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Ships brighten low marine clouds from emissions of sulfur and aerosols, resulting in visible "ship tracks". In 2020, new shipping regulations mandated an ∼80% reduction in the allowed fuel sulfur content. Recent observations indicate that visible ship tracks have decreased. Model simulations indicate that since 2020 shipping regulations have induced a net radiative forcing of +0.12 Wm−2. Analysis of recent temperature anomalies indicates Northern Hemisphere surface temperature anomalies in 2022–2023 are correlated with observed cloud radiative forcing and the cloud radiative forcing is spatially correlated with the simulated radiative forcing from the 2020 shipping emission changes. Shipping emissions changes could be accelerating global warming. To better constrain these estimates, better access to ship position data and understanding of ship aerosol emissions are needed. Understanding the risks and benefits of emissions reductions and the difficultly in robust attribution highlights the large uncertainty in attributing proposed deliberate climate intervention. Plain Language Summary: Ships have a unique climate effect due to brightening of low marine clouds, resulting in visible "ship tracks". These ship tracks are due to clouds interacting with ship emissions, particularly sulfur. Recently, regulations have drastically reduced allowable ship sulfur emissions. This has resulted in a decrease in observable ship tracks. Modeling and observations indicate that the reduction in ship sulfur emissions could have slightly warmed the planet starting in 2020. These changes are remarkably co‐incident with observed patterns of cloud changes and may have accelerated global warming. Key Points: Recent regulations on ship sulfur emissions have decreased ship tracks and resulted in +0.12 Wm−2 of radiative forcingObserved cloud anomalies are correlated with observed ocean temperature anomalies and shipping radiative forcingReduced ship emissions may have accelerated global warming contributing to recent warm Northern Hemisphere surface temperatures [ABSTRACT FROM AUTHOR]

Many different emission pathways exist that are compatible with the Paris climate agreement, and many more are possible that miss that target. While some of the most complex Earth System Models have simulated a small selection of Shared Socioeconomic Pathways, it is impractical to use these expensive models to fully explore the space of possibilities. Such explorations therefore mostly rely on one‐dimensional impulse response models, or simple pattern scaling approaches to approximate the physical climate response to a given scenario. Here we present ClimateBench—the first benchmarking framework based on a suite of Coupled Model Intercomparison Project, AerChemMIP and Detection‐Attribution Model Intercomparison Project simulations performed by a full complexity Earth System Model, and a set of baseline machine learning models that emulate its response to a variety of forcers. These emulators can predict annual mean global distributions of temperature, diurnal temperature range and precipitation (including extreme precipitation) given a wide range of emissions and concentrations of carbon dioxide, methane and aerosols, allowing them to efficiently probe previously unexplored scenarios. We discuss the accuracy and interpretability of these emulators and consider their robustness to physical constraints such as total energy conservation. Future opportunities incorporating such physical constraints directly in the machine learning models and using the emulators for detection and attribution studies are also discussed. This opens a wide range of opportunities to improve prediction, robustness and mathematical tractability. We hope that by laying out the principles of climate model emulation with clear examples and metrics we encourage engagement from statisticians and machine learning specialists keen to tackle this important and demanding challenge. Plain Language Summary: Many different emission pathways exist that are compatible with the Paris climate agreement, and many more are possible that miss that target. While some of the most complex Earth System Models have simulated a small selection of possible futures, it is impractical to use these expensive models to fully explore the space of possibilities. Such explorations therefore mostly rely on simple approximations of the global mean temperature response to a given scenario. Here we present ClimateBench—the first benchmarking framework based on a suite of state‐of‐the‐art simulations performed by a full complexity Earth System Model, and a set of baseline machine learning models that emulate its response to a variety of forcers. These emulators can predict annual mean global distributions of temperature, diurnal temperature range and precipitation (including extreme precipitation) given a wide range of emissions and concentrations of carbon dioxide, methane and aerosols, allowing them to efficiently probe previously unexplored scenarios. We also describe a set of evaluation metrics which we hope will entice statisticians and machine learning experts to tackle this important and demanding challenge. Key Points: We introduce the first benchmark for emulation of key spatially resolved climate variables derived from a full complexity Earth System ModelThree baseline emulators are presented which are able to predict regional temperature and precipitation with varying skillEvaluation metrics and areas for future research are presented to encourage further development of trustworthy data‐driven climate emulators [ABSTRACT FROM AUTHOR]

