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We present relativistic magnetohydrodynamic modelling of jets running into hydrostatic, spherically symmetric cluster atmospheres. For the first time in a numerical simulation, we present model cluster atmospheres based upon the universal pressure profile (UPP), incorporating a temperature profile for a 'typical' self-similar atmosphere described by only one parameter – M 500. We explore a comprehensive range of realistic atmospheres and jet powers and derive dynamic, energetic, and polarimetric data which provide insight into what we should expect of future high-resolution studies of AGN outflows. From the simulated synchrotron emission maps which include Doppler beaming we find sidedness distributions that agree well with observations. We replicated a number of findings from our previous work, such as higher power jets inflating larger aspect-ratio lobes, and the cluster environment impacting the distribution of energy between the lobe and shocked regions. Comparing UPP and β-profiles we find that the cluster model chosen results in a different morphology for the resultant lobes with the UPP more able to clear lobe material from the core; and that these different atmospheres influence the ratio between the various forms of energy in the fully developed lobes. This work also highlights the key role played by Kelvin–Helmholtz instabilities in the formation of realistic lobe aspect ratios. Our simulations point to the need for additional lobe-widening mechanisms at high jet powers, for example jet precession. Given that the UPP is our most representative general cluster atmosphere, these numerical simulations represent the most realistic models yet for spherically symmetric atmospheres. [ABSTRACT FROM AUTHOR]

Premise: The Aptian-Albian (121.4-100.5 Ma) was a greenhouse period with global temperatures estimated as 10-15°C warmer than pre-industrial conditions, so it is surprising that the most reliable CO 2 estimates from this time are <1400 ppm. This low CO 2 during a warm period implies a very high Earth-system sensitivity in the range of 6 to 9°C per CO 2 doubling between the Aptian-Albian and today., Methods: We applied a well-vetted paleo-CO 2 proxy based on leaf gas-exchange principles (Franks model) to two Pseudotorellia species from three stratigraphically similar samples at the Tevshiin Govi lignite mine in central Mongolia (~119.7-100.5 Ma)., Results: Our median estimated CO 2 concentration from the three respective samples was 2132, 2405, and 2770 ppm. The primary reason for the high estimated CO 2 but with relatively large uncertainties is the very low stomatal density in both species, where small variations propagate to large changes in estimated CO 2 . Indeed, we found that at least 15 leaves are required before the aggregate estimated CO 2 approaches that of the full data set., Conclusions: Our three CO 2 estimates all exceeded 2000 ppm, translating to an Earth-system sensitivity (~3-5°C/CO 2 doubling) that is more in keeping with the current understanding of the long-term climate system. Because of our large sample size, the directly measured inputs did not contribute much to the overall uncertainty in estimated CO 2 ; instead, the inferred inputs were responsible for most of the overall uncertainty and thus should be scrutinized for their value choices., (© 2024 Botanical Society of America.)

In the last decades, the increase in global industrialization and the consequent technological progress have damaged the quality of the environment. As a consequence, the high levels of hazardous compounds such as metals and gases released in the atmosphere and water, have raised several concerns about the health of living organisms. Today, many analytical techniques are available with the aim to detect pollutant chemical species. However, a lot of them are not affordable due to the expensive instrumentations, time-consuming processes and high reagents volumes. Last but not least, their use is exclusive to trained operators. Contrarily, colorimetric sensing devices, including paper-based devices, are easy to use, providing results in a short time, without particular specializations to interpret the results. In addition, the colorimetric response is suitable for fast detection, especially in resource-limited environments or underdeveloped countries. Among different chemical species, transition and heavy metals such as iron Fe(II) and copper Cu(II) as well as volatile compounds, such as ammonia (NH3) and acetaldehyde (C2H4O) are widespread mainly in industrialized geographical areas. In this work, we developed a colorimetric paper-based analytical device (PAD) to detect different contaminants, including Fe2+ and Cu2+ ions in water, and NH3 and C2H4O in air at low concentrations. This study is a “proof of concept” of a new paper sensor in which the intensity of the colorimetric response is proportional to the concentration of a detected pollutant species. The sensor model could be further implemented in other technologies, such as drones, individual protection devices or wearable apparatus to monitor the exposure to toxic species in both indoor and outdoor environments.

Several studies have attempted to determine the lower limit of atmospheric oxygen under which combustion can occur; however, none have been conducted within a fully controlled and realistic atmospheric environment. We performed experimental burns (using pine wood, moss, matches, paper, and a candle) at 20 degrees C in O2 concentrations ranging from 9 to 21% and at ambient and high CO2 (2000 parts per million) in a controlled environment room, which was equipped with a thermal imaging system and full atmospheric, temperature, and humidity control. Our data reveal that the lower O2 limit for combustion should be increased from 12 to 15%. These results, coupled with a record of Mesozoic paleowildfires, are incompatible with the prediction of prolonged intervals of low atmospheric O2 levels (10 to 12%) in the Mesozoic.

Copper sulfide deposition on cellulosic insulating materials in oil-immersed transformers is evaluated by heating tests stipulated by IEC 62535. Although this method is suitable for evaluation of the corrosivity of unused insulating oil, the subject remains in diagnosis of the insulating oil used. It is because dibenzyl disulfide (DBDS), which is the prime compounds that cause copper sulfide deposition, is consumed by the reaction with copper during operating of transformer. Therefore, it is necessary to detect the existence of DBDS in insulating oil diagnosed as non-corrosivity by IEC 62535. The proceeding paper [6] reports that Bibenzyl (BiBz) and Dibenzyl sulfide (DBS) will be formed in the insulating oil as by-products of copper sulfide formation between copper and DBDS in oxygen-poor atmosphere which imitated the closed-type transformers. These by-products are considered to be the indication of copper sulfide formation. However, the influence of oxygen and addition agent (e.g. 2,6-di-tert-butylp- cresol) on the mechanism of the by-product formation is unclear. The purpose of this study is to elucidate the influence of oxygen and DBPC in by-products formation for development of diagnosis. It became apparent that benzyl alcohol, benzaldehyde and benzoic acid generate as by-products of copper sulfide formation in the air atmosphere which imitated the open-breathing transformers. Furthermore, it became apparent that the reaction product of benzyl radical and the radical of DBPC generates as by-product of copper sulfide formation in the insulating oil containing DBPC. These by-products are detectable even if DBDS disappears. Therefore, it is thought that diagnosis of the open-breathing transformer is possible by detecting these by-products. [ABSTRACT FROM AUTHOR]

Research reported during the past decade has shown that global warming is roughly proportional to the total amount of carbon dioxide released into the atmosphere. This makes it possible to estimate the remaining carbon budget: the total amount of anthropogenic carbon dioxide that can still be emitted into the atmosphere while holding the global average temperature increase to the limit set by the Paris Agreement. However, a wide range of estimates for the remaining carbon budget has been reported, reducing the effectiveness of the remaining carbon budget as a means of setting emission reduction targets that are consistent with the Paris Agreement. Here we present a framework that enables us to track estimates of the remaining carbon budget and to understand how these estimates can improve over time as scientific knowledge advances. We propose that application of this framework may help to reconcile differences between estimates of the remaining carbon budget and may provide a basis for reducing uncertainty in the range of future estimates.

