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The issue of pedestrian-level wind environments around high-rise buildings is closely related to the comfort and safety of human settlements. In this paper, we study the effects of different wind direction angles and spacing ratios on the wind environment at pedestrian heights around buildings arranged in an equilateral triangle configuration. Three-dimensional steady-state numerical simulation was employed, with the standard k-ε model selected as the turbulence model. Wind speed ratios and different area ratio parameters are used to quantitatively express the degree and range of influence of wind speed by buildings. The results show that the maximum wind speed ratio at the corner of a building is greatly affected by the wind direction angle, with 45°, 135°, and 157.5° being the unfavorable wind direction angles. Conversely, the area ratio of different areas is greatly affected by the spacing ratio. As the spacing ratio increases, the mutual interference effect between buildings weakens, resulting in a better pedestrian wind environment. Owing to the unique layout of the building group, different degrees of ventilation corridors are formed among the three buildings. The wind speed amplification effect in the corridors is more significant, and the areas with poor wind environments are concentrated in these corridors. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dynamic velocity characteristics of wind have been studied over the past several decades. However, there was a lack of consideration for the incoming flow directions. Besides, the comfort assessment studies mainly focused on thermal comfort from the mechanism of heat transfer instead of wind comfort from the mechanism of tactile stimuli. This study carried out a mixed indoor and outdoor experiment. The indoor experiment was conducted with a room temperature of 29 °C and a relative humidity of 50%, which closely resembled the outdoor environmental conditions. Totally 17 healthy subjects dressed at 0.36 clo and being sedentary were exposed to five kinds of airflow during the experiment. According to the results, outdoor true natural wind was more preferred than directly supplied wind. This paper also proposed a novel wind comfort (WC) model by considering various air parameters. The model relied on tactile stimuli, which were the reflections of wind pressure fluctuations and could be affected by changes in velocity and direction of airflows. Based on these two dynamic characteristics, four wind perceptions, including wind intensity vote (WIV), velocity variation sense (VVS), direction variation sense (DVS) and overall enveloping sense (OES) were introduced and linearly regressed. The findings revealed that not only velocity but also the direction could affect the wind comfort evaluation. This paper will hopefully provide a better understanding of impacts of incoming flow directions on comfort and further rethink a novel route of dynamic wind environment imitation for future indoor environments. • We propose a wind comfort evaluation method that focuses on tactile stimuli. • Both velocity and incoming flow direction impact the wind comfort evaluation. • Four subjective perceptions included in wind comfort are newly introduced. • Simulated natural wind only copies the velocity feature of true natural wind. • Oscillating wind has better cooling effect but worse comfort than directly supplied wind. [ABSTRACT FROM AUTHOR]

Studies on the dynamic characteristics and comfort evaluation of natural and mechanical wind have been extensively conducted over the past two decades. However, in these contributions, varying wind directions were not considered. In this study, we systematically analysed different airflows from the perspective of the wind azimuth by using statistical analysis, power spectral analysis, wavelet analysis and chaos analysis. Several concepts are newly defined, such as the wind azimuth fluctuation rate (WAFR), the wind azimuth power spectral exponent (β a value) and the dimensionless parameter of the phase space curve (δ a value). The results show that the standard deviations (SDs) of the wind azimuth, WAFR, and β a values of typical natural wind are typically larger than those of mechanical wind, while the δ a value is lower. The differences in the direction characteristics between natural and mechanical wind highly agree with those in the velocity characteristics. To determine how the direction influences wind comfort, seventeen human subjects were invited to participate in a mixed experiment and exposed to five types of airflow. The results show that true natural wind was preferred, which may be due to the frequently changing direction. The findings also reveal that both the velocity and direction characteristics significantly influence wind comfort evaluations. By understanding the dynamic wind direction characteristics of airflows, this paper may provide new insights into further studies on characteristics, comfort assessments and the application of dynamic wind field in indoor built environments. • Typical tools for analysing wind velocity can also be used for direction. • Natural wind direction varies more randomly than simulated natural wind. • The incoming flow direction of oscillating wind is dynamic. • The comfort study found that natural wind is preferred over directly supplied wind. • Wind direction and velocity both play dominant roles in wind comfort evaluation. [ABSTRACT FROM AUTHOR]

Abstract This study aims to investigate the effect of wind direction (WD) on thermal and wind sensations, reconsider WS benchmarks, and propose modifications on physiological equivalent temperature (PET) and universal thermal climate index (UTCI) indices to reflect the effects of WD. A total of 1008 interviews were conducted outdoors with concurrent micrometeorological measurements in Tehran, Iran, comparing the preferred, neutral, neutral range, and acceptable ranges of UTCI and PET for subjects exposed to leeward and windward wind directions. The results indicated a deviation of 4.6 °C in neutral PET (nPET) and 4 °C in neutral UTCI (nUTCI) between windward and leeward wind directions. Additionally, the results showed that the subjects undergoing leeward wind direction revealed lower sensitivity to wind speed (WS), PET, and UTCI variations, and showed lower neutral and preferred temperatures/WS, and felt thermally acceptable in a wider gap. The results also disclosed that conducting the surveys neglecting the effects of WD may lead to a complete misunderstanding of the climate. Also, the empirical WS benchmarks were determined using techniques regularly used for thermal analysis. These benchmarks were specified separately for windward and leeward wind directions, knowledge of which may be useful in the planning and design of outdoor environments. Highlights • The effect of wind direction on outdoor thermal and wind sensations was investigated. • The subjects undergoing leeward wind direction revealed lower sensitivity to wind speed, PET, and UTCI variations. • Leeward subjects also had lower neutral and preferred temperatures, and felt thermally acceptable in a wider range. • It was showed that neglecting the effects of wind direction may lead to a complete misunderstanding of the climate. • Equations were proposed for considering the effect of wind direction in UTCI and PET indices. [ABSTRACT FROM AUTHOR]

