. A comparison of the present-day and pre-industrial simulations indicates that, for this contiguous United States domain, the higher-resolution increases ERF aer at the top of the model by about 12 %, which is mainly attributed to the strengthened indirect effect associated with aerosol–cloud interactions. [ABSTRACT FROM AUTHOR]

In recent times, there is a mammoth challenge for the world and mankind to deal with the frequent use and misuse of antibiotics and its casual discard to the water bodies. The scavenging degradation of antibiotics which are no longer in use from the environment is a growing concern and compulsively needs to be addressed. Herein, we have devised a novel and green protocol for the synthesis of Cu2O decorated on reduced graphene oxide (Cu2O/RGO) nanocomposite (NCs) using agro-waste, i.e., orange pomace extract (OPE) as a reducing and stabilizing agent for the degradation of antibiotic. The biogenically synthesized Cu2O/RGO NCs proved to emerge as an excellent degradation catalyst exhibiting efficiency of 98.68% within 15 min and 86.38% within 30 min for 10 mg/L DC concentration assisted by ultrasound waves and solar light respectively in separate reactions. The complete degradation process followed a pseudo-first-order kinetics with a rate constant of 0.29 min− 1 and 0.0542 min− 1 for sonocatalytic and photocatalytic degradation process, respectively. Surface area analysis showed that with the increase in the GO amount, the doxycycline degradation increases. An in-depth mechanistic account of sonocatalytic and photocatalytic process has been discussed followed by a radical scavenging test which validated the major role of the synthesized NCs in the degradation of DC. The extraordinary catalytic indulgence of biogenically synthesized graphene-based nanocatalyst opens newer avenues for future research in green chemistry and catalytic field. [ABSTRACT FROM AUTHOR]

The current study investigates the relationship among Aerosol Optical Depth (AOD), rain rate in aerosol types (fine-mode and coarse-mode), and meteorological conditions (such as relative humidity and vertical velocity) during Indian Summer Monsoon (ISM) over regions of the Gangetic plain (GP) and the Modified Core Monsoon Region (MCMR) of India. The Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products, including AOD and Angstrom Exponent (AE), the observed rainfall gridded data of India Meteorological Department (IMD) and reanalyzed data of relative humidity (RH), vertical velocity (VV) and wind speed and direction as meteorological variables from European Center for Medium Range Weather Forecasting (ECMWF) Reanalysis v5 (ERA5) are used for the period of 2003–2021. It is noticed that regions of GP and MCMR experienced significant rainfall suppression with increasing aerosol loading in moderately polluted condition and beyond moderately polluted condition, the different rain rate responses to aerosol loading is observed. Different aerosol types and meteorological conditions may have different influences on the AOD-rain rate relationship. It is found that an increase in AOD may suppress or enhance the rain rate in a region like GP where high RH condition prevails, as well as the presence of fine-mode aerosol can enhance the rain rate in a highly polluted condition (AOD ≥ 0.4). An increase in AOD may enhance the rain rate in conditions of high and low RH over the regions. In high and low updraft conditions, an increase in AOD suppresses the rain rate. Additionally, high (low) RH and high (low) updraft promote high (low) rain rate over the regions. [ABSTRACT FROM AUTHOR]

Actinium‐227 (227Ac) has been used as a powerful tracer of diapycnal mixing in the ocean, assuming that it is conservative and originates mainly from deep‐sea sediments. However, here we show an unexpectedly large source (continental margin) and sink (scavenging) of 227Ac in the ocean, based on high‐resolution 227Ac distributions obtained for the first time by mooring Mn‐fibers in the East Sea (Japan Sea). Although we expected a decrease in radium‐228 (228Ra) to 227Ac ratios with depth owing to their different half‐lives, the ratios increased with depth in the upper layer, indicating efficient removal of 227Ac by particle scavenging. In addition, unusually high 227Ac activities (∼15 dpm m−3) were observed in the surface layer, likely due to the horizontal transport of 227Ac‐enriched shelf water. Thus, our results suggest refining our understanding of the geochemical cycle and application of 227Ac in the ocean. Plain Language Summary: Distributions of 227Ac provide crucial information for the vertical mixing of the deep ocean on timescales of up to 100 years. However, behaviors of 227Ac in the ocean have not been well understood to date because of its extremely low concentration. In this study, we for the first time determined high‐resolution 227Ac profiles by mooring Mn‐fibers in a marginal sea of the northwestern Pacific Ocean. Our results display that the shelf source inputs as well as efficient removal by particle scavenging have been overlooked so far. In particular, we emphasize that the removal of 227Ac by particle scavenging revealed in this study should be considered when using 227Ac as a tracer of mixing rates in the ocean. Key Points: The high‐resolution measurement of 227Ac with our Mn‐fiber mooring method agrees very well with the onboard Mn‐fiber filtration methodSignificantly high 227Ac activities, which might originate from the 227Ac‐enriched shelf water, are observed in the surface layer (0–100 m)High 227Ac scavenging rates are calculated based on the increasing trend of 228Ra to 227Ac ratio with depth in the upper layer (0–1,000 m) [ABSTRACT FROM AUTHOR]

