Research on Endpoint Detection Algorithm in High Altitude Explosion Point Location Technology

Aiming at the problem of inadequate positioning accuracy of sound endpoints by the dual-element single-threshold endpoint detection algorithm and the single-element dual-threshold endpoint detection algorithm in the process of locating the sound source of weather modification bombs at high altitudes during artificial weather modification, a multi-element dual threshold endpoint detection algorithm. First, according to the characteristics of high-altitude explosion of weather modification bombs and ground reception, the sound signal is filtered and denoised, divided into frames, and windowed. Then, the time-domain feature short-term energy, short-term zero-crossing rate and frequency domain feature short-term information entropy of each frame of the sound signal are calculated, and double thresholds are set for detection. In this way, the start and end points of the explosion sound in the collected sound signal are found, and the data is imported into the positioning algorithm for processing, and then the explosion point of the weather modification bombs in the high air is located. The test results show that the method can accurately distinguish the end point of effective explosion sound, and has practical application value for the location of the sound source of the high-altitude explosion point of the weather modification bombs.

Are persistent aircraft trails a threat to the environment and health?

According to most scientific studies, media and governments, the white trails that can be seen behind aircraft in flight, corresponding to condensation mixed with engine particulate emissions, only persist under specific atmospheric conditions. They are called condensation trails, and cirrus contrails when they remain for hours to reach several kilometers wide. The fact that they have gradually filled the skies over the last twenty years would be due to the increase in air traffic. However, other official documents link these persistent trails to a weather modification technology called solar geoengineering by stratospheric aerosol injection (SAI). These sprays would be mainly composed of metallic particles (Al, Ba, Sr, Fe, nanoparticles) and sulfur, which would considerably increase air, soil and water pollution. Many of the current environmental and health problems are consistent with those described in the literature on solar geoengineering by SAI if this method was employed. For example, metal particles used are well known environmental contaminants, ozone layer depletion, cardiorespiratory diseases, neurodegenerative diseases, sunburn. The observations (whiter skies, less solar power) also correspond to the same risks as those described in the solar geoengineering works. Patents show that this weather modification technology has been known and mastered for a long time. In addition, some scientific papers as well as policy documents suggest that solar geoengineering by SAI has been used for many years. The amount of official information presented in this review is intended to open new ways of investigation, free of conflicts of interest, about the growing global pollution of persistent aircraft trails and their possible links with solar geoengineering by SAI.

Investigation of precipitation characteristics under the action of acoustic waves in the source region of the Yellow River

Acoustic agglomerations have increasingly attracted widespread attention as a cost-effective and environmentally friendly approach for fog removal and weather modification. In this study, research on precipitation interference and the agglomeration performance of droplet aerosols under large-scale acoustic waves was presented. In total, 49 field experiments in the source region of the Yellow River (SRYR) in the summer of 2019 were performed to reveal the influences of acoustic waves on precipitation, such as the radar reflectivity factor (Z), rain rate (R), and raindrop size distribution (DSD). A monitoring system that consisted of rain gauges and raindrop spectrometers was employed to monitor near-ground rainfall within a 5 km radius of the field site. The ground-based observations showed that acoustic waves could significantly affect the rainfall distribution and microstructure of precipitation particles. The average values of rainfall increased by 18.98%, 10.61%, and 8.74% within 2 km, 3 km and 5 km of the operation center with acoustic application. The changing trend of microphysical parameters of precipitation was roughly in line with variation of acoustic waves for stratiform cloud. Moreover, there was a good quadratic relationship between the spectral parameters λ and μ. Raindrop kinetic energy (eK) and the radar reflectivity factor (Z) both exhibited a power function relationship with the rain rate (R).

The FARM (Flexible Array of Radars and Mesonets)

The Flexible Array of Radars and Mesonets (FARM) Facility is an extensive mobile/quickly-deployable (MQD) multiple-Doppler radar and in-situ instrumentation network.The FARM includes four radars: two 3-cm dual-polarization, dual-frequency (DPDF), Doppler On Wheels DOW6/DOW7, the Rapid-Scan DOW (RSDOW), and a quickly-deployable (QD) DPDF 5-cm COW C-band On Wheels (COW).The FARM includes 3 mobile mesonet (MM) vehicles with 3.5-m masts, an array of rugged QD weather stations (PODNET), QD weather stations deployed on infrastructure such as light/power poles (POLENET), four disdrometers, six MQD upper air sounding systems and a Mobile Operations and Repair Center (MORC).The FARM serves a wide variety of research/educational uses. Components have deployed to >30 projects during 1995-2020 in the USA, Europe, and South America, obtaining pioneering observations of a myriad of small spatial and temporal scale phenomena including tornadoes, hurricanes, lake-effect snow storms, aircraft-affecting turbulence, convection initiation, microbursts, intense precipitation, boundary-layer structures and evolution, airborne hazardous substances, coastal storms, wildfires and wildfire suppression efforts, weather modification effects, and mountain/alpine winds and precipitation. The radars and other FARM systems support innovative educational efforts, deploying >40 times to universities/colleges, providing hands-on access to cutting-edge instrumentation for their students.The FARM provides integrated multiple radar, mesonet, sounding, and related capabilities enabling diverse and robust coordinated sampling of three-dimensional vector winds, precipitation, and thermodynamics increasingly central to a wide range of mesoscale research.Planned innovations include S-band On Wheels NETwork (SOWNET) and Bistatic Adaptable Radar Network (BARN), offering more qualitative improvements to the field project observational paradigm, providing broad, flexible, and inexpensive 10-cm radar coverage and vector windfield measurements.

