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Sample records for f-35 lightning ii

  1. Lightning Tracking Tool for Assessment of Total Cloud Lightning within AWIPS II

    NASA Technical Reports Server (NTRS)

    Burks, Jason E.; Stano, Geoffrey T.; Sperow, Ken

    2014-01-01

    Total lightning (intra-cloud and cloud-to-ground) has been widely researched and shown to be a valuable tool to aid real-time warning forecasters in the assessment of severe weather potential of convective storms. The trend of total lightning has been related to the strength of a storm's updraft. Therefore a rapid increase in total lightning signifies the strengthening of the parent thunderstorm. The assessment of severe weather potential occurs in a time limited environment and therefore constrains the use of total lightning. A tool has been developed at NASA's Short-term Prediction Research and Transition (SPoRT) Center to assist in quickly analyzing the total lightning signature of multiple storms. The development of this tool comes as a direct result of forecaster feedback from numerous assessments requesting a real-time display of the time series of total lightning. This tool also takes advantage of the new architecture available within the AWIPS II environment. SPoRT's lightning tracking tool has been tested in the Hazardous Weather Testbed (HWT) Spring Program and significant changes have been made based on the feedback. In addition to the updates in response to the HWT assessment, the lightning tracking tool may also be extended to incorporate other requested displays, such as the intra-cloud to cloud-to-ground ratio as well as incorporate the lightning jump algorithm.

  2. Lightning

    ERIC Educational Resources Information Center

    Pampe, William R.

    1970-01-01

    Presents basic physical theory for movement of electric charges in clouds, earth, and air during production of lightning and thunder. Amount of electrical energy produced and heating effects during typical thunderstorms is described. Generalized safety practices are given. (JM)

  3. Lightning Detection

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Lightning causes an estimated $50 million annually in damages to power lines, transformers and other electric utility equipment. Lightning strikes are not yet predictable, but U.S. East Coast Lightning Detection Network (LDN) is providing utilities and other clients data on lightning characteristics, flash frequency and location, and the general direction in which lightning associated storms are heading. Monitoring stations are equipped with direction finding antennas that detect lightning strikes reaching the ground by measuring fluctuations in the magnetic field. Stations relay strike information to SUNY-Albany-LDN operations center which is manned around the clock. Computers process data, count strikes, spot their locations, and note other characteristics of lightning, LDN's data is beamed to a satellite for broadcast to client's receiving stations. By utilizing real-time lightning strike information, managers are now more able to effectively manage their resources. This reduces outage time for utility customers.

  4. Lightning burns.

    PubMed

    Russell, Katie W; Cochran, Amalia L; Mehta, Sagar T; Morris, Stephen E; McDevitt, Marion C

    2014-01-01

    We present the case of a lightning-strike victim. This case illustrates the importance of in-field care, appropriate referral to a burn center, and the tendency of lightning burns to progress to full-thickness injury.

  5. Objective Lightning Probability Forecasting for Kennedy Space Center and Cape Canaveral Air Force Station, Phase II

    NASA Technical Reports Server (NTRS)

    Lambert, Winifred; Wheeler, Mark

    2007-01-01

    This report describes the work done by the Applied Meteorology Unit (AMU) to update the lightning probability forecast equations developed in Phase I. In the time since the Phase I equations were developed, new ideas regarding certain predictors were formulated and a desire to make the tool more automated was expressed by 45 WS forecasters. Five modifications were made to the data: 1) increased the period of record from 15 to 17 years, 2) modified the valid area to match the lighting warning areas, 3) added the 1000 UTC CCAFS sounding to the other soundings in determining the flow regime, 4) used a different smoothing function for the daily climatology, and 5) determined the optimal relative humidity (RH) layer to use as a predictor. The new equations outperformed the Phase I equations in several tests, and improved the skill of the forecast over the Phase I equations by 8%. A graphical user interface (GUI) was created in the Meteorological Interactive Data Display System (MIDDS) that gathers the predictor values for the equations automatically. The GUI was transitioned to operations in May 2007 for the 2007 warm season.

