Tales of future weather

Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like

Влияние состава бинарного растворителя CH3CN-H2O на кинетику окисления циклогексена п-бензохиноном в растворах катионных комплексов палладия(II)

During the study of cyclohexene oxidation by p-benzoquinones into cyclohexanone in water-organic solutions of cationic complexes of palladium(II) it was demonstrated that the initial reaction rate R0 depends complicatedly on water molar fraction for three studied solvents: acetonitrile (AN), dimethylformamide, and dimethylsulfoxide. In order to explain the obtained bimodal dependence for the example of AN-water system, modeling of phase equilibrium in the studied system was performed. The existence of two- and three-phase immiscibility areas as well as a three-component heteroazeotrope was found. By UV spectroscopy it was stated that varying of water molar fraction in the binary solvent substantially changes the state of starting cationic complexes [Pd(АН)x(H2O)4-x]2+. For mathematical description of medium effect on R0 value three models were proposed taking into account different factors, such as: a) physico-chemical properties of binary solvent; b) composition of possible associates AN-water; c) composition of starting [Pd(АН)x(H2O)4-x]2+ complexes. The adequate description of bimodal dependency was obtained in the model considering the changes of [Pd(АН)x(H2O)4-x]2+ complexes composition with simultaneous presence of an associate of (АН)2(H2O) composition.В ходе изучения кинетики окисления циклогексена п-бензохиноном до циклогексанона в водно-органических растворах катионных комплексов палладия(II) показано, что начальная скорость реакции R0 сложным образом зависит от мольной доли воды для трех изученных растворителей: ацетонитрил (АН), диметилформамид и диметилсульфоксид. На примере системы ацетонитрил-вода проведено моделирование фазовых равновесий в исследуемой системе, позволившее выявить наличие областей двух- и трехфазного расслаивания, а также трехкомпонентного гетероазеотропа. Методом УФ-спектроскопии установлено, что изменение мольной доли воды в бинарном растворителе существенно меняет состояние исходных катионных комплексов [Pd(АН)x(H2O)4-x]2+. Для математического описания эффектов влияния среды на величину R0 предложены три модели, учитывающие такие факторы, как: а) физико-химические свойства бинарного растворителя, б) состав возможных ассоциатов ацетонитрил-вода, в) состав исходных комплексов Pd(II). Адекватное описание бимодальной зависимости получено в рамках модели, рассматривающей изменение состава комплексов [Pd(АН)x(H2O)4-x]2+ с одновременным присутствием ассоциата состава (АН)2(H2O)

Влияние нейроаксиального блока на изменения гемодинамики у рожениц

The results of the multicentric study on «The safety of the spinal anesthesia during the caesarean section» describing the analysis of the hemodynamic changes due to neuroaxial block in parturients were presented. Thirteen clinics participated in the study. The volume of the sampling includes 2228 spinal anesthesia protocols. The study results confirm the consistency of some well-known regulations and standards of the safe performance of spinal anesthesia. Moreover, the following facts were revealed: the preinfusion during the spinal anesthesia does not have a preventive effect on arterial hypotension; the increase of the infusion volume results in elevating of the arterial hypotension frequency during spinal anesthesia; the bandaging of the lower extremities is a serious measure to prevent the hemodynamic complications; the application of 6% pentastarch solution for the postin-fusion is an effective method to prevent the arterial hypotension during spinal anesthesia for the cesarean section.Представлены результаты мультицентрового исследования «Безопасность спинномозговой анестезии во время операции кесарева сечения», относящиеся к изучению изменений гемодинамики у рожениц под влиянием нейроаксиального блока. В исследовании приняло участие 13 клиник. Объем изучаемой выборки составил 2228 протоколов спинномозговой анестезии. Результаты исследования подтвердили состоятельность ряда общеизвестных положений и стандартов безопасности проведения спинномозговой анестезии. Кроме того, было выявлено, что преинфузия при спинномозговой анестезии в акушерстве не оказывает профилактического действия в отношении артериальной гипотонии; увеличение объема преинфузии способствует повышению частоты случаев артериальной гипотонии во время спинномозговой анестезии; бинтование нижних конечностей является серьезной мерой профилактики гемодинамических осложнений; применение 6% раствора пентакрахмала в качестве постинфузии является эффективным методом профилактики артериальной гипотонии при спинномозговой анестезии операций кесарева сечения