Copper sulfide deposition on cellulosic insulating materials in oil-immersed transformers was investigated by heating tests stipulated by IEC 62535 with controlled atmospheres to which mineral insulating oils were exposed. Both oxygen in the atmosphere and 2,6-di-tert-butyl-p-cresol (DBPC) in the oil were found to accelerate the copper sulfide deposition on the insulating paper when the oil contains dibenzyl disulfide (DBDS). The weight of copper sulfide deposition on the insulating paper was found to increase when the oxygen concentration was increased up to 20 volume %. X-ray absorption near edge structure (XANES) analysis was applied to study the chemical bonding state of copper atoms in copper deposits on the insulating paper for the first time. It can be clarified the copper deposits on the insulating paper are mainly Cu2S and small amounts of CuO are contained. [ABSTRACT FROM PUBLISHER]

A low-cost and simple-arranged paper-based microplasma array device made by tape and Xerox paper was presented. Uniform array of discharge can be sustained in Ar, He, and ambient air atmosphere. Stable discharge can be sustained for at least 55 min when plasma is ignited in Ar ambient, based on the examination of time-resolved optical emission spectra. Throughout the conditions investigated, the power consumed by the device was well below 0.3 W. We also demonstrated that stable and uniform discharge can be generated when the device was bent to a radius of curvature of 2.5 mm. [ABSTRACT FROM PUBLISHER]

Atmospheric carbon dioxide enrichment (eCO 2 ) can enhance plant carbon uptake and growth 1-5 , thereby providing an important negative feedback to climate change by slowing the rate of increase of the atmospheric CO 2 concentration 6 . Although evidence gathered from young aggrading forests has generally indicated a strong CO 2 fertilization effect on biomass growth 3-5 , it is unclear whether mature forests respond to eCO 2 in a similar way. In mature trees and forest stands 7-10 , photosynthetic uptake has been found to increase under eCO 2 without any apparent accompanying growth response, leaving the fate of additional carbon fixed under eCO 2 unclear 4,5,7-11 . Here using data from the first ecosystem-scale Free-Air CO 2 Enrichment (FACE) experiment in a mature forest, we constructed a comprehensive ecosystem carbon budget to track the fate of carbon as the forest responded to four years of eCO 2 exposure. We show that, although the eCO 2 treatment of +150 parts per million (+38 per cent) above ambient levels induced a 12 per cent (+247 grams of carbon per square metre per year) increase in carbon uptake through gross primary production, this additional carbon uptake did not lead to increased carbon sequestration at the ecosystem level. Instead, the majority of the extra carbon was emitted back into the atmosphere via several respiratory fluxes, with increased soil respiration alone accounting for half of the total uptake surplus. Our results call into question the predominant thinking that the capacity of forests to act as carbon sinks will be generally enhanced under eCO 2 , and challenge the efficacy of climate mitigation strategies that rely on ubiquitous CO 2 fertilization as a driver of increased carbon sinks in global forests.

The article assesses the usefulness of synthetic vortex insertion prior to the extratropical transition of hurricanes. Significant improvements in the wind and precipitation patterns within the storm at landfall were observed in the atmospheric model with vortex insertion employed in the initial conditions. The numerical hindcasts employing the technique resolved a particular forecast dilemma involving interaction of Hurricane Michael with a preexisting area of low pressure to its north. Operational forecast models at the time had incorrectly developed the northern low at the expense of the hurricane, while the opposite occurred in reality and in the numerical simulations run in hindcast mode.

The article offers news briefs related to climatology. A cold tongue which is a narrow band of cool sea surface temperature (SST) is one of the salient features in the equatorial Pacific Ocean. Two of the factors that contributed to the weather-forecasting errors increase in time are the amplification uncertainties of nonlinearities in the initial state of the atmosphere and the model deficiencies leading the model to predict the wrong rate of change for even the most certain initial conditions. INSETS: DUDE, WE'RE, LIKE, PROTESTING;PLEASED TO ZAP YOU.

In the last decades, the increase in global industrialization and the consequent technological progress have damaged the quality of the environment. As a consequence, the high levels of hazardous compounds such as metals and gases released in the atmosphere and water, have raised several concerns about the health of living organisms. Today, many analytical techniques are available with the aim to detect pollutant chemical species. However, a lot of them are not affordable due to the expensive instrumentations, time-consuming processes and high reagents volumes. Last but not least, their use is exclusive to trained operators. Contrarily, colorimetric sensing devices, including paper-based devices, are easy to use, providing results in a short time, without particular specializations to interpret the results. In addition, the colorimetric response is suitable for fast detection, especially in resource-limited environments or underdeveloped countries. Among different chemical species, transition and heavy metals such as iron Fe(II) and copper Cu(II) as well as volatile compounds, such as ammonia (NH3) and acetaldehyde (C2H4O) are widespread mainly in industrialized geographical areas. In this work, we developed a colorimetric paper-based analytical device (PAD) to detect different contaminants, including Fe2+ and Cu2+ ions in water, and NH3 and C2H4O in air at low concentrations. This study is a "proof of concept" of a new paper sensor in which the intensity of the colorimetric response is proportional to the concentration of a detected pollutant species. The sensor model could be further implemented in other technologies, such as drones, individual protection devices or wearable apparatus to monitor the exposure to toxic species in both indoor and outdoor environments. [ABSTRACT FROM AUTHOR]