Below‐cloud scavenging (BS) is often underestimated in chemical transport models (CTMs) due to inaccurate parameterizations of BS coefficient for fine particle (Λ) caused by a shortage of high‐time resolution field observations. Rainfall ions and related air pollutants were measured hourly in Central China (CC) during 2019. BS contributed to 37%–68% of wet deposition for SO42– ${\text{SO}}_{4}^{2\mbox{--}}$, NO3– ${\text{NO}}_{3}^{\mbox{--}}$, and NH4+ ${\text{NH}}_{4}^{+}$ (SNA). By a bulk method coupled with brute‐force search, the Λ (10−2–10 hr−1) was parameterized for SNA in PM2.5, which was 1–3 orders of magnitudes higher than theoretical calculations in CTMs. These chemical‐specific Λ parameterizations were validated by EMEP model. Compared to baselines, updated simulations for annual SNA wet deposition increased by 3.3%–20.4% and for mean PM2.5 SNA concentrations reduced by 1.2%–40%, capturing measurements better. The contributions of scavenged gases to wet deposition below cloud were calculated as 9%–73%, exhibiting discrepancies (2%–17% for HNO3 and 19%–90% for SO2) with previous modeling results as different Λ schemes adopted in CTMs. The nonlinearity between Λ and precipitation intensity causes frequency exerting stronger impact on aerosol burden than intensity and duration. Periodic light rain with a precipitation amount of 1–10 mm per event can eliminate 60% of SNA in PM2.5 and is suggested as a routine procedure to improve local air quality. Analyzing a typical washout process after a haze event in CC, BS could reduce PM2.5 SNA concentrations by 44%–54% derived from improved parameterizations. Plain Language Summary: The below‐cloud scavenging (BS) is a key process for removing atmospheric aerosols. An underestimation of BS for fine particle (PM2.5) is common in chemical transport models (CTMs) and biases simulations. A comprehensive observation was conducted for 1 year to improve parameterizations of BS coefficient for PM2.5 compounds (Λ). These parameterizations were assessed with a CTM. The updates increased the modeled wet deposition fluxes and decreased aerosol concentrations. These results mimicked observations better than baselines. The diversity of BS parameterizations in CTMs enhanced uncertainties of numerical simulation evaluations. The nonlinearity pattern of Λ between precipitation intensity implies frequency imposing stronger impact on aerosol burden than intensity and duration. This principle determines periodic light rain more suitable for cleaning air pollutants routinely. Utilizing the observational parameterizations, the importance of washout on clearing haze was revealed. This work can improve numerical simulations and air pollution control policies. Key Points: The parameterizations of below‐cloud scavenging coefficients for fine particle compounds were improvedThe reliability of chemical‐specific parameterizations was verified by a chemical transport modelThe implications of improved parameterizations for numerical simulations and air pollution control were elucidated [ABSTRACT FROM AUTHOR]