The Hamburg Aerosol Module version 2.3 (HAM2.3) from the ECHAM6.3‐HAM2.3 global atmosphere‐aerosol model is coupled to the recently developed icosahedral nonhydrostatic ICON‐A (icon‐aes‐1.3.00) global atmosphere model to yield the new ICON‐A‐HAM2.3 atmosphere‐aerosol model. The ICON‐A and ECHAM6.3 host models use different dynamical cores, parameterizations of vertical mixing due to sub‐grid scale turbulence, and parameter settings for radiation balance tuning. Here, we study the role of the different host models for simulated aerosol optical thickness (AOT) and evaluate impacts of using HAM2.3 and the ECHAM6‐HAM2.3 two‐moment cloud microphysics scheme on several meteorological variables. Sensitivity runs show that a positive AOT bias over the subtropical oceans is remedied in ICON‐A‐HAM2.3 because of a different default setting of a parameter in the moist convection parameterization of the host models. The global mean AOT is biased low compared to MODIS satellite instrument retrievals in ICON‐A‐HAM2.3 and ECHAM6.3‐HAM2.3, but the bias is larger in ICON‐A‐HAM2.3 because negative AOT biases over the Amazon, the African rain forest, and the northern Indian Ocean are no longer compensated by high biases over the sub‐tropical oceans. ICON‐A‐HAM2.3 shows a moderate improvement with respect to AOT observations at AERONET sites. A multivariable bias score combining biases of several meteorological variables into a single number is larger in ICON‐A‐HAM2.3 compared to standard ICON‐A and standard ECHAM6.3. In the tropics, this multivariable bias is of similar magnitude in ICON‐A‐HAM2.3 and in ECHAM6.3‐HAM2.3. In the extra‐tropics, a smaller multivariable bias is found for ICON‐A‐HAM2.3 than for ECHAM6.3‐HAM2.3. Plain Language Summary: Aerosols are tiny particles in the air which are either emitted into the atmosphere directly or formed from precursor gases such as sulfur dioxide. Aerosols reflect and absorb solar radiation and affect the radiative properties of clouds. In order to estimate how changing emissions of aerosol precursor gases and aerosols affect the radiation budget of the atmosphere, aerosol models are coupled to global atmosphere models. Here, an aerosol model that has already been part of a well‐established coupled model is coupled to a recently developed atmosphere model. The reasons for differences between the original and the new model are investigated and simulated aerosol optical thickness is evaluated against observations. The aerosol optical thickness over subtropical oceans is lower in the new model, which is in better agreement with estimates from satellite observations. This better agreement is traced back to a parameter setting in the cloud description part in the new model. However, because cancellation of positive and negative biases is reduced in the new model, the global mean aerosol optical thickness is biased lower the new model. A bias score based on several meteorological variables is lower in the new model because of lower biases in the extra‐tropics. Key Points: The new ICON‐A‐Hamburg Aerosol Module version 2.3 (HAM2.3) global atmosphere‐aerosol model is introducedThe sensitivity of simulated aerosol optical thickness (AOT) to using two different host models but the same aerosol module is investigatedA positive AOT bias over subtropical oceans is remedied in ICON‐A‐HAM2.3 because of a different parameter setting in the host model [ABSTRACT FROM AUTHOR]

