Simulation of temperate freezing lakes by one-dimensional lake models : performance assessment for interactive coupling with regional climate models

A systematic assessment of the ability of two selected 1-D lake models (the model of S.W. Hostetler and the Freshwater Lake model) to simulate lake surface temperature and fluxes for different lake conditions, corresponding to typical temperate freezing lakes of North America, through a set of offline tests, is presented. Results suggest that both models perform well in shallow lakes, while important differences between modelled and observed water temperatures and ice-cover duration can be noticed in deeper lakes. These differences could be partially attributed to the biases in the driving data and most importantly to the lack of representation of complex processes in the models, such as horizontal transfer of water and heat, ice drift, etc. Sensitivity of the models to lake depth, water transparency, explicit snow and snow/ice albedo is presented and possible ways of improving the performance of the 1-D lake models are proposed

Ideal MHD stability of tokamak plasmas with moderate and low aspect ratio

The need of durable and abundant energy sources for future ages stimulates the studies of thermonuclear energy sources, based on hot plasma confinement by magnetic fields. The most developed concept of hot plasma trap is the tokamak, where the plasma confinement is obtained by a combination of external magnetic fields with the magnetic field of the current flowing in the plasma torus. The stability of the tokamak plasma is the main subject of the present work. The hot plasma is approximated by the model of the ideal magnetohydrodynamics (ideal MHD) as a superconductive liquid. Being relatively simple, this model describes basic plasma stability properties and establishes necessary stability conditions. The analytical ideal MHD theory is well developed, but some assumptions, required for analytical treatment may not be valid for the plasmas of modern tokamaks and for future tokamak-based reactors. To circumvent this numerical codes have been created. These codes are free from such limitations, but they are not as convenient in use as analytical formulae. In the present work the validity of the analytical approach for the conditions of tokamaks like TCV and MAST is examined in comparison with numerical code predictions by studying the dependence of the ideal MHD stability on plasma toroidicity and shape parameters. The experimental study of the plasma dependence on triangularity, carried out on the TCV tokamak, is consistent with the results of the numerical calculations. A new formula, describing the ideal MHD stability dependence on plasma toroidicity and shape parameters is proposed for use in modern tokamaks and future reactors. This formula could be used instead of analytical expansions, which are not valid in such conditions. The ideal MHD stability of highly elongated TCV plasmas has been studied using numerical codes and the optimum plasma shape, which allows higher plasma performance, was found. Experimental data on the high elongation plasmas in TCV are consistent with the numerical predictions. Advanced tokamak plasma configurations, which provide better plasma properties, are amongst the main goals of the TCV tokamak research activity. The ideal MHD stability analysis of such plasmas, using numerical codes, can be useful for optimization of plasma parameters, and designing new experiments with improved plasma performance. Reversed shear plasmas with internal transport barrier were analyzed and the influence of the plasma pressure and current profiles on the ideal MHD stability of these plasmas was examined in detail. By fine tuning of the electron cyclotron heating and current drive system of TCV it was found that it might be possible to improve the plasma performance in reversed shear plasmas, by creating the optimal current and pressure profiles

Reanalysis-driven climate simulation over CORDEX North America domain using the Canadian Regional Climate Model, version 5: model performance evaluation

The performance of reanalysis-driven Canadian Regional Climate Model, version 5 (CRCM5) in reproducing the present climate over the North American COordinated Regional climate Downscaling EXperiment domain for the 1989–2008 period has been assessed in comparison with several observation-based datasets. The model reproduces satisfactorily the near-surface temperature and precipitation characteristics over most part of North America. Coastal and mountainous zones remain problematic: a cold bias (2–6 °C) prevails over Rocky Mountains in summertime and all year-round over Mexico; winter precipitation in mountainous coastal regions is overestimated. The precipitation patterns related to the North American Monsoon are well reproduced, except on its northern limit. The spatial and temporal structure of the Great Plains Low-Level Jet is well reproduced by the model; however, the night-time precipitation maximum in the jet area is underestimated. The performance of CRCM5 was assessed against earlier CRCM versions and other RCMs. CRCM5 is shown to have been substantially improved compared to CRCM3 and CRCM4 in terms of seasonal mean statistics, and to be comparable to other modern RCMs

Risk of the building deformation because of above-permitted standard subsidence

The authors suppose that the vulnerability of natural-and-technical system in relation to the subsidence can be equated to the financial costs of repair or new construction with the summation of losses from the temporary exception of this system from the economic activity. Then the vulnerability can be considered as the economic damage, and risk can be considered as the multiplication of damage by the probability of a dangerous event. The method of calculation of geological risk is offered in the article and can be applied in practice by geologists, mathematicians and designers