Novel coal gangue-based persulfate catalyst (CG-FeCl2) was successfully synthesized by the means of calcinating under nitrogen atmosphere with the addition of ferrous chloride tetrahydrate (FeCl2·4H2O). The phase transformation of the prepared materials and gas products during the heating process are thoroughly investigated. It is suggested that ferrous chloride participated in the phase transformation and formed Si-O-Fe bonds. And the main gaseous products are H2O, H2, and HCl during the heating process. Besides, the ability of CG-FeCl2 to activate peroxymonosulfate (PMS) for catalytic degradation of polycyclic aromatic hydrocarbons (PAHs) and phenol was deeply studied. More than 95% of naphthyl, phenanthrene and phenol were removed under optimizied conditions. In addition, 1O2, ·OH, and SO4·− were involved in the CG-FeCl2/PMS system from the free radical scavenging experiment, where 1O2 played a major role during the oxidation process. Furthermore, CG-FeCl2/PMS system exhibited superior stability in a relatively wide pH range and the presence of common anion from related degradation experiments. Overall, the novel CG-FeCl2 is an efficient and environmentally friendly catalyst, displaying potential application prospect in the field of PAHs and phenol-contaminated wastewater treatment. [ABSTRACT FROM AUTHOR]

The south-central interior of Andalusia experiences intricate precipitation patterns as a result of its semi-arid Mediterranean climate and the impact of Saharan dust and human-made pollutants. The primary aim of this study is to monitor the inter-relations between various factors, such as aerosols, clouds, and meteorological variables, and precipitation systems in Granada using ground-based remote sensing and in situ instruments including a microwave radiometer, ceilometer, cloud radar, nephelometer, and weather station. Over an 11-year period, we detected rain events using a physical retrieval method that employed microwave radiometer measurements. A composite analysis was applied to them to construct a climatology of the temporal evolution of precipitation. It was found that convective rain is the dominant precipitation type in Granada, accounting for 68 % of the rain events. The height of the cloud base is mainly distributed at an altitude of 2 to 7 km. Integrated water vapor (IWV) and integrated cloud liquid water (ILW) increase rapidly before the onset of rain. Aerosol scattering at the surface level and hence the aerosol concentration are reduced during rain, and the predominant mean size distribution of aerosol particles before, during, and after rain is almost the same. A meteorological environment favorable for virga formation is observed in Granada. The surface weather station detected rainfall later than the microwave radiometer, indicating virga according to ceilometer and cloud radar data. We used 889 rain-day events identified by weather station data to determine precipitation intensity classes and found that light rain is the main precipitation intensity class in Granada, accounting for 72 % of the rain-day events. This can be a result of the high tropospheric temperature induced by the Andalusian climate and the reduction of cloud droplet size by the high availability of aerosol particles in the urban atmosphere. This study provides evidence that aerosols, clouds, and meteorological variables have a combined impact on precipitation which can be considered for water resource management and improving rain forecasting accuracy. [ABSTRACT FROM AUTHOR]

Forensic taphonomic studies are regionally specific and improve time since death estimates for medico‐legal casework. Within forensic taphonomy and carrion ecology, vertebrate scavengers are under‐researched with many studies conducted using multiple, unclothed carcasses. This is a forensically unrealistic experimental design choice with unknown impact. The effect of variation in carrion biomass on the decomposition ecosystem, particularly where vertebrate scavengers are concerned, requires clarification. To assess the effect of carrion biomass load on vertebrate scavenging and decomposition rate, seasonal baseline data for single, clothed ~60 kg porcine carcasses were compared to clothed multiple‐carcass deployments, in a forensically relevant habitat of Cape Town, South Africa. Decomposition was tracked via weight loss and bloat progression and scavenging activity via motion‐activated cameras. The single carcasses decayed more quickly, particularly during the cooler, wetter winter, strongly correlated with concentrated Cape gray mongoose (Galerella pulverulenta) scavenging activity. On average and across seasons, the single carcasses lost 68% of their mass by day 32 (567 accumulated degree days [ADD]), compared to 80 days (1477 ADD) for multi‐carcass deployments. The single carcasses experienced substantially more scavenging activity, with longer visits by single and multiple mongooses, totaling 53 h on average compared to 20 h for the multi‐carcass deployments. These differences in scavenging activity and decay rate demonstrate the impact of carrion biomass load on decomposition for forensic taphonomy research. These findings need corroboration. However, forensic realism requires consideration in taphonomic study design. Longitudinally examining many single carcasses may produce more forensically accurate, locally appropriate, and usable results. [ABSTRACT FROM AUTHOR]