Pockets of open cells sometimes form within closed‐cell stratocumulus cloud decks but little is known about their statistical properties or prevalence. A convolutional neural network was used to detect occurrences of pockets of open cells (POCs). Trained on a small hand‐logged data set and applied to 13 years of satellite imagery the neural network is able to classify 8,491 POCs. This extensive database allows the first robust analysis of the spatial and temporal prevalence of these phenomena, as well as a detailed analysis of their micro‐physical properties. We find a large (30%) increase in cloud effective radius inside POCs as compared to their surroundings and similarly large (20%) decrease in cloud fraction. This also allows their global radiative effect to be determined. Using simple radiative approximations we find that the instantaneous global annual mean top‐of‐atmosphere perturbation by all POCs is only 0.01 W/m2. Plain Language Summary: The amount of sunlight that reaches, and warms, the surface of the earth is heavily influenced by clouds, in particular marine stratocumulus clouds, a type of low‐lying cloud that forms above cold‐upwelling regions of the ocean. Marine stratocumulus clouds form in two distinct regimes; open‐cells and closed‐cells. Closed‐cell clouds have a higher cloud cover and reflectivity than open‐cell clouds. Small pockets of open cell clouds sometimes form within larger regions of closed‐cell clouds; these are referred to as "pockets of open cells." Here we use machine learning to detect occurrences of this phenomenon and characterize them in a long‐term satellite data set. This allows their effect on the climate to be determined for the first time. Despite substantial local‐scale changes in cloud properties, we find that their effect on the climate is small. Key Points: Convolutional Neural Networks are used to detect 8,491 pockets of open cells in marine stratocumulus between 2005 and 2018The first comprehensive analysis of their microphysical and climatological properties is presentedTheir global radiative effect is found to be negligible. Closing all POCs would lead to an instantaneous top‐of‐atmosphere imbalance of only 0.01 W/m2 [ABSTRACT FROM AUTHOR]

Mesotrione (2‐[4‐(methylsulfonyl)‐2‐nitrobenzoyl]‐1,3‐cyclohexanedione) is a proven effective weed control product in agricultural and turf settings but its use within a hydroseeding mixture has not been investigated. Two experiments were conducted to evaluate the effects of (1) mesotrione rate and (2) duration of herbicide exposure on turf establishment and weed populations through hydroseeding establishment methodology. The experimental design of both studies was a randomized complete block, incorporating a split‐plot in the second study, with four replications and repeated in two years. Perennial ryegrass (Lolium perenne L., variety not stated) was hydroseeded on a silt loam soil (pH 7.0) in summer at 39 g m−2 in a slurry delivering 6.1 L m−2. Treatments in the first study were mesotrione rates of 0.000, 0.088, 0.175, and 0.263 kg a.i. ha−1. Treatments in the second study were duration of mixture in tank before applying of 0, 2, and 4 h, with and without mesotrione at 0.175 kg a.i. ha−1. Turfgrass percent cover, turfgrass injury, and weed populations were assessed for both studies. The addition of mesotrione at any rate to the hydroseeding slurry did not reduce desired turf populations; in many cases, the amount of desired turf cover increased. Weed populations were significantly reduced by all mesotrione rates; the effect was most evident at the two highest rates. No treatments caused turf injury. Length of time in the hydroseeding slurry did not reduce herbicide efficacy or desired turf populations, or cause turf injury. [ABSTRACT FROM AUTHOR]

Sod production has been criticized as being unsustainable because of the soil export that occurs at each harvest. Wastewater treatment residuals (biosolids) disposal is often limited by nutrient or metal accumulation in the soil. Biosolids‐based sod production may be a solution to minimize soil loss and land‐apply wastewater residuals. The objectives of this study were to assess biosolids‐based sod production impact on import and export of nutrients, heavy metals, carbon, and to quantify soil loss from sod harvest with and without biosolids. Anaerobically digested, dewatered sludge (Cake) and Cake mixed with sand and sawdust (MetroMix) were applied at three rates based on estimated plant available nitrogen (PAN). An additional treatment mimicked conventional sod production practices that rely on synthetic fertilizer. All biosolids rates and sources increased Mehlich‐3 extractable phosphorus (P) to > 175 mg kg−1 in the harvested sod, which could contribute to P runoff or leaching at the site of establishment. Heavy metal concentrations from both biosolids sources were below EPA loading limits and would require over 200 years of regular application (22 Mg ha−1) to exceed EPA maximum cumulative loading limits. Biosolids at 22 Mg ha−1 did little to reduce soil mineral matter loss compared to conventionally grown sod. After two sod production cycles, soil carbon increased by 50% in the surface soil (0–10 cm), but was reduced at a depth of 20–30 cm. While high P concentrations in the biosolids limit repeated applications, moderate use of biosolids may alleviate reliance on synthetic fertilizers for N and P. [ABSTRACT FROM AUTHOR]

