COSMO Model Research Articles

Prediction of Redox Potentials for Ac, Th, and Pa in Aqueous Solution.

Density functional theory in conjunction with small core pseudopotentials and the associated basis sets was used to calculate potentials for multiple redox couples, covering a range of oxidation states for Ac (0 to III), Th (0 to IV), and Pa (0 to V) in aqueous solution. Solvation effects were incorporated using a supermolecule-continuum approach, with 30 water molecules representing two solvation shells, and the COSMO and SMD implicit solvation models. The calculated geometries for Ac(III), Th(IV), and Pa(V) were in reasonable agreement with the available experimental data. Using the COSMO model with the B3LYP functional, the calculated redox potentials were within ±0.2 V from experiment for most redox couples. Several pathways were explored for the Pa(V/IV) redox couple for different forms of Pa(V) and Pa(IV). Most Pa(V/IV) redox couples have very similar potentials, ranging from 0 to -0.4 V up to a pH of 1.4. At pH = 1.4, the potentials shift to values that are more negative than -0.7 V, reflecting the growing unfavorable nature of the redox process at higher pH levels. The calculated values for An(III/II) potentials were consistent with prior estimates and the available experimental data. The predicted redox potentials for An(II/I) were highly negative, as expected. For An(I/0) potentials, Th and Pa exhibited positive values, contrasting with the negative values calculated for Ac. The An+m/An(0) potentials agreed better with the experimental data when using the COSMO solvation model as compared to the SMD model.

Hydration behavior of D-calcium pantothenate (vitamin B5) in the presence of sugar-based deep eutectic solvents at different temperatures: experimental and theoretical study

Considerable efforts have been devoted in recent years to enhancing the efficacy medicinal substance, leading to the discovery of innovative drug formulations and delivery techniques. The successful design of these processes necessitates a profound understanding at the molecular level of how these substances interact with biological membranes. Thorough thermodynamic investigations provide invaluable insights into these interactions and aid in selecting suitable compounds for pharmaceutical production. This study aims to determine the density and speed of sound for D-calcium pantothenate in mixtures of water and deep eutectic solvents (DESs), specifically choline chloride/sucrose, choline chloride/ glucose, and choline chloride/ fructose (with 2:1 molar ratio) over a temperature range of 288.15 K to 318.15 K under atmospheric pressure. In order to predict the behavior of molecules, COSMO model (the Conductor-Like Screening Model) offer complementary strengths in quantum chemistry. This approach allows for calculating solvation free energies, making it ideal for predicting properties like solubility, where understanding solvent-solute interactions is crucial. By correlating the measured parameters using standard relationships, important partial molar parameters such as apparent molar volumes and apparent molar isentropic compressibility are calculated. Additionally, apparent molar isobaric expansion, and Hepler’s constant are derived from the density and speed of sound data. The experimental apparent molar volumes, and apparent molar isentropic compressibility data is fitted to the Redlich-Meyer equation to obtain significant quantities such as standard partial molar volume, and partial molar isentropic compression. The comprehensive thermodynamic analysis of this studied system holds immense significance for advancements in the pharmaceutical industry.

Reduced floating-point precision in regional climate simulations: an ensemble-based statistical verification

Abstract. The use of single precision in floating-point representation has become increasingly common in operational weather prediction. Meanwhile, climate simulations are still typically run in double precision. The reasons for this are likely manifold and range from concerns about compliance and conservation laws to the unknown effect of single precision on slow processes or simply the less frequent opportunity and higher computational costs of validation. Using an ensemble-based statistical methodology, Zeman and Schär (2022) could detect differences between double- and single-precision simulations from the regional weather and climate model COSMO. However, these differences are minimal and often only detectable during the first few hours or days of the simulation. To evaluate whether these differences are relevant for regional climate simulations, we have conducted 10-year-long ensemble simulations over the European domain of the Coordinated Regional Climate Downscaling Experiment (EURO-CORDEX) in single and double precision with 100 ensemble members. By applying the statistical testing at a grid-cell level for 47 output variables every 12 or 24 h, we only detected a marginally increased rejection rate for the single-precision climate simulations compared to the double-precision reference based on the differences in distribution for all tested variables. This increase in the rejection rate is much smaller than that arising from minor variations of the horizontal diffusion coefficient in the model. Therefore, we deem it negligible as it is masked by model uncertainty. To our knowledge, this study represents the most comprehensive analysis so far on the effects of reduced precision in a climate simulation for a realistic setting, namely with a fully fledged regional climate model in a configuration that has already been used for climate change impact and adaptation studies. The ensemble-based verification of model output at a grid-cell level and high temporal resolution is very sensitive and suitable for verifying climate models. Furthermore, the verification methodology is model-agnostic, meaning it can be applied to any model. Our findings encourage exploiting the reduction of computational costs (∼30 % for COSMO) obtained from reduced precision for regional climate simulations.