  6. Ball lightning

    NASA Astrophysics Data System (ADS)

    Stenhoff, Mark

    Ball lightning is alleged by some to be a rare atmospheric phenomenon usually associated with thunderstorms, while others hold that it does not exist. This controversy has continued for centuries. This study comprises a critical evaluation of evidence for the existence of ball lightning. An historical review of the controversy is first presented, giving a chronological account of developments in ball lightning theories and of important observations alleged to be of the phenomenon. Other phenomena which might be mistaken for ball lightning are then subjected to a more detailed study than has hitherto been published, and the means by which such misidentifications could be recognized areestablished. A discussion of psychological and perceptual aspects indicates that descriptions could not always be taken at face value, and that many accounts of alleged ball lightning would be expected to contain substantial inaccuracies. The original intention to evaluate cases of alleged ball lightning already published in scientific journals was abandoned because there was no standardisation of information content, and because the majority of reports contained insufficient information for evaluation. Many reports had been written in a style which indicated an assumption that ball lightning was the cause of the event. Approximately 200 unpublished reports were therefore collected and subjected to evaluation. It was found that the majority of reports of alleged ball lightning could be explained by other means, and there was only a very small residue of reports which could not easily be thus explained. A large proportion of the reports could be attributed to corona discharge effects such as St Elmo's fire, or by familiar effects of conventional linear lightning. The validity of many previously published statistical studies of ball lightning was shown to be doubtful. The thesis concludes with a comparitive discussion of the merits and demerits of some of the diverse physical models

  7. Lightning Phenomenology

    NASA Astrophysics Data System (ADS)

    Kawasaki, Zen

    This paper presents a phenomenological idea about lightning flash to share the back ground understanding for this special issue. Lightning discharges are one of the terrible phenomena, and Benjamin Franklin has led this natural phenomenon to the stage of scientific investigation. Technical aspects like monitoring and location are also summarized in this article.

  8. [Transfection efficiency of adenoviral vector AD5/F35 to malignant hematopoietic cells of different origins].

    PubMed

    Wabg, Kai; Peng, Jian-Qinag; Yuan, Zhen-Hua; Wu, Xiao-Bin

    2006-06-01

    This study was aimed to investigate the transfection efficiency of adenoviral vector AD5/F35 to hematopoietic malignant cells lines of various origins and AD5/F35 cytotoxicity. The hematologic malignant cell lines of various origins were transfected by AD5/F35-EGFP at different multiple of infection (MOI) and AD5-EGFP was used as control; the proportion of fluorescence positive cells was detected by flow cytometry; the killing effect of virus on infective target cells was assayed by MTT and observed by fluorescence microscopy. The results showed that the transfection efficiency of AD5/F35 vector to cell line of myeloid origin was > 99% at MOI = 30, the transfective efficiency of AD5 vector was 26.4% at MOI = 1,000; the transfection efficiency of AD5/F35 vector and AD5 vector to cell line of B cell origin were 11.7% and 5.7%, respectively, at MOI = 1,000. AD5/F35 and AD5 vectors could not effectively transfect cells of T cell origin, no fluorescence positive cells were detected at MOI = 1,000; no significant killing effect of AD5/F35 vector on infective target cells was observed at MOI = 1,000. It is concluded that AD5/F35 vector infection has definite selectivity to hematologic malignant cells of various origin, the infection ability of AD5/F35 vector to cells of myeloid origin is stronger than that to cells of B cell origin, the cytotoxicity of AD5/F35 vector to infective target cells is small. The AD5/F35 vector is preferable to AD5 vector in respect of infection ability and offers good prospects of application in gene therapy for myeloid leukemia cells as target cells.

  9. 78 FR 44102 - Record of Decision for F35A Training Basing Final Environmental Impact Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... Department of the Air Force Record of Decision for F35A Training Basing Final Environmental Impact Statement... second ROD for the F-35A Training Basing Final Environmental Impact Statement (FEIS). The ROD states the... (42 U.S.C. 4321, et seq.) and the Air Force's Environmental Impact Analysis Process (EIAP) (32...

  10. 77 FR 47826 - Record of Decision for F35A Training Basing Final Environmental Impact Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-10

    ... Department of the Air Force Record of Decision for F35A Training Basing Final Environmental Impact Statement... United States Air Force signed the ROD for the F35A Training Basing Final Environmental Impact Statement... the provisions of the NEPA of 1969 (42 USC. 4321, et seq.) and the Air Force's Environmental...

  11. Absorption of gamma-ray photons in a vacuum neutron star magnetosphere: II. The formation of 'lightnings'

    SciTech Connect

    Istomin, Ya. N. Sob'yanin, D. N.

    2011-10-15

    The absorption of a high-energy photon from the external cosmic gamma-ray background in the inner neutron star magnetosphere triggers the generation of a secondary electron-positron plasma and gives rise to a lightning-a lengthening and simultaneously expanding plasma tube. It propagates along magnetic fields lines with a velocity close to the speed of light. The high electron-positron plasma generation rate leads to dynamical screening of the longitudinal electric field that is provided not by charge separation but by electric current growth in the lightning. The lightning radius is comparable to the polar cap radius of a radio pulsar. The number of electron-positron pairs produced in the lightning in its lifetime reaches 10{sup 28}. The density of the forming plasma is comparable to or even higher than that in the polar cap regions of ordinary pulsars. This suggests that the radio emission from individual lightnings can be observed. Since the formation time of the radio emission is limited by the lightning lifetime, the possible single short radio bursts may be associated with rotating radio transients (RRATs).

