Littérature scientifique sur le sujet « Interior lightning »

AbstractA 30-yr climatology of lightning days and associated synoptic meteorological patterns are characterized across the interior western United States (WUS). Locally centered composite analyses show preferred synoptic meteorological patterns with positive 500-hPa geopotential height anomalies located to the northeast and negative sea level pressure anomalies to the northwest and collocated with local lightning days. Variations in preferred patterns for local lightning days are seen across the interior WUS. Areas not commonly affected by the North American monsoon system including the western Great Basin and northern Rocky Mountains show higher-amplitude anomalies of geopotential height, moisture, and midtropospheric instability patterns suggesting the importance of episodic midlatitude dynamics to lightning days in such locations. By contrast, locations closer to the core of the North American monsoon show weaker anomalies, likely reflecting the prevalence of favorable mesoscale dynamics key to lightning production during warm-season months in locations in the interior Southwest. Meteorological patterns for select locations are explored in more detail and two case studies of notably active lightning events are presented. Results from this observational analysis provide a foundation for evaluating meteorological conditions on lightning days in climate model simulations for the interior WUS.

The relationship between lightning strike density, vegetation, and elevation was investigated at three different spatial scales: (i) interior Alaska (~630 000 km2), (ii) six longitudinal transects (~100 000 km2), and (iii) 17 individual physiographic subregions (~50 000 km2) within Alaska. The data consisted of 14 years (1986–1999) of observations by the Alaska Fire Service lightning strike detection network. The best explanation for the variation in lightning strike density was provided by a combination of the areal coverage of boreal forest and elevation. Each of these factors has the potential to influence the convective activity. Our study suggests that in a region that is climatically favorable for air-mass thunderstorms, surface properties may enhance local lightning storm development in the boreal forest. Lightning strikes were found to occur frequently both in mountainous areas and at river flats, which is contrary to results from previous Alaskan studies.

Abstract Lightning occurring with less than 2.5 mm of rainfall—typically referred to as ‘dry lightning’—is a major source of wildfire ignition in central and northern California. Despite being rare, dry lightning outbreaks have resulted in destructive fires in this region due to the intersection of dense, dry vegetation and a large population living adjacent to fire-prone lands. Since thunderstorms are much less common in this region relative to the interior West, the climatology and drivers of dry lightning have not been widely investigated in central and northern California. Using daily gridded lightning and precipitation observations (1987–2020) in combination with atmospheric reanalyses, we characterize the climatology of dry lightning and the associated meteorological conditions during the warm season (May–October) when wildfire risk is highest. Across the domain, nearly half (∼46%) of all cloud-to-ground lightning flashes occurred as dry lightning during the study period. We find that higher elevations (>2000 m) receive more dry lightning compared to lower elevations (<1000 m) with activity concentrated in July-August. Although local meteorological conditions show substantial spatial variation, we find regionwide enhancements in mid-tropospheric moisture and instability on dry lightning days relative to background climatology. Additionally, surface temperatures, lower-tropospheric dryness, and mid-tropospheric instability are increased across the region on dry versus wet lightning days. We also identify widespread dry lightning outbreaks in the historical record, quantify their seasonality and spatial extent, and analyze associated large-scale atmospheric patterns. Three of these four atmospheric patterns are characterized by different configurations of ridging over the continental interior and offshore troughing. Understanding the meteorology of dry lightning across this region can inform forecasting of possible wildfire ignitions and is relevant for assessing changes in dry lightning and wildfire risk in climate projections.

Abstract Summertime cloud-to-ground lightning strikes are responsible for the majority of wildfire ignitions across vast sections of the seasonally dry western United States. In this study, a strong connection between active phases of the Madden–Julian oscillation (MJO) and regional summertime lightning activity was found across the interior western United States. This intraseasonal mode of lightning activity emanates northward from the desert Southwest across the Great Basin and into the northern Rocky Mountains. The MJO is shown to provide favorable conditions for the northward propagation of widespread lightning activity through the amplification of the upper-level ridge over the western United States and the development of midtropospheric instability. Given the relative predictability of the MJO with long lead times, results allude to the potential for intraseasonal predictability of lightning activity and proactive fire management planning.

