Climatic Conditions Of Central Europe Research Articles

Critical Period of Weed Control in Maize as Influenced by Soil Tillage Practices and Glyphosate Application

Increasing evidence on environmental and economic benefits has raised farmers’ interest in adopting alternative, less intensive soil management practices. To evaluate the influence of weed-competitive ability in response to a different tillage regime, a field study was conducted in maize under humid Central European climatic conditions in Slovenia. This study was established as a split-plot arrangement with three tillage practices (TPs) as the main plot: conventional (CN), conservation (CS), and no tillage (NT); this was combined with glyphosate application and the weed removal timing as the subplot. The weed removal timings were at the V3, V6, V9, V15, and R1 maize stages, with weed-free and weed season-long monitoring. The beginning and the end of the critical period of weed control (CPWC), based on a 5% maize yield loss rate, were determined by fitting the four-parameter log-logistic equations to the relative maize dry grain yield. The weed dry biomass from maize germination until the R1 growth stage in the NT TP was consistently lower than that in the CN and CS TP. Moreover, the NT TP resulted in a shorter CPWC (39 days after emergence (DAE)) compared to the CN (57 DAE) and CS (58 DAE). The results of CTWR (critical timing of weed removal) showed that less intensive tillage operations in the CS resulted in an earlier need for weed control (V2 and 23 DAE) compared to the CN (V3 and 39 DAE) and NT (V3 and 40 DAE). Our study suggests that the intensive tillage operations performed in the CN TP and the pre-sowing use of non-selective burndown herbicide in the NT delay the CTWR by more than 2 weeks, thus reducing the need for early post-emergence herbicide application in maize.

Long-term prediction of the effects of climate change on indoor climate and air quality

Limiting the negative impact of climate change on nature and humans is one of the most pressing issues of the 21st century. Meanwhile, people in modern society spend most of the day indoors. It is therefore surprising that comparatively little attention has been paid to indoor human exposure in relation to climate change. Heat action plans have now been designed in many regions to protect people from thermal stress in their private homes and in public buildings. However, in order to be able to plan effectively for the future, reliable information is required about the long-term effects of climate change on indoor air quality and climate.The Indoor Air Quality Climate Change (IAQCC) model is an expediant tool for estimating the influence of climate change on indoor air quality. The model follows a holistic approach in which building physics, emissions, chemical reactions, mold growth and exposure are combined with the fundamental parameters of temperature and humidity. The features of the model have already been presented in an earlier publication, and it is now used for the expected climatic conditions in Central Europe, taking into account various shared socioeconomic pathway (SSP) scenarios up to the year 2100.For the test house examined in this study, the concentrations of pollutants in the indoor air will continue to rise. At the same time, the risk of mold growth also increases (the mold index rose from 0 to 4 in the worst case for very sensitive material). The biggest problem, however, is protection against heat and humidity. Massive structural improvements are needed here, including insulation, ventilation, and direct sun protection. Otherwise, the occupants will be exposed to increasing thermal discomfort, which can also lead to severe heat stress indoors.

An alien parasite in a changing world - Ashworthius sidemi has lost its traditional seasonal dynamics.

A non-native nematode Ashworthius sidemi has emerged in captive fallow deer in Central and Eastern Europe over the last decade. Although this parasite has been spreading in the wild outside it's native distributional range and colonising local European host species since the middle of the last century, limited information has been published on the seasonality of A. sidemi and its susceptibility to anthelmintics. To address this knowledge gap, we conducted a study to investigate seasonal dynamics of the non-native parasite in the current Central European climate conditions. We collected freshly voided faecal pellets at four-week intervals from February 2018 to February 2020 at a fallow deer reserve with a known history of A. sidemi presence. The faecal pellets obtained were pooled after each site visit (n = 25) and coprocultured to obtain the third stage larvae of trichostrongylid nematodes at monthly intervals. Total genomic DNA was extracted from the recovered larvae. Using real-time multiplex PCR, A. sidemi DNA was detected in 17 out of 25 larval samples (68% prevalence). During the monitoring period, the annual administration of ivermectin based premix (Cermix) took place in January 2018, 2019, and 2020, and additionally a mixture of rafoxanide and mebendazole (Rafendazol) was administered once in spring 2019. The probability of parasite presence was significantly influenced by the time since the drug administration (p = 0.048) and the mean temperature at the location (p = 0.013). Larval samples negative for A. sidemi were always identified shortly after the drug administration. However, rapid pasture contamination by the parasite eggs from two to three months after Cermix administration and within one month after Rafendazol administration suggest only a short-lived efficacy of both administered drugs. The abundance of A. sidemi DNA was positively affected by mean temperature (p = 0.044) and remained relatively stable throughout the monitoring period, with the highest peak in August 2018 and 2019. Pasture contamination with A. sidemi eggs occurred almost all year round, with the exception of the beginning of 2018, 2019, and 2020. These findings indicate adaptation of a non-native parasite to the current climatic conditions of the Czech Republic resulted in negligible seasonal patterns of parasite egg shedding.