As one of the dominant sinks of aerosol particles, wet scavenging greatly influences aerosol lifetime and interactions with clouds, precipitation, and radiation. However, wet scavenging remains highly uncertain in models, hindering accurate predictions of aerosol spatiotemporal distributions and downstream interactions. In this study, we present a flexible, computationally inexpensive method to identify meteorological variables relevant for estimating wet scavenging using a combination of aircraft, satellite, and reanalysis data augmented by trajectory modeling to account for air mass history. We assess the capabilities of an array of meteorological variables to predict the transport efficiency of black carbon (TE BC) using a combination of nonlinear regression, curve fitting, and k -fold cross-validation. We find that accumulated precipitation along trajectories (APT) – treated as a wet scavenging indicator across multiple studies – does poorly when predicting TE BC. Among different precipitation characteristics (amount, frequency, intensity), precipitation intensity was the most effective at estimating TE BC but required longer trajectories (>48 h) and including only intensely precipitating grid cells. This points to the contribution of intense precipitation to aerosol scavenging and the importance of accounting for air mass history. Predictors that were most able to predict TE BC were related to the distribution of relative humidity (RH) or the frequency of humid conditions along trajectories, suggesting that RH is a more robust way to estimate TE BC than APT. We recommend the following alternatives to APT when estimating aerosol scavenging: (1) the 90th percentile of RH along trajectories, (2) the fraction of hours along trajectories with either water vapor mixing ratios >15 g kg -1 or RH >95 %, and (3) precipitation intensity along trajectories at least 48 h along and filtered for grid cells with precipitation >0.2 mm h -1. Future scavenging parameterizations should consider these meteorological variables along air mass histories. This method can be repeated for different regions to identify region-specific factors influencing wet scavenging. [ABSTRACT FROM AUTHOR]

Aquaporins (AQPs) allow the diffusion of hydrogen peroxide (H2O2) and act as ROS scavenging systems, which are important for controlling the redox state of cells. Recently, cerium oxide nanoparticles were found to increase the water and H2O2 permeability by modulating AQPs. To further analyze the action of nanoparticles (NPs) on AQP, we examined the effect of the NPs presenting different core compositions (CeO2, Gd2O3, Fe3O4, and TiO2), hydrodynamic sizes, and surface functionalization. The NPs produced an increase in H2O and H2O2 permeability as a general trend. The hydrodynamic sizes of the NPs in the range of 22–100 nm did not produce any significant effect. The chemical nature of the NPs' core did not modify the effect and its intensity. On the other hand, the NPs' functionalized surface plays a major role in influencing both water and H2O2 permeability. The results suggest that NPs can play a significant role in controlling oxidative stress in cells and might represent an innovative approach in the treatment of a number of pathologies associated with an increased oxidative status. [ABSTRACT FROM AUTHOR]

The evolution of ice‐phase particles within precipitating clouds depends on the environmental properties of the cloud and on physical characteristics of the particles themselves, which can be modified by airflow over steep terrain. Through employing a unique Lagrangian particle‐based precipitation model, this study investigates the sensitivities in ice‐phase particle growth and transport due to variabilities in riming processes over an orographic barrier. This analysis is applied to two wintertime stratiform cyclones sampled by in situ aircraft over windward slopes during the Olympic Mountains Experiment. For both events, we simulate the ice‐phase particle evolution and trajectory within a two‐dimensional prescribed state representative of median observed cloud properties. Sensitivity simulations were constructed based on observed variabilities in supercooled liquid water (SLW) properties and its vertical extent above the melting level. Perturbations of SLW concentration equivalent to the 85th and 15th percentiles of observed values, which typically amounted to a change of less than 0.05 g m−3, resulted in respective increases or decreases in the ice‐phase contribution to surface precipitation mass by as much as 50% and horizontal particle trajectories differences exceeding 10 km. Similar sensitivities were found in response to varying the vertical extent of SLW above the melting level and to adjustments in mean SLW droplet size. The significant precipitation response to small variations in cloud properties principally arises from changing rates of rime mass accumulation and correspondingly, increases in particle fall speed. Considerations for the numerical representation of the riming process and its complex effects on precipitation are discussed. Plain Language Summary: Precipitating clouds produce rain and snow at varying rates depending on the properties of the cloud. At below freezing temperatures in clouds, it is common to have a mixed‐phase layer where ice crystals and liquid droplets, in a supercooled state, coexist. Collection of the supercooled liquid droplets on the ice crystals greatly affects the mass and fall speed of the ice crystals, thereby affecting where, and how much, precipitation reaches the surface. In this study, we use a numerical model to simulate the evolution of individual precipitating ice crystals and evaluate sensitivities to the concentration and distribution of supercooled liquid droplets in the cloud. Based on variabilities measured in clouds upstream of the Olympic Mountains, small changes in the concentration of supercooled liquid droplets, the size of the liquid droplets, or the depth of the mixed‐phase layer produces changes in rain rates of up to 50% and increases or decreases in the distance a particle travels by as much as 10 km. We discuss the implications of these significant sensitivities to the precipitation rate and fall characteristics. Key Points: Particle‐based models provide frameworks for simulating the evolution and trajectory of precipitating particles in stratiform winter stormsFor sufficiently deep mixed‐phase clouds, small variations in supercooled liquid water mass may alter precipitation rates by as much as 50%Particle trajectory is significantly modulated by mixed‐phase layer depth through cumulative adjustments in fall velocity during riming [ABSTRACT FROM AUTHOR]