Experiences with >50,000 Crowdsourced Hail Reports in Switzerland

Crowdsourcing is an observational method that has gained increasing popularity in recent years. In hail research, crowdsourced reports bridge the gap between heuristically defined radar hail algorithms, which are automatic and spatially and temporally widespread, and hail sensors, which provide precise hail measurements at fewer locations. We report on experiences with and first results from a hail size reporting function in the app of the Swiss National Weather Service. App users can report the presence and size of hail by choosing a predefined size category. Since May 2015, the app has gathered >50,000 hail reports from the Swiss population. This is an unprecedented wealth of data on the presence and approximate size of hail on the ground. The reports are filtered automatically for plausibility. The filters require a minimum radar reflectivity value in a neighborhood of a report, remove duplicate reports and obviously artificial patterns, and limit the time difference between the event and the report submission time. Except for the largest size category, the filters seem to be successful. After filtering, 48% of all reports remain, which we compare against two operationally used radar hail detection and size estimation algorithms, probability of hail (POH) and maximum expected severe hail size (MESHS). The comparison suggests that POH and MESHS are defined too restrictively and that some hail events are missed by the algorithms. Although there is significant variability between size categories, we found a positive correlation between the reported hail size and the radar-based size estimates

Object-based analysis of simulated thunderstorms in Switzerland: application and validation of automated thunderstorm tracking with simulation data

We present a feasibility study for an object-based method to characterise thunderstorm properties in simulation data from convection-permitting weather models. An existing thunderstorm tracker, the Thunderstorm Identification, Tracking, Analysis and Nowcasting (TITAN) algorithm, was applied to thunderstorms simulated by the Advanced Research Weather Research and Forecasting (AR-WRF) weather model at convection-permitting resolution for a domain centred on Switzerland. Three WRF microphysics parameterisations were tested. The results are compared to independent radar-based observations of thunderstorms derived using the MeteoSwiss Thunderstorms Radar Tracking (TRT) algorithm. TRT was specifically designed to track thunderstorms over the complex Alpine topography of Switzerland. The object-based approach produces statistics on the simulated thunderstorms that can be compared to object-based observation data. The results indicate that the simulations underestimated the occurrence of severe and very large hail compared to the observations. Other properties, including the number of storm cells per day, geographical storm hotspots, thunderstorm diurnal cycles, and storm movement directions and velocities, provide a reasonable match to the observations, which shows the feasibility of the technique for characterisation of simulated thunderstorms over complex terrain

Present climate and climate change over North America as simulated by the fifth-generation Canadian regional climate model

The fifth-generation Canadian Regional Climate Model (CRCM5) was used to dynamically downscale two Coupled Global Climate Model (CGCM) simulations of the transient climate change for the period 1950–2100, over North America, following the CORDEX protocol. The CRCM5 was driven by data from the CanESM2 and MPI-ESM-LR CGCM simulations, based on the historical (1850–2005) and future (2006–2100) RCP4.5 radiative forcing scenario. The results show that the CRCM5 simulations reproduce relatively well the current-climate North American regional climatic features, such as the temperature and precipitation multiannual means, annual cycles and temporal variability at daily scale. A cold bias was noted during the winter season over western and southern portions of the continent. CRCM5-simulated precipitation accumulations at daily temporal scale are much more realistic when compared with its driving CGCM simulations, especially in summer when small-scale driven convective precipitation has a large contribution over land. The CRCM5 climate projections imply a general warming over the continent in the 21st century, especially over the northern regions in winter. The winter warming is mostly contributed by the lower percentiles of daily temperatures, implying a reduction in the frequency and intensity of cold waves. A precipitation decrease is projected over Central America and an increase over the rest of the continent. For the average precipitation change in summer however there is little consensus between the simulations. Some of these differences can be attributed to the uncertainties in CGCM-projected changes in the position and strength of the Pacific Ocean subtropical high pressure

Experience in the use of simultaneous operations in dermatology and cosmetology

Background. Simultaneous (combined, simultaneous) operations are operations in which up to five different surgical procedures are performed simultaneously during one surgical intervention. According to WHO statistics, about a third of all surgical patients need simultaneous operations. A feature of medical interventions in dermatovenereology and cosmetology is the unwillingness and unwillingness of the patient to experience tangible pain discomfort during the procedures. The arsenal of modern cosmetology is constantly replenished with technologies that not only provide convincing clinical effects, but are also capable of provoking a negative psycho-emotional state in a patient who undergoes certain painful manipulations. Aims. To reflect the experience of a private medical organization, which is one of the first in the country to actively introduce simultaneous surgery in dermatology for several years. Materials and methods. Clinical observation, examination results. Results. In 2022, 32 surgical interventions were performed simultaneously with a dermatovenereologist in this clinic. Also, the clinic regularly performs simultaneous operations in the following combinations: hysteroscopy (with or without curettage) + removal of benign melanocytic/non-melanocytic skin tumors; surgical treatment of hemorrhoids + removal of papillomas/nevi; surgical treatment of anal fissure + removal of papillomas/nevi; laser vaporization of the pilonidal sinus + removal of genital warts; laparoscopic cholecystectomy + removal of nevi. Conclusion. The use of simultaneous operations in dermatovenerological practice is economically justified and justified, taking into account the modern possibilities of anesthetic care, improving their technical and medical support. Simultaneous combined operations exclude psycho-emotional experiences of the forthcoming repeated surgical intervention in patients and allow the surgeon to conduct high-quality medical interventions in a comfortable environment