КИНЕТИКА ПРОЦЕССА ОКИСЛИТЕЛЬНОГО ХЛОРИРОВАНИЯ МЕТАНА

Heterogeneous oxidative chlorination of methane was investigated. The target product is methyl chloride. The investigated terms and conditions of oxychlorination of methane: process temperature 400°C, pressure 0.1-0.9 MPa, catalyst (% weight.): copper chloride (II) 1-8%; potassium chloride 2.5%; lanthanum chloride 1%; carrier - aluminosilicate. Powder X-ray diffractometry and electron microscopy showed that the active catalyst components (CuCl2, KCl, LaCl3) are unevenly distributed on the support surface (α-Al2O3·SiO2) and form agglomerates with a high salt content, including binary chlorides such as KCuCl3, K2CuCl3 or K2CuCl4, hydrates K2CuCl4·2H2O and CuCl2·2H2O and hydroxychlorides Cu3Cl4(OH)2 and Cu2Cl(OH)3. The kinetics of methane oxychlorination was studied in a gradientless reactor at 400°C and pressure 0.1 - 0.9 MPa by varying the partial pressures of the reactants. Analysis of the products was carried out by GC. An equation of the reaction rate including partial pressures of methane, hydrogen chloride and water to the 0.77, 0.01 and 0.64 power, respectively, but of zero order by oxygen and chlorine provides an adequate description of methyl chloride formation rate. Significant influence of water partial pressure is proved for the reaction under consideration.Гетерогенно-каталитическая реакция окислительного хлорирования метана, целевым продуктом которой является хлористый метил, изучена при температуре 400°С и варьировании давления в диапазоне 0.1-0.9 МПа. Методами дифрактометрии и электронной микроскопии показано, что активные компоненты катализатора (CuCl2, KCl, LaCl3) распределяются неравномерно на поверхности носителя (α-Al2O3·SiO2), образуя агломераты с повышенным содержанием солей, в том числе двойных хлоридов, таких как KCuCl3, K2CuCl3 или K2CuCl4, гидрата K2CuCl4·2H2O и гидроксихлоридов состава Cu3Cl4(OH)2 и Cu2Cl(OH)3. Кинетические закономерности изучены в проточном безградиентном по парциальным давлениям реакторе при 400°С методом однофакторного эксперимента при варьировании парциальных давлений реагентов. Анализ продуктов проводили методом газовой хроматографии. Обработкой кинетических данных степенными уравнениями показано, что адекватное описание скорости образования хлористого метила обеспечивает уравнение, в которое входят парциальные давления метана, хлористого водорода и воды в степенях 0.77, 0.01 и 0.64, соответственно, при нулевых порядках по кислороду и хлору

Aandacht voor veiligheid

De komende decennia worden er tussen de 500.000 en 1.500.000 woningen gebouwd waarvan een groot deel in laag Nederland. Deze studie laat zien dat door deze woningen overstromingsbestendig te bouwen schadereductie mogelijk is. Het schaderisico wordt dan nog eens een factor 2 minder als naast een Business as Usual variant nieuwbouwwoningen worden opgehoogd tot +5 m NAP. De kosten van opgehoogde nieuwbouwhuizen zijn hoger en variëren tussen de 0,4 en 1.7 miljard euro/jaar, hetgeen overeenkomt met 0,1-0,5% van het BNP. Dijkversterking levert de hoogste reductie op in het schaderisico bij de gehanteerde scenario’s. Gevolgbeperkende maatregelen in de ruimtelijk ordening als additionele oplossingsrichting zijn echter goed mogelijk als er ook een economische perspectief is bijvoorbeeld door middel van multifunctioneel ruimtegebruik

Storylines: an alternative approach to representing uncertainty in physical aspects of climate change