Abstract Cloud-to-ground (CG) lightning data are used in this study to trace the daily patterns of thunderstorms in time and space across the topographically diverse southeastern United States. Four reoccurring patterns of thunderstorms (i.e., local, multilocal, regional, and widespread) are identified on the basis of the size of the region of CG lightning as well as the spatial pattern of the flashes within this region. To identify these patterns, hourly maps of CG flashes are produced over five summer seasons (June–August) and used to identify thunderstorm events on all days in which at least one CG lightning is observed. Thunderstorm events are defined by a temporally and spatially clustered hourly pattern of lightning flashes. The spatial pattern of lightning associated with each event is examined during the hour in which the flash density is the highest and is used to classify the event. The geographical and temporal patterns of each thunderstorm type are described. Also, flash densities are calculated at spatial scales ranging from 1- to 100-km radial distance. Over half of the identified thunderstorm events in the study were confined to the local scale and contained relatively few flashes. They were most common early in the morning and in the mountainous portions of the study area. Widespread events, on the other hand, showed a dense coverage of flashes within a given hour over a majority of the area. Although they occurred much less frequently (i.e., once every 8 days across most locales), they were responsible for the highest number of CG lightning flashes in the study region; furthermore, they produced the highest flash densities, both at the local and regional scale. A radar echo classification revealed that these events were not tied to mesoscale convective systems, but rather to the early afternoon development of numerous convective cell clusters and lines across the study area.

Because of the fast development of high buildings and large mansions and the increasing applications of electronic information technology, all kinds of advanced electronic equipments are installed in buildings. These equipments have qualities of low insulation, weak endurance of overvoltage and overcurrent and sensitivity for EMC disturb. Then more and more serious hazards and indirect economic losses are arising from lightning disturbance. Therefore, in order to cut down such big losses it is really necessary to conduct the research of stroke-incidence rules and take effective measures to protect buildings against lightning. Theories and practice show that the lightning protection is a systematic engineering. The exterior protection and interior protection should be constituted as an integer. This paper mainly studies the telecommunication equipments in the building disturbed and harmed by the lightning electromagnetic field. To protect this injure effectively we must find out the distributions of the lightning electromagnetic field in the building. Three cases of the lightning electromagnetic field distributions in the building have been discussed in the paper.

AbstractLightning is a key driver of wildfire activity in Alaska. Quantifying its historical variability and trends has been challenging because of changes in the observational network, but understanding historical and possible future changes in lightning activity is important for fire management planning. Dynamically downscaled reanalysis and global climate model (GCM) data were used to statistically assess lightning data in geographic zones used operationally by fire managers across Alaska. Convective precipitation was found to be a key predictor of weekly lightning activity through multiple regression analysis, along with additional atmospheric stability, moisture, and temperature predictor variables. Model-derived estimates of historical June–July lightning since 1979 showed increasing but lower-magnitude trends than the observed record, derived from the highly heterogeneous lightning sensor network, over the same period throughout interior Alaska. Two downscaled GCM projections estimate a doubling of lightning activity over the same June–July season and geographic region by the end of the twenty-first century. Such a substantial increase in lightning activity may have significant impacts on future wildfire activity in Alaska because of increased opportunities for ignitions, although the final outcome also depends on fire weather conditions and fuels.

Examining the relationship of El Ni&ntilde;o to weather patterns in Alaska shows wide climate variances that depend on the teleconnection between the tropics and the northern latitudes. However, the weather patterns exhibited in Alaska during and just after moderate to strong El Ni&ntilde;o episodes are generally consistent: above normal temperature and precipitation along the Alaskan coast, and above normal temperature and below normal precipitation in the interior, especially through the winter. The warm, dry conditions in the Alaskan interior increase summer wildfire potential. Statistics on the area burned since 1940 show that 15 out of 17 of the biggest fire years occurred during a moderate to strong El Ni&ntilde;o episode. These 15 years account for nearly 63% of the total area burned over the last 58 years. Evidence points to increased dry thunderstorms and associated lightning activity during an El Ni&ntilde;o episode; the percentage of total area burned by lightning caused fires during five episodes increased from a normal of less than 40% to a high of about 96%.

