Typical Weather Conditions Research Articles

Analysis of Aircraft Routing Strategies for North Atlantic Flights by Using AirTraf 2.0

Climate-optimized routing is an operational measure to effectively reduce the climate impact of aviation with a slight increase in aircraft operating costs. This study examined variations in the flight characteristics among five aircraft routing strategies and discusses several characteristics of those routing strategies concerning typical weather conditions over the North Atlantic. The daily variability in the North Atlantic weather patterns was analyzed by using the European Center Hamburg general circulation model (ECHAM) and the Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model in the specified dynamics mode from December 2008 to August 2018. All days of the ten complete winters and summers in the simulations were classified into five weather types for winter and into three types for summer. The obtained frequency for each of the weather types was in good agreement with the literature data; and then representative days for each weather type were selected. Moreover, a total of 103 North Atlantic flights of an Airbus A330 aircraft were simulated with five aircraft routing strategies for each representative day by using the EMAC model with the air traffic simulation submodel AirTraf. For every weather type, climate-optimized routing shows the lowest climate impact, at which a trade-off exists between the operating costs and the climate impact. Cost-optimized routing lies between the time- and fuel-optimized routings and achieves the lowest operating costs by taking the best compromise between flight time and fuel use. The aircraft routing for contrail avoidance shows the second lowest climate impact; however, this routing causes extra operating costs. Our methodology could be extended to statistical analysis based on long-term simulations to clarify the relationship between the aircraft routing characteristics and weather conditions.

Research on Type Selection of Diving Tower in 110kV Single and Double Circuit Transmission Line

With the continuous development of EHV (UHV) transmission lines，new lines often need to drill through the built lines，so it is urgent to study the type of diving towers. Based on typical weather conditions and commonly used ground wire models, the basic type and tower type selection of 110kV single and double circuit overpass towers in high altitude areas are studied, and two single and double circuit overpass tower schemes are planned and arranged. And according to the pole tower structure design and optimization theory, the 110kV single-circuit diving tower and the 110kV dual-circuit diving tower are optimized from the structural optimization layout and the pole tower structure node optimization design. The research results show that the single-circuit diving tower adopts the wine glass tower, and the wires are arranged horizontally, and the double-circuit diving tower effectively reduces the height of the tower. The dish-shaped tower is used, and the single-circuit wires are arranged in a triangle pattern, which provides a certain practical guiding significance for the 110kV diving-across technology application.

Analysis of Land Surface Energy Changes at Zhufeng Station in Qinghai Tibet Plateau in 2008

The surface radiation balance and partial meteorological elements in the Qomolangma region were analyzed by using the flux observation data of Qomolangma stations in 2008 in the High-Resolution Integrated Observation Dataset of Earth-Atmosphere Interaction Process of the National Tibetan Plateau Scientific Data Center. The main conclusions are as follows: 1) The influence of weather conditions on the total solar radiation is more significant at high altitudes. For 2008, radiation on average each component change after comparative analysis, not only from atmospheric radiation, upward curve comparison verified the surface temperature in the plateau area affected by the solar total radiation that largest at the same time from the curve of the downward shortwave radiation found in contrast, although the Everest region influenced by latitude and longitude and altitude. However, the maximum value of short- wave downward solar radiation at noon appears in spring and April, and the maximum value of summer radiation at noon is even lower than that in autumn. 2) In the analysis of the typical weather conditions of continuous sunny days and continuous rainstorm, it is found that the net radiation and the Upward short-wave radiation are affected by the underlying surface change, and the amplitude of the net radiation and Upward short-wave radiation are close to the original atmosphere because the atmospheric environment in the Qomolangma region is close to the original atmosphere, so the net radiation and Upward short-wave radiation are affected by the underlying surface change under any weather conditions. 3) Surface water content has obvious influence on radiation and reflectivity by changing the properties of underlying surface, and the response energy changes the fastest when the upward shortwave radiation has higher humidity.