As climate change research becomes increasingly applied, the need for actionable information is growing rapidly. A key aspect of this requirement is the representation of uncertainties. The conventional approach to representing uncertainty in physical aspects of climate change is probabilistic, based on ensembles of climate model simulations. In the face of deep uncertainties, the known limitations of this approach are becoming increasingly apparent. An alternative is thus emerging which may be called a ‘storyline’ approach. We define a storyline as a physically self-consistent unfolding of past events, or of plausible future events or pathways. No a priori probability of the storyline is assessed; emphasis is placed instead on understanding the driving factors involved, and the plausibility of those factors. We introduce a typology of four reasons for using storylines to represent uncertainty in physical aspects of climate change: (i) improving risk awareness by framing risk in an event-oriented rather than a probabilistic manner, which corresponds more directly to how people perceive and respond to risk; (ii) strengthening decision-making by allowing one to work backward from a particular vulnerability or decision point, combining climate change information with other relevant factors to address compound risk and develop appropriate stress tests; (iii) providing a physical basis for partitioning uncertainty, thereby allowing the use of more credible regional models in a conditioned manner and (iv) exploring the boundaries of plausibility, thereby guarding against false precision and surprise. Storylines also offer a powerful way of linking physical with human aspects of climate change

Recent progress in understanding and projecting regional and global mean sea-level change

Considerable progress has been made in understanding the present and future regional and global sea level in the 2 years since the publication of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change. Here, we evaluate how the new results affect the AR5’s assessment of (i) historical sea level rise, including attribution of that rise and implications for the sea level budget, (ii) projections of the components and of total global mean sea level (GMSL), and (iii) projections of regional variability and emergence of the anthropogenic signal. In each of these cases, new work largely provides additional evidence in support of the AR5 assessment, providing greater confidence in those findings. Recent analyses confirm the twentieth century sea level rise, with some analyses showing a slightly smaller rate before 1990 and some a slightly larger value than reported in the AR5. There is now more evidence of an acceleration in the rate of rise. Ongoing ocean heat uptake and associated thermal expansion have continued since 2000, and are consistent with ocean thermal expansion reported in the AR5. A significant amount of heat is being stored deeper in the water column, with a larger rate of heat uptake since 2000 compared to the previous decades and with the largest storage in the Southern Ocean. The first formal detection studies for ocean thermal expansion and glacier mass loss since the AR5 have confirmed the AR5 finding of a significant anthropogenic contribution to sea level rise over the last 50 years. New projections of glacier loss from two regions suggest smaller contributions to GMSL rise from these regions than in studies assessed by the AR5; additional regional studies are required to further assess whether there are broader implications of these results. Mass loss from the Greenland Ice Sheet, primarily as a result of increased surface melting, and from the Antarctic Ice Sheet, primarily as a result of increased ice discharge, has accelerated. The largest estimates of acceleration in mass loss from the two ice sheets for 2003–2013 equal or exceed the acceleration of GMSL rise calculated from the satellite altimeter sea level record over the longer period of 1993–2014. However, when increased mass gain in land water storage and parts of East Antarctica, and decreased mass loss from glaciers in Alaska and some other regions are taken into account, the net acceleration in the ocean mass gain is consistent with the satellite altimeter record. New studies suggest that a marine ice sheet instability (MISI) may have been initiated in parts of the West Antarctic Ice Sheet (WAIS), but that it will affect only a limited number of ice streams in the twenty-first century. New projections of mass loss from the Greenland and Antarctic Ice Sheets by 2100, including a contribution from parts of WAIS undergoing unstable retreat, suggest a contribution that falls largely within the likely range (i.e., two thirds probability) of the AR5. These new results increase confidence in the AR5 likely range, indicating that there is a greater probability that sea level rise by 2100 will lie in this range with a corresponding decrease in the likelihood of an additional contribution of several tens of centimeters above the likely range. In view of the comparatively limited state of knowledge and understanding of rapid ice sheet dynamics, we continue to think that it is not yet possible to make reliable quantitative estimates of future GMSL rise outside the likely range. Projections of twenty-first century GMSL rise published since the AR5 depend on results from expert elicitation, but we have low confidence in conclusions based on these approaches. New work on regional projections and emergence of the anthropogenic signal suggests that the two commonly predicted features of future regional sea level change (the increasing tilt across the Antarctic Circumpolar Current and the dipole in the North Atlantic) are related to regional changes in wind stress and surface heat flux. Moreover, it is expected that sea level change in response to anthropogenic forcing, particularly in regions of relatively low unforced variability such as the low-latitude Atlantic, will be detectable over most of the ocean by 2040. The east-west contrast of sea level trends in the Pacific observed since the early 1990s cannot be satisfactorily accounted for by climate models, nor yet definitively attributed either to unforced variability or forced climate change