Wind Strength Research Articles

Statistical Properties of the Distribution and Generation of Kinetic‐Scale Flux Ropes in the Terrestrial Dayside Magnetosheath

AbstractThe generation of kinetic‐scale flux ropes (KSFRs) is closely related to magnetic reconnection. Both flux ropes and reconnection sites are detected in the magnetosheath and can impact the dynamics upstream of the magnetopause. In this study, using the Magnetospheric Multiscale satellite, 12,623 KSFRs with a scale <20 RCi are statistically studied in the Earth's dayside magnetosheath. It is found that they are mostly generated near the bow shock (BS), and propagate downstream in the magnetosheath. Their quantity significantly increases as the scale decreases, consistent with a flux rope coalescence model. Moreover, the solar wind parameters can control the occurrence rate of KSFRs. They are more easily generated at high Mach number, large proton density, and weak magnetic field strength of the solar wind, similar to the conditions that favor BS reconnection. Our study shows a close connection between KSFR generation and BS reconnection.

Study on Estimation of Typhoon Damage Thresholds in Coastal Region

Typhoon damage in coastal areas is a complex disaster characterized by heavy rain, strong winds, and turbulent waves. The strength of these strong winds and waves is determined by the intensity of the typhoon. In this study, a variable representing strong winds and waves was developed. A damage prediction model using rainfall, wind, and the developed variable was then proposed and thresholds for each variable were calculated across cities, counties, and districts located in coastal areas. Two damage prediction models were compared based on variables. Standard normal variables related to strong winds and rainfall by duration were calculated using Empirical Copula. The first logistic regression model was constructed using these variables. The second model used a multiple logistic regression model, considering strong winds and rainfall by duration. Although there are more cities, counties, and districts where the multiple logistic regression model exhibited better accuracy, there have been several instances where the typhoon damage induction threshold suggested by this model was abnormal. On the other hand, a relatively stable critical value was yielded using standard normal variables by Empirical Copula. This is because standard normal variables are calculated based on the probability according to the order of rainfall and strong wind magnitude. Hence, the critical value falls within the minimum and maximum range of observed values. According to the research results, it is possible to predict whether typhoon damage will occur in cities, counties, and districts located in coastal areas using the typhoon information provided by the Korea Meteorological Administration during a typhoon event, which can aid in preparing for typhoon disasters.

Experimental and numerical study on transportation performance of ionic wind generator with distributed auxiliary heat source

Ionic wind technology can be used to achieve directional airflow transportation and local heat and mass transfer enhancement, which are suitable in the field of food drying. Ionic wind can be coupled with medium- and low-temperature heat sources to achieve collaborative heat and mass transfer while satisfying the requirements of efficient drying and maintaining food quality. However, the distributed heat source introduces ambient temperature gradients. Notably, different ambient temperature gradients of the generator exert obvious effects on the local molecular number as well as particle energy; this can affect the gas transportation performance of the generator, which has not been clarified thus far. Herein, the gas transportation performance of a wire-mesh ionic wind generator operating at different heat-source temperatures is experimentally and numerically investigated. The experimental results show that ionic wind generators operating at normal atmospheric temperature are more beneficial to obtaining a high mass flow rate and local velocity of ionic wind. Additionally, continuously increasing the heat source temperature can improve the transportation performance of ionic wind generators. In the simulation, an electrohydrodynamic (EHD) force is introduced to indicate ionic wind strength. The simulated EHD force reaches the highest value without a temperature difference between the two electrodes. The variation trend of the simulation results is consistent with that of the experimental results. The simulation results emphasize the combined effects of particle energy and air molecule number on ionic wind strength, which can explain the phenomena observed in the experiments. This study thus provides a theoretical guideline for the design and combined application of ionic wind generators and distributed auxiliary heat sources.