Potential of V-Si72, V-C72, and V-Al36N36 as catalysts for oxygen reduction reaction.

The capacities of V-Si72, V-C72, and V-Al36N36 nanocages to catalyze the ORR processes have been investigated. The acceptable pathways of ORR processes on V-Si72, V-C72, and V-Al36N36 nanocages have been examined by DSD-PBEPBE-D3/aug-cc-pVDZ, PW91PW91/aug-cc-pVDZ, and COSMO model in the gas phase and water. The ΔGreaction values of reaction steps of ORR pathways on V-Si72, V-C72, and V-Al36N36 nanocages are calculated. The Eadoption and Eformation of V-Si72, V-C72, and V-Al36N36 nanocages are negative values and these nanostructures are stable materials. The H2O has the lowest Eadsorption on V-Si72, V-C72, and V-Al36N36 nanocages. The *OH formation, creation of *OH-OH*, and formation of O* are rate-determining steps of ORR mechanisms. The overpotential values of ORR processes on V-Si72, V-C72, and V-Al36N36 nanocages are 0.41, 0.37, and 0.30V, respectively. The V-Al36N36 nanocage have lower overpotential for ORR processes than V-Si72 and V-C72 nanocages by DSD-PBEPBE-D3/aug-cc-pVDZ, PW91PW91/aug-cc-pVDZ, and COSMO model in the gas phase and water. The V-Al36N36 nanocage have more negative ∆Greaction for reaction steps of ORR than V-Si72 and V-C72 nanocages. The V-Al36N36 nanocage with lower overpotential is proposed as an effective catalyst for ORR processes via studied pathways. The DSD-PBEPBE-D3/aug-cc-pVDZ method has been used to optimize and calculate the frequencies of V-Si72, V-C72, and V-Al36N36 nanocages in GAMESS software. The complexes of O, OH, OOH, and H2O with V-Si72, V-C72, and V-Al36N36 nanocages are optimized and frequencies are determined by the DSD-PBEPBE-D3/aug-cc-pVDZ method. The Gactivation and ∆Greaction of ORR pathways on V-Si72, V-C72, and V-Al36N36 nanocages are calculated by DSD-PBEPBE-D3/aug-cc-pVDZ, PW91PW91/aug-cc-pVDZ, and COSMO model in the gas phase and water.

СОСТОЯНИЕ И РАЗВИТИЕ СИСТЕМЫ ЧИСЛЕННОГО НЕГИДРОСТАТИЧЕСКОГО КРАТКОСРОЧНОГО ПРОГНОЗА ПОГОДЫ COSMO-RUSIB ДЛЯ УРАЛО-СИБИРСКОГО РЕГИОНА

The paper describes the configuration of the COSMO-Ru6Sib system with a horizontal grid spacing of 6.6 km adapted to regional conditions. The COSMO-Ru2Sib configuration with a horizontal grid spacing of 2.2 km is also considered. The results of modifying this configuration using weather radar data assimilation as well as urban canopy parameterization are presented and discussed. The results of numerical experiments for the COSMO-Ru6Sib with the COSMO and ICON-LAM models as compute kernels are also presented.