Oceanographic observations carried out during 2016 and 2017 onboard INS Sagardhwani in the Southeastern Arabian Sea are used to study the inter-annual variability of the upwelling. In 2016, the strong upwelling signatures are noticed in the observations (SST < 27°C and strong up-slopping of isotherms) as well as in the satellite derived sea level anomaly data. Whereas in 2017 the low sea level in June (-2 cm) are weakened during the mid of July (+3 cm) along the southern track (8 °N and 9 °N). This decrease in the strength in 2017 can be attributed to two major reasons. One is the presence of an anti-cyclonic eddy along the coast (8.5 °N, 76.5 °E) weakens the upwelling processes and second is the weak northerly component of the wind compared to 2016. In addition, Lakshadweep low is less prominent and situated towards the southern side (around 7°N) of its usual region of occurrence in 2017. The inter-annual variability of upwelling during July 2016 and 2017 is investigated using the 3D ocean model Princeton Ocean Model. Experiments with model in different combinations of forcing reveals that the alongshore wind component is the major parameter influencing the upwelling characteristics during these periods. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Japanese Society of Snow & Ice / Seppyo is the property of Japanese Society of Snow & Ice and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ambiente e Água is the property of Revista Ambiente e Agua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Currently, no clear standards exist for determining urban building natural ventilation rates, especially under varying realistic meteorological conditions. In this study, ventilation rates are determined using tracer gas decay and pressure-based measurements for a full-scale (6 m tall) cube. The cube was either isolated (2 months of observations) or sheltered within a staggered array (7 months), for both single-sided and cross ventilation (openings 0.4 m × 1 m). Wind speeds at cube height ranged between 0.04 m s −1 and 13.1 m s −1 . Errors for both ventilation methods are carefully assessed. There is no discernible linear relation between normalised ventilation rates from the two methods, except for cross ventilation in the array case. The ratio of tracer gas and pressure derived ventilation rates is assessed with wind direction. For single-sided (leeward opening) cases it approached 1. For cross ventilation the ratio was closer to 1 but with more scatter. One explanation is that agreement is better when internal mixing is less jet-dominated, i.e. for oblique directions in the isolated case and for all directions for unsteady array flows. Sheltering may reduce the flushing rate of the tracer gas from the cube relative to internal mixing rate. This new dataset provides an extensive range of conditions for numerical model evaluation and for understanding uncertainty of ventilation rates. Knowledge of the latter is critical in building design. [ABSTRACT FROM AUTHOR]

Determining the distribution pattern of wind-driven rain (WDR) on a building facade can provide crucial boundary conditions for analyzing its heat and moisture transfer, and this is often performed using semi-empirical models. However, the accuracy of semi-empirical models remains questionable, particularly with uncertain input data. In this study, high-resolution field measurements were performed on a pilot building to verify the accuracy of the ISO and ASHRAE semi-empirical models under different data processing methods for wind velocity and direction. The results indicate that the WDR catch ratios calculated using the ASHRAE model are always larger than those of the ISO model with the same input wind velocity and direction. Combining the wind velocity and direction from the probability statistics with the ASHRAE model produces the most accurate results, with predictions ranging from 101%–279% of the measured values. Wind velocity and direction averages based on vector averages are unsuitable for semi-empirical models. • Field measurements of wind-driven rain are carried out on a pilot building. • Average wind speed and direction affect the accuracy of semi-empirical models. • Average wind speed and direction based on probability statistics is optimal. • Results from the ASHRAE model are more realistic than those from the ISO model. [ABSTRACT FROM AUTHOR]

City residents desire to enjoy more outdoor recreational activities, such as walking, cycling and picnicking. The authors’ earlier study reported that thermally comfortable environment could be generated in a local space at hot summer in a subtropical city. The present study aims to further assess the variations of the thermal perceptions for the temperate autumn and cool winter in the two same outdoor sites on an campus via on-site monitoring at the pedestrian level winds and thermal parameters at two sample days (sunny and cloudy) in a precinct. The daytime wind directions were also recorded from a nearby urban weather station and used for the analysis on the differences of wind and thermal comfort between the two surveying sites. The instantaneous thermal perceptions were assessed using PET (Physiological Equivalent Temperature) and the PET based index, normalized environmental parameter differences. Results indicate that the wind speed differences become smaller between the two sites due to their different building designs and the changes of wind directions in summer and winter. Not as the hot summer, the PET results note that the space without shading, directly subject to solar radiation, which can provide a thermally comfortable area at a sunny day in the cool seasons. Specifically in winter, wind speed difference is not contributed significantly to improve the thermal comfort while adaptive sunshine can obtain better thermal perception. The results reconfirm the possibility that a local outdoor thermal comfort zone can be built at selected urban spots even in cool seasons and provide a reminder for planners to consider the seasonal impacts in precinct planning within high dense city. [ABSTRACT FROM AUTHOR]

Dunefields are very common in the northern coastal zone of northeast Brazil. They have the potential to yield important information about paleoclimate, paleo-winds and regional winds and their response to sea-level fluctuations during the Holocene. We reconstructed the coastal dunes geochronological evolution of northwest Ceará State – Brazil, in the last 3000 cal yrs BP, using detailed analyses of lithostratigraphy, microfossil (foraminifera), wind regime, dune monitoring and 8 radiocarbon dates. The chronology was based on 14 C dating in eolianites and monitoring transversal mobile dunes movement processes. Radiocarbon date results indicated that the dunes corresponding to eolianites revealed ages between 2760–2480 and 980–750 cal yrs BP, suggesting that the vast transversal mobile dunefields were formed after this period in similar condition to the current sea-level. We considered that the material transportation by the prevailing east winds towards the transversal dunes is estimated in the order of 11.0 m/year, thus the current aeolian system is less than 1000 yrs BP. [ABSTRACT FROM AUTHOR]