Revisiting the effect of increasing horizontal resolution on the evolution of El Niño in a coupled model

The ENSO (El Niño southern oscillation) in the tropical Pacific plays a crucial role in regulating the Indian summer monsoon. Many mechanisms have been proposed to explain the positive and negative feedback associated with the ENSO through air-sea interaction in the tropical Pacific. Historical run data at varying oceanic and atmospheric resolutions from the MPI-ESM model is analyzed and compared with observations to determine the possible reasons for the much earlier onset and delayed withdrawal of ENSO in the coupled model. Increasing the resolution of the oceanic and atmospheric components of the coupled model helps in well-resolving the annual cycle of sea surface temperature in the tropical Pacific. There is a significant improvement in the early onset and late withdrawal of El Niño in the coupled model with increasing horizontal resolution of the model components. The weak subsurface propagation along the 20 °C isotherm in the equatorial Pacific improves on increasing the horizontal resolution of the coupled model. Similar to observations, there is a clear eastward extension of convection, 20° east of the dateline, in the equatorial tropical Pacific in the coupled model during ENSO years. Increasing the resolution of the oceanic and atmospheric components of the coupled model improves the simulation of convective activity over the western Pacific along with the improved magnitude of anomalous zonal wind strength during El Niño years. However, the presentation of convective activity over the equatorial Pacific deteriorated on increasing atmospheric resolution further to T255 due to the enhanced value of the interannual amplitude of intraseasonal zonal wind around the international dateline. Also, the coupled model does not capture the accurate eastward propagation of the Madden Julian Oscillation envelope over the western Pacific. While higher resolutions showed improvement in the representation of El Niño events in terms of their number and duration, challenges persisted in accurately capturing the frequency of these events and their related triggering mechanisms. Understanding the intricate interplay of factors influencing the evolution of El Niño requires further research and progress in modeling strategies.

Mechanisms Controlling Interannual Variability of Seasonal Hypoxia Off the Changjiang River Estuary

AbstractHypoxia has long been a symptom of deteriorating ecosystem that threatens the health of estuarine and coastal waters. Episodic hypoxia events and intraseasonal variation of coastal hypoxia have been amply investigated. However, interannual variability of coastal hypoxia has only been assessed in few regions. Bottom hypoxia forms seasonally off the Changjiang River Estuary in the East China Sea mainly due to the large riverine inputs. Large river discharge and its interactions with ambient water combine to contribute to the development of episodic hypoxia events and the intraseasonal migration of bottom hypoxia. However, little is known about the interannual variation of bottom hypoxia in this region. This study used a well‐evaluated, coupled physical–biogeochemical model to explore the long‐term feature of hypoxia in the East China Sea. The bottom water in the hypoxic zone lost oxygen with a rate of −1.2 mmol/m3/year. Bottom hypoxia showed large interannual variations of geographical location, severity, volume expansion, and sustainment. Large Changjiang River discharge was a prerequisite for hypoxia formation and the associated interannual variation. The interannual variations in the direction and strength of shelf wind controlled long‐term distribution of Changjiang diluted water. The delivery of freshwater fundamentally determined the strength of vertical stratification and the rates of biogeochemical cycles, contributing 73% of the interannual variation of bottom hypoxia.

The response of wildfire regimes to Last Glacial Maximum carbon dioxide and climate

Abstract. Climate and fuel availability jointly control the incidence of wildfires. The effects of atmospheric CO2 on plant growth influence fuel availability independently of climate, but the relative importance of each in driving large-scale changes in wildfire regimes cannot easily be quantified from observations alone. Here, we use previously developed empirical models to simulate the global spatial pattern of burnt area, fire size, and fire intensity for modern and Last Glacial Maximum (LGM; ∼ 21 000 ka) conditions using both realistic changes in climate and CO2 and sensitivity experiments to separate their effects. Three different LGM scenarios are used to represent the range of modelled LGM climates. We show large, modelled reductions in burnt area at the LGM compared to the recent period, consistent with the sedimentary charcoal record. This reduction was predominantly driven by the effect of low CO2 on vegetation productivity. The amplitude of the reduction under low-CO2 conditions was similar regardless of the LGM climate scenario and was not observed in any LGM scenario when only climate effects were considered, with one LGM climate scenario showing increased burning under these conditions. Fire intensity showed a similar sensitivity to CO2 across different climates but was also sensitive to changes in vapour pressure deficit (VPD). Modelled fire size was reduced under LGM CO2 in many regions but increased under LGM climates because of changes in wind strength, dry days (DDs), and diurnal temperature range (DTR). This increase was offset under the coldest LGM climate in the northern latitudes because of a large reduction in VPD. These results emphasize the fact that the relative magnitudes of changes in different climate variables influence the wildfire regime and that different aspects of climate change can have opposing effects. The importance of CO2 effects imply that future projections of wildfire must take rising CO2 into account.

Stop me if you can: quantification of the effect of interfaces between plots on the dispersal of Cosmopolites sordidus.