Globally, the textile industry contributes to pollution through accidental discharges or discharge of contaminated wastewater into waterways, significantly affecting water quality. These pollutants, including dye molecules, are environmental hazards for aquatic and terrestrial life. The field of visible light-mediated photocatalysis has experienced rapid growth, driven by the utilization of photocatalysts that can absorb low-energy visible light and effectively degrade dyes. In the present study, we report a simple method to controllably synthesize Fe2O3, ZnO, and ZnFe2O4 using the one-pot synthesis method. In the subsequent step, copper (Cu) was deposited on the surface of ZnFe2O4 (forming ZnFe2O4-Cu) using a facile, green, and cost-effective method. The synthesized samples were characterized using various techniques, including XRD, UV-Vis DRS, FT-IR, SEM-EDX, HR-TEM, XPS, PL, and BET analysis. These techniques were employed to investigate the composition, morphology, structure, and photophysical properties of as-prepared samples. The ZnFe2O4-Cu nanocomposite demonstrated efficient photocatalytic activity for degrading RhB dye pollutants under visible light. The photocatalyst was successfully reused for three consecutive cycles without significantly decreasing performance. Furthermore, during the study, the radical scavenging test emphasized the role of different radicals in the degradation of dye pollutants. This research has the potential to enable the efficient production of high-performance photocatalysts that can rapidly eliminate ecologically harmful dyes from aqueous solutions. [ABSTRACT FROM AUTHOR]

The interaction between biomass burning aerosols and clouds remains challenging to accurately determine, in part because of difficulties using direct observations to account for influences on aerosol concentrations from precipitation scavenging and dilution due to air mass mixing and separating those signals from source contributions. The prevalence of mixing versus precipitation processes in air laden with biomass burning aerosol (BBA) in the southeast Atlantic lower free troposphere (FT) and marine boundary layer (MBL) is assessed during three observation periods (September 2016, August 2017, and October 2018) during the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign. Significant sources of BBAs over the African continent combined with regional circulation patterns result in BBA-laden air flowing from the continent over the southeast Atlantic in the lower FT, then subsiding onto the semi-permanent stratocumulus cloud deck, and entraining into the MBL. This study is broken into two parts, first analyzing hydrologic histories of the BBA air in the lower FT and then carrying out a similar assessment in the underlying MBL. Both analyses leverage joint measurements of water concentration and its heavy isotope ratio, interpreted in the previously established (q , δD) phase space framework. For the lower-FT analysis, in situ observations (water concentration, water isotope ratios) in the lower FT are combined with satellite and Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), global reanalysis data into simple analytical models to constrain hydrologic histories. We find that even simple models are capable of detecting and constraining the primary processes at play, e.g., distinguishing air masses that experienced moist convection and precipitation (likely over the continent) from those that underwent dry convection and turbulent mixing. Regression of the aircraft data onto a simple model of convective detrainment is used to develop a metric of total precipitation for the in situ measurements and then compared to an aerosol metric of black carbon scavenging also derived from the in situ measurements (the ratio of black carbon to carbon monoxide, BC/CO). There is a strong correlation between the two, suggesting black carbon scavenging has been detected and partially quantified, if only in a relative manner. In comparison, weak correlation is found between BC/CO and the total water concentration itself. The above method is expanded to test for entrainment and precipitation influences on BBA concentrations in the MBL. This is more difficult than the FT analysis since signals are subtle and limited by imperfect knowledge of the water and isotope ratios of the entrained air mass at cloud top. For some of the MBLs observed during 2016 and 2018, lower cloud condensation nuclei (CCN) concentrations occur in the sub-cloud layer coincident with isotopic evidence of precipitation, indicating aerosol scavenging, but more complex models are needed to produce definitive conclusions. For the 2017 observation period, with the highest sub-cloud CCN concentrations, there is no connection between precipitation signals and CCN concentrations, likely indicating the importance of different geographic sampling and air mass history in that year. Nonetheless, these findings along with the FT analysis suggest that utilizing isotope ratio signals may be an aid in addressing cloud–aerosol challenges. Especially for the FT case, these findings support the pursuit of more complex models combined with targeted in situ data to constrain BC scavenging coefficients in a manner which can guide model parameterizations, leading to improvements in the accuracy of simulated BC concentrations and lifetimes in climate models. [ABSTRACT FROM AUTHOR]