Aeolian rat-tails (ARTs) are a previously undocumented, regionally-ubiquitous aeolian abrasion feature observed on matrix-supported ignimbrite surfaces in the Puna Plateau of Northwest Argentina. ARTs consist of an abrasion-resistant lithic clast projecting above the surface with a lee tail or ‘keel’ in the more erodible matrix. Size is controlled by the dimensions of the windward lithic clast, ranging from centimetre to meter scale; spatial density varies with clast content, which may reflect variations in ignimbrite facies. Field observations suggest ARTs follow a definable evolutionary sequence. First, an abrasion-resistant lithic clast contained within the ignimbrite is exposed to abrasion at the surface. Impacts from abrading particles erode the softer ignimbrite matrix adjacent to the clast. The clast shelters the leeward surface under a unimodal abrasion direction, creating a tail that tapers downwind and elongates as the clast emerges. Clasts become dislodged from the matrix as the surrounding surface erodes, ultimately destroying the feature if the clast is small enough to be mobilized directly by wind or impacting particles. This evolutionary sequence explains the morphology of ARTs and the presence of loose clasts on the ignimbrite surface, which contributes to the development of other landforms in the region, such as periodic bedrock ridges, yardangs, and megaripples. Satellite and rover images suggest similar features also exist on Mars. Because the formation and preservation of ARTs is contingent on unimodal abrasion direction, their orientation can be used as an indicator of long-term aeolian sediment transport direction. [ABSTRACT FROM AUTHOR]

Computational fluid dynamics (CFD) techniques are used to investigate effects of both wind direction and wind speed on net solar heat gain of south wall with internal insulation in winter. Results show that wind effect has a significant influence on the net solar heat gain, where the impact of wind direction is stronger than that of wind speed. For regions in lower reaches of the Yangtze River, difference of their average net solar heat gains (NSHGS) is about 20% due to various wind speeds and wind directions. Buildings in districts with a dominant wind direction of north achieve the highest solar energy utilization. [ABSTRACT FROM AUTHOR]

Road side shapes, including balconies, have great impacts on airflow around buildings, but the couple-effect of the balcony structure and wind direction on the canyon ventilation has not been fully studied. Considering five wind directions (α = 0°, 30°, 45°, 60°, and 90°) and three discontinuous balcony arrangements (leeward-side balcony, windward-side balcony, and both-sides balconies), this study aims to investigate the effect of wind directions on the ventilation of the canyon with balconies via computational fluid dynamics (CFD). The turbulence modelling method is validated by reported wind-tunnel experiment in the literature. Moreover, ACH (air exchange rate) and NEV (net escape velocity) were used to evaluate the ventilation capability of the canyon. The results demonstrates that under all the wind directions, the ventilation capacity of the canyon with the balconies is lower than that of the regular canyon. Also, at most wind directions (α = 0°, 30°, 45°, and 60°) except α = 90°, the ventilation of the canyon with leeward-side balcony is the best, and that is the worst in the canyon with both-sides balconies. In addition, for all the canyon with balconies, with the increase of α , the ventilation capacity of the leeward pedestrian domain (leeward NEV *) becomes lower. From the result of this study, it is recommended that when designing buildings with balconies, balconies should be arranged in the buildings on the leeward side as far as possible. This paper will be useful for urban planners to design cities with high self-ventilation capacity. • Five wind directions and three discontinuous balcony arrangements were considered. • Canyon with balconies has lower ventilation capacity than regular canyon. • Canyon with leeward-side balcony has the best ventilation capacity. • Ventilation in the pedestrian zones is influenced greatly by the wind direction. [ABSTRACT FROM AUTHOR]

• There is a strong link between blowout morphology and the pattern of airflow. • The pattern of airflow within blowout is related to the regional wind direction. • Airflow undergoes separation and deflection in the leeward of the deflation basin. • Corkscrew vortices are the determinant of upwind expansion of the deflation basin. The formation and development of blowouts is an important surface indication of sand drift activity in semiarid grassland areas; thus, an accurate understanding of their morphological evolution characteristics and dynamic processes is of significance for grassland desertification control. This study analyzed the long-term topographic change of a trough blowout developed on a fixed sand dune in the Otindag sandy land of China via ground measurements from 2011 to 2020 and examined the short-term airflow structure through field observations. The results indicated that the area of the deflation basin shows a state of continuous growth. The expansion of the deflation basin was most obvious on the western, southwestern and southern slopes, which is contrary to the regional prevailing wind direction. As airflow passes over the blowout, there is significant airflow steering with the change in topography, and the degrees of airflow steering and acceleration are determined by the direction of the approaching wind. Airflow expands and decelerates on the leeward side of the deflation basin, causing flow separation and producing a recirculation zone on the sheltered lee slopes. Based on a detailed analysis of the results, we suggest that the soil collapse and sand avalanches caused by vortices are the main reasons for the upwind expansion of the deflation basin. Collectively, these findings reveal a strong link between the blowout morphology and the airflow pattern. [ABSTRACT FROM AUTHOR]