Due to the complexity of the multiple scattering problem for shortwave radiative transfer in Earth's atmosphere, operational physical retrieval algorithms commonly use a plane parallel Radiative Transfer Model (RTM). This so-called One-Dimensional (1-D) assumption allows practical retrieval algorithms to be implemented. In order to understand the impacts of this assumption for low altitude, unresolved clouds observed by OCO-2, the Three-Dimensional (3-D) radiative transfer model SHDOM is used to generate synthetic observations which are then processed by the operational retrieval algorithm based on a 1-D RTM. Simulations are performed over three realistic surface spectral albedos, corresponding to snow, vegetation, and bare soil. The results show that the existing cloud screening algorithm has difficulty identifying sub-Field of View (FOV), unresolved clouds that fill less than half of the FOV. The unresolved clouds introduce a bias in the retrieved CO2 concentration, as quantified by the dry air mole fraction (XCO2). The biases are relatively small (less than 1 ppm) when the albedo at 2.1 µm is high, which is common over bare land surfaces. For cases with low 2.1 µm albedo, such as snow, the bias becomes much larger, up to 5 ppm. These results indicate that the XXCO2 retrieval appears robust to 3-D scattering effects from unresolved low level clouds when the short wave infrared surface albedo is large, but for darker surfaces these clouds can introduce significant biases. [ABSTRACT FROM AUTHOR]

This paper is intended to summarize the research conducted during the first 2 years of the Dragon 5 project 59,332 (geophysical and atmospheric retrieval from Synthetic Aperture Radar (SAR) data stacks over natural scenarios). Monitoring atmospheric phenomena, encompassing both tropospheric and ionospheric conditions, holds pivotal significance for various scientific and practical applications. In this paper, we present an exploration of advanced techniques for estimating tropospheric and ionospheric phase screens using stacks of Synthetic Aperture Radar (SAR) images. Our study delves into the current state-of-the-art in atmospheric monitoring with a focus on spaceborne SAR systems, shedding light on their evolving capabilities. For tropospheric phase screen estimation, we propose a novel approach that jointly estimates the tropospheric component from all the images. We discuss the methodology in detail, highlighting its ability to recover accurate tropospheric maps. Through a series of quantitative case studies using real Sentinel-1 satellite data, we demonstrate the effectiveness of our technique in capturing tropospheric variability over different geographical regions. Concurrently, we delve into the estimation of ionospheric phase screens utilizing SAR image stacks. The intricacies of ionospheric disturbances pose unique challenges, necessitating specialized techniques. We dissect our approach, showcasing its capacity to mitigate ionospheric noise and recover precise phase information. Real data from the Sentinel-1 satellite are employed to showcase the efficacy of our method, unraveling ionospheric perturbations with improved accuracy. The integration of our techniques, though presented separately for clarity, collectively contributes to a comprehensive framework for atmospheric monitoring. Our findings emphasize the potential of SAR-based approaches in advancing our knowledge of atmospheric processes, thus fostering advancements in weather prediction, geophysics, and environmental management. [ABSTRACT FROM AUTHOR]