Effect of the variation of N on productivity of solar energy based single slope water purifier integrated with N alike partly covered compound parabolic concentrating solar collectors

The effect of the variation of N on productivity of solar energy based single slope water purifier integrated with N alike partly covered parabolic concentrating solar collectors has been carried out to know the effect of N on productivity when plurality collectors have been used in such system. A typical day of July & December of New Delhi has been taken into consideration for the analysis and further solved on MATLAB. For a typical weather condition, average energy output value has been taken into account to obtain output annual energy. The corresponding monetary value has been evaluated taking the commercial rate of water as INR 6 per kg followed by evaluating the productivity. An input has been taken from IMD-Pune, India for the mathematical computation. It has been noticed in the study that value of productivity increases by increasing the number of collector at given values of water depth and fluid flow per unit time.

Design Considerations of a Subsea Shuttle Tanker System for Liquid Carbon Dioxide Transportation

AbstractSubsea pipelines and umbilicals are used for the transportation of fluids and electrical power between subsea installations and floating production units (FPUs). The installation and maintenance of these systems can be expensive. In a conventional subsea field development, the produced fluids can be transported from the well to a FPU where they can be offloaded to a tanker (surface ship). In the case of carbon dioxide (CO2) injection into the well, the direction of flow is reversed, i.e., CO2 flows from the tanker to the FPU, down the riser base and through the subsea pipelines to the well. This offloading process is weather-dependent and cannot be performed in severe weather conditions, i.e., strong winds and large waves. This paper presents a novel subsea shuttle tanker system proposed by Equinor ASA designed to be a possible alternative to subsea pipelines, umbilicals, and tanker ships. The subsea shuttle is intended to operate submerged under the sea surface to transport liquid CO2 from an existing offshore/land facility where CO2 is captured to a subsea well where the CO2 is injected into the reservoir. As the shuttle is subsea, it can operate under any type of weather conditions. Even though the subsea shuttle is proposed as a vehicle for liquid CO2 transport, it can also transport other types of cargo such as hydrocarbons, injection fluids, electrical power, or subsea tools. The paper will discuss the most important design considerations surrounding the subsea shuttle tanker.

A multi-objective optimization framework for designing climate-resilient building forms in urban areas

With the increasing global awareness about the impacts of climate change on the built environments, the need for improving the climate resilience of buildings is being more acknowledged. Despite the high number of relevant studies, there is a lack of frameworks to assess the resiliency of buildings and urban areas. This study presents a multi-objective framework to optimize the form of buildings against its energy performance and thermal comfort considering its resiliency to the uncertainties of climate change during three thirty-years periods (2010-2099) of a warm region. Three performance sections related to building’s form are identified and categorized for the impact assessment including (1) urban form, (2) orientation, and (3) transparency with ten influencing parameters. The analysis of non-dominated solutions out of the optimization process showed that the annual energy performance (cooling and heating demand) of the urban areas can improve about 34% in both typical and extreme weather conditions whilst maintaining thermal comfort by optimizing the overall form of the buildings with similar built density and heights. Moreover, Buildings with 15 to 30-degree rotations and 33% glazing ratio showed the highest energy performance. Finally, the top 20 resilient building forms with the highest energy performance and climate resiliency were selected out of the database of results to derive design suggestions.

Impact assessment of river dust on regional air quality through integrated remote sensing and air quality modeling

Sand and dust storms in arid and semiarid regions deteriorate regional air quality and threaten public health security. To quantify the negative effects of river dust on regional air quality, this study selected the estuary areas located in central Taiwan as a case study and proposed an integrated framework to measure the fugitive emission of dust from riverbeds with the aid of satellite remote sensing and wind tunnel test, together with the concentrations of particulate matter with a diameter of <10 μm (PM10) around the river system by using The Air Pollution Model. Additionally, the effects of 25 types of meteorological conditions on the health risk due to exposure to dust were evaluated near the estuary areas. The results reveal landscape changes in the downstream areas of Da'an and Dajia rivers, with an increase of 370,820 m2 and 1,554,850 m2 of bare land areas in the dry season compared with the wet season in Da'an and Dajia rivers, respectively. On the basis of the maximum emission of river dust, PM10 concentration increases considerably during both wet and dry seasons near the two rivers. Among 25 different types of weather conditions, frontal surface transit, outer-region circulation from tropical depression system, weak northeast monsoons, and anticyclonic outflow have considerable influence on PM10 diffusion. In particular, weak northeast monsoons cause the highest health risk in the areas between Da'an and Dajia rivers, which is the densely populated Taichung City. Future studies should attempt to elucidate the environmental impact of dust in different weather conditions and understand the spatial risks to human health due to PM10 concentration. Facing the increasing threat of climate and landscape changes, governments are strongly encouraged to begin multimedia assessments in environmental management and propose a long-term and systematic framework in resources planning.