Cosmopolites sordidus is one of the most damaging pests of banana worldwide. To date, most studies addressed the control of this pest at the plot level, without considering the landscape scale whereas between plots dispersion could be important. The aim of this study was to investigate the ability of C. sordidus to cross contrasted field interfaces. The ten following interfaces were investigated: forests, hedgerows, field tracks, grassy areas, finely and coarsely tilled soil zones, ditches with and without water, vegetable gardening zones, and pheromone trap lines. Individually marked weevils were released on one side of the interface and recovered daily on the other side, allowing the estimation of the velocity and the crossing success of C. sordidus for each interface. Highest permeabilities (with a crossing success above 70%) were obtained for vegetable gardening zones, finely tilled soil zones, forests, and coarsely tilled soil zones. Intermediate permeabilities were measured for hedgerows, field tracks, grassy areas, and ditches without water. Only the line of pheromone traps and submerged ditches had a strong barrier effect on C. sordidus, with a crossing success below 12%. Wind strength, percentage of sky, and vegetation height were negatively correlated to the C. sordidus crossing success. Overall, our results showed that only ditches with water and lines of pheromone traps were efficient in stopping the dispersal of C. sordidus. The next step will be to conduct research to incorporate the use of these two interfaces at farm and landscape scale into integrated pest management strategies. This article is protected by copyright. All rights reserved.

The influence of synoptic wind on land–sea breezes

AbstractParticularly challenging classes of heterogeneous surfaces are ones where strong secondary circulations are generated, potentially dominating the flow dynamics. In this study, we focus on land–sea breeze (LSB) circulations resulting from surface thermal contrasts, in the presence of increasing synoptic pressure forcing. The relative importance and orientation of the thermal and synoptic forcings are measured through two dimensionless parameters: a heterogeneity Richardson number (measuring the relative strength of geostrophic wind and convection induced by buoyancy), and the angle α between the shore and geostrophic wind. Large‐eddy simulations reveal the emergence of various regimes where the dynamics are asymmetric with respect to α. Along‐shore cases result in deep LSBs similar to the scenario with no synoptic background, irrespective of the geostrophic wind strength. Across‐shore simulations exhibit a circulation cell that decreases in height with increasing synoptic forcing. However, at the highest synoptic winds simulated, the circulation cell is advected away with sea‐to‐land winds, while a shallow circulation persists for land‐to‐sea cases. Scaling analysis that relates the internal parameters Qshore (net shore volumetric flux) and qshore (net shore advected kinematic heat flux) to the external input parameters results in a succinct model of the shore fluxes that also helps explain the physical implications of the identified LSBs. Finally, the vertical profiles of the shore‐normal velocity and shore‐advected heat flux are used, with the aid of k‐means clustering, to independently classify the LSBs into four regimes (canonical, sea‐driven, land‐driven, and advected), corroborating our visual categorization.

Predictability of the East Africa long rains through Congo zonal winds

AbstractEast Africa is highly vulnerable to extreme weather events, such as droughts and floods. Skillful seasonal forecasts exist for the October–November–December short rains, enabling informed decisions, whereas seasonal forecasts for the March–April–May (MAM) long rains have historically had low skill, limiting preparation capacity. Therefore, improved long rains prediction is a high priority and would contribute to climate change resilience in the region. Recent work has highlighted how lower‐troposphere Congo zonal winds in MAM strongly impact regional moisture fluxes and the long rains total precipitation. We therefore approach long rains predictability through the predictability of the Congo winds. We analyze a set of hindcasts from a dynamical prediction system that is able to reproduce the long rains—Congo winds relationship in its individual ensemble members. Encouragingly, in observations, the strength of MAM Congo zonal winds and East Africa rainfall show substantial correlation with the MAM Atlantic (including North Atlantic Oscillation, NAO) and Indo‐Pacific variability, suggestive of ocean influence and potential predictability. However, these features are replaced by different teleconnections in the hindcast ensemble mean fields. This is also true for NAO linkage to Congo winds, despite correct representation in individual members, and good skill in hindcasting the NAO itself. The net effect is strongly negative skill for the Congo winds. We explore statistical correction methods, including using the Congo zonal wind as an anchor index in a signal‐to‐noise calibration for the long rains. This is considered a demonstration of concept, for subsequent implementation using models with better Congo zonal wind skill. Indeed, the clear signals found in the Atlantic (including Mediterranean) and Indo‐Pacific, studied here both in observations and a dynamical prediction system, motivate evaluation of these features across other prediction systems, and offer the prospect of improved physically‐informed long rains dynamical predictions.