β-caryophyllonic acid (BCA), as an important precursor of aqueous secondary organic aerosols (aqSOA), has adverse effects on the atmospheric environment and human health. However, the key atmospheric chemical reaction process in which BCA participates in the formation of aqueous secondary organic aerosols is still unclear. In this study, the reaction mechanism and kinetics of BCA with ·OH and O 3 were investigated by quantum chemical calculations. The initiation reactions between BCA and ·OH include addition and H-abstraction reaction pathways, subsequent intermediates will also react with O 2 , ultimately undergo a cracking reaction to generate small molecular substances. The reaction of BCA with O 3 can generate primary ozone oxides and the Criegee Intermediates oIM3, subsequent main reaction products include keto-BCA, as well as other small molecule aqSOA precursors. The entire reaction process increases the O/C ratio of aqSOA in the aqueous phase and generates products of small molecules such as 4-formylpropionic acid, which plays an important role in the formation of aqSOA. At 298K, the transformation rate constants of BCA initiated by ·OH and O 3 are 1.47 × 10 10  M -1  s -1 and 3.16 × 10 5  M -1  s -1 , respectively, the atmospheric lifetimes of BCA reacting with ·OH range from 0.86 h-5.40 h, while the lifetimes of BCA reacting with O 3 range from 0.44 h-10.04 years. This suggests that BCA primarily reacts with ·OH. However, under higher O 3 concentrations, its ozonolysis becomes significant, promoting the formation of aqSOA. According to the risk assessment, the toxicity of most transformation products (TPs) gradually decreased, but the residual developmental toxicity could not be ignored. In this paper, the atmospheric liquid phase oxidation mechanisms of sesquiterpene unsaturated derived acid were studied from the microscopic level, which has guiding significance for the formation and transformation of aqSOA in atmosphere., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In this study, we statistically demonstrated that an anomalous high of 40 K fallout in the atmospheric fallout in Kagoshima City is caused by heavy ashfall associated with eruptions of Sakurajima volcano. Sakurajima is one of the most active volcanoes in Japan, and its repeated explosive eruptions cause large amounts of ash to fall on Kagoshima City. The fallout of crust-derived natural radionuclides, 40 K, 212 Pb, and 214 Bi, from the atmosphere in Kagoshima City showed a significant correlation with the number of eruptions of Sakurajima volcano and the amount of ashfall in Kagoshima City. In contrast, no significant correlation was found between 40 K and 7 Be fallout. The 40 K fallout indicates that almost all of the atmospheric fallout in Kagoshima City is composed of volcanic ash particles. The contribution from mineral and sea salt particles other than volcanic ash is minimal. The mass balance of the observed 40 K fallout, ashfall, and atmospheric fallout yield indicates that there is a significant amount of volcanic ash deposition that is not accounted for as ashfall. In most cases, the ash deposition observed as ashfall is only 30-70 wt% of the total deposition collected as atmospheric fallout samples, and the remaining portion is fine-grained and behaves as suspended volcanic ash particles, which significantly impact the atmospheric environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Here we present the UCI Fluxtron, a cost-effective multi-enclosure dynamic gas exchange system that provides an adequate level of control of the experimental conditions for investigating biosphere-atmosphere exchange of trace gases. We focus on the hardware and software used to monitor, control, and record the air flows, temperatures, and valve switching, and on the software that processes the collected data to calculate the exchange flux of trace gases. We provide the detailed list of commercial materials used and also the software code developed for the Fluxtron, so that similar dynamic enclosure systems can be quickly adopted by interested researchers. Furthermore, the two software components -Fluxtron Control and Fluxtron Process- work independently of each other, thus being highly adaptable for other experimental designs. Beyond plants, the same experimental setup can be applied to the study of trace gas exchange by animals, microbes, soil, or any materials that can be enclosed in a suitable container., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Glacial bodies in the Peruvian Andes Mountains store and supply freshwater to hundreds of thousands of people in central Peru. Atmospheric black carbon (BC) is known to accelerate melting of snow and ice, in addition to contributing to air pollution and the health of people. Currently there is limited understanding on the sources and temporal variability of BC in valley and mountain environments in Peru. To address this problem, this study combined surface observations of BC collected during 2022-2023 with WRF model simulations and HYSPLIT trajectories to analyze the dispersion and sources of BC in valley and high elevation environments and the associated local atmospheric circulations. Results show high BC concentrations are associated with the valley-mountain wind system that occurs on both sides of the Huaytapallana mountain range. A pronounced circulation occurs on the western slopes of Huaytapallana when concentrations of BC increase during daylight hours, which transports atmospheric pollutants from cities in the Mantaro River Valley to the Huaytapallana mountain range. Low concentrations of BC are associated with circulations from the east that are channeled by the pronounced ravines of the Andes-Amazon transition. On average, during the season of highest BC concentrations (July-November), the relative contributions of fossil fuels are dominant to biomass burning at the valley observatory and are slightly lower at the Huaytapallana observatory. These results demonstrate the need to promote mitigation actions to reduce emissions of BC and air pollution associated with forest fires and local anthropogenic activity., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Elver Villalobos Puma reports was provided by National Institute for Research on Glaciers and Mountain Ecosystems. Elver Villalobos-Puma reports a relationship with National Institute for Research on Glaciers and Mountain Ecosystems that includes: employment. Elver Villalobos-Puma has patent pending to Lincensee. co-author previously employed by INAIGEM Company-A.M If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lake Erhai is a potentially phosphorus (P)-limited lake and its water quality may have been affected by atmospheric P deposition. However, there have been few studies on atmospheric P deposition in this lake. In this study, we established five wet deposition monitoring sites and two dry deposition monitoring sites around Lake Erhai to quantify the wet and dry deposition of total phosphorus (TP), including dissolved inorganic phosphorus (DIP), dissolved organic phosphorus (DOP) and particulate phosphorus (PP) from July 2022 to June 2023. Wet deposition fluxes of P species were collected by automatic rainfall collection instrument, and dry deposition fluxes were estimated using airborne concentration measurements and inferential models. The results reveal that among the different P components, DOP had the highest contribution (50%) to wet TP deposition (average all sites 12.7 ± 0.7 mg P m 2 /yr), followed by PP (40%) and DIP (10%). Similarly, DOP (51%) was the major contributor to dry TP deposition (average two sites 2.4 ± 0.9 mg P m 2 /yr), followed by DIP (35%) and PP (14%). Wet deposition dominated the annual total TP deposition (wet plus dry), accounting for approximately 83%. The key seasons for dry deposition were spring and autumn, which accounted for 64% of the annual total dry TP deposition. In comparison, wet deposition was significantly higher in the summer, accounting for 73% of the annual total wet TP deposition. The results of the potential source contribution function and concentration-weighted trajectories analysis indicate that local source emission and long-range transport from surrounding cities jointly exerted a substantial influence on aerosol P concentrations, particularly in the eastern and northwestern regions of the lake. These findings provide a comprehensive understanding of the different P components in atmospheric deposition, which is beneficial for developing effective strategies to manage the P cycle in Lake Erhai., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The Earth's atmosphere contains ultrafine particles known as aerosols, which can be either liquid or solid particles suspended in gas. These aerosols originate from both natural sources and human activities, termed primary and secondary sources respectively. They have significant impacts on the environment, particularly when they transform into ultrafine particles or aerosol nanoparticles, due to their extremely fine atomic structure. With this context in mind, this review aims to elucidate the fundamentals of atmospheric-derived aerosol nanoparticles, covering their various sources, impacts, and methods for control and management. Natural sources such as marine, volcanic, dust, and bioaerosols are discussed, along with anthropogenic sources like the combustion of fossil fuels, biomass, and industrial waste. Aerosol nanoparticles can have several detrimental effects on ecosystems, prompting the exploration and analysis of eco-friendly, sustainable technologies for their removal or mitigation.Despite the adverse effects highlighted in the review, attention is also given to the generation of aerosol-derived atmospheric nanoparticles from biomass sources. This finding provides valuable scientific evidence and background for researchers in fields such as epidemiology, aerobiology, and toxicology, particularly concerning atmospheric nanoparticles., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The main purpose of this study is to evaluate the near-zero wind velocity measurement performance of two separate 1.5 μm all-fiber coherent Doppler lidars (CDL). The performance characterization is performed through the presentation of the results from two separate atmospheric field campaigns. In one campaign, a recently developed continuous wave (CW) CDL benefiting from an image-reject front-end was deployed. The other campaign utilized a different CW CDL, benefiting from a heterodyne receiver with intermediate frequency (IF) sampling. In both field campaigns the results are compared against a sonic anemometer, as the reference instrument. The measurements clearly show that the image-reject architecture results in more accurate measurements of radial wind velocities close to zero. Close-to-zero velocities are usually associated with the vertical component of the wind and are important to characterize. [ABSTRACT FROM AUTHOR]

This work presents a new iterative method for optimally selecting a vertical retrieval grid based on the location of the information content while accounting for inter-level correlations. Sample atmospheres initially created to parametrise the RTTOV forward model are used to compare the presented iterative vertical selection method with two other common approaches, which are using levels of equal vertical spacing and selecting levels based on the cumulative trace of the averaging kernel matrix (AKM). This new method is shown to outperform compared methods for synthesized profile retrievals with IASI of temperature, H2O, O3, CH4, and CO. However, the benefits of using the more complicated iterative approach compared to the simpler method of referencing the cumulative trace of the AKM are slight and may not justify the added effort. Furthermore, comparing retrievals using a globally optimized static grid vs. an atmosphere specific one shows that a static grid is likely appropriate for retrievals of O3, CH4, and CO. However, developers of temperature and H2O retrieval schemes may at least consider using adaptive or location specific vertical retrieval grids. [ABSTRACT FROM AUTHOR]