Environmental effects of silver iodide emitted by hail suppression systems in Aragón (Spain)

<p>Weather modification by means of cloud seeding techniques is widely implemented across the world. In areas where hail suppression systems are installed, silver iodide (AgI) particles are used.</p><p>Silver particles fall back to the surface thank to atmospheric deposition. In this research we follow a holistic approach to analyse silver accumulation in water, soils and sediments of Aragón (North-East Spain), where AgI emissions have been released for the last fifty years. We have also assessed silver bioaccumulation in plants and biota, and we have tested its effects in plant growth.</p><p>Our results show that silver concentrations in water and soils of areas covered by hail suppression networks are higher than in further areas, although concentrations are below legal thresholds. We have also observed that silver seems to be absorbed by plants and biota, which would act as a silver outflow and it may help to remove silver from the ecosystems.</p><p><strong>Acknowledgements</strong></p><p>This work was funded by Spanish State Research Agency and FEDER Funds via AgroSOS project (PID2019-108057RB-I00) and DONAIRE project (CGL2015-68993-R), and thanks to a pre-doctoral grant awarded by the Government of Aragon to J. M. Orellana-Macías (BOA 20/ 07/2017).</p>

Impact of stocking density on the rearing environment and growth performance of broiler chicken

The consequence of high stocking density in commercial production of broiler chickens under the changing climate could predispose the chickens to adverse conditions. Therefore, this study was conducted to investigate the influence of stocking density on the rearing environment and performance of broiler chicken. Ninety (90) one day-old chicks of Arbor acre breed were used as experimental units in the trial that lasted eight (8) weeks. The bird were randomly assigned to three treatments of stocking densities 5, 10 and 15 birds/m2 with three replicates per treatment. The birds were raised in deep litter system bedded with woodshaving at 1 m2 per replicate. They were fed ad libitum with commercial broiler diets with drinking water supplied without restrictions. The meteorological data (Temperature and Relative Humidity) within the pen were obtained using the Maxims thermocron i-button Temperature and Humidity sensors and a stand-alone automated weather station was deployed outside the pen house which measured Temperature and Relative humidity parameters within the premises (Figure 1c), which were programmed to measure at 10 minutes sampling interval. Data collected were on daily ambient temperature and relative humidity, feed intake, water intake, weight gain and computed feed conversion ratio. The temperature of the broiler pens was found inversely related to its relative humidity across the treatments with relative fluctuations as the birds grow. Temperature within the pens (ambient temperature) increased with the stocking densities; stocking density 15 birds/m2 (25.94±0.125oC -31.79±0.360oC) being the hottest while 5 birds/m2 (25.47±0.136oC - 31.43±0.353oC ) was the least. Birds at stocking density of 5 birds/m2 (90.00g/bird/week – 2197.78g/bird/week) performed better in terms of growth and followed by those of 10 birds/m2 (95.00g/bird/week – 2018.52g/bird/week). Stocking densities of 15 birds/m2 (84.19g/bird/week – 1907.44g/bird/week) recorded the lowest weight gain. The combine influence of weather parameters (temperature and relative humidity) in bringing about growth of the birds diminishes as the stocking density increases. There was virtually no significant influence of the stocking densities on weekly mean temperature and relative humidity in the broiler chicken pens throughout the period of the study. Therefore, for eight weeks rearing period under any of the stocking density levels, fatality of weather modification could be prevented within the rearing environment through provision of adequate ventilation. La conséquence de la forte densité d'élevage dans la production commerciale de poulets de chair dans le climat changeant pourrait prédisposer les poulets à des conditions défavorables. Par conséquent, cette étude a été menée pour étudier l'influence de la densité d'élevage sur l'environnement d'élevage et les performances des poulets de chair. Quatrevingt-dix (90) poussins d'un jour de race 'Arbor acre' ont été utilisés comme unités expérimentales dans l'essai qui a duré huit (8) semaines. Les oiseaux ont été assignés auhasard à trois traitements de densités de peuplement de 5, 10 et 15 oiseaux / m2 avec trois répétitions par traitement. Les oiseaux ont été élevés dans un système de litière profonde recouvert d'un rasage de bois à 1 m2 par répétition. Ils ont été nourris ad libitum avec des régimes commerciaux pour poulets de chair avec de l'eau potable fournie sans restrictions. Les données météorologiques (température et humidité relative) à l'intérieur du stylo ont été obtenues à l'aide des capteurs de température et d'humidité 'Maximsthermocron i-button' et une station météorologique automatisée autonome a été déployée à l'extérieur de l'enclos qui mesurait les paramètres de température et d'humidité relative dans les locaux (Figure 1c), et ils ont été programmés pour mesurer à 10 minutes d'intervalle d'échantillonnage. Les données recueillies concernaient la température ambiante quotidienne et l'humidité relative, la consommation alimentaire, la consommation d'eau, le gain de poids et le taux de conversion alimentaire calculé. La température des enclos a été trouvée inversement proportionnelle à son humidité relative pendant les traitements avec des fluctuations relatives à mesure que les oiseaux grandissent. La température à l'intérieur des enclos (température ambiante) augmentait avec les densités de stockage ; densité de peuplement 15 oiseaux / m2 (25,94 ± 0,125 ° C -31,79 ± 0,360 ° C) étant le plus chaud tandis que 5 oiseaux / m2 (25,47 ± 0,136 ° C -31,43 ± 0,353 ° C) était le moins. Les oiseaux ayant une densité de peuplement de 5 oiseaux / m2 (90,00 g / oiseau / semaine - 2197,78 g / oiseau / semaine) ont obtenu de meilleurs résultats en termes de croissance et suivis par ceux de 10 oiseaux / m2 (95,00 g / oiseau / semaine - 2018,52 g / oiseau / semaine). Des densités de peuplement de 15 oiseaux / m2 (84,19 g / oiseau / semaine - 1907,44 g / oiseau / semaine) ont enregistré le gain de poids le plus faible. L'influence combinée des paramètres météorologiques (température et humidité relative) dans la croissance des oiseaux diminue au fur et à mesure que la densité d'élevage augmente. Il n'y avait pratiquement aucune influence significative des densités de peuplement sur la température moyenne hebdomadaire et l'humidité relative dans les enclos de poulets de chair pendant toute la période de l'étude. Par conséquent, pendant une période d'élevage de huit semaines, quel que soit le niveau de densité de peuplement, la mortalité due aux modifications climatiques pourrait être évitée dans l'environnement d'élevage grâce à une ventilation adéquate.