Dynamic characteristics of external luminance of highway tunnel in cold area

The external luminance of highway tunnels in cold areas is a key parameter for the lighting design of the tunnel entrance section. Due to the influence of the tunnel portal form, tunnel orientation, solar radiation intensity and solar irradiation angle, the external luminance of the tunnel varies with different seasons and different times. At present, there are relatively few studies on the time-varying characteristics of the external luminance of highway tunnels in cold areas. Relying on the Wunvfeng extra-long tunnel, combined with different tunnel opening orientations, the changes in the luminance of the tunnel exterior with time under several typical weather conditions are analyzed. The dynamic characteristics of the external luminance outside the tunnel in the cold area was obtained, which provide more detailed and reliable data for tunnel design. It has reference value for the lighting design and operation control of the entrance section of the tunnel and the design of light reduction outside the tunnel.

Investigation on the long-term performance of solar thermal powered adsorption refrigeration system based on hourly accumulated daily cycles

When simulating a daily performance of a solar thermal powered adsorption refrigeration system, daily weather data (i.e. daily maximum and minimum ambient temperatures and daily total solar radiation) are normally used to simulate a 24-h refrigeration cycle. However, the simulation obtained in this way is not that accurate, due to which could not reflect real hourly processes during the daytime. In present study, hourly weather data, especially during the isosteric and desorption processes in the sunshine duration, has been utilised to simulate hourly accumulated daily cycles. Seven possible cycles, depending on hourly weather change patterns, have been identified in this study. It has been found that the desorption process is not necessarily an isobar process as previous studies assumed, which depends on real hourly weather changes. Therefore, an improved mathematical model has been developed and validated. It has been found that the accuracy of the simulation with hourly weather data has been improved by up to 5%, compared to that of the model using daily weather data. The simulated error in one-day performance would be accumulated if a long-time performance of such a system was required to be simulated. Therefore, a case-study is conducted to demonstrate the difference between the two models when simulating a daily performance under three typical weather conditions.

Determination of eddy dissipation rate by Doppler lidar in Reykjavik, Iceland

AbstractThe temporal and spatial scale of atmospheric turbulence can be highly dynamic, requiring sophisticated methods for adequate detection and monitoring with high resolution. Doppler light detection and ranging (lidar) systems have been widely used to observe and monitor wind velocity and atmospheric turbulence profiles as Doppler lidar systems can provide continuous information about wind fields. The use of lidars in the subarctic region is particularly challenging as aerosol abundance can be very low, leading to weak backscatter signals. In the present study, we analysed data collected with a Leosphere Windcube 200S lidar system stationed in Reykjavik, Iceland, to estimate the eddy dissipation rate (EDR) as an indicator of turbulence intensity. For this purpose, we retrieved radial wind velocity observations from velocity–azimuth display scans and computed the EDR based on the Kolmogorov theory. We compared different noise filter thresholds, scan strategies and calculation approaches during typical Icelandic weather conditions to assess the accuracy and the uncertainty of our EDR estimations. The developed algorithm can process raw lidar observations, retrieve EDR and determine the qualitative distribution of the EDR. The processed lidar observations suggest that lidar observations can be of high importance for potential end‐users, for example air traffic controllers and aviation safety experts. The work is an essential step towards enhanced aviation safety in Iceland where aerosol concentration is in general low and severe turbulence occurs regularly.