The cement industry is the second largest source of anthropogenic mercury (Hg) emissions in Europe, accounting for 11% of global anthropogenic Hg emissions. The main objective of this study was to examine the influence of Hg emissions from the Salonit Anhovo cement plant on Hg levels measured in the ambient air at Vodarna, 1 km downwind from the flue gas chimney. The findings reveal that the plant raw mill operational status plays an important role in Hg concentrations in the flue gas emitted from the plant. Emitted total gaseous mercury was, on average, higher (49.4 μg/m3) when raw mills were in the direct mode (both raw mills-off) and lower (23.4 μg/m3) in the combined mode (both raw mills-on). The average Hg concentrations in Vodarna were 3.14 ng/m3 for gaseous elemental mercury, 53.7 pg/m3 for gaseous oxidised mercury, and 41.9 pg/m3 for particulate bound mercury for the whole measurement period. Atmospheric Hg speciation in Vodarna, coupled with plant emissions and wind data, has revealed that the total gaseous mercury emitted from the cement plant is clearly related to all Hg species measured in Vodarna. Wind blowing from the northeastern quadrant (mostly NE, ENE) is responsible for the elevated Hg levels in Vodarna, where gaseous oxidised mercury levels are highly linked to the cement plant emissions. However, elevated levels of Hg species in the absence of northeastern winds indicate potential inputs from other unknown local sources as well as inputs from regional and global transport mechanisms. [Display omitted] • Raw mill operation in the cement plant influence Hg emitted in the flue gas. • The combined operation of raw mills resulted in lower concentrations of Hg. • Dispersion of Hg species from the plant was influenced by the wind direction. • Reactive mercury in air was related to plant emissions and wind direction. [ABSTRACT FROM AUTHOR]

The urban areas discomfort is related to the increase of local temperatures due to the geometrical characteristics and thermal properties of the built environment. This study shows the results of a FEM analysis through which a urban canyon geometry has been modelled. A 3D domain has been considered taking into account three different wind directions and to geometrical parameters variation, such as the aspect ratio (Height- Width) and the urban canyon length. [ABSTRACT FROM AUTHOR]

The brink is the highest point of the slip face, while the crest is considered as the highest point of the barchan. It has been reported that the crest and the brink could coincide or separate by a distance with sharp drop of the slope called the brink line. In this work we report field measurements showing longitudinal profiles of barchans from the Moroccan Atlantic Sahara desert. Our measurements show how the brink line nucleates, migrates toward the crest and disappears. In addition, we discuss these results according to erosion rate and variability of wind direction. [ABSTRACT FROM AUTHOR]

A three-dimensional circulation model (the Environmental Fluid Dynamic Code) was used to examine the role that physical forcing (river discharge, wind speed and direction) plays in controlling hypoxia in waters adjacent to the Yangtze Estuary. The model assumes that the biological consumption of oxygen is constant in both time and space, which allows the role of physical forcing in modulating the oxygen dynamics to be isolated. Despite of the simplicity of this model, the simulation results showed that it can reproduce the observed variability of dissolved oxygen in waters adjacent to the Yangtze Estuary, thereby highlighting the important role of changes in physical forcing in the variation of hypoxia. The scenarios tested revealed appreciable changes in the areal extent of hypoxia as a function of wind speed and wind direction. Interestingly, well-developed hypoxia was insensitive to river discharge. [ABSTRACT FROM AUTHOR]

Copyright of Boletim de Geografia is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As wind flows around a sharp-edged body, the resulting separated flow becomes complicated, with multiple separations and reattachments as well as vortex recirculation. This widespread and unpredictable phenomenon has long been studied academically as well as in engineering applications. In this study, the flow characteristics around rectangular prisms with five different aspect ratios were determined through wind tunnel experiments and a detached eddy simulation, that placed the objects in a simulated deep turbulent boundary layer at Re = 4.6 × 104. A series of rectangular prisms with the same height (h = 80 mm), different longitudinal lengths (/ = 0.5/î, h, and 2h), or different transverse widths (w = 0.5h, h, and 2li) were employed to observe the effects of the aspect ratio. Furthermore, five wind directions (0°, 10°, 20°, 30°, and 45°) were selected to observe the effects of the wind direction. The simulated results of the surface pressure were compared to the wind tunnel experiment results and die existing results of previous papers. The vortex and spectrum were also analyzed to determine the detailed flow structure around the body. The paper also highlights the pressure distribution around the rectangular prisms with respect to the different aspect ratios. With an increasing transverse width the surface suction pressure on the top and side surfaces becomes stronger. In addition, depending on the wind direction, the pressure coefficient experiences a large variation and can even change from a negative to a positive value on the side surface of the cube model. [ABSTRACT FROM AUTHOR]

Validation and measurements of a Floating LiDAR (Light Detection And Ranging) Device (FLD) were performed at Hsing-Da Harbor in the south of Taiwan from October 16 th to 26 th , 2013. Six range gate heights were set at 50m, 70m, 90m, 110m, 150m and 200m from the FLD sensor lens. Wind speeds, wind directions and turbulence intensities measured by the FLD were compared with those measured by a portable LiDAR, installed on the top of Taiwan Ocean Research Institute (TORI) building. The distance between two LiDARs was about 320m. 1388 available timestamp datapoints were recorded during the deployment campaign. During the test period, the majority of the wind directions were from the north. The averaged wind speeds for the range gate of #1∼6 were 4.7, 4.9, 5.3, 5.5, 5.6 and 5.8m/s respectively with the corresponding maximum 10-minute average wind speeds 13.6, 14.2, 14.8, 15.9, 15.9 and 16.9m/s and the averaged turbulent intensities 0.187, 0.190, 0.191, 0.193, 0.197 and 0.192 for the six range gates. The results showed good agreements with 10 minute averaged data of the wind speed and wind direction measured by the two LiDARs. This implied that the motion compensation function of the FLD performed as specified. The present preliminary test and validation results showed good performance from the FLD, which will be a key tool for assessment of offshore wind resources in future offshore wind farm developments. [ABSTRACT FROM AUTHOR]