Habitat Temperatures of the Red Firebug, Pyrrhocoris apterus: The Value of Small-Scale Climate Data Measurement.

Ambient temperature is a main parameter that determines the thriving and propagation of ectothermic insects. It affects egg and larval development as well as adults' survival and successful overwintering. Pyrrhocoris apterus is a herbivorous bug species almost ubiquitous in Eurasia. Its distribution extends from the Atlantic Coast to Siberia, Northwest China and Mongolia. After introduction, it established successfully in the USA, Central America, India and Australia, which indicates a high invasive potential of this species. We determined the climatic conditions in Central Europe in a habitat where P. apterus has been continuously observed for decades. We conducted temperature measurements in the habitat and in the microhabitats where individuals could be found during the year and set them against freely available climate data commonly used to characterize habitat climate. Our temperature measurements were also compared to thermal limits (critical thermal minima and maxima). Although ambient temperatures outside the thermal boundaries of P. apterus can and do occur in the habitat, the bugs thrive and propagate. Microhabitat measurement in winter showed that individuals sought areas with favorable temperatures for hibernation. In particular, these areas are not (always) represented in large-scale climate tables, leading to possible misinterpretation of future patterns of spread of invasive species spread.

An optimisation study of PCM triple glazing for temperate climatic conditions – Dynamic analysis of thermal performance

PCM-windows can play an important role in the protection of buildings against overheating but also as systems for effective storage of solar energy. The presented study indicated the optimal solution for the triple-glazed window where one cavity is fullfilled with phase change material (PCM) in temperate climatic conditions characteristic for Poland. Regarding different thicknesses, positions, and temperatures of phase change material, the a recommended solution was determined using the simulation technique. The computational model was developed, numerically verified, and experimentally validated. The entire meteorological year analyses were done for the climatic conditions of Central Europe, considering windows exposed to facing the South. The optimal solution was determined using two methods - the Weighted Sum method and the Fuzzy Sets method. Both point out a variant with a PCM layer located in the inner cavity and the average melting temperature of PCM equal to 25 °C. However, different criteria and sets of linguistic variables in fuzzy sets determined different optimal PCM thicknesses ranging from 5 to 20 mm.

Effect of a Soil-Applied Humic Ameliorative Amendment on the Yield Potential of Switchgrass Panicum virgatum L. Cultivated under Central European Continental Climate Conditions

The yield potential of switchgrass was verified by testing seven cultivars in a small-scale experiment carried out from 2018 to 2022 on Gleyic Fluvisol under Central European conditions. The treatments are as follows: pre-sowing (i/HA) soil humic preparation Humac AGRO (based on leonardite) with an ameliorative dose of 1000.0 kg ha−1 or (ii/NPK) basic nutrition with a dose of 220.0 kg ha−1 NPK; an annual dose of 70 kg ha−1 N was applied to both treatments (HA, NPK) and compared to (iii/UC) untreated control. A dry matter (DM) yield of 9.02 t ha−1 was achieved in the total average, which varied from 0.05 t ha−1 to 60.64 t ha−1. The yield was affected mainly by years (F-ratio 106.64), then by nutrition (F-ratio 79.03), followed by cultivars (F-ratio 56.87), and finally by replications (F-ratio 0.00). Switchgrass productivity increased according to the utility year; however, the driest year (2020—388 mm, 2021—372 mm, and 2022—288 mm) changed the order of the three full utility years (12.44, 19.13, and 7.73 t ha−1 DM, respectively). HA gives the highest DM yield of 13.69 t ha−1 on average with values of 9.19 and 4.19 for NPK and UC, respectively. The cultivars order was EG 1101 ˃ BO Master ˃ EG 1102 ˃ Kanlow ˃ Alamo ˃ Carthage ˃ NJ Ecotype (21.15, 12.48, 8.14, 7.70, 6.34, 4.47, and 2.89 t ha−1 DM when ranking average yield or 60.64, 45.20, 29.92, 29.15, 17.87, 9.86, and 5.93 t ha−1 DM when ranking maximal yields).