The uncertainty in present‐day anthropogenic forcing is dominated by uncertainty in the strength of the contribution from aerosol. Much of the uncertainty in the direct aerosol forcing can be attributed to uncertainty in the anthropogenic fraction of aerosol in the present‐day atmosphere, due to a lack of historical observations. Here, we present a robust relationship between total present‐day aerosol optical depth and the anthropogenic contribution across three multimodel ensembles and a large single‐model perturbed parameter ensemble. Using observations of aerosol optical depth, we determine a reduced likely range of the anthropogenic component and hence a reduced uncertainty in the direct forcing of aerosol. Plain Language Summary: Despite the impacts of global warming already being felt around the world, it is still unclear how much of the effect of greenhouse gasses is being offset by the cooling effect of atmospheric aerosol through the scattering of incoming sunlight and the modification of clouds. A large part of the difficulty in determining the effect of aerosol is in understanding the proportion of present‐day aerosol that is due to human activity. In this work, we demonstrate a strong relationship between the total amount of aerosol in the present‐day atmosphere (something we can measure) and the amount due to human activity (something we cannot). We further show that this allows us to reduce the uncertainty in the cooling effect of aerosols. Key Points: A strong relationship is demonstrated between total present‐day aerosol loading and the anthropogenic contribution, across a variety of modelsObservations of the total present‐day aerosol loading are thus used to constrain uncertainty in anthropogenic aerosol and aerosol direct forcingApplying these constraints to one million samples of a 26‐parameter perturbed parameter ensemble leads to a clear‐sky RFari estimate of −0.69 ± 0.14 Wm−2 [ABSTRACT FROM AUTHOR]

Unanticipated declines among exploited species have commonly occurred despite harvests that appeared sustainable prior to collapse. This is particularly true in the oceans where spatial scales of management are often mismatched with spatially complex metapopulations. We explore causes, consequences, and potential solutions for spatial mismatches in harvested metapopulations in three ways. First, we generate novel theory illustrating when and how harvesting metapopulations increases spatial variability and in turn masks local‐scale volatility. Second, we illustrate why spatial variability in harvested metapopulations leads to negative consequences using an empirical example of a Pacific herring metapopulation. Finally, we construct a numerical management strategy evaluation model to identify and highlight potential solutions for mismatches in spatial scale and spatial variability. Our results highlight that spatial complexity can promote stability at large scales, however, ignoring spatial complexity produces cryptic and negative consequences for people and animals that interact with resources at small scales. Harvesting metapopulations magnifies spatial variability, which creates discrepancies between regional and local trends while increasing risk of local population collapses. Such effects asymmetrically impact locally constrained fishers and predators, which are more exposed to risks of localized collapses. Importantly, we show that dynamically optimizing harvest can minimize local risk without sacrificing yield. Thus, multiple nested scales of management may be necessary to avoid cryptic collapses in metapopulations and the ensuing ecological, social, and economic consequences. [ABSTRACT FROM AUTHOR]

Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of aerosol radiative forcing over the industrial era based on multiple, traceable, and arguable lines of evidence, including modeling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes constrain the forcing from aerosol‐radiation interactions. A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol‐driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction is less clear, and the influence on mixed‐phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to a 68% confidence interval for the total aerosol effective radiative forcing of ‐1.6 to ‐0.6 W m−2, or ‐2.0 to ‐0.4 W m−2 with a 90% likelihood. Those intervals are of similar width to the last Intergovernmental Panel on Climate Change assessment but shifted toward more negative values. The uncertainty will narrow in the future by continuing to critically combine multiple lines of evidence, especially those addressing industrial‐era changes in aerosol sources and aerosol effects on liquid cloud amount and on ice clouds.Plain Language Summary: Human activities emit into the atmosphere small liquid and solid particles called aerosols. Those aerosols change the energy budget of the Earth and trigger climate changes, by scattering and absorbing solar and terrestrial radiation and playing important roles in the formation of cloud droplets and ice crystals. But because aerosols are much more varied in their chemical composition and much more heterogeneous in their spatial and temporal distributions than greenhouse gases, their perturbation to the energy budget, called radiative forcing, is much more uncertain. This review uses traceable and arguable lines of evidence, supported by aerosol studies published over the past 40 years, to quantify that uncertainty. It finds that there are two chances out of three that aerosols from human activities have increased scattering and absorption of solar radiation by 14% to 29% and cloud droplet number concentration by 5 to 17% in the period 2005–2015 compared to the year 1850. Those increases exert a radiative forcing that offsets between a fifth and a half of the radiative forcing by greenhouse gases. The degree to which human activities affect natural aerosol levels, and the response of clouds, and especially ice clouds, to aerosol perturbations remain particularly uncertain.Key Points: An assessment of multiple lines of evidence supported by a conceptual model provides ranges for aerosol radiative forcing of climate changeAerosol effective radiative forcing is assessed to be between ‐1.6 and ‐0.6 W m−2 at the 16–84% confidence levelAlthough key uncertainties remain, new ways of using observations provide stronger constraints for models [ABSTRACT FROM AUTHOR]

Tropospheric aerosol radiative forcing has persisted for many years as one of the major causes of uncertainty in global climate model simulations. To sample the range of plausible aerosol and atmospheric states and perform robust statistical analyses of the radiative forcing, it is important to account for the combined effects of many sources of model uncertainty, which is rarely done due to the high computational cost. This paper describes the designs of two ensembles of the Met Office Hadley Centre Global Environment Model‐U.K. Chemistry and Aerosol global climate model and provides the first analyses of the uncertainties in aerosol radiative forcing and their causes. The first ensemble was designed to comprehensively sample uncertainty in the aerosol state, while the other samples additional uncertainties in the physical model related to clouds, humidity, and radiation, thereby allowing an analysis of uncertainty in the aerosol effective radiative forcing. Each ensemble consists of around 200 simulations of the preindustrial and present‐day atmospheres. The uncertainty in aerosol radiative forcing in our ensembles is comparable to the range of estimates from multimodel intercomparison projects. The mean aerosol effective radiative forcing is −1.45 W/m2 (credible interval of −2.07 to −0.81 W/m2), which encompasses but is more negative than the −1.17 W/m2 in the 2013 Atmospheric Chemistry and Climate Model Intercomparison Project and −0.90 W/m2 in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The ensembles can be used to reduce aerosol radiative forcing uncertainty by challenging them with multiple measurements as well as to isolate potential causes of multimodel differences. Plain Language Summary: Atmospheric aerosol particles such as dust, pollutants, and smoke interfere with light from the Sun and modify the properties of clouds and thereby affect Earth's climate. However, the effect that aerosols have on climate is one of the major causes of uncertainty in global climate model simulations. We performed a large number of climate model simulations (called an ensemble), with many parts of the model slightly varied, in order to understand the complex behavior of the model and to explore the causes of uncertainty in model outputs. This paper describes the designs of two climate model ensembles and provides the first analyses of the causes of model uncertainty. The first ensemble was designed to comprehensively understand the behavior of aerosols in the atmosphere, while the other includes more general uncertainties in atmospheric processes that can affect aerosols. Each ensemble consists of around 200 simulations. The ranges of the aerosol climate effect in our ensembles are comparable to the ranges of previous estimates from studies that analyzed multiple climate models. These ensembles can be used to reduce uncertainty in how aerosols affect climate by comparing with satellite and ground‐based measurements. Key Points: Two ensembles of atmospheric simulations were performed perturbing aerosol and physical parameters under different model setupsThousands of Gaussian process emulators sampling parameter spaces enabled statistical analyses of model's parametric uncertainty.Fully explored parametric uncertainty of aerosol radiative forcing in a model was found to be comparable to that in multimodel studies [ABSTRACT FROM AUTHOR]