The Equilibrium Simplified Aerosol Model for Climate version 12 (EQSAM4Clim-v12) has recently been revised to provide an accurate and efficient method for calculating the acidity of atmospheric particles. EQSAM4Clim is based on an analytical concept that is not only sufficiently fast for numerical weather prediction (NWP) applications, but also free of numerical noise, which makes it attractive also for air quality forecasting. EQSAM4Clim allows the calculation of aerosol composition based on the gas-liquid-solid and the reduced gas-liquid partitioning with the associated water uptake for both cases, and can therefore provide important information about the acidity of the aerosols. Here we provide a comprehensive description of the recent changes made to the aerosol acidity parameterization (referred to a version 12) which builds on the original EQSAM4Clim. We evaluate the pH improvements using a detailed box-model and compare against previous model calculations and both ground-based and aircraft observations from US and China covering different seasons and scenarios. We show that, in most cases, the simulated pH is within reasonable agreement with the results of the E-AIM reference model and of satisfactory accuracy. [ABSTRACT FROM AUTHOR]

In this work, hydrogen peroxide (H 2 O 2) is produced using an optimized electrochemical cell equipped with a gas diffusion electrode (GDE) as cathode, reaching efficiencies as high as 20.1%, when operating in a single compartment configuration, which increases up to the range 50–60, when a proton exchange membrane is used to separate the anodic and cathodic compartments, pointing out the great significance of the anodic oxidation of H 2 O 2 and the scavenging effects of the oxidants produced on the anode surface. As compared to previous materials tested, the GDE implemented in this cell underwent a more sustainable manufacturing procedure and exhibited an outstanding performance. The H 2 O 2 produced electrochemically is dosed to the real leachate of an industrial dump, strongly polluted with derivatives of lindane. This waste is associated to the operation of a large facility in the seventies and contains different isomers of hexachlorocyclohexane and other chlorinated hydrocarbons, produced during the ageing of the dump. Effects of the addition of iron (II) sulfate salts and irradiation of UVC were also evaluated. All electrochemically-assisted technologies evaluated (named as chemical (EACO), Fenton (EAFO), photolysis (EAPO) and photo-Fenton (EAPFO) oxidations) were able to successfully remove the pollutants, although with important differences in the efficiencies reached. Results demonstrate that EACO, that is, oxidation by molecular H 2 O 2 is the most effective treatment for the treatment of this type of wastes, pointing out that activation of H 2 O 2 to hydroxyl radicals, either by electrochemically assisted Fenton or photolysis is not positive for this waste. As well, among the different pollutants contained in the raw waste, removal of hexachlorocyclohexane (HCHs) and non-chlorinated volatile organic compounds (VOCs) stands out (both groups being the primary species contained in the wastes). These results are very important not only because of the outstanding productions of H 2 O 2 reached with the novel approach of electrochemical cell used, but also because of the implications of the mechanistic understanding of the attack of H 2 O 2 species in the design of a full-scale application to remediate this real important problem. [Display omitted] • Improved production of H 2 O 2 with a novel GDE and cell. • H 2 O 2 is produced with efficiencies over 20% in non-divided configurations. • Improved efficiency when using divided cells, with values as high as 50–60%. • Several electrochemical H 2 O 2 based technologies suitable for degradation wastes. • Unexpectedly H 2 O 2 more efficient that hydroxyl radicals in destroying CHCs. [ABSTRACT FROM AUTHOR]