Nutritional Evaluation of Quinoa Genetic Resources Growing in the Climatic Conditions of Central Europe

Quinoa displays huge genetic variability and adaptability to distinct climatic conditions. Quinoa seeds are a good source of nutrients; however, the overall nutritional composition and nutrient content is influenced by numerous factors. This study focused on the nutritional and morphologic evaluation of various quinoa genotypes grown in the Czech Republic. Significant differences between years were observed for morphological traits (plant height, inflorescence length, weight of thousand seeds). The weather conditions in the year 2018 were favorable for all the morphological traits. The protein content of quinoa accessions ranged between 13.44 and 20.01% and it was positively correlated to mauritianin. Total phenolic content varied greatly from year to year, while the antioxidant activity remained relatively stable. The most abundant phenolic compounds were the flavonoids miquelianin, rutin, and isoquercetin. Isoquercetin, quercetin, and N-feruoloyl octopamine showed the highest stability under variable weather conditions in the analyzed years. A total of six compounds were detected and quantified in quinoa for the first time. Most varieties performed well under Central European conditions and can be considered a good source of nutrients and bioactive compounds. These data can be used as a source of information for plant breeders aiming to improve the quality traits of quinoa.

Faster evapotranspiration recovery compared to canopy development post clearcutting in a floodplain forest

Actual evapotranspiration (ETa) is a key component of the water balance, and its accurate quantification of spatiotemporal variation is essential to improve the understanding of soil–plant-atmosphere-hydrosphere interactions. While in situ point measurements allow for the determination of the ETa of a particular ecosystem or land cover type, remote sensing methods make it possible to divide and evaluate the rate of ETa of different ecosystems in the landscape and would allow better management of the water resource system, especially if those are partly or permanently limited. The goal of this paper was to analyze the impact of clearcutting during standard forest management practices in floodplain forests and its effect on the water regime of the area. We selected the Lanžhot floodplain forest area (48.681°N 16.950°E, 155 m a.s.l.) that represents a biologically and hydrologically unique area of remnant floodplain forest within the upper Danube River basin. Since clearcutting represents a drastic intervention into the ecosystem including changes in canopy structure and local microclimate, we hypothesized that the impact of the clearcut on the overall water balance is long-term in the order of decades as a result consequence of logging of the mature forest and changes in local microclimatic conditions in disturbed areas. To analyze the impacts of clearcutting on ETa, we applied the METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) remote sensing model. METRIC was validated in the Central European climatic conditions using two ground eddy covariance measurements systems over grassland and floodplain forest. The evaluated model METRIC was then applied to quantify ETa in three areas of interest in the floodplain forest, where in 2015–2021, mature vegetation was targeted for removal, modification of the soil surface, and subsequent planting of a new generation of English oak trees (Quercus robur L.). Immediately after the removal of vegetation cover, METRIC detected an annual decrease in ETa by 35–40%, while leaf area index (LAI) decreased by 70–80%. This was followed by a quick recovery of the ETa/ETo (where ETo represents FAO-56 reference evapotranspiration), reaching similar values as uncut surrounding vegetation during the third year, while LAI recovery was detected in the fifth year after the removal of vegetation cover. The rapid recovery of the ETa/ETo rejected the initial hypothesis, and studies showed that the newly formed stand replaced the ETa/ETo rate of the mature stand in the floodplain forest conditions of Central Europe in the fourth year, suggesting that the impacts of clearcutting on the hydrology may be temporally relatively limited.