Natural Deep Eutectic Solvent-Based Ultrasound-Assisted Extraction of Flavonoids from Fagopyrum tataricum Bran

In this study, eleven kinds of flavonoids were identified from F. tataricum bran (FTB) by UPLC-Q-TOF-MS, and HPLC-DAD analysis revealed that four compounds, including rutin, quercetin, kaempferol, and nicotiflorin, were the most significant components. Subsequently, natural deep eutectic solvent-based ultrasound-assisted extraction (NADES-UAE) was employed to extract flavonoids from FTB. Among the six kinds of NADES prepared, choline chloride–ethylene glycol (ChCl-EG) was identified as a promising candidate for extracting flavonoids due to its superior extraction performance. The extraction conditions were statistically investigated using response surface methodology conducted by Box-Behnken design (BBD). The optimal operational conditions were as follows: ultrasonic time 268 s, ultrasonic temperature 76 °C, and liquid–solid ratio 43 mL/g, which resulted in a high total flavonoid yield of 40.29 mg/g. Afterwards, the efficient extraction mechanism of NADES-UAE was comprehensively explored through FT-IR spectra, COSMO model, and microstructural analysis. In conclusion, NADES-UAE extraction is considered a green, efficient, and sustainable method for FTB flavonoids.

Urban heat and pollution island in the Moscow megacity: Urban environmental compartments and their interactions

Cities are highly interconnected systems where specific interactions between various urban environments occur due to the Urban Heat Island (UHI) and Urban Pollution Island (UPI) effects. Four compartments of the environment (atmospheric air, road dust, streamflow, and people) are discussed for Moscow city. Long-term meteorological, radiative, air quality, and precipitation measurements, the non-hydrostatic regional numerical COSMO model, and extensive hydrological and geochemical sampling were used. To characterize mortality and UPI interaction, a family of distributed lag non-linear models (DLNM) was applied. The study reveals increased aerosols concentrations which reduce the incoming solar radiation and increase the atmospheric longwave radiation. UHI strengthens the low-troposphere convergence due to urban breeze circulation and atmospheric circulation due to elevated surface roughness, the effect which leads to 11.6% heaviest precipitation increase compared to background values. Increased precipitation doubles streamflow rates and enhances the contribution of rain floods to annual flow. Similar geochemical associations with Sb, W, Zn, Cd, Pb, and Cu were found in aerosol PM10, indicating transport and road dust impact. Finally, associations between high temperatures and human mortality which are generally stronger at high levels of air pollution for both PM10 and NO2, and for lag 1 day and 2–6 days are discussed.

Modelling the effects of potential climate change on the dynamics of multi-species mountain pastures: A case study in Gran Paradiso National Park, Italy

CONTEXTPasture dynamics of Alpine areas are linked to the complex cryospheric hydrology of Alpine catchment and to the interspecies competition, which are in turn expected to change remarkably under prospective global warming scenarios. OBJECTIVEThis study aimed at assessing the impact of climate change on the productivity of mountain pastures in the Gran Paradiso National Park (Italy). METHODSThe hydrological model Poli-Hydro was used, coupled with the Poli-Pasture model, able to simulate pasture growth, which was further integrated with CoSMo model to consider interspecific competition. Two (competing) species were chosen for low altitude LowAlt areas (below 1800 m asl), Trifolium alpinum and Dactylis glomerata, and two for high altitude HighAlt areas (above 1800 m asl), Festuca rubra and Nardus stricta. Model tuning and evaluation were performed against estimates of leaf area index (LAI), derived from satellite imagery during 2005–2019. Then, climate change impacts were projected until 2100 by considering four IPCC AR6 scenarios and six GCMs. Target variables included a set of agroclimatic indices, LAI and pasture yield. RESULTS AND CONCLUSIONSDue to the projected increase in temperatures during the XXI century, a measurable potential increase in productivity would be expected, especially in the highest areas (up to +97% by 2050, and + 123% by 2100 for the SSP5–8.5 scenario). The relative abundance of pasture species appears to remain mostly stable; at most, the species with higher fodder value even increases slightly. This suggests that a loss in the overall quality of biomass should not occur. These results provide preliminary evidence for the potential development of livestock farming, and thus of a relevant part of the economy in the valleys, at higher altitudes than now. However, to a certain extent pasture performance could be threatened by the projected reduction in summer rainfall, and possibly spreading of pests with increasing temperature. SIGNIFICANCEThe results obtained here could be useful for policy makers, and scientists in the field of pasture/grasslands management, to depict scenarios of future productivity, and to support redefinition of periods, and areas designated for grazing activities in the mountains.