Carbon dioxide exchange between the atmosphere and forested subtropical wetlands is largely unknown. Here we report a first step in characterizing this atmospheric-ecosystem carbon (C) exchange, for cypress strands and pine forests in the Greater Everglades of Florida as measured with eddy covariance methods at three locations (Cypress Swamp, Dwarf Cypress and Pine Upland) for one year. Links between water and C cycles are examined at these three sites, and methane emission measured only at the Dwarf Cypress site. Each forested wetland showed net C uptake (retained in the soil and biomass or transported laterally via overland flow) from the atmosphere monthly and annually. Net ecosystem exchange (NEE) of carbon dioxide (CO2) (difference between photosynthesis and respiration, with negative values representing net ecosystem uptake) was greatest at the Cypress Swamp (-1000 gCm-2 year-1), moderate at the Pine Upland (-900 gCm-2 year-1), and least at the Dwarf Cypress (-500 gCm-2 year-1). Methane emission was a negligible part of the C (12 gCm-2 year-1) budget when compared to NEE. However, methane (CH4) production was considerable in terms of global warming potential, as about 20 g CH4 emitted per m² year was equivalent to about 500 g CO2 emitted per m² year. Changes in NEE were clearly a function of seasonality in solar insolation, air temperature and water availability from rainfall. We also note that changes in the satellite-derived enhanced-vegetation index (EVI) served as a useful surrogate for changes in net and gross atmospheric-ecosystem C exchange at these forested wetland sites. [ABSTRACT FROM AUTHOR]

This article explores the overlooked history of atmospheric electricity in the last third of the nineteenth century, delineating the work of Austrian physicist Franz Exner and German schoolteachers Julius Elster and Hans Geitel, and identifying the consequences of their work for twentieth-century physics. Since the earliest days of electrical science, the constant electrification of the atmosphere had been a persistent puzzle, with histories by historians and physicists alike typically focusing on what came after the discovery of gaseous ions in the atmosphere in 1899: cosmic rays, radioactivity, particle physics, and quantum phenomena. I argue that Exner and Elster and Geitel's creative work in atmospheric electricity before 1899 provided the essential conditions for these twentieth-century discoveries. Their divergent theories, experiments, instruments, and environments, developed to understand the origins of the atmosphere's electrification, provided a setting for new ideas about charge, determinism, and measurement to arise. This paper expands on the existing scholarship that has pointed to the fruitful interactions between physics and meteorology in British contexts in this period. In disentangling Exner's and Elster and Geitel's differing views on geographical and meteorological conditions I offer a new perspective on the recent vertical turn in the history of science. The paper concludes by suggesting that while the ionic revolution of 1899 was foundational for much of twentieth-century physics, it constituted a significant theoretical undoing for atmospheric electricians, leaving the field with even less understanding of the atmosphere's electrification than before. [ABSTRACT FROM AUTHOR]

The annual average CO2 difference between baseline data from Mauna Loa and the southern Hemisphere increased by ~ 0.8 µmolmol-1 (0.8 ppm) between 2009 and 2010, a step unprecedented in over 50 years of reliable data. We find no evidence for coinciding, sufficiently large and rapid, source/sink changes. A statistical anomaly is unlikely due to the highly systematic nature of the variation in observations. An explanation for the step, and the subsequent 5 year stability in this north-south difference, involves inter-hemispheric atmospheric exchange variation. The selected data describing this episode provide a critical test for studies that employ atmospheric transport models that interpret global carbon budgets and inform management of anthropogenic emissions. [ABSTRACT FROM AUTHOR]

The atmospheric boundary layer (ABL) exhibit multilayered thermal structure especially in polar atmosphere during extreme winters. These thermal inversions are originated based on the combined forcing of local and large scale synoptic meteorology. At the local scale the thermal inversion layer forms near the surface and plays a central role in controlling the surface radiative cooling; however, depending upon the large scale synoptic meteorological forcing, an upper level thermal inversion can also exist topping the local ABL. In this article a numerical methodology is developed to determine all-thermal inver sion layers present in a given temperature profile and deduce some of their thermodynamic properties. The algorithm extract from the temperature profile the most important temperature variations defining thermal layers. This is accomplished by a linear interpolation function of variable length that minimizes an error function. The algorithm functionality is demonstrated on actual radiosonde profiles to deduce all-present inversion layers with an error fraction set independently. [ABSTRACT FROM AUTHOR]

This paper describes an attempt to use data obtained from sodar (sound detection and ranging) for short-term forecasting of PM 10 concentration levels in Krakow. Krakow is one of the most polluted cities in central Europe (CE) in terms of PM 10 concentration. This is due to the high municipal emissions. Thanks to intensive corrective actions taken by the city authorities, these are being effectively eliminated, but the unfavourable topographic location of the city limits natural ventilation. The article describes all these conditions, focusing on presenting the method of short-term correction of air quality for the time needed to take quick corrective actions by the city authorities in the event of anticipated exceedances of the permissible values. Based on several years of measurements of the physical properties of the atmosphere with sodar, the authors of the paper suggest that sodar data could be considered for operational use to generate short-term predictions. The proposed method is based on the use of the spectrum, i.e. the set of amplitudes of signals returning to the sodar receiver from the reflection of a single-frequency sound transmission and its characteristic properties depending on the physical state of the atmosphere. Similar spectra were parameterised with a single numerical value using statistical methods. It was found that, in some cases preceding high concentrations of PM 10 , the spectral parameters had similar values. This made it possible to develop a forecasting method for such concentrations by using data mining to search for conditions in historical data closest to the state of the atmosphere at the time of forecasting. In this part of the study, data from 2017–2018 were used. In the next step, three methods of using the sodar data developed for PM 10 prediction were proposed, comparing them with the method without sodar use. The study results were tested on independent material using data concerning the episodes of high concentrations of pollutants from October 2021 to March 2022 in Krakow. The findings were considered to be encouraging, also taking into account the speed and low cost of preparing the forecast. [ABSTRACT FROM AUTHOR]

This paper presents research results on CO2 emissions originating from maritime vessels with various main engine settings. The impact (i.e., the volume and amount) of gas emissions into the environment is shown, along with the characteristics of the marine fuel used. This research was carried out on a container vessel sailing on a fixed route between Rotterdam and St. Petersburg. It covered mainly two different engine operations, at 124 RPM and 100 RPM settings, in the Kiel Canal area. The purpose of this study is to demonstrate that the engine setting of 100 RPM compared to the same voyage through the Kiel Canal, with an engine setting of 124 RPM, leads to a significant reduction of CO2 emissions. Though proving such a thesis seems to be evident, the analysis in the paper shows that, in practice, mainly due to time constraints and engineers' assumptions of engine technical status, the higher speeds are still preferred over lower ones. In studies not related to passive use or active methods, only specific and simplest methods of obtaining CO2 emissions are presented. [ABSTRACT FROM AUTHOR]