  12. Lightning Science: Five Ways Lightning Strikes People

    MedlinePlus

    ... Centers Products and Services Contact Us Glossary Lightning Science: Five Ways Lightning Strikes People It is not ... of a streamer injury. For more on the science of lightning: National Severe Storms Laboratory NWS Colorado ...

  13. Lightning Protection

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Kit-built airplanes are more affordable because they are assembled by the owner and do not require Federal Aviation Administration (FAA) certification. The Glasair III, is an advanced technology homebuilt, constructed of a fiberglass and graphite fiber composite material, and equipped with digital instruments. Both technologies make the airplane more susceptible to lightning effects. When Glasair manufacturer, Stoddard-Hamilton, decided that lightning protection would enable more extensive instrument flight and make the plane more marketable, they proposed a joint development program to NASA Langley Research Center (LAR). Under a Small Business Innovation Research (SBIR) contract, Langley contractors designed and tested a lightning protection system, and the Glasair III-LP became the first kit-built composite aircraft to be lightning tested and protection-verified under FAA guidelines for general aviation aircraft.

  14. Evidence for a Second F35 Pion-Nucleon Resonance near 2000 MeV

    NASA Astrophysics Data System (ADS)

    Manley, D. Mark

    1984-06-01

    A recent isobar-model, partial-wave analysis of πN-->ππN finds strong indications of the F35 pion-nucleon resonance belonging to the (70,L=2+) baryon multiplet. This conclusion is drawn from recent predictions of baryon decays obtained with baryon compositions determined by the Isgur-Karl quark model. The highly inelastic F35 resonance is observed through its dominant p-wave decay to ρN.

  15. Cloud and Cloud-to-ground Lightning Detection at LF and VHF: Early Results from Global Atmospherics' Dallas-Fort Worth LDAR-II and IMPACT/ESP Research Networks

    NASA Astrophysics Data System (ADS)

    Demetriades, N.; Murphy, M. J.; Cummins, K. L.

    2001-12-01

    Global Atmospherics, Inc. (GAI) recently installed a regional Lightning Detection and Ranging (LDAR-II) network and a regional VLFLF lightning detection network of IMPACTESP and LPATS IV sensors (configured to detect both cloud-to-ground lightning and cloud discharges) for research purposes in the vicinity of Dallas-Fort Worth (DFW) International Airport. The LDAR-II and VLF/LF networks became fully operational on 1 March 2001 and 10 June 2001, respectively. The DFW LDAR-II network is made up of 7 sensors, with 20 to 30 km baselines, that can detect pulses of radiation produced by the electrical breakdown processes of lightning in a 5-MHz band within a subset of the VHF (50-120 MHz) band. This regional LDAR-II network can map lightning flashes in 3-dimensions within approximately 150 km of the center of the network, degrading in performance with increasing range. Expected lightning flash detection efficiency is greater than 99% within the interior of the DFW LDAR-II network (a range of 30 km from DFW International Airport) and greater than 90% out to a range of 150 km from DFW International Airport. Expected three-dimensional location accuracy for individual pulses of radiation is better than 100 m within the interior of the network and better than 2 km to a range of 150 km from the network center. Early analysis of the DFW LDAR-II and VLF/LF networks has involved comparisons with the U.S. National Lightning Detection Network (NLDN) and radar base reflectivity images from the DFW National Weather Service (NWS) radar. The results of these comparisons will be summarized for representative thunderstorm cases. In addition, a specific case involving an extensive "spider lightning" discharge will be presented. This discharge originated at a distance of more than 50 km from DFW airport, traveled a total path of approximately 150 km, and initiated four isolated cloud-to-ground discharges - one of which resulted in a safety-related incident at DFW airport.

  16. Usage of the SYSCAP II circuit analysis program to determine semiconductor failure threshold levels caused by lightning/EMP transients

    NASA Astrophysics Data System (ADS)

    Rusher, D. L.; Kleiner, C. T.

    1983-06-01

    An improved technique for calculating semiconductor junction heating resulting from arbitrary time-varying source terms is described. A FORTRAN subroutine is developed which permits solution of the convolution integral in the SYSCAP circuit analysis program which will simulate the thermal transient for each semiconductor of interest in a circuit subject to lightning/electromagnetic pulses disturbances. An example circuit is used to demonstrate the techniques; the results compare favorably with laboratory test data.