Assessing the Regional Climate Response to Different Hengduan Mountains Geometries With a High‐Resolution Regional Climate Model

AbstractThe Hengduan Mountains (HM) are located on the southeastern edge of the Tibetan Plateau and feature high mountain ridges (>6,000 m MSL) separated by deep valleys. The HM region also features an exceptionally high biodiversity, believed to have emerged from the topography interacting with the climate. To investigate the role of the HM topography on regional climate, we conduct simulations with the regional climate model COSMO at high horizontal resolutions (at ∼12 km and a convection‐permitting scale of ∼4.4 km) for the period 2001–2005. We conduct one control simulation with modern topography and two idealized experiments with modified topography, inspired by past geological processes that shaped the mountain range. In the first experiment, we reduce the HM's elevation by applying a spatially non‐uniform scaling to the topography. The results show that, following the uplift of the HM, the local rainy season precipitation increases by ∼25%. Precipitation in Indochina and the Bay of Bengal (BoB) also intensifies. Additionally, the cyclonic circulation in the BoB extends eastward, indicating an intensification of the East Asian summer monsoon. In the second experiment, we remove deep valleys by applying an envelope topography to quantify the effects of terrain undulation with high amplitude and frequency on climate. On the western flanks of the HM, precipitation slightly increases, while the remaining fraction of the mountain range experiences ∼20% less precipitation. Simulations suggest an overall positive feedback between precipitation, erosion, and valley deepening for this region, which could have influenced the diversification of local organisms.

Climatological analysis of urban heat island effects in Swiss cities

AbstractThis work presents a high‐resolution spatiotemporal analysis of the urban heat island (UHI) effect in Swiss cities during the last 6 years. The entire alpine country is simulated at once using the COSMO model at 1.1 km resolution, validated against a dense national measurement network. Additionally, the bulk parametrisation TERRA URB is used to model the dynamical and thermal effects of urban areas. The resulting data allows us to perform the first comprehensive analysis over the entire Switzerland, with a focus on the UHI effect with intra‐urban and across cities comparisons, and to report on the current state of urban warming. Despite the medium‐small size of the cities, the UHI is of considerable magnitude especially when considering peak values in ideal weather conditions. The present results confirm previous analyses performed for individual cities, and shed new light on the country‐wide picture by highlighting features such as the marked seasonality of the UHI intensity as well as the influence of local climate and topographical features on the urban climate. A thorough discussion is also presented highlighting the absence of simple relationships between UHI intensity and bulk city parameters and weather patterns.

Flux coupling approach on an exchange grid for the IOW Earth System Model (version 1.04.00) of the Baltic Sea region

Abstract. In this article the development of a high-resolution Earth System Model (ESM) for the Baltic Sea region is described. In contrast to conventional coupling approaches, the presented model features an additional (technical) component, the flux calculator, which calculates fluxes between the model components on a common exchange grid. This approach naturally ensures conservation of exchanged quantities, a locally consistent treatment of the fluxes, and facilitates interchanging model components in a straightforward manner. The main purpose of this model is to downscale global reanalysis or climate model data to the Baltic Sea region as typically, global model grids are too coarse to resolve the region of interest sufficiently. The regional ESM consists of the Modular Ocean Model 5 (MOM5) for the ocean and the COSMO model in CLimate Mode (CCLM, version 5.0_clm3) for the atmosphere. The bi-directional ocean–atmosphere coupling allows for a realistic air–sea feedback that outperforms the traditional approach of using uncoupled standalone models, as typically pursued with the EURO-CORDEX protocol. In order to address marine environmental problems (e.g., eutrophication and oxygen depletion), the ocean model is internally coupled with the marine biogeochemistry model, ERGOM, set up for the Baltic Sea's hydrographic conditions. The regional ESM can be used for various scientific questions such as climate sensitivity experiments, reconstruction of ocean dynamics, study of past climates, and natural variability, as well as investigation of ocean–atmosphere interactions. Therefore, it can serve for a better understanding of natural processes via attribution experiments that relate observed changes to mechanistic causes.

Improving Quantum Chemical Solvation Models by Dynamic Radii Adjustment for Continuum Solvation (DRACO).