Neste estudo foi realizada uma análise comparativa da ocorrência de raios do tipo nuvem-solo (NS), medidos por sensores em superfície e o total de raios (NS e intra-nuvem - IN), derivados de sensoriamento remoto por satélite, objetivando estabelecer uma proporção dos raios NS entre ambos os Lightning Location System (LLS) para o leste da Amazônia. Foram utilizados dados da STARNET e do banco de dados LRTMS (OTD/LIS). A metodologia de análise consistiu no cálculo da Razão Z, da Proporção de Incidência de Raios NS e da Correlação de Pearson. Adicionalmente também foi realizada uma investigação sobre a relação da quantidade de raios NS em função da altitude do relevo. Os resultados apontaram que a incidência de raios NS tem uma oscilação média mensal de 7,5% a 20,4% do total de raios medidos por sensoriamento remoto e a quantidade varia de acordo com o tipo de superfície, sendo que na região oceânica observou-se baixa incidência de raios NS, nas regiões mais próximas ao litoral observou-se no primeiro semestre os maiores valores da proporção de incidência de raios NS, enquanto que no interior do continente, o máximo de atividade elétrica do tipo nuvem-solo apresenta maiores percentuais durante o segundo semestre. Também foi constatado que o relevo não altera a proporção de incidência dos raios NS, uma vez que não foi encontrada uma relação direta somente com a altura do relevo. Relationship Between Total Lightning and Cloud-To-Ground Lightning in Eastern AmazoniaA B S T R A C TAn analysis of the occurrence of cloud-to-ground (CG) lightning, measured by ground-based sensors, and total lightning (CG and intra-cloud (IC) lightning), detected by satellite remote sensing, was performed in this study to compare the proportion of CG lightning between the two lightning location systems (LLS) in Eastern Amazonia. STARNET and LRTMS (OTD/LIS) data were used. The method of analysis consisted of calculating the Z ratio, the proportion of incidence of CG lightning and the Pearson correlation coefficient. Furthermore, the variation in the number of CG lightning flashes as a function of terrain altitude was also investigated. The results indicated that the mean monthly CG lightning incidence ranges from 7.5% to 20.4% of the total lightning measured by remote sensing and that the number of CG lightning flashes varies according to surface type. More specifically, the oceanic region showed low CG lightning incidence, with the regions closest to the coast having the highest proportion of CG lightning incidence in the first semester; in contrast, the CG electrical activity peaked inland during the second semester. The results also showed that the terrain had no effect on the proportion of CG lightning incidence because no direct relationship with terrain height alone was found.Keywords: Proportion, Z Ratio, Terrain Altitude.