The aim of the present work is to use graphical methods based on the evaluation of selected trace metals (Mn, Cu, Cr, V and Ni) and wind direction monitoring data to identify sources of trace metal in the main urban areas of the Cantabria Region (Northern Spain). These graphical methods take into account the frequency of wind in each sector and the measured concentration of trace elements in PM10. The comparison between the contribution of wind and selected trace metals to each sector is presented in polar diagrams. The main conclusions derived from these diagrams are compared to those obtained from radial diagrams based on pollutant concentration roses computed from daily metal levels and hourly wind direction data. The procedure, based on plotting the ratio between the contribution of trace metals and wind data to each sector on polar diagrams, may result in an easier interpretation. Finally, both procedures are applied to data from three sampling sites located in Santander Bay, to study the influence of point sources on the levels of Mn. The analysis of the results shows that similar conclusions were obtained from both methods. These methods are primarily recommended when large emissions are produced by local point sources. [ABSTRACT FROM AUTHOR]

Migration of the Mythimna turca population was monitored using a searchlight trap on Beihuang island, providing direct evidence that M. turca migrates across the Bohai Strait. Migratory trajectories demonstrated that M. turca mainly moved northward in prevailing southerly winds from June to August and moved southward during spells of north-easterly winds during September. [Display omitted] • The study showed that M. turca is a migratory insect. • M. turca migrated across the Bohai Sea in two distinct periods. • M. turca mainly moved northward in spring and summer and moved southward in autumn. The double line moth, Mythimna turca (Linnaeus, 1761) (Lepidoptera: Noctuidae), is an important widely distributed insect species. Studies on the moth in European countries have focused on population monitoring and in China on taxonomy of Mythimna and distribution surveys of M. turca. However, whether M. turca is a migratory insect is unknown. Here, migration of the moth population was monitored using a searchlight trap from 2004 to 2020 on Beihuang island, Northern China, providing direct evidence that M. turca migrates across the Bohai Strait seasonally, in late May to early September. Population dynamics, ovarian development, wind direction and possible migration trajectories were also analyzed. Most moths migrated in June and at the end of August and the beginning of September, and a few migrated in May, July and October. The average duration of this windborne migratory period of M. turca was 93 d. Migratory trajectories demonstrated that M. turca mainly moved northward in spells of southerly winds from June to August and moved southward in spells of northerly winds during September. This new key information about the ecology of M. turca population will aid the formulation of M. turca management strategies. [ABSTRACT FROM AUTHOR]

The novel Pulse technique measures the building airtightness in a dynamic approach, involving a low-pressure pressurisation process, typically in 1–10Pa. It is known that the wind effect is one of the main sources of uncertainty for airtightness testing. The literature review revealed that the wind impact on measuring building airtightness has been explored in relation to the steady pressurisation method (i.e., the blower door), while there is limited research investigating the validity of the Pulse measurement under various natural wind conditions. In this study, in total, 423 Pulse tests were performed to measure the building airtightness of a five-bedroom dwelling located at the University of Nottingham, UK, under natural wind conditions. The viability of the Pulse technique for delivering airtightness measurements under different wind conditions was assessed, including the impacts of the wind speed and the wind direction on the Pulse measurements. Based on the measured air leakage rates, the threshold of maximum wind speed that led the Pulse measurements to have repeatability greater than ±10% is 5.0 m/s at 2.2 m above ground level (i.e., approximately equivalent to the meteorological wind speed of 7.9 m/s). On the other hand, the directional wind study showed that at lower wind speeds, the wind direction has a lesser influence on the Pulse measurement than the wind speed itself. Practically, multiple Pulse tests are recommended for minimising the wind impact on building airtightness measurement when adverse wind conditions are present. •423 Pulse tests were conducted in a UK detached house under natural wind conditions. •Investigations of impacts of wind speed and wind direction on Pulse measurements. •Wind speed limit for the Pulse measurement with uncertainty of ±10% was identified. •Wind direction has a lesser influence on the Pulse measurement than the wind speed. •Multiple Pulse tests are recommended for minimising the wind impact. [ABSTRACT FROM AUTHOR]

The turbulent nature of wind significantly complicates the airflow-exchange process at single openings that function as both inlets and outlets simultaneously. For such flow problems, describing the ventilation rate using a constant value is insufficient if the fluctuating intensity is too large. This paper uses a large eddy simulation (LES) model combined with the tracer gas concentration decay method to investigate fluctuating ventilation characteristics through a single opening under various approaching wind directions. The numerical method is validated against a field measurement of single-sided ventilation rates. Results show that wind direction (which characterizes the external airflow pattern) greatly influences the airflow exchange at a single opening. The ventilation rate is relatively steady for a windward opening and shows more unsteadiness for a lateral and a leeward opening. The airflow-exchange process is mainly driven by the mean flow at the windward opening and is dominated by the turbulent flow at the lateral opening. The findings from this study imply that the turbulence-induced component of single-sided ventilation rates should always be considered, especially for non-windward openings. [ABSTRACT FROM AUTHOR]