We present the Dynamic Radii Adjustment for COntinuum solvation (DRACO) approach, which employs precomputed atomic partial charges and coordination numbers of the solute atoms to improve the solute cavity. As such, DRACO is compatible with major solvation models, improving their performance significantly and robustly at virtually no extra cost, especially for charged solutes. Combined with the purely electrostatic CPCM and COSMO models, DRACO reduces the mean absolute deviation (MAD) of the solvation free energy by up to 4.5 kcal mol-1 (67%) for a large data set of polar and ionic solutes. Even in combination with the highly empirical universal solvation model (SMD), DRACO substantially reduces the MAD for charged solutes by up to 1.5 kcal mol-1 (39%), while neutral solutes are slightly improved (0.2 kcal mol-1 or 16%). We present an interface of DRACO with two computationally efficient atomic charge models that enables fully automated, out-of-the-box calculations with the widely used program packages Orca and TurboMole.

The implementation of dust mineralogy in COSMO5.05-MUSCAT

Abstract. Mineral dust aerosols are composed of a complex assemblage of various minerals depending on the region in which they originated. Given the different mineral composition of desert dust aerosols, different physicochemical properties and therefore varying climate effects are expected. Despite the known regional variations in mineral composition, chemical transport models typically assume that mineral dust aerosols have uniform composition. This study adds, for the first time, mineralogical information to the mineral dust emission scheme used in the chemical transport model COSMO–MUSCAT. We provide a detailed description of the implementation of the mineralogical database, GMINER (Nickovic et al., 2012), together with a specific set of physical parameterizations in the model's mineral dust emission module, which led to a general improvement of the model performance when comparing the simulated mineral dust aerosols with measurements over the Sahara region for January–February 2022. The simulated mineral dust aerosol vertical distribution is tested by a comparison with aerosol lidar measurements from the lidar system PollyXT, located at Cape Verde. For a lofted mineral dust aerosol layer on 2 February at 05:00 UTC the lidar retrievals yield a dust mass concentration peak of 156 µg m−3, while the model calculates the mineral dust peak at 136 µg m−3. The results highlight the possibility of using the model with resolved mineral dust composition for interpretation of the lidar measurements since a higher absorption in the UV–Vis wavelengths is correlated with particles having a higher hematite content. Additionally, the comparison with in situ mineralogical measurements of dust aerosol particles shows that more of them are needed for model evaluation.

A Wind Field Reconstruction from Numerical Weather Prediction Data Based on a Meteo Particle Model

In the present work, a methodology for wind field reconstruction based on the Meteo Particle model (MPM) from numerical weather prediction (NWP) data is presented. The development of specific wind forecast services is a challenging research topic, in particular for what concerns the availability of accurate local weather forecasts in highly populated areas. Currently, even if NWP limited area models (LAMs) are run at a spatial resolution of about 1 km, this level of information is not sufficient for many applications; for example, to support drone operation in urban contexts. The coupling of the MPM with the NWP limited area model COSMO has been implemented in such a way that the MPM reads the NWP output over a selected area and provides wind values for the generic point considered for the investigation. The numerical results obtained reveal the good behavior of the method in reproducing the general trend of the wind speed, as also confirmed by the power spectra analysis. The MPM is able to step over the intrinsic limitations of the NWP model in terms of the spatial and temporal resolution, even if the MPM inherits the bias that inevitably affects the COSMO output.

Expanding the library of sumanene molecular receptors for caesium-selective potentiometric sensors.

This paper reports the synthesis and characterization of eight sumanene molecular receptors for the selective recognition of caesium cations (Cs+). The sumanene derivatives differed in the number (from one to nine), type (electron donating or electron withdrawing) and method of the attachment (functionalization of sumanene at the benzylic or aromatic carbons) of substituents in the sumanene skeleton. The ultimate goal of this work was to investigate the prospective use of various sumanene derivatives in the design of Cs+-selective potentiometric sensors, thus, expanding the library of sumanene receptors for such applications. Spectroscopic fluorescence titration with caesium hexafluorophosphate revealed that the formation of sandwich complexes is highly favourable, but the steric hindrance of bulky substituents can disrupt this preference. In the case of triaryl-substituted sumanene derivatives, theoretical calculations show that, indeed, sandwich complexes are energetically more advantageous by 2.3 times than 1 : 1 complexes. Furthermore, such functionalization significantly increases receptor solubility in the polymeric membrane of the potentiometric sensors, which was quantitatively evaluated with the COSMO model.