Shading of golf course putting greens often reduces turf quality (TQ). Observations suggested velvet bentgrass (Agrostis canina L., VBG) was more shade tolerant than creeping bentgrass (A. stolonifera L., CBG). Our objectives were to compare the TQ and growth response of 'Vesper' VBG and 'Tyee' CBG to N rates and growth regulator application under 80% shade. The experimental design was a randomized block, strip-split plot with four replications. Foliar urea N was applied every 14 d at annual N rates of 49, 98, and 196 kg ha-1. Trinexapac-ethyl (TE, 0.00 and 0.05 kg a.i. ha-1) was applied every 28 d. Treatments were applied May through October 2009 and 2010. Data collected were TQ, clipping yield, relative chlorophyll index (RCI), and ball roll distance. Nitrogen rate affected TQ more than TE application, though effects of both factors were significant in both years. Turf quality differences between species only affected TQ in 2010 when CBG had higher TQ than VBG on 9 of 19 dates. Rating date and N rate accounted for most clipping yield differences. In 2009, VBG had less clipping yield than CBG. Differences in RCI were greatest in 2010, with 196 kg ha-1 N having significantly lower RCIs than the other N rates when compared across rating dates. Nitrogen rate and species each affected ball roll distances. Neither VBG nor CBG provided acceptable putting green TQ at 80% shade. Application of TE and 49 kg ha-1 yr-1 N resulted in the highest TQ for the longest duration. [ABSTRACT FROM AUTHOR]

Abstract: Vibrio cholerae, the causative agent of cholera, releases several virulence factors including secreted proteases when it infects its host. These factors attack host cell proteins and break down tissue barriers and cellular matrix components such as collagen, laminin, fibronectin, keratin, elastin, and they induce necrotic tissue damage. The secreted protease PrtV constitutes one virulence factors of V. cholerae. It is a metalloprotease belonging to the M6 peptidase family. The protein is expressed as an inactive, multidomain, 102 kDa pre-pro-protein that undergoes several N- and C-terminal modifications after which it is secreted as an intermediate variant of 81 kDa. After secretion from the bacteria, additional proteolytic steps occur to produce the 55 kDa active M6 metalloprotease. The domain arrangement of PrtV is likely to play an important role in these maturation steps, which are known to be regulated by calcium. However, the molecular mechanism by which calcium controls proteolysis is unknown. In this study, we report the atomic resolution crystal structure of the PKD1 domain from V. cholera PrtV (residues 755–838) determined at 1.1 Å. The structure reveals a previously uncharacterized Ca2+-binding site located near linker regions between domains. Conformational changes in the Ca2+-free and Ca2+-bound forms suggest that Ca2+-binding at the PKD1 domain controls domain linker flexibility, and plays an important structural role, providing stability to the PrtV protein. [Copyright &y& Elsevier]

Urban vegetative plantings are considered desirable to mitigate and filter stormwater runoff and nonpoint-source pollution. Phosphorus fertilization of turfgrass may enhance P in urban runoff; however, the amount of P from nonfertilized, native vegetation that could potentially replace some turf is not known. This study was conducted to measure the relative contributions of nonfertilized, native prairie vegetation and fertilized turfgrass to runoff water and P loads. Six replicates of side-by-side mature urban prairie and turfgrass were monitored for mean annual runoff volumes and P loads, biomass production, vegetative nutrient composition, and changes in soil moisture. Vegetation type did not significantly affect seasonal or annual runoff volumes or P loads. The mean annual total P loads of 0.46 kg ha-1 for prairie and 0.28 kg ha-1 for turfgrass were significant and comparable to those reported by other researchers when studied separately. Total P concentrations in runoff water from prairie and turf vegetation were above USEPA limits, averaging 1.86 and 1.63 mg L-1, respectively, over 2 yr. Averaged across 2 yr, 78% of runoff P was collected when the soil was frozen. Biomass P reductions over the period of November to April were strongly related to quantities of runoff total P from frozen soil (R² = 0.874). Phosphorus losses from urban areas appeared to be primarily correlated with runoff depth, not vegetation type, because correlation coefficients revealed 86 and 45% of the Year 1 and Year 2 total P loads were directly accounted for by runoff volumes. [ABSTRACT FROM AUTHOR]

This article discusses declining surface water quality and eutrophication within urban environments which has forced municipalities to restrict the use of turfgrass fertilizers and vegetative buffer strips. The authors investigated the effects of prairie and turfgrass plant communities and three impervious/pervious surface ratios on runoff water quality and quantity. They report similar runoff volumes, phosphorus, and sediment loading from fertilized turfgrass and non-fertilized prairie vegetation. A significant portion of the annual runoff occurred over frozen soil and negated the effects of buffer size and vegetation type. Vegetation appeared to be a significant contributor to non-point source pollution.