Aerosol—Cloud Interaction with Summer Precipitation over Major Cities in Eritrea

This paper presents the spatiotemporal variability of aerosols, clouds, and precipitation within the major cities in Eritrea and it investigates the relationship between aerosols, clouds, and precipitation concerning the presence of aerosols over the study region. In Eritrea, inadequate water supplies will have both direct and indirect adverse impacts on sustainable development in areas such as health, agriculture, energy, communication, and transport. Besides, there exists a gap in the knowledge on suitable and potential areas for cloud seeding. Further, the inadequate understanding of aerosol-cloud-precipitation (ACP) interactions limits the success of weather modification aimed at improving freshwater sources, storage, and recycling. Spatiotemporal variability of aerosols, clouds, and precipitation involve spatial and time series analysis based on trend and anomaly analysis. To find the relationship between aerosols and clouds, a correlation coefficient is used. The spatiotemporal analysis showed larger variations of aerosols within the last two decades, especially in Assab, indicating that aerosol optical depth (AOD) has increased over the surrounding Red Sea region. Rainfall was significantly low but AOD was significantly high during the 2011 monsoon season. Precipitation was high during 2007 over most parts of Eritrea. The correlation coefficient between AOD and rainfall was negative over Asmara and Nakfa. Cloud effective radius (CER) and cloud optical thickness (COT) exhibited a negative correlation with AOD over Nakfa within the June–July–August (JJA) season. The hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model that is used to find the path and origin of the air mass of the study region showed that the majority of aerosols made their way to the study region via the westerly and the southwesterly winds.

An Optimal Control Perspective on Weather and Climate Modification

Intentionally altering natural atmospheric processes using various techniques and technologies for changing weather patterns is one of the appropriate human responses to climate change and can be considered a rather drastic adaptation measure. A fundamental understanding of the human ability to modify weather conditions requires collaborative research in various scientific fields, including, but not limited to, atmospheric sciences and different branches of mathematics. This article being theoretical and methodological in nature, generalizes and, to some extent, summarizes our previous and current research in the field of climate and weather modification and control. By analyzing the deliberate change in weather and climate from an optimal control and dynamical systems perspective, we get the ability to consider the modification of natural atmospheric processes as a dynamic optimization problem with an emphasis on the optimal control problem. Within this conceptual and unified theoretical framework for developing and synthesizing an optimal control for natural weather phenomena, the atmospheric process in question represents a closed-loop dynamical system described by an appropriate mathematical model or, in other words, by a set of differential equations. In this context, the human control actions can be described by variations of the model parameters selected on the basis of sensitivity analysis as control variables. Application of the proposed approach to the problem of weather and climate modification is illustrated using a low-order conceptual model of the Earth’s climate system. For the sake of convenient interpretation, we provide some weather and climate basics, as well as we give a brief glance at control theory and sensitivity analysis of dynamical systems.