Accurate quantification of gaseous emissions from livestock buildings to the atmosphere requires accurate determination of the ventilation rate and the representative gas concentration in the exhaust air. But there is a lack in the investigation of reasons and uncertainties for selecting sampling points and locations in naturally ventilated dairy (NVD) buildings. The objective of this study was to investigate uncertainties in calculating AER based on carbon dioxide (CO2) balance method. The experiment was carried out in an NVD building located in north-east Germany. Concentrations of CO2 were continuously measured inside the barn at eight uniformly distributed points and outside the barn at four points. Air exchange rate (AER) per hour was calculated using the concentration difference between inside and outside the barn where inside concentrations of 4 sampling locations left (4PL), middle (4PM), right (4PR) and corner (4PC) of the barn, 6 sampling locations in left (6PL), right (6PR) and randomly (6RS) selected points inside the barn were used, then compared with AER calculated using an average CO2 concentration of 8 sampling points (8PA) according to the CO2 balance method. The results showed that the relative AER calculation differences using 4PL, 4PM, 4PR, 4PC, 6PL, 6PR, and 6 RS were -49 to 112%, -5 to 26%, -29 to 34%, -12 to 13%, -5 to 44%, -14 to 10% and -8 to 4% compared to 8PA. The variations in relative differences are because of uncertainties involved in point concentration measurement due to the variations of outside wind speed and direction. [ABSTRACT FROM AUTHOR]

Pinellas County is a peninsula on the west coast of Florida that receives sea breeze driven convective rainfall during the summer months. To improve forecasting of local mesoscale phenomena, the spatial variability of summer rainfall in Pinellas was examined in relation to dominant wind directions and speeds, atmospheric stability, and atmospheric moisture content for the months of June, July, and August from 2003 to 2007. Radiosonde data from the Ruskin, Florida National Weather Service (NWS) Station, Pinellas County rain gauge data, and radar-estimated rainfall totals from the NWS Advanced Hydrologic Prediction Service were used to examine different meteorological parameters and their relationships with the spatial variability of summer precipitation across the peninsula. Dominant daily wind direction categories were divided into six 60 degree increments: 1-60°, 61-120°, 121-160°, 161-240°, 241-300°, and 301-360°. Precipitable water had a significant positive correlation with precipitation in four of the six wind direction categories (61-120°, 121-180°, 181-240°, and 241-300°). Higher wind speeds associated with a southerly wind direction revealed significant positive relationships with precipitation. Composites of radar-derived rainfall estimates indicate that rain fell primarily in the center of the peninsula under a variety of wind directions, often with two daily maxima. Composites also show that the greatest potential for high precipitation amounts comes with westerly winds (241-300°). [ABSTRACT FROM AUTHOR]

The orientation of the streets and the height of continuous buildings cut off summer breezes and the prevailing wind in Izmir, Turkey. Compared with the northern parts of Turkey, the summer period in Izmir is relatively hot, humid and long. Due to the dense urban structure and the expansion of hard surface materials, the temperature in the city centre is higher than this centre's surroundings and this effect is called the urban heat island. Consequently, pedestrian comfort in the city drops dramatically especially in locations where the wind flow is obstructed by buildings. In addition, natural ventilation through the building façades is weakened due to the low average wind speed in the streets. For better outdoor and indoor comfort the citizens in Izmir should benefit from the prevailing wind and summer breezes locally named ‘imbat’ in the sea-land direction. Therefore, the existing situation is examined through the field study in order to understand the natural ventilation potential at the pedestrian level in the selected main streets in Izmir. [ABSTRACT FROM AUTHOR]

Evaluating the extent of exposure to chemicals in absence of continuous measurements of their concentration in air and direct measures of personal exposure is crucial for epidemiological studies. Dispersion models can be a useful tool for reproducing spatio-temporal distribution of contaminants emitted by a specific source. However, they cannot easily be applied to short-term epidemiological studies because they require precise information on daily emission scenarios for a long time, which are generally not available. The aim of this study was to better assess the exposure in the industrial area of Brindisi, which suffers from various critical epidemiological situations, by integrating air pollution concentration data, emissions and model simulations concerning a specific point source. The results suggest that in the absence of direct exposure data and detailed information on specific pollutants associated to an emission, population exposure may be better assessed by taking into account proxy pollutants and the wind (direction and speed) as a potential health effects modifier. [ABSTRACT FROM AUTHOR]

The mountain or hill with lots of natural vegetation in a city has obvious cooling effects, so it can play a significant role in the regulation of urban microclimate and mitigation of urban heat island (UHI). In this paper, the influences of wind direction on the cooling effects of the Zijin Mountain in Nanjing were evaluated. Firstly, the land surface temperature (LST) was obtained based on 15 Landsat-8 images from 2013 to 2020, and the wind directions in 4 h before the satellite crossing time were calculated. Then, two remote sensing images with opposite wind directions were compared and analyzed to explore the influences of wind direction on the cooling effects of the Zijin Mountain. The results showed that both the cooling buffer zone method and the cooling area method proposed in this paper had proved that the wind direction had great influences on the cooling effects of the mountain vegetation in urban area. In addition, it was also found that the larger the wind speed differences of group images, the greater the influences of the wind direction on the cooling effects. This study will be helpful and meaningful for urban microclimate analyses and urban planning research. • A comparative evaluation method using two remote sensing images is proposed. • Wind direction has great influences on the cooling effects of mountain vegetation. • The larger the wind speed differences, the greater the influences of the wind direction. [ABSTRACT FROM AUTHOR]

This work studies the impact of the substitution of a traffic light for a modern roundabout on carbon monoxide concentration. The estimate of CO concentration is made by means of the CAL3QHC dispersion model, considering only passenger vehicles as emitting sources. Local traffic and meteorological parameters had been adopted and the emission factors had been estimated using CMEM emission model. The maximum observed values in eight different wind directions had been compared, considering both moving and queued vehicles. The adopted model showed that the maximum concentrations of CO in the roundabout scenario were about 50% of the obtained values with the use of the signalised intersection. Concentration maps analysis demonstrated that not only the maximum values are higher in the case of the traffic light, but the area of the concentration curves is larger. These analyses are important for proper environmental management and contribute to traffic engineers seeking environmentally sustainable solutions. [ABSTRACT FROM AUTHOR]