Mortality among 108 radio-tagged 2-year-old smolts of Atlantic salmon Salmo salar passed through a 17-MW Kaplan turbine was estimated at Holyoke Dam on the Connecticut River. The survival of test and control fish in 1981 was determined by comparing their rate of downstream movement with that of 28 prekilled fish. The survival of test fish in 1982 was determined as in 1981 by using nine prekilled fish. At full power generation, the mean percent turbine-induced mortality at 2 h (95% confidence interval in parentheses) was 11.8 (3.8-18.0) in 1981 and 13.7 (1.9-22.5) in 1982. [ABSTRACT FROM AUTHOR]

Rapid adjustments are responses to forcing agents that cause a perturbation to the top of atmosphere energy budget but are uncoupled to changes in surface warming. Different mechanisms are responsible for these adjustments for a variety of climate drivers. These remain to be quantified in detail. It is shown that rapid adjustments reduce the effective radiative forcing (ERF) of black carbon by half of the instantaneous forcing, but for CO2 forcing, rapid adjustments increase ERF. Competing tropospheric adjustments for CO2 forcing are individually significant but sum to zero, such that the ERF equals the stratospherically adjusted radiative forcing, but this is not true for other forcing agents. Additional experiments of increase in the solar constant and increase in CH4 are used to show that a key factor of the rapid adjustment for an individual climate driver is changes in temperature in the upper troposphere and lower stratosphere. Plain Language Summary: Long‐term global warming can be estimated with knowledge of how climate forcing agents affect the Earth's top‐of‐atmosphere energy imbalance or effective radiative forcing. Changes in climate forcers, such as greenhouse gases, the Sun's intensity, or emission of aerosol particles, typically impose a direct change in the energy budget, termed an instantaneous radiative forcing. Further to this, a climate forcer may induce changes in the atmosphere, such as a change in thermal structure, clouds, or humidity. These changes themselves, termed rapid adjustments, contribute to the top‐of‐atmosphere energy budget. Together, the instantaneous radiative forcing plus rapid adjustments equals the effective radiative forcing. We show that for different climate forcing agents, the rapid adjustments behave very differently and are driven by different atmospheric mechanisms. For example, rapid adjustments add to the instantaneous forcing for a carbon dioxide increase, due to a cooling of the stratosphere, but oppose instantaneous forcing for black carbon, driven by a warming troposphere and lowering of cloud height. Understanding rapid adjustments gives a more complete picture of the climate effects of different climate forcers. Key Points: Rapid adjustments affect the Earth's energy balance in different ways for greenhouse gas, aerosol, and solar forcingRadiative kernels and partial radiative perturbations are used to diagnose rapid adjustments from atmospheric and cloud changesNoncloud adjustments agree well between models, whereas cloud adjustments exhibit more spread [ABSTRACT FROM AUTHOR]

Different climate drivers influence precipitation in different ways. Here we use radiative kernels to understand the influence of rapid adjustment processes on precipitation in climate models. Rapid adjustments are generally triggered by the initial heating or cooling of the atmosphere from an external climate driver. For precipitation changes, rapid adjustments due to changes in temperature, water vapor, and clouds are most important. In this study we have investigated five climate drivers (CO2, CH4, solar irradiance, black carbon, and sulfate aerosols). The fast precipitation responses to a doubling of CO2 and a 10‐fold increase in black carbon are found to be similar, despite very different instantaneous changes in the radiative cooling, individual rapid adjustments, and sensible heating. The model diversity in rapid adjustments is smaller for the experiment involving an increase in the solar irradiance compared to the other climate driver perturbations, and this is also seen in the precipitation changes. Plain Language Summary: Future projections of precipitation changes are uncertain, both on regional and global scales. Understanding the climate models' diversity of precipitation change and how these models respond to various climate drivers, such as greenhouse gases and aerosols, is a key topic in climate research. Using sophisticated techniques, we quantify the processes altering precipitation changes on a short time scale and show that changes in the vertical profile of temperature, water vapor, and clouds contribute very differently to precipitation changes for various climate drivers. Our results show that model diversity in precipitation changes varies strongly between the climate drivers. Key Points: Separation of instantaneous and rapid adjustment contributions to precipitation changesContributions of rapid adjustments to precipitation changes differ substantially between climate driversRadiative kernels are applied to understand individual rapid adjustment terms [ABSTRACT FROM AUTHOR]