Connected vehicle real-time traveler information messages for freeway speed harmonization under adverse weather conditions: Trajectory level analysis using driving simulator

This paper employed a high-fidelity driving simulator to investigate the impacts of the Wyoming Department of Transportation (WYDOT) Connected Vehicle (CV) Pilot’s Traveler Information Messages (TIMs) on drivers’ speed selection and the safety benefits of their speed harmonization. Three driving simulator experiment scenarios were developed to simulate the typical traffic and weather conditions on the rural Interstate 80 (I-80) in Wyoming. A total of 25 professional drivers from the WYDOT and trucking industry were recruited to participate in the driving simulator experiment. Participants’ instantaneous speeds at various locations were collected to reveal the effects of CV TIMs on their speed selection. The results showed that average speed profiles under CV scenarios were generally lower than under baseline scenarios, particularly for winter conditions (snowy and severe weather). The variance of speed under CV scenarios was found to be significantly lower than the baseline scenarios, indicating that CV TIMs have the potential to harmonize the variations in speed. In addition, for the work zone driving simulator experiment, this research revealed that the mean time-to-collision (TTC) under baseline scenario is approximately 40 % lower than CV scenario, and the mean deceleration to avoid a crash (DRAC) under baseline scenario is approximately 19.3 % higher than CV scenario. These findings suggest that CV TIMs can reduce the risk of crashes. Research findings would provide the WYDOT with early insights into the effectiveness of CV TIMs, which could assist with developing more efficient transportation management strategies under adverse weather conditions.

Effects of an oasis protective system on aeolian sediment deposition: a case study from Gelintan oasis, southeastern edge of the Tengger Desert, China

Desert-oasis ecotones are boundary areas between oases and desert ecosystems. Large efforts to control sediment and stabilize these boundaries depend on understanding sedimentary processes, especially aeolian transport and deposition. Previous studies on aeolian sediment deposition have focused primarily on a single land surface type or a single engineering approach. Few studies have considered deposition in a multi-layer oasis protective system. A complete oasis protective system consists of an outer bare sand area, a sand barrier zone, a shrub and herbaceous plant zone, and a farmland shelter zone. This study used sedimentary analysis to quantify grain-size characteristics in samples from the four land surfaces under different types of weather conditions in the Gelintan oasis of the Tengger Desert, the fourth largest desert in China. The results showed that aeolian sediment deposition decreased from the outer bare sand area through the oasis protective system and into the interior. The four land surface types showed significant differences in deposition volume (P < 0.05). Deposited sediment showed gradual decrease in dominant grain-size from sand to silt, but sediment deposited during dust weather contained a larger coarse-grained fraction. From the outer desert to the inner oasis, transport mechanisms shifted from saltation (sand) to suspension (silt and smaller) in non-dust weather. During dust weather, deposition primarily occurs from near-surface aeolian sand transport with saltation. Sediment sorting decreased from exterior to interior zones of the protective system while skewness and kurtosis showed no significant change (P < 0.05). These results can help inform strategies for stabilizing and protecting desert-oasis ecotones in this region and other localities.

Economic and environmental analysis of a novel rural house heating and cooling system using a solar-assisted vapour injection heat pump

An efficient low-carbon system is proposed to meet the heating and cooling demands of rural houses in cold regions. Mini-channel solar panels incorporating a novel multiple-throughout-flowing loop are used for heat collection, whilst a vapour injection air source heat pump (VI-ASHP) is innovatively combined with an underfloor heating and cooling system. To demonstrate the system, a multiple-throughout-flowing mini-channel solar thermal panel array of 36 m2 and a VI-ASHP of 40 kW heating capacity have been built and tested. Subsequently, mathematical models of the solar-assisted VI-ASHP system are established and compared with the experimental data. Based on the validated models, the energetic, economic and environmental performance is investigated under the typical weather conditions for a northern Chinese city (Taiyuan). The results indicate that, for a common rural house employing the proposed novel system, the proportion of the annual heat requirement, cooling load and hot water heating energy provided by solar thermal energy, photovoltaic energy and electricity from the power grid is 74.6%, 6.9%, and 18.5% respectively, thus giving a total energy supply proportion of 81.5% from solar energy. In addition, compared with a coal-powered system, our system has a cost payback period of 6.52 years and a life-cycle net cost saving of 56328.4RMB, thus the proposed system provides a greater economic performance. Furthermore, it can save 5tons of anthracite coal and reduce carbon emissions by 12.1tons annually. The proposed solar-assisted VI-ASHP has the potential to fulfil heating and cooling demands whilst reducing carbon emissions in northern China.