The movement and motion of cloud mass have great effect on runoff and time of precipitation occurrence is rarely equal in all subbasins of one watershed. Ignoring storm movement influences on runoff simulation and decreases the accuracy of peak flow estimation. The direction and velocity of wind are important factors of cloud mass movement and the time of reaching cloud mass to gravity center of subbasins can be determined using it. According to lack of moment information in Height of cloud formation, direction and velocity information of wind on ground surface was used. Precipitation in subbasins was decomposed based on the rainfall of the nearest recording rain-gauge station and the time of its occurrence in each subbasin was determined considering direction and velocity of wind. Results showed that after determining the time of rainfall occurrence in subbasins based on direction and velocity wind, peak flow of simulated hydrograph had more similarity with observed peak flow, but in most cases, the effect of velocity and direction of wind on runoff volume was effectless. [ABSTRACT FROM AUTHOR]

Abstract: Severe wind is a major natural hazard in Xinjiang Uygur Autonomous Region, China. Using a 55-station network, we collected wind statistics along the Lanxin Railway, particularly in the Alashankou, 30-li, and 100-li wind zones. Wind speed and direction varies throughout the province: the mean speed of extreme wind gusts is greater in the north where wind direction is mainly western and northwestern; in the south the wind direction is primarily northeastern and southeastern. Detailed analyses show that the prevailing direction of extreme winds follows the gaps of the mountain. The terrain effect enhances wind speed and creates the three wind zones. Severe winds occur mostly in during April and August and are caused primarily by Siberian cold fronts (spring) and thunderstorms (summer). We analyzed the probability of extreme wind speed using the Gumbel Model, and calculated annual maximum daily extreme wind speed values for the three wind zones over desired return periods. [Copyright &y& Elsevier]

A field monitoring was conducted to examine the wind-attenuation effect of mangrove plantations at the Sanjiang Bay of Dongzhai Harbor, Hainan Province of South China. The wind speed and wind direction were measured at a site 50 m away from the offshore forest fringes of Sonneratia apetala and Kandelia obovata plantations and 2 m above the ground. Both the S. apetala and the K. obovata plantations had obvious effect in attenuating the speed of the wind from northerly to the shore, with the mean wind speed decreased by > 85% and the better effect of K. obovata plantation. With the increase of the wind speed, the wind-attenuation effect of the plantations presented a trend of decreasing first and remained stable then. At 50 m away from the offshore forest fringe of S. apetala plantation, the wind-attenuation rate was higher than 89. 8% when the mean wind speed was lower than 5 m · s-1, tended to be stable when the mean wind speed was 10 m·s-1, and turned to be 58.9% - 63.6% when the mean wind speed was higher than 15 m·s-1. The S. apetala plantation had better wind attenuation effect in warmer season than in colder season. Under the extremely adverse weather like typhoon, the mean wind speed and extreme wind speed at 50 m away from the offshore forest fringe of S. apetala plantation were decreased by 59.4% and 53.2%, respectively. [ABSTRACT FROM AUTHOR]

The Community Multiscale Air Quality (CMAQ) model was used along with the Weather Research and Forecasting (WRF) model to study air quality modelling sensitivity to various Planetary Boundary Layer (PBL) schemes and Land Surface Models (LSMs). The performance is assessed and quantified by comparing results with surface observations and the outputs provided by the fifth generation Mesoscale Model (MM5) when coupled to the CMAQ model. The evaluated meteorological variables include temperature, wind speed and direction and mixing ratio, while the CMAQ evaluation focuses on ozone concentrations. Differences were observed in circulatory patterns and meteorological variables, which influence spatial ozone distributions and concentrations. [ABSTRACT FROM AUTHOR]

Parameters related with natural and traffic producing turbulences are estimated for four street canyons considering all wind directions. Available data include air pollution concentrations measured in Göttinger Strasse (Hannover, Germany), Schildhornstrasse (Berlin, Germany), Jagtvej (Copenhagen, Denmark) and Hornsgatan (Stockholm, Sweden), background pollution, wind speed and direction measured on the roof of a nearby building and information of traffic flow. Results show that coefficients a and b, related to natural- and traffic-produced turbulences, vary with wind direction. The variation of critical wind speed with traffic density and wind direction is also studied for each street canyon. [ABSTRACT FROM AUTHOR]

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Abstract: In order to investigate the effect of meteorological factors on PM2.5 in Beijing, the continuous observation data which from July to September of 2006-2008 of Baolian and Shangdianzi stations are used to analyze. The result showed that: the transportation of southerly wind aggravated the fine particulate pollution degree of urban, and it is also the primary reason of the pollution in rural area. PM2.5 concentration decreased as the northerly wind increased in both urban and rural areas. This indicates that the northerly wind is relatively clear, can dilute and disperses the pollutants in the Beijing area, but the southerly wind play the opposite role. Hourly precipitation above 1mm can eliminate PM2.5 effetely. [Copyright &y& Elsevier]