Negli ultimi tre decenni l'elettronica delle telecomunicazioni mobili ha subito un grande miglioramento, questo ramo dell'elettronica si è rivelato una delle principali forze trainanti nello sviluppo delle nuove tecnologie CMOS. in tutto il mondo richiedono dispositivi portatili estremamente performanti, più veloci, più affidabili, a basso consumo energetico. Questa situazione è diventata estremamente favorevole per lo sviluppo di dispositivi digitali ad alte prestazioni in grado di raggiungere velocità e capacità di memoria prima incredibili. Anche i blocchi di costruzione analogici devono essere integrati in nodi profondamente ridimensionati, al fine di adattarsi ai circuiti integrati digitali . Il primo compito di questo lavoro di tesi è stata l'implementazione e la misurazione di diversi circuiti integrati in due nodi tecnologici profondamente scalati come CMOS bulk a 28 nm e FinFET (Fin Field Effect Transistor) a 16 nm. In particolare, il secondo di questi introduce novità sulla struttura del transistor utilizzato per implementare i circuiti. Ciascun circuito realizzato incontra diverse difficoltà dovute al particolare comportamento di tali tecnologie avanzate, in particolare in termini di basso intrinsic gain e basso output voltage swing come conseguenza della bassa tensione di alimentazione. Ho lavorato nel progetto FinFET16 con il compito principale di realizzare e validare il layout di un filtro analogico Super-Source-Follower fully-differential del 4° ordine. Dopo le misurazioni, il filtro raggiunge 15,1 dBm IIP3 in banda a 10 MHz e toni di ingresso 11 MHz, con un consumo energetico di 968 µW da una singola tensione di alimentazione da 1 V. Il rumore integrato in banda è 85,78 µVrms per una figura di merito complessiva di 162,8 dB (j-1) che supera lo stato dell'arte dei filtri analogici. Ho anche collaborato come layoutista in altri due progetti realizzati con tecnologia CMOS a 28 nm. Il primo è stato il progetto PRIN Brain28nm che riguarda l'implementazione di una catena di acquisizione del segnale neurale. L'obiettivo di questo lavoro era la realizzazione di un biosensore che utilizza la struttura EOMOSFET con il nodo tecnologico CMOS a 28 nm. L'utilizzo di questa tecnologia rende questo circuito più competitivo rispetto ai biosensori presenti in letteratura. L'ultimo progetto è stato il progetto Pignoletto realizzato in collaborazione con RedCat Devices. Esso riguarda l'implementazione e l'analisi teorica di due diverse tipologie di circuiti integrati misurati sotto irraggiamento: due celle digitali e un convertitore da analogico a digitale. Nella seconda parte del mio terzo anno ho iniziato un'attività lavorativa presso la sede di Pavia della AMS come validation engineer. Questa azienda è leader mondiale nel campo dell'Automotive Interior Lightning. ll progetto che sto portando avanti prevede la realizzazione di un setup di validazione per un IC, al fine di verificare il corretto svolgimento delle molteplici funzioni per le quali questo chip è progettato. Una prima analisi, utile allo studio preliminare per la realizzazione del setup, è stata effettuata attraverso l'utilizzo di un FPGA su cui è stato caricato il codice che realizza la parte logica dell'IC utilizzando il software Quartus. Una volta validato il corretto funzionamento dell'FPGA, attraverso l'utilizzo di un microcontrollore STM32, sono state testate e correttamente validate diverse configurazioni e funzioni. Lo scopo finale di questa attività, che proseguirà nei prossimi mesi, è la validazione di alcune modalità di comunicazione tra diversi dispositivi, fondamentali per l'interfaccia dell'IC con gli standard automotive, e la creazione di una versione aggiornata del codice FPGA e della sua successiva verifica. Questa attività sembra essere una novità nel campo del design di circuiti integrati perché potrebbe permettere di evidenziare eventuali problemi.
In the last three decades Mobile Telecommunication (TLC) electronics has undergone a great improvement, this limited branch of electronics proved to be one of the major driving motor in the development of the new Complementary Metal-Oxide-Semiconductor (CMOS) technologies. People all around the world ask for extremely performing portable devices, faster, more reliable, low power consuming and with impressive memory capability. This situation has become extremely favorable for the development of high performance digital devices which are able to reach speed and memory capability previously unbelievable. Also analog building blocks must be integrated in deeply down-scaled node, in order to adapt with digital integrated circuits (ICs). First task of this thesis work was the implementation and measurement of different integrated circuits in two deep sub-micron technology nodes as 28nm bulk-CMOS and 16nm FinFET (Fin Field Effect Transistor). In particular the second one of these introduces novelty about the structure of transistor used to implement the circuits. Each circuit created faces various difficulties due to the particular behaviour of such advanced technologies, in particular in terms of low intrinsic gain and limited signal swing as consequence of low supply voltage. I worked in FinFET16 project with the main task to realize and validate the layout of a 4^th Order Fully-Differential Super-Source-Follower Analog Filter. After measurements the filter achieves 15.1 dBm in-band IIP3 at 10 MHz & 11 MHz input tones, with 968 µW power consumption from a single 1V supply voltage. In-band integrated noise is 85.78 µVrms for an overall Figure-of-Merit of 162.8 dB (j-1) which outperforms analog filters State-of-the-Art. I also collaborated as layoutist in other two projects realized with 28nm CMOS technology. The first one was the PRIN Brain28nm project that concerns the implementation of a neural signal acquisition chain. The goal of this work was the realization of a biosensor that uses the EOMOSFET structure with the 28nm CMOS technological node. The use of this technology makes this circuit more competitive when compared to the biosensors present in literature. The last one was Pignoletto project realized in collaboration with RedCat Devices. It concerns the implementation and theorical analysis of two different typologies of ICs measured under radiation: two digital cells and one Analog to Digital Converter. Under radiation measurements will be realize in January 2023. In the second part of my third year I started a work activity in Pavia site of AMS-Osram S.r.l as validation engineer. This company is a world leader in the field of optical sensors and the application of the latter in the automotive sector. The project I am carrying out involves the creation of a validation setup for an IC, in order to verify the correct performance of the multiple functions for which this chip is designed. A first analysis, useful for the preliminary study for the realization of the setup, was carried out through the use of an FPGA (Cyclone1000) on which the code that realizes the logic part of the IC was loaded using the Quartus software. Once the correct operation of the FPGA was validated, through the use of an STM32 micro-controller, various configurations and functions have been tested and correctly validated. The final purpose of this activity, which will continue in the coming months, is the validation of some communication methods between different devices, fundamental for the interface of the IC with automotive standards, and the creation of an updated version of the FPGA code and its subsequent verification. This activity appears to be a novelty in the field of integrated circuit design as it would allow to highlight problems and malfunctions of the circuit.