Environmental and behavioural drivers of Antarctic krill distribution at the South Orkney Islands: A regional perspective

Antarctic krill (Euphausia superba) is a key species in the marine ecosystem of the Southern Ocean, but is also the target of a commercial fishery, with an important fishing ground in the South Orkney Islands region. The potential for competition for krill between predators and the fishery requires risk management strategies for the fishery, underpinned by an understanding of the key physical and behavioural drivers of krill movement and retention in target areas. Here, we present the results of a regional modelling study, combining a high-resolution ocean-sea ice model and an individual-based model parameterised for krill, to elucidate the roles of oceanographic variability and krill behaviour on patterns of transport and retention on and around the South Orkney Plateau. Simulations suggest that oceanic transport from sources around the Antarctic Peninsula is restricted by the northward flowing Antarctic Slope Current. Around the South Orkney Plateau, anticyclonic flows associated with the Weddell Front and the shelf edge transport krill rapidly towards the main fishing grounds to the northwest of the plateau. Transport onto the shelf and subsequent retention are influenced by the strength and direction of regional winds; weaker on-shelf transport and shorter retention times are associated with stronger westerly and northerly winds. The incorporation of sea-ice associated behaviour, whereby krill are moved with sea ice when sea ice is present, significantly modifies the patterns from purely oceanic transport; it reduces the influence of strong regional oceanic flows and increases transport of krill to the South Orkneys region from the Antarctic Peninsula. The inclusion of diel vertical migration also modifies predicted patterns from oceanic transport, but to a lesser extent, and moderates the impact of including sea-ice associated behaviour. We highlight the importance of understanding the behaviour of krill, including age-dependent behavioural changes in response to sea ice conditions, for modelling and management of Antarctic krill populations.

Stochastic models of ventilation driven by opposing wind and buoyancy

Stochastic versions of a classical model for natural ventilation are proposed and investigated to demonstrate the effect of random fluctuations on stability and predictability. In a stochastic context, the well-known deterministic result that ventilation driven by the competing effects of buoyancy and wind admits multiple steady states can be misleading. With fluctuations in the buoyancy exchanged with an external environment modelled as a Wiener process, such systems tend to reside in the vicinity of global minima of their potential, rather than states associated with metastable equilibria. For a heated space with a leeward low-level and windward high-level opening, sustained buoyancy-driven flow opposing the wind direction is unlikely for wind strengths exceeding a statistically critical value, which is slightly larger than the critical value of the wind strength at which bifurcation in the deterministic system occurs. When fluctuations in the applied wind strength are modelled as an Ornstein–Uhlenbeck process, the topology of the system’s potential is effectively modified due to the nonlinear role that wind strength has in the equation for buoyancy conservation. Consequently, large fluctuations in the wind of sufficient duration rule out the possibility of sustained ventilation opposing the wind direction at large base wind strengths.

Southward displacement of the glacial westerly jet over Asia driven by enhanced Arctic amplification after the Mid-Brunhes Event

The climate and paleoenvironmental evolution of the East Asian continent and adjacent Northwest Pacific Ocean is governed by the interplay of the region's dominant features in oceanic and atmospheric circulation, which control the redistribution of heat and moisture. In the atmospheric realm, the subtropical westerly jet stream and East Asian monsoon are crucial components of climate evolution over East Asia, an area that is inhabited by almost half of the world's population. Reconstruction of long-term changes in atmospheric circulation in this region is to date scarce, especially on timescales predating the last glacial-interglacial cycle. Here, we reconstruct dust fluxes, marine productivity and water temperatures in the Northwest Pacific Ocean using lipid biomarkers both from terrestrial and marine organisms and elemental scanning data. Land-plant derived wax lipids in the studied sediments were used as indicators for dust fluxes and hence are representative of past changes in wind strength and pathways. We evaluate changes both in the zonal westerlies and monsoonal winds over the past 1 Ma and across major climatic events. Prior to the Mid-Brunhes Event (MBE; ~ 430 ka ago), concentrations of these compounds showed a distinct glacial-interglacial pattern, which we relate to past changes in the position of the westerly jet stream. We demonstrate substantial changes in wind patterns across the MBE, resulting in reduced dust fluxes to the Northwest Pacific in ensuing glacials. We propose that the westerly jet was permanently located south of the Himalaya-Tibetan Plateau through peak glacials, fostered by amplified Arctic cooling.