Parametric influence study of cryogenic hydrogen dispersion on theoretical aspect

In this paper, we proposed a theoretical model to study the dispersion of hydrogen. The model given a correlation between the concentration and temperature for cryogenic gases. The model based on adiabatic mixing hypothesis and neglected exterior heat sources, and thought the gas mixture was always at quasi-steady state. Real-gas law was adopted, and thermal physical properties of the gases are obtained from NIST REFPROP database. The concentration curve approximately appears a decreasing straight line, and turns on dew point and ice point, since heat released from water vapor phase change. Compared with liquid hydrogen and liquid natural gas spill experimental data, the model obtained well agreement solutions.Effects of three typical weather conditions (atmospheric temperature, relative humidity and barometric pressure) on hydrogen dispersion were quantitatively studied. It is confirmed that the dispersion is excited in summer, and is depressed in winter and transition seasons with increased ambient temperature. With increased ambient temperature, the effect of increased enthalpy reduction of the dry air components and the effect of the water latent heat are respectively dominate in the 268.15–293.15 K and 293.15–308.15 K ranges. Compared to ambient temperature and barometric pressure, relative humidity has the strongest positive effect on hydrogen dispersion, and the slight dampening effect of barometric pressure could be neglected.

Numerical simulation of underground seasonal cold energy storage for a 10 MW solar thermal power plant in north-western China using TRNSYS

This paper aims to explore an efficient, cost-effective, and water-saving seasonal cold energy storage technique based on borehole heat exchangers to cool the condenser water in a 10 MW solar thermal power plant. The proposed seasonal cooling mechanism is designed for the areas under typical weather conditions to utilize the low ambient temperature during the winter season and to store cold energy. The main objective of this paper is to utilize the storage unit in the peak summer months to cool the condenser water and to replace the dry cooling system. Using the simulation platform transient system simulation program (TRNSYS), the borehole thermal energy storage (BTES) system model has been developed and the dynamic capacity of the system in the charging and discharging mode of cold energy for one-year operation is studied. The typical meteorological year (TMY) data of Dunhuang, Gansu province, in north-western China, is utilized to determine the lowest ambient temperature and operation time of the system to store cold energy. The proposed seasonal cooling system is capable of enhancing the efficiency of a solar thermal power plant up to 1.54% and 2.74% in comparison with the water-cooled condenser system and air-cooled condenser system respectively. The techno-economic assessment of the proposed technique also supports its integration with the condenser unit in the solar thermal power plant. This technique has also a great potential to save the water in desert areas.

Synthetic Aperture Radar Image Classification: a Survey

In this review paper, several studies and researches were surveyed for assisting future researchers to identify available techniques in the field of classification of Synthetic Aperture Radar (SAR) images. SAR images are becoming increasingly important in a variety of remote sensing applications due to the ability of SAR sensors to operate in all types of weather conditions, including day and night remote sensing for long ranges and coverage areas. Its properties of vast planning, search, rescue, mine detection, and target identification make it very attractive for surveillance and observation missions of Earth resources. With the increasing popularity and availability of these images, the need for machines has emerged to enhance the ability to identify and interpret these images effectively. This is due to the fact that SAR image processing requires the formation of an image from the measured radar scatter returns, followed by a treatment to discover and define the image's composition. After reviewing several previous studies that succeeded in achieving a classification of SAR images for specific goals, it became obvious that they could be generalized to all types of SAR images. The most prominent use of Convolutional Neural Networks (CNN) was successful in extracting features from the images and training the neural network to analyze and classify them into classes according to these features. The dataset used in this model was obtained from the Moving and Stationary Target Acquisition and Recognition (MSTAR) database, which consists of a set of SAR images of military vehicles, for which the application of the CNN approach achieved a final accuracy of 97.91% on ten different classes.

Биологические особенности плодообразования и формирования урожая семян лядвенца рогатого (Lotus corniculatus L.)