The black salt marsh mosquito, Aedes taeniorhynchus, is a serious nuisance pest and a potential vector of a number of arboviruses. This study examined the effect of wind direction, wind speed, temperature, and time of year on the abundance of Ae. taeniorhynchus collected in CO2-baited light traps at 12 sites in the Florida Keys during 2004. The dependent variable analyzed was the natural log of weekly mosquito abundance. The previous week's wind speed and wind direction, and the current week's temperature were used as independent variables. Simple and multiple linear regression models were used to assess the significance and nature of association between the meteorological variables and the natural log of mosquito abundance, and to determine whether the meteorological variables had significant associations with mosquito abundance after also controlling for time of year. Week of year was treated as a circular independent variable in the regression models, using the sine and cosine of week in radians to model the periodic seasonal fluctuation in mosquito abundance. Mosquito abundance was significantly associated with all meteorological variables and with week of year. Individually, previous week's wind speed and wind direction, and current week's temperature were able to explain respectively 24.5%, 24.5%, and 52.1% of the variation in mosquito abundance observed over the year. Week of year had the strongest individual association with mosquito abundance, explaining 65.7% of the variation in mosquito abundance. The meteorological variables were still significantly associated with mosquito abundance, after controlling for week of year. Week and the meteorological variables together explained 79.2% of the variation in mosquito abundance. The regression models fit to the data from this study suggest a strong periodic seasonal variation in mosquito abundance, with meteorological conditions explaining a significant portion of the variation beyond the seasonal trend. [ABSTRACT FROM AUTHOR]

Aerosols samplings by bulk filtration and by use of a high volume cascade impactor were performed taking into account wind directions simultaneously at an urban and a rural site in Northern France. Fifteen major and trace species were considered to study characteristics of the particles collected. Evolution of the Weighted Mean Diameter vs. the wind direction, profiles of the Mass Size Function (MSF), values of the dry deposition fluxes, distribution between the coarse particles (>1 μm) and the fine particles (<1 μm), neutralisation ratio between NH4+ and SO42-, NO3- are discussed in this work. [ABSTRACT FROM AUTHOR]

Abstract: Strong westerly winds that emanate from San Gorgonio Pass, the lowest point between Palm Springs and Los Angeles, California, dominate aeolian transport in the Coachella Valley of the western Sonoran Desert. These winds deposit sand in coppice dunes that are critical habitat for several species, including the state and federally listed threatened species Uma inornata, a lizard. Although wind directions are generally defined in this valley, the wind field has complex interactions with local topography and becomes more variable with distance from the pass. Local, dominant wind directions are preserved by growth patterns of Larrea tridentata (creosote bush), a shrub characteristic of the hot North American deserts, and ventifacts. Exceptionally long-lived, Larrea has the potential to preserve wind direction over centuries to millennia, shaped by the abrasive pruning of windward branches and the persistent training of leeward branches. Wind direction preserved in Larrea individuals and clones was mapped at 192 locations. Compared with wind data from three weather stations, Larrea vectors effectively reflect annual prevailing winds. Ventifacts measured at 24 locations record winds 10° more westerly than Larrea and appear to reflect the direction of the most erosive winds. Based on detailed mapping of local wind directions as preserved in Larrea, only the northern half of the Mission-Morongo Creek floodplain is likely to supply sand to protected U. inornata habitat in the Willow Hole ecological reserve. [Copyright &y& Elsevier]

An understanding of pollution sources and emissions, and their interactions with terrain and the atmosphere is the most important step in developing appropriate air pollution management plans and action strategies. In this study, relationship between sulphur dioxide (SO2) concentration and meteorological parameters such as wind direction, wind speed, temperature, air pressure, precipitation, sunshine amount, sunshine duration, and relative humidity is modeled by using winter season data (November through March) between years 1996 and 2006. An artificial neural network (ANN) can be used in assessing the dynamics of complex non-linear systems. Since the relation between SO2 concentrations and many meteorological parameters is complex, an ANN model is developed to predict the SO2 levels. Wind direction is modeled as the combination of two variables, which enables to appropriately define the wind direction. The ANN model exhibited an R-squared value of 0.85. Correlation coefficient of SO2 concentrations for one day difference is 0.82, and two-day difference is 0.60. This relationship was introduced to the model by adding an autoregressive structure to the ANN. [ABSTRACT FROM AUTHOR]

The article reports on the effect of wind direction on cross-pollination in wind-pollinated genetically modified crops. Regulatory threshold restrict genetically modified presence in conventional crops in Europe. To reduce field-to-field cross-pollination to an acceptable level, minimum distances for the spatial separation of fields are often recommended. It is proposed that methods to predict the range in levels of cross-pollination based on the limited data typically available from field trials. A suitable time lags between peak flowering in adjacent fields that could be introduced to reduce cross-pollination to a specified level.

The study of seed dispersal has received considerable attention in tropical ecology with emphasis placed on its role in the maintenance of species diversity. Since seeds of numerous high-value tropical timber trees are nominally or actively wind dispersed, the subject is also of interest to tropical foresters. In central Africa, up to 70% of harvested timber trees are wind dispersed, including African mahoganies of the genus Entandrophragma. The dual goals of managing many remote areas in central Africa for both biodiversity and timber production values has led to the consideration of low impact logging techniques. In the Central African Republic, increasing light downwind of Entandrophragma has been proposed as a way of increasing regeneration and recruitment of these trees. Mean wind direction at the time of dehiscence of Entandrophragma angolense and Entandrophragma cylindricum was compared with compass orientation of seed shadows for five individuals in mature, undisturbed forest. Mean wind direction was found to be toward the northeast for morning, afternoon, and daily winds and was significantly different from the orientation of seed shadows for all trees. Mean branch direction did not vary significantly from a random pattern, but matched the direction of the seed shadow better than wind direction did. It is concluded that harvesting interventions aimed at increasing light downwind of Entandrophragma will not necessarily benefit seedlings of the species at the study site and further silvicultural research is needed to determine appropriate management interventions, particularly in remote areas of Africa where conservation values are important. [Copyright &y& Elsevier]