Impact of Zonal and Meridional Atmospheric Flow on Surface Climate and Extremes in the Southern Hemisphere

Abstract The Southern Annular Mode (SAM) describes the annular or zonal component of the large-scale atmospheric circulation in the Southern Hemisphere (SH) extratropics and influences surface climate across the SH. Although this annular flow is dominant in austral summer, in other seasons considerable zonal asymmetries are evident, reflecting a zonal wave 3 (ZW3) pattern. We define an index representing asymmetric flow using the first two leading modes of meridional wind variability in the SH. Two orthogonal ZW3 indices are used together to capture longitudinal shifts in the wave train and their connection to tropical convection. We compare the impacts of the SAM and ZW3 on surface climate by examining composites of temperature and precipitation fields during each season. Impacts on mean and extreme surface climates are assessed. We find that the SAM and ZW3 are not clearly separated modes, but rather, ZW3 modulates the impact of the SAM across the midlatitudes. The SAM influence on regional temperature and precipitation is similar for both mean impacts and extremes. The ZW3 influence on extremes is more varied across indices and does not always reflect the ZW3 impact on mean fields. Notably, amplified ZW3 activity has a significant influence on the number of midlatitude fronts and frontal rainfall, highlighting the importance of considering ZW3 when exploring the surface climate impacts of large-scale SH circulation states, particularly for nonsummer seasons. Significance Statement Variations in the strength and position of the midlatitude westerly winds have a strong influence on surface climates. While these winds are predominantly zonally symmetric in the Southern Hemisphere, few studies to date have explored the role of the asymmetric component of this circulation, particularly for seasons outside of summer. By defining two new indices of meridional circulation, this study reveals new important impacts on temperature, rainfall, and the likelihood of extreme climates in regions of southern Australia and South America, and sea ice regions around Antarctica. These findings question the validity of considering only zonal-mean winds for climate studies of the Southern Hemisphere and have important implications for the seasonal forecasting and predictability of extreme climate events in the near future.

Interannual Migration of the Summertime Eastward Jet in the South China Sea Associated With the Upper Layer Thickness Distribution

AbstractThe summertime eastward jet (SEJ) in the South China Sea (SCS) can be regarded as the boundary between the southern and northern upper circulation of the SCS in climatology. The dynamic process of SEJ migration in response to the variation of SCS summer monsoon (SCSSM) strength on the interannual scale is investigated, based on the Simple Ocean Data Assimilation (SODA) dataset and by a 1.5‐layer reduced gravity model. Analysis shows that SEJ position is closely related to SCSSM strength, with southward/northward migration of SEJ coinciding with stronger/weaker SCSSM. Besides migration of wind stress curl (WSC) zero‐line and north‐south difference of WSC variation, the north‐south difference of the SCS upper layer thickness (ULT) in summer, that is, thick in the southern SCS and thin in the northern SCS, also plays a significant role in the dynamic process of SEJ migration. It is the joint effect of wind strength and ULT distribution. With the variation of SCSSM strength, the thinner ULT in the northern SCS corresponds to the larger magnitude of potential vorticity (PV) variation inputted by wind stress, which leads to more pronounced strengthening/weakening of the western boundary current (WBC) in the northern SCS than that in the southern SCS. Then, the north and south WBCs compete with each other until the upper layer circulation reaches a new equilibrium state, and SEJ migrates southward/northward accordingly.

The Variable Detection of Atmospheric Escape around the Young, Hot Neptune AU Mic b

Photoevaporation is a potential explanation for several features within exoplanet demographics. Atmospheric escape observed in young Neptune-sized exoplanets can provide insight into and characterize which mechanisms drive this evolution and at what times they dominate. AU Mic b is one such exoplanet, slightly larger than Neptune (4.19 R ⊕). It closely orbits a 23 Myr pre-main-sequence M dwarf with an orbital period of 8.46 days. We obtained two visits of AU Mic b at Lyα with Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph. One flare within the first HST visit is characterized and removed from our search for a planetary transit. We present a nondetection in our first visit, followed by the detection of escaping neutral hydrogen ahead of the planet in our second visit. The outflow absorbed ∼30% of the star’s Lyα blue wing 2.5 hr before the planet’s white-light transit. We estimate that the highest-velocity escaping material has a column density of 1013.96 cm−2 and is moving 61.26 km s−1 away from the host star. AU Mic b’s large high-energy irradiation could photoionize its escaping neutral hydrogen in 44 minutes, rendering it temporarily unobservable. Our time-variable Lyα transit ahead of AU Mic b could also be explained by an intermediate stellar wind strength from AU Mic that shapes the escaping material into a leading tail. Future Lyα observations of this system will confirm and characterize the unique variable nature of its Lyα transit, which, combined with modeling, will tune the importance of stellar wind and photoionization.