The article discusses the proposed conservation of the name Omphalodes verna for a herbarium species. Topics discussed include the attempts to expand the tautonym rule by analogy to the parahomonymy provision, the recording of the original spelling of the name and the use of the name for a perennial herb cultivated as an ornamental. Also mentioned are the ways by which the name can be saved.

The production method of spores significantly influences the resistance of spores used as bioindicators (BI) in the validation of sterilization of packaging material surfaces in aseptic food manufacturing. Therefore, the standardization of the spore production method represents an important and desirable goal in industrial BI production to ensure reliable validation test results. Previously, we recommended a two-step production approach for submerged spore production, in which the cultivation phase to obtain high cell mass was separate from the sporulation phase. In this work, a one-step manufacturing process was investigated to reduce production complexity and facilitate standardization of spore production. It was found that one-step BI production is technically possible but at the expense of spore yield. The two-step manufacturing process can realize almost 10-fold higher spore yields., (© 2022 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Clouds are a key player in the global climate system, affecting the atmospheric water and energy budgets, and they are strongly coupled to the large-scale atmospheric circulation. Here, we examine the co-variability of the atmospheric energy and water budget imbalances in three different global model configurations-radiative-convective equilibrium, aqua-planet, and global simulations with land. The gradual increase in the level of complexity of the model configuration enables an investigation of the effects of rotation, meridional temperature gradient, land-sea contrast, and seasonal cycle on the co-variability of the water and energy imbalances. We demonstrate how this co-variability is linked to both the large-scale tropical atmospheric circulation and to cloud properties. Hence, we propose a co-variability-based framework that connects cloud properties to the large-scale tropical circulation and climate system and is directly linked to the top-down constrains on the system-the water and energy budgets. In addition, we examine how the water and energy budget imbalances co-variability depends on the temporal averaging scale, and explain its dependency on how stationary the circulation is in the different model configurations. Finally, we demonstrate the effect of an idealized global warming and convective aggregation on this co-variability., Competing Interests: The authors declare no conflicts of interest relevant to this study., (© 2022 The Authors. Journal of Advances in Modeling Earth Systems published by Wiley Periodicals LLC on behalf of American Geophysical Union.)

Tropical deep convection can aggregate into large clusters, which can have impacts on the local humidity and precipitation. Sea surface temperature (SST) gradients have been shown to organize convection, yet there has been little work done to investigate the impact of diabatic heating perturbations in the atmosphere on the aggregation of convection. Here we investigate how anomalous diabatic heating of the atmospheric column, through an idealized aerosol plume, affects the existence and mechanisms of convective aggregation in non-rotating, global radiative-convective equilibrium simulations. We show that the aerosol forcing has the ability to increase the degree of aggregation, especially at lower SSTs. Detailed investigation shows that the diabatic heating source incites a thermally driven circulation, forced by the shortwave perturbation. The increase in aggregation is caused in part by this circulation, and in part by the longwave heating anomalies occurring due to the surface convergence of moisture and convection. At higher SSTs, longwave feedbacks are crucial for the aggregation of convection, even with the shortwave heating perturbation. At lower SSTs, convection is able to aggregate with the shortwave perturbation in the absence of longwave feedbacks. These perturbations provide a link to studying the effects of absorbing aerosol plumes on convection, for example during the Indian monsoon season. We argue that, as there is aggregation for plumes with realistic aerosol absorption optical depths, this could be an analogue for real-world organization in regions with high pollution., (© 2021 The Authors. Journal of Advances in Modeling Earth Systems published by Wiley Periodicals LLC on behalf of American Geophysical Union.)