TEMPERA is a new ground-based radiometer which measures in a frequency range from 51-57 GHz radiation emitted by the atmosphere. The instrument operates thermally stabilized inside a lab. With this instrument it is possible to measure temperature profiles from ground to about 50 km. This is the first ground-based instrument with the capability to retrieve temperature profiles simultaneously for the troposphere and stratosphere. The measurement is done with a filterbank in combination with a digital Fast-Fourier-Transform spectrometer. A hot load and a noise diode are used as stable calibration sources. The optics consist of an off-axis parabolic mirror to collect the sky radiation. Due to the Zeeman effect on the emission lines used, the maximum height for the temperature retrieval is about 50 km. The effect is apparent in the measured spectra. The performance of TEMPERA is validated by comparison with nearby radiosonde and satellite data from the Microwave Limb Sounder on the Aura satellite. In this paper we present the design and measurement method of the instrument followed by a description of the retrieval method, together with a validation of TEMPERA data over its first year, 2012. [ABSTRACT FROM AUTHOR]

Beryllium-7 activity concentrations in the atmosphere and precipitation were continuously measured every day between April 2011 and December 2015 in Dazaifu, western Japan. The measured data were quantitatively analyzed to determine the precipitation-induced variation in 7 Be activity concentrations. The average concentrations on nonprecipitation and precipitation days were 5.5 and 3.8 mBq/m 3 , respectively. This difference of 31% (1.7 mBq/m 3 ) on average, was attributable to the washout effect, which was more significant in the summer. Regarding the association between 7 Be activity concentration and precipitation, the concentration remained at a similar level for the small precipitation amount of <5.0 mm/day and showed a decreasing trend (but was insignificant) for the precipitation of 5.0-10.0 mm/day. A significant decrease in the concentration was observed for ≥10 mm/day. Furthermore, when precipitation occurred on two successive days, the 7 Be activity concentrations on the second day significantly decreased regardless of precipitation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Plutonium, as well as fission products such as 137 Cs, had been released into the earth environment in 1945 after the first atmospheric nuclear explosion of plutonium bomb in the desert of New Mexico (USA, July 16) and later over Nagasaki (August 9), followed then by many other explosions. Thus, plutonium cycling in the atmosphere and ocean has become a major public concern as a result of the radiological and chemical toxicity of plutonium. However, plutonium isotopes and 137 Cs are important transient tracers of biogeochemical and physical processes in the environment, respectively. In this review, we show that both physical and chemical approaches are needed to comprehensively understand the behaviors of plutonium in the atmosphere and ocean. In the atmosphere, plutonium and 137 Cs attach with aerosols; thus, plutonium moves according to physical and chemical processes in connection with aerosols; however, since plutonium is a chemically reactive element, its behavior in an aqueous environment is more complicated, because biogeochemical regulatory factors, in addition to geophysical regulatory factors, must be considered. Meanwhile, 137 Cs is chemically inert in aqueous environments. Therefore, the biogeochemical characteristics of plutonium can be elucidated through a comparison with those of 137 Cs, which show conservative properties and moves according to physical processes. Finally, we suggest that monitoring of both plutonium and 137 Cs can help elucidate geophysical and biogeochemical changes from climate changes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The interactions of the micro-mechanism of hydroxymethanesulfonic acid (HMSA) with the typical small organic molecule in atmospheric (X = methanol, formaldehyde, formic acid, methyl formate, dimethyl ether, acetone) has been investigated by density functional theory (DFT), quantum theory of atoms in molecules (QTAIM), Generalized Kohn-Sham Enery Decomposition Analysis (GKS-EDA) and the atmospheric clusters dynamic code (ACDC). The results of DFT show that the stable six- to eight-membered ring structures are easily formed in HMSA-X clusters. According to the topological analysis results of the AIM theory and the IRI method, a strong hydrogen bonding interaction is present in the complex. GKS-EDA results show that electrostatic energy is the main contributor to the interaction energy as it accounts for 51 %-55 % of the total attraction energy. The evaporation rates of HMSA-HMSA and HMSA-HCOOH clusters were much lower than those of the other HMSA complexes. In addition, the Gibbs energy of formation (ΔG) of HMSA-X dimers is investigated under atmosphere temperature T = 217-298 K and p = 0.19-1.0 atm, the ΔG decreased with decreasing of the atmosphere temperature and increased with the decrease of atmospheric pressure, indicating that the low temperature and high pressure may significantly facilitate to the formation of dimers., Competing Interests: Declaration of competing interest First of all, thank you very much for your busy schedule to view the submitted manuscripts. I confirm that this manuscript has not been submitted to some other journal. There are no financial conflicts to declare, I guarantee that the above statement is true, and I shall bear corresponding responsibilities arising from any violation of the statement therefrom. All data is provided in full in the results section of this paper. I guarantee that the above statement is true, and I shall bear corresponding responsibilities arising from any violation of the statement therefrom., (Copyright © 2024 Elsevier Inc. All rights reserved.)