Investigation of Multi-Timescale Sea Level Variability near Jamaica in the Caribbean Using Satellite Altimetry Records

There is a dearth of studies characterizing historical sea level variability at the local scale for the islands in the Caribbean. This is due to the lack of reliable long term tide gauge data. There is, however, a significant need for such studies given that small islands are under increasing threat from rising sea levels, storm surges, and coastal flooding due to global warming. The growing length of satellite altimetry records provides a useful alternative to undertake sea level analyses. Altimetry data, spanning 1993–2019, are used herein to explore multi-timescale sea level variability near the south coast of Jamaica, in the northwest Caribbean. Caribbean basin dynamics and largescale forcing mechanisms, which could account for the variability, are also investigated. The results show that the average annual amplitude off the south coast of Jamaica is approximately 10 cm with a seasonal peak during the summer (July–August). The highest annual sea levels occur within the Caribbean storm season, adding to the annual risk. The annual trend over the 27 years is 3.3 ± 0.4 mm/yr when adjusted for Glacial Isostatic Adjustment (GIA), instrumental drift, and accounting for uncertainties. This is comparable to mean global sea level rise, but almost twice the prior estimates for the Caribbean which used altimetry data up to 2010. This suggests an accelerated rate of rise in the Caribbean over the last decade. Empirical Orthogonal Function (EOF) and correlation analyses show the long-term trend to be a basin-wide characteristic and linked to warming Caribbean sea surface temperatures (SSTs) over the period. When the altimetry data are detrended and deseasoned, the leading EOF mode has maximum loadings over the northwest Caribbean, including Jamaica, and exhibits interannual variability which correlates significantly with a tropical Pacific-tropical Atlantic SST gradient index, local wind strength, and the Caribbean Low Level Jet (CLLJ). Correlations with the El Niño Southern Oscillation (ENSO) in summer, seen in this and other studies, likely arise through the contribution of the ENSO to the SST gradient index and the ENSO’s modulation of the CLLJ peak strength in July. The results demonstrate the usefulness of altimetry data for characterizing sea level risk on various timescales for small islands. They also suggest the potential for developing predictive models geared towards reducing those risks.

Study on Installation of the Vertical Axis Wind Turbines on the Upper Floors of High-Rise Buildings

Introduction. Nowadays the sector of high-rise and super high-rise buildings construction is rapidly developing. The deficiency of non-renewable energy sources and the deterioration of the environment are two major problems faced by every country. Therefore, the wind power engineering is intensely developing and is able not only to stop the rapid deterioration of environmental situation but also to improve accessibility of energy supply and considerably reduce the deficit of energy. It is rational to use the wind power to source the clean renewable energy for the high-rise buildings by installing the vertical axis wind turbines on the upper floors of the buildings. The aim of the work is to confirm that the vertical axis wind turbines are the best appropriate for installation on the upper floors of high-rise buildings in the cities due to unique advantages thereof (simple design, easy maintenance, adaptability to complicated and changeable wind environment, long operation life), which ensure the supply of the cities with the safe and clean green energy.Materials and Methods. A small-size vertical axis wind turbine was taken for the study. The operation efficiency of various wind turbines was measured by changing the wind strength and direction under the same environmental conditions to determine whether a vertical axis wind turbine could operate safely, sustainably and efficiently in the complicated and changing wind environment of the city. Alongside it was proved that for ensuring the supply of the cities with the safe and clean energy the installation of the vertical axis wind turbines on the upper floors of high-rise buildings is more appropriate compared to the installation of horizontal ones.Results. By changing the wind strength and direction, it was found that the vertical axis wind turbines have good and stable operation efficiency and can provide a constant source of clean energy for urban development in a safer and more stable way.Discussion and Conclusions. The vertical axis wind turbines are ideally adapted to the complicated and changing wind conditions of the upper floors of high-rise buildings and can be safely and efficiently operated, making positive contribution to reducing the energy load and improving the state of environment.