Ein Update zur Leishmaniose des Hundes: Diagnostik, Therapie und Monitoring

Canine infections with Leishmania (L.) infantum are gaining significance in Germany due to rising numbers of dogs imported from endemic countries, frequent travel and changing of climatic conditions in Central Europe. Dogs without any clinical signs suspicious for vector-borne infections imported from other countries to Germany should be tested immediately after import and 6 months later. In dogs with clinical signs suspicious for leishmaniosis, direct and indirect detection methods of the pathogen as well as hematology, biochemistry, serum protein electrophoresis and C-reactive protein are recommended. For treatment and monitoring of canine leishmaniosis, the LeishVet-guidelines are highly recommended. Different therapeutic options include first-line, second-line, and third-line drugs. For dose adjustments of allopurinol, the "step plan" should be taken in consideration. Due to climatic changes, habitats of sandflies as transmitting vectors of leishmaniosis are expanding. Next to vectorial transmission mating, transplacental infections, bite wounds, and blood transfusions were described in canine leishmaniosis. Additionally, L. infantum is a zoonotic vector-borne infectious pathogen, which is important regarding the "One-health"-aspect.

Effect of the Climatic Conditions in Central Europe on the Growth and Yield of Cornelian Cherry Cultivars

Fruit of Cornelian cherry can be used fresh or processed, and cultivation practices are developing in this direction. Due to the rarity of its cultivation, Cornelian cherry is harvested from natural sites of occurrence. However, the fruit from natural sites is of lower quality than the cultivars, as their seedlings differ in terms of fruit ripening. The objective of this experiment was the evaluation of approximately a dozen cultivars in terms of growth and fruit yield under the conditions of Central Europe. The effect of climatic conditions on the onset date of particular phenological stages was also assessed. All the analysed cultivars are suitable commodity crops, but they should be accurately selected depending on the direction of production. The first phenological stage of Cornelian cherry is the appearance of inflorescences before the development of leaves. The start of particular phenophases depends on the temperature and precipitation. Cornelian cherries cultivated under ecological conditions show satisfactory fruit size and generally a small percentage of stone. Most cultivars have an elongated fruit shape, and the shape factor decreases with their growth and ripening. The fruit grows along a double sigmoid, and its first intensive growth occurs following the extinction of intensive shoot growth.

Numerical Evaluation of the Hygrothermal Performance of a Capillary Active Internal Wall Insulation System under Different Internal Conditions.

In certain situations, internal insulation is the only possible renovation option. However, it is risky where there is high humidity in a building and ventilation is not working sufficiently. The internal insulation retrofit changes the original thermal and moisture balance of a wall, therefore, it is necessary to carefully design it already at the initial stage. This paper analyses four interior insulation systems based on open diffusion capillary active materials: wood fibreboards (flex and rigid), perlite boards, and microporous calcium silicate. The hygrothermal performance under the climatic conditions of Central Europe (Poland) was assessed using the WUFI Plus software, taking into account the dynamic variation of indoor and outdoor conditions. The analysis included three insulation thicknesses with different ventilation rates and varying moisture loads. The results show that the hygrothermal properties of the wall change with the increase of insulation thickness and depend on the individual moisture properties of the material. In addition, both the reduction of moisture load and more intensive air exchange improve the hygrothermal properties at the interface between the insulation and the wall. Of all the solutions analysed, the system with perlite board and the system with wood fibreboard showed the worst hygric properties. Conversely, the highest risk of mould and interstitial condensation was recorded for the flex wood fibreboard solution.

Extensive Roof Greenery as a Response to Heat Islands: Some Problems

Abstract Extensive roof greenery is one of the ways to reduce the extent and impact of urban heat islands. A prerequisite is the correct design and operation of both the structural and vegetation part of a roof. If adequate maintenance, especially irrigation of the greenery, cannot be ensured, the use of extensive roof greenery can also be counterproductive. The case study to be presented deals with problems of a flat roof with extensive greenery above an underground garage under Central European climate conditions. Infrequent irrigation leads to extremely high temperatures of the substrate in the summer and makes the purpose of this roof pointless. The contribution analyzes the reason for the failure of the vegetation part of the roof, which was claimed to be maintenance-free, points out fire safety issues, and suggests improvements that might be considered in similar cases. At the present time, which is marked by the climate change crisis, there is great societal pressure to build green roofs. However, if it is not possible to ensure their perfect functionality, it is perhaps better to use classically proven types of roofs, but with greater reflectivity of the top layer surface.