The vehicle has become an intelligent product by innovative technologies. However, most of the new technologies address human safety, such as lane keeping or emergency brake assistance. The smart optimization of the driver’s well-being through sensitivity of the technology has been neglected so far. Thus, this study investigates the influence of emotion-sensitive lighting on the driver. Individual light interactions are based on detected emotions of the driver to enhance the individual driving experience. IntroductionLight and colors have an archaic effect on humans (Goldstein 2015). They trigger the human diencephalon to release the serotonin as well as cortisol. For example, light blue components in the light suppress melatonin release. This driver feels awake or concentrated. (Sabine Harrasko-Kocmann) Different factors such as traffic jams, aggressive driving behavior of other road users and challenging weather conditions have a negative impact on the driver’s feeling (Bitkina et al. 2019). The consequences are negative emotions such as anger, fear and worry, which in turn lead to inattention and insecurity. Also factors like tiredness and physical exhaustion can impact the human well-beeing. As a result, the driver is unfocused and annoyed after the ride or agitated and restless. Furthermore, stress for example, increases the risk of accidents because people become inattentive (Evers 2011). To counteract this and positively influence the driving experience, specific lighting interactions are intended to enhance the driver's feelings. In this work, lighting is used to influence the driver's mood. The aim of the study is to investigate whether the targeted use of light contributes to increase the well-being and which use-cases are particularly suitable.ApproachFig.1 shows the scientific approach for this work. Firstly, requirements are defined. They are based on a literature review on the psychological effects of light, an investigation of the target groups and a reflection on highly emotional driving situations. For testing, three use cases are defined in detail. The first deals with increasing the driver's concentration, the second with targeted stress reduction and the third with positive reinforcement of emotion. They include the emotional level of the driver, his or her journey start and destination, the target emotion, and the light interaction to achieve this emotion. A vehicle-prototype is modified to test the individual scenarios. Besides LED strips along the windscreen, the door frames and interior ambient lights, screens are installed in the doors and the roof [Fig.2]. In this way, not only individual light colors and intensities can be visualized, but also more complex, dynamic movements. To get a uniform effect the interior lights are synchronized with the visualization of the screens.Fig.2: CAD rendering of the prototype. One screen is placed in each of the doors and one in the roof. LED strips run along the windscreen and door frame. Ambient lights at the whole interior.For the qualitative study, 35 test persons are interviewed by using the prototype [Fig.3]. All test persons passing though the three use-cases. In order to measure the success of the light effect, the pulse and surface moisture of the skin are measured. In addition, there is a discussion before and after each use case. ConclusionThe prototype has been built and the lightning interaction implemented. During the preparation of this abstract, the user testings are conducted. The full paper and also the oral presentation will show more details about the methodology and the evaluation of the testing.