Control Scheme for AC-DC Grid Connected Hybrid Energy System for Power Quality Improvement

Abstract: Renewable electricity assets inclusive of air, solar, water, biomass, and many others. Are crucial for sustainable development and social development, in addition to assembly power wishes through the usage of renewable electricity resources. Complete renewable electricity such as wind strength is needed in the energy device to lessen environmental influences. The project proposes the STATCOM manage plan for grid-connected wind electricity structures to increase strength excellent. The bang-bang controller changed into advanced for STATCOM primarily based at the hysteresis cutting-edge manipulate scheme. STATCOM has been merged with common coupling to reduce electricity excellent problems. The STATCOM manage scheme implemented for the grid related wind strength era machine used to enhance the power quality is simulated the usage of the MATLAB / Simulink inside the electricity device block set. This proposed scheme ensures an increase in energy great in production output.

Effects of the Carbon Intensity Index Rating System on the Development of the Northeast Passage

For many years, the Suez Canal (also known as the Suez Route) has been the main route connecting Europe and Asia. However, compared with the Suez Route, the Northeast Passage could save up to 41% of the journey. The ship carbon intensity index (CII) rating system of the International Maritime Organization (IMO) came into effect in 2023. This study took an existing bulk carrier on the Europe–Asia route as an example to calculate the attained CII values at different sailing speeds. It was found that, regardless of external factors, when the ship speed dropped from 14.4 knots (85% maximum continuous rating (MCR)) to 12.6 knots (55% MCR), the corresponding attained CII value decreased from 6.48 g/ton·nm to 5.19 g/ton·nm. Therefore, sailing speed was the key factor influencing the attained CII value, and it was independent of the shipping distance. In addition, when the ship’s sailing output power was between 85% MCR and 75% MCR, for every 5% decrease in MCR, its attained CII value would decrease by 0.13 g/ton·nm, and the fuel consumption amount would decrease by 1 ton/day. However, when the ship sailed at an output power of 75% MCR to 55% MCR, for every 5% decrease in MCR, the attained CII value would decrease even more, up to 0.26 g/ton·nm. In addition, the attained CII value would be reduced by up to 100% and fuel consumption amount would be reduced by up to 1.5 ton/day, resulting in a 50% fuel saving effect. Therefore, to obtain a better CII rating, the optimal ship speed should be set between 75% MCR and 55% MCR according to the wave and wind strengths. However, although slow-speed sailing is the most efficient factor, the number of sailing days would also be extended. Through the ratio created by dividing the distance of the Northeast Passage by the Suez Route, whether the Northeast Passage has the benefit of balancing shipping schedules could be judged. The outcome indicated that a ratio lower than 1 would result in a more balanced shipping schedule. Compared with 2019, the number of ships sailing through the Northeast Passage in 2021 increased significantly by 132%, and the average dead weight tonnage of the ships also rose from 18,846 tons to 23,736 tons. This study found that, with the implementation of the carbon reduction policy of the CII rating, ships sailing through the Northeast Passage could continue to develop toward the trend of large-sized vessels and steady increase in ship number.

Загрязнение воздушной среды формальдегидом и оценка риска канцерогенных эффектов

This article discusses the issues of air pollution with formaldehyde and the impact of this pollutant on the health of the population of the city of Lipetsk. The study revealed patterns of increase in the concentration of formaldehyde in the warm season (May–September). In the daily dynamics of concentrations, peak values occur during daytime and evening hours, which is associated with the cumulative effect of pollution and traffic congestion in the evening rush hour. The minimum values are recorded in the cold season and in the morning hours. The morning “rush hour” does not affect the concentrations as the sampling takes place earlier. It has been established that meteorological conditions influence the concentration of formaldehyde. An increase in air temperature correlates with an increase in the concentration of formaldehyde, especially in the daytime and evening hours, which is explained by increased solar insolation and warming of the atmospheric air. An increase in wind strength and air humidity, on the contrary, reduces the content of pollutants in the air. An assessment of the impact of formaldehyde on the health of the population, associated with the presence of a carcinogen in the atmosphere, showed that the city of Lipetsk is characterized by the maximum acceptable risk. The individual carcinogenic risk for the Traktorny District and areas near busy highways (the Ring of the Pipe Plant intersection) is 6 · 10-5. This level of risk is assessed as the maximum acceptable. In these areas, the presence of formaldehyde in the air can provoke 5–6 additional cases of oncological diseases per year. Such values require monitoring and implementation of measures to reduce the negative impact.