Soybean (Glycine max (L.) Merr.) Growth, Yield, and Nodulation in the Early Transition Period from Conventional Tillage to Conservation and No-Tillage Systems

Soybean (Glycine max (L.) Merr.) is the most important protein crop globally, with its cultivation area in Europe on the increase. To investigate how alternative tillage systems affect soybean growth, yield performance, and nitrogen fixation capacity in the early conversion period from conventional tillage to conservation and no-tillage practices, a field study was conducted in 2020 under the humid central European climatic conditions of Slovenia. A complete randomized block design with four repetitions was used for the three different tillage systems (conventional, conservation, and no-tillage). The results show that the majority of the studied soybean growth parameters (e.g., plant density, nodes per plant, and shoot and root dry matter) and the yield components (e.g., pods per plant, and 100-seed mass) were greatest for the reference conventional tillage system. The conventional system also showed significantly greater dry nodule mass (p < 0.01) and proportion of large-sized nodules (>4 mm) on both the tap root (p < 0.05) and the lateral roots (p < 0.001). A positive linear correlation between nitrogen content and nodule production in the roots also suggested increased nitrogen fixation for the conventional system. The less intensive conservation and no-tillage systems resulted in significantly greater soil compaction, which negatively affected early plant establishment and resulted in significantly decreased plant densities. Despite the large differences in plant stands and individual plant performances, no significant differences were seen for dry seed yields between these tillage systems. Dry seed yields for the conventional and conservation systems were 4.54 and 4.48 t ha−1, respectively, with only minor (non-significant) yield reduction for the no-tillage system, at 4.0 t ha−1. These data show that soybean cultivation in the early transition period to less intensive tillage systems have no major yield losses under these less suitable agro-climatic conditions if correct crop and weed management measures are implemented.

Nutritive value for ruminants of different fresh and ensiled sorghum (Sorghum bicolor (L.) Moench) varieties harvested at varying maturity stages

ABSTRACT The occurrence of the Western corn rootworm and increasing frequency of summer droughts have reduced forage maize yields and quality in Central Europe in recent years. Therefore, sorghum (Sorghum bicolor (L.) Moench) has been increasingly used as alternative forage in ruminant feeding, although information on the nutritive value of whole crop sorghum silage (WCSS) under Central European climate conditions is scarce. This research project aimed to study differences between sorghum varieties and harvest dates regarding dry matter (DM) yield, chemical composition of fresh panicle, fresh stover, fresh whole plant and WCSS as well as whole tract digestibility and energy content of WCSS. For this purpose, six sorghum varieties, classified by their predominant use (biomass, silage, grain), were cultivated and harvested at three maturity stages (late milk stage, dough stage, full maturity). Furthermore, WCSS quality was compared with feed value of fresh and ensiled forage maize. Dry matter yield was higher (p < 0.05) in biomass sorghum (24.9 t/ha) compared to other sorghum varieties (12.4 to 16.7 t/ha). However, panicle proportion was lowest in biomass sorghum (10.5%), highest in grain sorghum (59.1%) and intermediate in silage sorghum. Fibre content declined and starch content increased with rising panicle proportion in fresh panicle, fresh whole plant and WCSS. Therefore, whole tract organic matter digestibility (66.8%) and metabolisable energy (ME) content (9.49 MJ/kg DM) were highest in grain sorghum silage. Especially low ME content was found in the biomass sorghum silage (7.43 MJ/kg DM). Dry matter yield of sorghum increased between late milk and dough stage of maturity, while it remained constant afterwards. Furthermore, ME content of WCSS rose tendentially (0.05 < p < 0.10) between late milk and dough stage of maturity and dropped again between dough stage and full maturity. Highest nutritive value of WCSS is achieved if grain sorghum varieties are used and both nutritive value and DM yield are optimised if harvest is carried out at dough stage of maturity. However, compared to forage maize, grain sorghum varieties have disadvantages both in DM yield and in nutritive value under common Central European climate conditions.