DFT investigation on the structural and vibrational behaviours of the non-protein amino acids in hybrid explicit/continuum solvent: a case of the zwitterions γ-aminobutyric and α - aminoisobutyric acids.

The influence of hybrid solvation models on the molecular structures and vibrational characteristics of g-aminobutyric acid (GABA) and a-aminoisobutyric acid (AIB) zwitterions was assessed by employing a variety of Density Functional Theory (DFT). The quantum chemical methods included the B3LYP and B3PW91 hybrid functionals and the 6‑311++G(d,p) basis set. The most stable conformation derived from the potential energy surface (PES) scans using the B3LYP/6-311++G(d,p) model chemistry for each studied molecule was predicted within a continuum environment represented by the COSMO and SMD solvation models. The stable structures were subsequently immersed in explicit/COSMO and explicit/SMD hybrid solvation models, where 10 and 8 water molecules were explicitly positioned around the functional groups of the GABA and AIB zwitterions, respectively. The number of water molecules chosen was sufficient to prevent proton transfer among the carboxylate group (COO-) and the ammonium group (NH3+) within each molecule under investigation. After optimizing the geometry of each hydrated complex, the normal vibrational modes were determined. The scaled theoretical frequencies obtained from the various model chemistries were then compared to available experimental data from infrared (IR) and Raman spectroscopy. In the case of GABA and AIB molecules, the comparisons revealed that the B3LYP/6-311++G(d,p) model chemistry yielded wavenumber values that closely matched the experimental IR and Raman data, particularly when the explicit/SMD solvent was employed. The computed results indicate deviations of less than 4% when compared to the experimental data for the two molecules under investigation.

Climate Change Response of Tropical Atlantic Clouds in a Kilometer‐Resolution Model

AbstractEstimates of the tropical cloud feedback of global climate models (GCMs) show a large inter‐model spread due to the small‐scale nature of convective cloud processes. Estimates from large‐eddy simulations (LES) are more consistent among themselves, but difficult to scale to the climate system. Here we consider a compromise between GCMs and LES, and study how tropical clouds over the Atlantic respond to a climate perturbation in a regional kilometer‐resolution model. We perform two 4‐year‐long simulations at 3.3 km horizontal grid spacing with the limited‐area model COSMO on a 9,000 × 7,000 km2 domain covering the tropical Atlantic: a control simulation and a climate change simulation using the pseudo‐global warming approach. In a previous publication we have demonstrated that this approach yields a credible representation of the tropical climate without the double‐ITCZ bias commonly seen in GCMs. Here we address the cloud feedback and find a reduction of ITCZ high‐cloud cover resulting in a negative longwave cloud feedback similar to the CMIP6 ensemble mean. We find a reduction of stratocumulus clouds, which we argue is primarily a thermodynamic response. More surprisingly, the shallow cumulus cloud cover over the West Atlantic increases, which we argue is due to increased stability resulting in weaker entrainment and a more humid boundary layer. The mean shortwave cloud feedback over the tropical Atlantic is positive, comparable to the CMIP6 ensemble mean. The emerging estimate of the total cloud‐radiative feedback over the Atlantic is slightly negative, consistent with CMIP6 GCMs, but it is substantially stronger than that of the driving GCM.

The application of a plant community model to evaluate adaptation strategies for alleviating climate change impacts on grassland productivity, biodiversity and forage quality