CH 4 serves as an important greenhouse gas, yet limited knowledge is available in global and regional CH 4 cycling, particularly in widely distributed karst terrain. In this study, we investigated an upland in Puding Karst Ecosystem Research Station, and explored CH 4 concentration and/or flux in atmosphere, soil and cave using a closed static chamber method and an eddy covariance system. Meanwhile, we monitored atmospheric temperature, precipitation, temperature and wind velocity in the cave entrance. The results demonstrated that atmospheric CH 4 and actual soil CH 4 fluxes in the source area of eddy covariance system were -0.19 ± 8.64 nmols -1 m -2 and -0.16 nmols -1 m -2 respectively. The CH 4 concentrations in Shawan Cave exhibited 10 ∼ 100-fold lower than that of the external atmosphere. CH 4 oxidation rate dominated by methane-oxidizing bacteria was 1.98 nmols -1 m -2 in Shawan Cave when it combined with temperature difference between cave and external atmosphere. Therefore, CH 4 sink in global karst subterranean spaces was estimated at 106.2 Tg CH 4 yr -1 . We supplemented an understanding of CH 4 cycling paths and fluxes in karst terrain, as well as CH 4 sinks in karst subterranean space. Further works require to establish a karst ecosystem observation network to conduct long-term integrated studies on CH 4 fluxes regarding atmosphere, soils, plants and caves., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Anthropogenic shifts in seas are reshaping fishing trends, with significant implications for aquatic food sources throughout this century. Examining a 21-year abundance dataset of Argentine shortfin squids Illex argentinus paired with a regional oceanic analysis, we noted strong correlations between squid annual abundance and sea surface temperature (SST) in January and February and eddy kinetic energy (EKE) from March to May in the Southwest Atlantic. A deeper analysis revealed combined ocean-atmosphere interactions, pinpointed as the primary mode in a rotated empirical orthogonal function analysis of SST. This pattern produced colder SST and amplified EKE in the surrounding seas, factors crucial for the unique life stages of squids. Future projections from the CMIP6 archive indicated that this ocean-atmosphere pattern, referred to as the Atlantic symmetric pattern, would persist in its cold SST phase, promoting increased squid abundance. However, rising SSTs due to global warming might counteract the abundance gains. Our findings uncover a previously unrecognized link between squids and specific environmental conditions governed by broader ocean-atmosphere interactions in the Southwest Atlantic. Integrating these insights with seasonal and decadal projections can offer invaluable information to stakeholders in squid fisheries and marine conservation under a changing climate., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This study aimed to investigate the occurrence of eight nitrosamines (NAs) in particulate (PM 2.5 ) and gaseous phases and assess the human health risk associated with these compounds in an urban area of Chuncheon, Gangwon State, South Korea, across four sampling seasons. The findings revealed that the total concentrations of eight NAs measured during the sampling period exceeded the public health recommendation of 0.3 ng/m 3 provided by the Norwegian Institute of Public Health, indicating a potential human health risk from NA exposures. In particular, the average total NA concentration observed in the gaseous samples during the winter of 2021 was 18.1 ± 6.46 ng/m 3 . The primary emission sources could potentially impact the concentrations of NAs in the atmosphere due to their significant positive correlation with primary emission species such as NO 2 , CO, and SO 2 . Moreover, the levels of particulate NAs during the summer were negatively correlated with O 3 , suggesting that their formation might be influenced by ozonation in the aqueous aerosol phase. In addition, the total NA concentrations measured in the gaseous phase were four to six times higher than those measured in the PM 2.5 phase throughout the sampling period. Thus, domestic sources have the potential to impact the pollution levels of the research area more significantly than long-range atmospheric transport. In particular, the highest concentrations of NAs in the gas phase were observed during the winter, while the lowest concentrations were recorded in the summer, possibly influenced by photolysis. Nevertheless, the study suggested that tertiary amines might contribute to the presence of gaseous NAs in sunlight. Consequently, further studies focusing on the occurrence of tertiary amines in the gas phase should be considered. The cumulative lifetime cancer risks estimated from inhalation exposure exceeded the acceptable risk level of 10 ⁻6 for all age groups across all four seasons. Therefore, it is crucial to implement effective control measures to mitigate potential health risks associated with exposure to NAs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In September 2017, numerous measurement stations recorded large surface concentrations of Ru106 in Europe. This event was well recorded by various monitoring stations worldwide and offer a valuable framework to compare the modelling strategies deployed to quickly evaluate where the plume goes and with what concentrations. In general, the source and its intensity are not known and hypotheses have to be done. Models have to be fast and accurate: Lagrangian and Eulerian are often used but rarely compared. In this study, the FLEXPART Lagrangian model and the WRF-CHIMERE Eulerian models are used to simulate the emissions, transport and deposition of this source of Ru106. First, it is shown that the hypothesis of location, timing and intensity of the source is realistic, by comparison to surface measurements. Second, sensitivity analysis performed with the Eulerian model and several transport scheme showed that this model may provide better results than the Lagrangian one. It opens the door to further development, including chemistry and mixing with other pollutants during these specific events., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The article presents a study which develops a rapid retrieval method for observation of integrated longwave and shortwave top-of-atmosphere irradiances from Meteosat Second Generation (MSG)/SEVIRI (RRUMS). It uses the spatial and temporal resolution of MSG/SEVIRI retrieve the integrated longwave and shortwave radiation. Result shows that the linear combination of the thermal infrared channels can reliably calculate the longwave radiative flux (OLR).

Strong Thermal Emission Velocity Enhancement (STEVE), is a captivating optical phenomenon typically observed in the mid‐latitude ionosphere. This paper presents an intriguing observation of a STEVE event at high‐latitudes, approximately 10 degrees poleward of previously documented observations. This event was recorded in Yellowknife, Canada, by a TREx RGB imager and a citizen scientist. Swarm satellites traversed the latitude of the observation, measuring extreme westwards ion drift velocities exceeding 4 km/s. Such velocities are more typically associated with the subauroral region located at mid‐latitudes, rather than at the high‐latitudes reported here. Significantly, this event occurred without a substorm, which differs from previous STEVE observations. While high‐latitude radars detected fast ionospheric equatorward flows, GOES satellite did not record any injections. These observations suggest that the inner magnetosphere is highly inflated. This unique case study raises new questions surrounding subauroral dynamics and the influence of magnetospheric configurations on ionospheric responses. Plain Language Summary: Strong Thermal Emission Velocity Enhancement, also known as STEVE, is a fascinating nighttime optical phenomenon that takes place in the upper part of Earth's atmosphere. It can be easily recognized by its distinctive appearance as a narrow white‐mauve arc that is associated with strong westward flows and is situated just equatorward of the auroral oval. Previous research has shown that STEVE events occur together with intense ionospheric flows and occur after specific disturbances in the near‐Earth space environment known as substorms. They have found that substorms are important for creating the special conditions that lead to STEVE and other subauroral enhancements. In our study, we focus on a unique STEVE event that did not occur after a substorm. Furthermore, this observation took place under remarkably quiet solar wind conditions; nevertheless, strong ionospheric flows were recorded. This unusual case raises new questions about the atmospheric responses and how it is affected by the configuration of the magnetic field in space. By investigating these special circumstances, we hope to learn more about STEVE and its causes, which will help us advance our knowledge in the complex ionosphere‐magnetosphere‐solar wind coupled system. Key Points: Non‐storm and non‐substorm Strong Thermal Emission Velocity Enhancement (STEVE) occurrenceStrong subauroral flows during quiet geomagnetic conditionsThe ionospheric electrodynamics of this STEVE event differ from previous studies [ABSTRACT FROM AUTHOR]