Persistence of Xanthomonas campestris pv. campestris in Field Soil in Central Europe.

Xanthomonas campestris pv. campestris (Xcc) is a bacterium that causes black rot of crucifers. The greatest losses of brassica crop production usually result from seed-borne infection, but carry-over of inoculum in field soil may also be possible. The aim of this study was to monitor persistence of Xcc in field soil in central Europe using a conventional PCR assay with hrpF primers and a two-step nested real-time PCR assay using Zur primers. The work has demonstrated that nested real-time PCR can be used to improve the analytical sensitivity for detection of Xcc in soil compared to conventional PCR, and that Xcc may persist in soil for up to two years following an infected brassica crop in central European climatic conditions.

First remains of Diplocynodon cf. ratelii from the early Miocene sites of Ahníkov (Most Basin, Czech Republic)

Fossil crocodylians from the early Miocene (Eggenburgian, MN3a) sites of Ahnikov (Most Basin, Czech Republic) are described in this paper. The new material presented here includes over 200 remains (bones, teeth and osteoderms), and therefore constitutes the largest crocodylian sample known from the fossil record of the Czech Republic. Assignment of the specimens to the fossil alligatoroid taxon Diplocynodon cf. ratelii Pomel, 1847 (family Diplocynodontidae) is justified by the presence of several cranial and postcranial features. In the Czech Republic, this species has been previously reported only from the Tusimice site (MN3, Most Basin, Ohre/Eger Graben). The majority of the material reported from Ahnikov is composed of disarticulated juvenile individuals. Both sites are most likely attributable to the specific environment of swampy areas, where crocodile hatchlings would hide from predators. The presence of the genus Diplocynodon supports the assumption of rather warm climatic conditions in Central Europe during the early to middle Miocene, as well as a swampy depositional environment previously inferred for Ahnikov. However, some squamate taxa suggest the existence of additional, surrounding palaeoenvironment characterised by a more open landscape with slightly drier conditions.

Soil Respiration under 90 Year-Old Rye Monoculture and Crop Rotation in the Climate Conditions of Central Poland

This study, aimed at assessing the rate of soil respiration under different crop rotation and fertilization conditions, was carried out on long-term (since 1923) experimental plots with rye monoculture and 5-crop rotation in Skierniewice (Central Poland). The treatments included mineral-organic (CaNPK+M) and organic (Ca+M) fertilization (where M is farmyard manure). Soil respiration was measured in situ by means of infrared spectroscopy using a portable FTIR spectrometer Alpha. CO2 fluxes from CaNPK+M-treated soils under cereals cultivated in monoculture and crop rotations were not statically different. Respiration of soil under lupine cultivated in crop rotation was higher than under cereals. N-fertilization and its succeeding effect increased soil respiration, and significantly altered its distribution over the growing season. Our results indicate that in the climatic conditions of Central Europe, respiration of sandy soils is more dependent on the crop species and fertilization than on the crop rotation system. Omission of mineral fertilization significantly decreases soil respiration. The CO2 fluxes were positively correlated with soil temperature, air temperature, and soil content of NO3− and NH4+.

The Impacts of Tracking System Inaccuracy on CPV Module Power

The accuracy and reliability of solar tracking greatly impacts the performance of concentrator photovoltaic modules (CPV). Thus, it is of utmost significance to know how deviations in tracking influence CPV module power. In this work, the positioning characteristics of CPV modules compared to the focus points were investigated. The performance of CPV modules mounted on a dual-axis tracking system was analysed as a function of their orientation and inclination. The actual experiment was carried out with CPV cells of 3 mm in diameter. By using a dual tracking system under real weather conditions, the module’s position was gradually modified until the inclination differed by 5° relative to the optimal position of the focus point of the CPV module. The difference in inclination was established by the perfect perpendicularity to the Sun’s rays. The results obtained specifically for CPV technology help determine the level of accuracy that solar tracking photovoltaic systems are required to have to keep the loss in power yield under a certain level. Moreover, this power yield loss also demonstrated that the performance insensitivity thresholds of the CPV modules did not depend on the directions of the alterations in azimuthal alignment. The novelty of the research lies in the fact that earlier, no information had been found regarding the tracking insensitivity point in CPV technologies. A further analysis was carried out to compare the yield of CPV to other, conventional photovoltaic technologies under real Central European climate conditions. It was shown that CPV needs a sun tracking accuracy of at least 0.5° in order to surpass the yield of other PV technologies. Besides providing an insight into the tracking error values of solar tracking sensors, it is believed that the results might facilitate the planning of solar tracking sensor investments as well as the economic calculations related to 3 mm cell diameter CPV system investments.