The limited use of birdsfoot trefoil (Lotus corniculatus L.) in feed production is determined by a large shortage of its seeds. Currently, the supply of certified seeds on the commercial market is about ten times less than the scientifically based volume of the need for the seed material of this crop. The biological feature of the birdsfoot trefoil is the continuous shoot formation and growth during the entire growing season, the extended flowering period. This makes it difficult to determine the optimal timing and methods of harvesting seed stands. Harvesting is associated with large crop losses due to uneven ripening of beans and their strong cracking in hot weather with low relative humidity. The abundance of a large number of green shoots increases the humidity of the grass stand. This is very difficult to thresh and require desiccation. The choice of optimal time and method of threshing is the most difficult stage technology seed production of birdsfoot trefoil. Studies have shown that when 69–93% of the beans were browned, the biological yield reached its maximum values of 308–320 kg/ha. This period in typical weather conditions occurred 35–50 days after the beginning of flowering. During this period, the filling of seeds stopped. Crop performance has reached the standard values. The optimal period of direct threshing with pre-desiccation of the herbage, which provided the highest actual seed collection of 191–206 kg/ha, is the period of browning about 70% of the beans.

Experimental investigation of underground seasonal cold energy storage using borehole heat exchangers based on laboratory scale sandbox

In order to overcome the intermittent nature of renewable energy resources, borehole thermal energy storage (BTES) systems are found to be a feasible option these days. Previous research data shows that most of the BTES projects are related to heat storage and there are very few underground cold storage applications. The proposed research work is based on the experimental strategy to determine the extracted energy storage potential in typical weather condition areas. It emphasizes on the mathematical model for soil extracted energy storage system and derives similar function relationship of soil TES system based on similarity theory. A laboratory-scale sandbox is designed with similar scale factor n = 20. Sandbox system is operated in peak winter months from October to March according to the weather data for Dunhuang, China. Approximately 69 % of the input energy is charged into the soil. Soil temperature is reduced up to 11 °C during the extraction period. The maximum heat flux value is recorded 65 W.m−2. The experimental results reveal the practicality of proposed research method. It can be used to fulfill cooling load requirements for air conditioning systems and solar thermal power plants located in desert areas with water shortage issues.

Multiscale modeling of the atmospheric environment over a forest canopy

Vegetation constitutes one of the fundamental types of land use on Earth. The presence of trees in urban areas can decrease local winds and exchange sensible and latent heat with the surrounding environments, thus exerting notable influences on the urban microenvironment. A better understanding of the turbulent transfer of momentum and scalars around vegetation canopy could significantly contribute to improvement of the urban environment. This work develops a large-eddy simulation (LES) method that is applicable to model the flow and scalar transport over the forest canopy. We study the atmospheric flow over complex forested areas under typical weather conditions by coupling LES to the mesoscale model. Models of radiation and energy balance have been developed with explicit treatment of the vegetation canopy. By examining the flow over a forest canopy under a range of stability conditions, we found that buoyancy enhances or suppresses turbulent mixing in unstable or stable atmosphere respectively, with decreasing or increasing wind shear, respectively. From the multiscale modeling of the Beijing Olympic Forest Park, the present coupling scheme proves to better resolve the diurnal variations in wind speed, temperature, and relative humidity over complex urban terrains. The coupling scheme is superior to the traditional mesoscale model in terms of wind field simulation. This is mainly because the coupling scheme not only takes the influences of external mesoscale flow into consideration, but also resolves the heterogeneous urban surface at a fine scale by downscaling, thus better reproducing the complex flow and turbulent transport in the urban roughness sublayer.

Evaluation of Atmospheric Detrimental Effects on Free Space Optical Communication System for Delhi Weather

Abstract Free Space Optical (FSO) communication systems are gaining popularity due to its tremendous speed, advanced capacity, cost effectiveness, secure and easy to deploy wireless networks. This technology has proven an effective choice for last mile applications and hard to reach areas where deployment of optical fibre links is not feasible. But FSO link is highly weather dependent and as signal passes through the atmospheric channel, the main impairments are the atmospheric turbulence, which induce fading and deteriorate the system performance. Delhi has a great potential for FSO communication because of its clear skies. Since there is no analysis for weather condition found in Delhi, this work provides analysis of typical Delhi weather condition ranging from heavy to light rain, fog and clear sky. The performance of FSO link is analysed in terms of attenuation and link length margin under different weather condition. The results are concluded to identify which atmospheric condition influences more on FSO link performance.