Powerful lightning strikes generate broadband electromagnetic signals. At Extremely Low Frequencies (ELF), the signal partly leaks into the ionosphere and produces whistlers that can be detected by satellites. Indeed, the satellites of the European Space Agency (ESA) Swarm Earth Explorer mission can detect those signals during 250 Hz burst‐mode acquisition campaigns of their Absolute Scalar Magnetometers (ASM). The dispersion of these whistlers depends on their propagation path and the distribution of ionization in the ionosphere crossed along that path. In this paper, we introduce a technique to derive a new measure of ionosphere electron content, the Total square‐Root Electron Content (TREC), using the arrival times of two frequencies of the whistler signal. We validate this approach by using data from ionosondes and from in situ measurements of the electron density at Swarm location. This technique brings new opportunities for sounding the ionosphere in regions poorly observed by other techniques. Plain Language Summary: A lightning strike generates an electromagnetic impulse that propagates within Earth's atmosphere and eventually leaks out into the ionosphere. As it propagates through the ionosphere toward low‐Earth orbiting (LEO) satellites, it gets converted into a so‐called whistler, with high frequencies arriving earlier than low frequencies. This frequency dispersion depends on the state of the ionosphere. Here, we analyse such whistler waves detected by magnetometers onboard the European Space Agency Swarm satellites to recover information about the state of the ionosphere below the satellites. We first introduce a new metric, the Total Root Electron Content (TREC), which quantifies the cumulative value of the square root of electron density along the path of the whistler. We next propose a method to recover the TREC from the analysis of the whistler dispersion. We finally validate this method by using independently derived ionospheric electron density profiles to infer expected TREC values. Our results show that whistlers detected by LEO satellites can be used to locally improve the widely used empirical International Reference Ionosphere model. Such whistler inferred TREC values could be used to sound the ionosphere above places difficult to sample with conventional measuring techniques, and help better model and understand the highly dynamic ionosphere. Key Points: Total square‐Root Electron Content (TREC) is a new measure of the ionospheric electron content for electromagnetic signals in the ELF bandA method to retrieve TREC from fractional‐hop whistlers in the ELF detected by the ESA Swarm mission is proposedThe method is validated using TREC computed with independently constrained electron density profiles close to the Swarm whistler locations [ABSTRACT FROM AUTHOR]

This study investigates the effects of sea spray on extreme precipitation forecast in Beijing of China between 28 July and 2 August 2023 as a case test. In this case, fully coupled model increased upward moisture in the Bohai and Yellow Seas and increased accumulated rainfall by 21% in North China. For the extreme precipitation events with the 5‐day accumulated precipitation exceeding 500 mm, the atmosphere‐only model did not forecast the events; the coupled model without sea spray performed well with the 0.29 threat score (TS) and 88 mm root mean square error (RMSE); in the fully coupled model, the effects of sea spray increased atmospheric instability, which increased the precipitation around Beijing and yielded a more accurate forecast with the 0.37 TS and 65 mm RMSE. This paper suggests a scientific clue to improve numerical simulation for extreme rainfall events, however, more cases are still needed for statistical evaluation. Plain Language Summary: Although meteorological forecasting ability has been improved considerably during the past decades, precipitation during extreme events remains typically underestimated. Improving model accuracy for heavy rainfall events is, indeed, a ground challenge. In this study, we conducted three numerical experiments under different conditions to evaluate the effects of sea spray on extreme precipitation forecasts for the Beijing extreme rainfall event between 28 July and 2 August 2023. Our results indicated that for this 5‐day forecasting case, including sea spray in the simulations enhanced precipitation in North China by transporting more moisture from the Bohai and Yellow Seas upward into the atmosphere. The moister and warmer air caused by sea spray effects was transported to Beijing through northwestward wind and lifted by the local terrain, then caused a more unstable atmosphere and higher intensity of precipitation around Beijing. By using statistical indicators and setting different precipitation thresholds for this extreme rainfall case, we determined that in this case, the fully coupled model including sea spray yielded more accurate forecast. To statistically evaluate the effects of sea spray in extreme precipitation forecasts, more cases are still needed. Key Points: Fully coupled model led more upward moisture in the Bohai and Yellow Seas and increased 5‐day accumulated rainfall by 21% in North ChinaFully coupled model improved the forecasting threat score from 0 to 0.37 with the 5‐day accumulated precipitation exceeding 500 mmSea spray led to more unstable atmosphere for the Beijing extreme rainfall event, yielding a more accurate forecast [ABSTRACT FROM AUTHOR]

In recent years, the role of the atmosphere in the formation of the chemical composition of water in Lake Baikal and its tributaries has been increasing. In this regard, the study of equivalent black carbon (eBC) in the air above the lake and its coast has an important practical application. This paper presents the results of the mass concentration of eBC and submicron aerosol in the air above the water area of Lake Baikal, which were obtained during expeditions onboard research vessels in the summer of 2019 and 2023. We analyzed the data from the coastal monitoring station Listvyanka. To measure eBC, an MDA-02 aethalometer was used in the water area of the lake, and a BAC-10 aethalometer at the Listvyanka station. The background level of the eBC concentration in the air at different areas of the lake ranged between 0.15 and 0.3 µg m−3. The results of the two expeditions revealed the influence of the coastal settlements and the air mass transport along the valleys of the lake's large tributaries on the five- to twentyfold growth of the eBC concentration in the near-water atmosphere. In the diurnal dynamics of eBC near settlements, we recorded high values in the evening and at night. In background areas, the diurnal dynamics were poorly manifested. In the summer of 2019, there were smoke plumes in the water area of Lake Baikal from distant wildfires and a local fire site on the east coast of the lake. The eBC concentration increased to 5–6 µg m−3, which was 10 to 40 times higher than the background. The long-range transport of plumes from coal-fired thermal power plants in large cities of the region made the major contribution to the eBC concentration at «Listvyanka» in winter, which data on aerosol, gas impurities, and meteorological parameters confirmed. [ABSTRACT FROM AUTHOR]

Clouds are key to understanding the atmosphere and climate, and a long series of satellite observations provide invaluable information to study their properties. EUMETSAT has published Release 1 of the Optimal Cloud Analysis (OCA) Climate Data Record (CDR), which provides a homogeneous time series of cloud properties of up to two overlapping layers, together with uncertainties. The OCA product is derived using the 15 min Spinning Enhanced Visible and Infrared Imager (SEVIRI) measurements onboard Meteosat Second Generation (MSG) in geostationary orbit and covers the period from 19 January 2004 until 31 August 2019. This paper presents the validation of the OCA cloud-top pressure (CTP) against independent lidar-based estimates and the quality assessment of the cloud optical thickness (COT) and cloud particle effective radius (CRE) against a combination of products from satellite-based active and passive instruments. The OCA CTP is in good agreement with the CTP sensed by lidar for low thick liquid clouds and substantially below in the case of high ice clouds, in agreement with previous studies. The retrievals of COT and CRE are more reliable when constrained by solar channels and are consistent with other retrievals from passive imagers. The resulting cloud properties are stable and homogeneous over the whole period when compared against similar CDRs from passive instruments. For CTP, the OCA CDR and the near-real-time OCA products are consistent, allowing for the use of OCA near-real time products to extend the CDR beyond August 2019. [ABSTRACT FROM AUTHOR]