Long-Term Statistics of Riming in Nonconvective Clouds Derived from Ground-Based Doppler Cloud Radar Observations

AbstractRiming is an efficient process of converting liquid cloud water into ice and plays an important role in the formation of precipitation in cold clouds. Due to the rapid increase in ice particle mass, riming enhances the particle’s terminal velocity, which can be detected by ground-based vertically pointing cloud radars if the effect of vertical air motions can be sufficiently mitigated. In our study, we first revisit a previously published approach to relate the radar mean Doppler velocity (MDV) to rime mass fraction (FR) using a large ground-based in situ dataset. This relation is then applied to multiyear datasets of cloud radar observations collected at four European sites covering polluted central European, clean maritime, and Arctic climatic conditions. We find that riming occurs in 1%–8% of the nonconvective ice containing clouds with median FR between 0.5 and 0.6. Both the frequency of riming and FR reveal relatively small variations for different seasons. In contrast to previous studies, which suggested enhanced riming for clean environments, our statistics indicate the opposite; however, the differences between the locations are overall small. We find a very strong relation between the frequency of riming and temperature. While riming is rare at temperatures lower than −12°C, it strongly increases toward 0°C. Previous studies found a very similar temperature dependence for the amount and droplet size of supercooled liquid water, which might be closely connected to the riming signature found in this study. In contrast to riming frequency, we find almost no temperature dependence for FR.

Data analysis of a monitored building using machine learning and optimization of integrated photovoltaic panel, battery and electric vehicles in a Central European climatic condition

Climate change is the biggest challenge of the present era. Buildings being one of the largest consumers of energy can help address this issue in various ways. The objective of the present study is to simulate and optimize a photovoltaic-based energy system integrated with onsite battery and electric vehicles for a demo site in Belgium in the Central European climatic conditions. The energy system of the demo site consists of photovoltaic-thermal panels, providing electricity and heat to the building, a battery as well as several long- and short-term thermal storages to reduce electricity curtailment and import. In the present study, the focus is on the optimization of the electric vehicle and battery charging and the import from the electrical network. Monitored data from the demo site is processed using a machine learning method to identify overproduction curtailment and electric vehicle charging events and to generate profiles of the photovoltaic (PV) energy production, feasible time windows and energy requirements for electric vehicle charging and building’s energy demand. These profiles and data are then used in an optimization method using linear and mixed integer programming to minimize the annual cost of the purchased electricity. Different case studies in terms of PV capacity, battery capacity and electric vehicle charging scenarios are investigated to compare against the performance of the real system. Various criteria, such as the curtailment of the PV production, imported energy cost, onsite energy fraction and matching indicators and lastly the net-zero energy balance of the building are considered to compare the results of the case studies. The study shows that machine learning can be used for the investigation of the monitored data, which can be later used for simulating and optimizing the case studies. The results shows that PV panels with 20 kWp (PV generation to demand ratio of 97%) and battery capacity of 16.1 kWh can result in annual energy cost saving of up to 807€ (31% reduction) with PV curtailment ratio of 34%, compared with the installed real demo building that has 10 kWp PV panels (PV generation to demand ratio of 49%) and battery capacity of 32.2 kWh. This would lead to an increase in the onsite-energy fraction indicator from 45% to 68%. Moreover, this combination can bring the building closer to the net-zero energy balance if the surplus electricity is exported rather than being curtailed. The optimization of the energy system in terms of equipment sizing and operation control is needed to increase the techno-economic performance of the whole system.