Grasslands are environments characterized by an elevated biodiversity in plant species, which dynamically evolves over time as a function of management practices, soil properties, and climate conditions. Climate change can locally affect grassland growth and floristic composition and, in turn, the quality and quantity of provided ecosystem services. We show how the use of the plant community model CoSMo allows to explicitly account for the dynamics of floristic composition as response to environmental variables. This, in turn, allows quantifying climate change impacts on grasslands growth and composition and evaluating alternative strategies to improve adaptation in the mid-term. As a case study, we focused on mountain areas in the northern Apennines (Italy), where temporary alfalfa (Medicago sativa L.)-dominated grasslands are sown for the production of Parmesan cheese. Five sites and four alternative climate scenarios (RCP4.5 and RCP8.5 projections as provided by the HadGEM2 and GISS general circulation models) were considered, to explore a wide range of agro-environmental conditions. Results showed that the observed dynamics of floristic composition and biomass accumulation were successfully simulated, with a mean absolute error lower than 10% for floristic composition and less than 1 t ha−1 for total biomass. Climate change impacts were globally negative, with a clear decrease of forage production as compared to the baseline (from -3.6% to -14.3% according to the climate scenario). The biodiversity of the plant community also declined (12.5% average decrease in the inverse Simpson index) due to the increase in alfalfa dominance. The latter, however, led to preserve the forage crude protein content (+0.9% on average). Guidelines for optimizing grassland productivity and forage protein under future climate were defined, mainly focused on reducing the alfalfa field duration, sowing grass-legume mixtures, and delaying the last cut of the season. These practices can be easily adopted under operational farming conditions to support the adaptation of temporary grasslands to climate change. According to our knowledge, this is one of the first study of climate change impact that uses a plant community model to explicitly considers phytocoenosis dynamics, biodiversity, and their effect on forage production (quantity and quality). Considering the role of grasslands as providers of key ecosystem services ‒ especially in marginal areas ‒ we believe that our modelling approach can support the identification of effective adaptation strategies to address future climate challenges.

Predicting the solubility of gases in imidazolium-based ionic liquids with SAFT-VR Mie EoS by a novel approach based on COSMO

This theoretical study presents a novel approach to predict the solubility of CO2 and CH4 in Ionic Liquids (ILs) under various pressures and temperatures using the predictive SAFT-VR Mie equation of state combined with the COSMO calculations. This approach involves estimating the segment number, diameter, and segment energy of the ionic liquid using the molecular volume from the COSMO model. The 2B and 4C association schemes were examined for ILs. The predicting results obtained through this innovative strategy demonstrate excellent accuracy in predicting gas solubility. The average absolute relative deviation of the most optimal association scheme scenario ranges from 4.8 to 14.2% for CO2 and 5.7 to 6.4% for CH4, respectively, without the need for binary interaction parameters.

Severe convective outbreak in Siberia in May 2020: Event analysis and high-resolution simulation

Western Siberia is exposed to extreme wind events caused by severe convective storms. However, our knowledge on such storms in Siberia is still fragmentary compared to other parts of the world primarily due to the lack of weather radar data. These storms cause substantial damage, which signifies the need for comprehensive assessment of their characteristics and predictability even on the basis of existing data. In this paper, we present a case study analysis of a severe weather outbreak that occurred on 25–26 May 2020 in Western Siberia, during a record six-month heatwave that lasted in Siberia from January to June. The outbreak resulted in six fatalities and substantial economic losses. Using various satellite data and damage reports we found that two consecutive mesoscale convective systems (MCSs) developed within the outbreak having an exceptionally long total track about 2000 km and causing large-scale forest damage with a total area of 64.5 km2. Such an exceptionally long path was supported by a strong mid-tropospheric jet, which settled extremely high values of wind shear that fostered the development of the outbreak. To analyze the accuracy of the forecast of the MCS and three associated windstorms on 26 May, we performed a set of simulations with the COSMO and ICON numerical weather prediction models launched with convection-permitting resolution (2.2 km) with different forecast lead times. Both models successfully predicted the most severe windstorm with the <50 km spatial displacement and the <1.5 h time shift, but COSMO generally simulated more strong wind. However, two other windstorms of that day were predicted with lower accuracy. The simulation results revealed a limited sensitivity of the model to variations in initial soil temperature and moisture. Together with the better performance of the forecast with >24 h lead time, this emphasized the predominant role of large-scale dynamics and the minor role of local factors in the outbreak formation and development. In particular, the intrusion of the upper tropospheric high potential vorticity streamer along the blocking periphery induced strong deep convection and determined the severe character of the outbreak. Specifically, the studied outbreak had an exceptional longevity compared to other long-lived windstorms observed in Northern Eurasia at the blocking periphery.