Naturally available, stable, and heavy water molecules such as HDO and H 218 O have a lower saturation vapour pressure than the most abundant light water molecule H 216 O; therefore, these heavy water molecules preferentially condense and rain out during cloud formation. Stable water isotope observations thus have the potential to provide information on cloud processes in the trade-wind region, in particular when combined with high-resolution model simulations. In order to evaluate this potential, nested COSMO iso (isotope-enabled Consortium for Small Scale Modelling;) simulations with explicit convection and horizontal grid spacings of 10, 5, and 1 km were carried out in this study over the tropical Atlantic for the time period of the EUREC 4 A (Elucidating the role of clouds-circulation coupling in climate;) field experiment. The comparison to airborne in situ and remote sensing observations shows that the three simulations are able to distinguish between different mesoscale cloud organisation patterns as well as between periods with comparatively high and low rain rates. Cloud fraction and liquid water content show a better agreement with aircraft observations with higher spatial resolution, because they show strong spatial variations on the scale of a few kilometres. A low-level cold-dry bias, including too depleted vapour in the subcloud and cloud layer and too enriched vapour in the free troposphere, is found in all three simulations. Furthermore, the simulated secondary isotope variable d -excess in vapour is overestimated compared to observations. Special attention is given to the cloud base level, which is the formation altitude of shallow cumulus clouds. The temporal variability of the simulated isotope variables at cloud base agrees reasonably well with observations, with correlations of the flight-to-flight data as high as 0.7 for δ2 H and d -excess. A close examination of isotopic characteristics under precipitating clouds, non-precipitating clouds, clear-sky and dry-warm patches at the altitude of cloud base shows that these different environments are represented faithfully in the model with similar frequencies of occurrence, isotope signals, and specific-humidity anomalies as found in the observations. Furthermore, it is shown that the δ2 H of cloud base vapour at the hourly timescale is mainly controlled by mesoscale transport and not by local microphysical processes, while the d -excess is mainly controlled by large-scale drivers. Overall, this evaluation of COSMO iso , including the isotopic characterisation of different cloud base environments, suggests that the simulations can be used for investigating the role of atmospheric circulations on different scales for controlling the formation of shallow cumulus clouds in the trade-wind region, as will be done in part 2 of this study. [ABSTRACT FROM AUTHOR]

Potato peel is a waste generated in large amounts in the food industry; however, it has been shown that these residues are an important source of antioxidant compounds. The effect of potato peel powder addition (2, 5, and 10%) on the physicochemical, sensory, and antioxidant status of pork patties during refrigerated storage (2 °C/9 days/under dark) was evaluated. Polyphenol content and antioxidant activity of potato peel powder ethanol extract were determined. Pork patties were subjected to proximate chemical composition, physicochemical, and sensory evaluations. Results showed that potato peel ethanol extract at the highest used concentration (500 µg/mL) is an important source of total phenolic (>50 mg gallic acid equivalents/g) and chlorogenic acid compounds (ca. 40 mg chlorogenic acid equivalents/g) and exerts free radical scavenging (>50% of DPPH inhibition) and reducing power activity (<0.5 abs) (p < 0.05). Additionally, potato peel powder incorporation in raw pork patties reduces changes in pH, lipid oxidation, water-holding capacity, cooking loss weight, and color values during storage. Although an effect was observed on texture and sensory values (color and appearance) of raw patties, depending on addition level (p < 0.05), no differences were found in color appearance, odor, flavor, juiciness, fat sensation, texture, and overall acceptability of cooked patties between treatments (p > 0.05). The use of potato peel powder as a natural antioxidant for meat products is recommended. [ABSTRACT FROM AUTHOR]