  17. Lightning Detection in a Flash

    NASA Technical Reports Server (NTRS)

    2001-01-01

    In a joint project with NASA's Kennedy Space Center, Global Atmospherics, Inc. (GAI), participated in the upgrade and commercialization of the Lightning Detection and Ranging (LDAR) System. Under a Space Act Agreement, GAI and Kennedy agreed to the joint development of a new LDAR system that meets the needs of both NASA and private industry. The resulting development was a volumetric lightning mapping system. NASA operates a three- dimensional LDAR system capable of determining the exact location and altitude of in-cloud and cloud-to-cloud lightning. Under the Space Act Agreement, GAI contributed its wealth of experience and resources to update and improve the current lightning mapping system used by NASA. Previously, commercial systems were only capable of locating cloud-to-ground lightning. The resulting innovations allowed GAI to position the LDAR system for commercial applications. The upgraded product has the ability to measure in-cloud and cloud-to-cloud lightning. Notable improvements have also been made in the system's location accuracy and signal detection. The new product, known as LDAR II, is targeted for use by utility providers, aviation companies, airports, and commercial space vehicle launch facilities. Presently, forecasting services, research facilities, and a utility company are using the system.

  18. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey; Chronis, Themis

    2015-01-01

    Using satellite-based methods that provide accurate 0-1 hour convective initiation (CI) nowcasts, and rely on proven success coupling satellite and radar fields in the Corridor Integrated Weather System (CIWS; operated and developed at MIT-Lincoln Laboratory), to subsequently monitor for first-flash lightning initiation (LI) and later period lightning trends as storms evolve. Enhance IR-based methods within the GOES-R CI Algorithm (that must meet specific thresholds for a given cumulus cloud before the cloud is considered to have an increased likelihood of producing lightning next 90 min) that forecast LI. Integrate GOES-R CI and LI fields with radar thresholds (e.g., first greater than or equal to 40 dBZ echo at the -10 C altitude) and NWP model data within the WDSS-II system for LI-events from new convective storms. Track ongoing lightning using Lightning Mapping Array (LMA) and pseudo-Geostationary Lightning Mapper (GLM) data to assess per-storm lightning trends (e.g., as tied to lightning jumps) and outline threat regions. Evaluate the ability to produce LI nowcasts through a "lightning threat" product, and obtain feedback from National Weather Service forecasters on its value as a decision support tool.

  19. Natural lightning flashes: from observation to modeling

    NASA Astrophysics Data System (ADS)

    Defer, E.; Farges, T.; Barthe, C.; Bovalo, C.; Pinty, J.-P.; Chong, M.; Soula, S.; Ortéga, P.

    2011-12-01

    Different ground-based and space-based sensors are currently used to characterize and locate Earth lightning flashes like VHF mappers, VLF systems with short or long baseline, optical CCD camera and more recently microphone arrays. Concurrent observations with such equipments offer a unique description of the different processes occurring during the life of a lightning flash (triggering phase, leader development and junction phase). While the detection of lightning flashes becomes mature, more challenging investigations are still needed on i{)} Lightning Nitrogen Oxide (LINOx) production and on ii{)} the modeling of natural lightning discharges, even if ''engineer'' lightning schemes combined with electrification schemes are already implemented in numerical cloud resolving models. The PEACH project, the Atmospheric Electricity component of the upcoming field experiment HyMeX, will offer a unique opportunity for the European community to document and characterize the Mediterranean lightning activity with observations and modeling from the lightning scale to the regional scale and to gather the French community in preparation for the validation of future space-based missions like TARANIS and MTG-LI and for the interpretation of their lightning observations.

  20. Lightning superbolts

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A rare type of lightning bolt previously not thought to occur in flatlands has been identified in Oklahoma prairie storms and could pose a danger to structures not built to withstand it. Researchers at NOAA say the discovery could indicate that buildings or power plants designed on the assumption that such destructive bolts do not occur in flatland might not be safe. The positive charge cloud-to-ground flashes once were thought to strike only when triggered by a tall structure or mountaintop, or, on rare occasions, at the end of a storm.‘Most storms never produce this kind of lightning. In a few storms, there may be one positive bolt, just as the storm is dissipating—sort of the last gasp of the storm,’ according to David Rust of the National Severe Storms Laboratory. Rust added that the triggered bolts often are very high current, making them especially destructive. ‘We know these bolts don't occur in garden variety storms. We are trying to find if the occurrence of this kind of lightning is linked with storm severity,’ Rust said

  1. 76 FR 39392 - Record of Decision for the F-35 Force Development Evaluation and Weapons School Beddown, Nellis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Air Force Record of Decision for the F-35 Force Development Evaluation and Weapons School... Air Force signed the ROD for the F-35 Force Development Evaluation (FDE) and Weapons School...

  2. Lightning Physics and Effects

    NASA Astrophysics Data System (ADS)

    Orville, Richard E.

    2004-03-01

    Lightning Physics and Effects is not a lightning book; it is a lightning encyclopedia. Rarely in the history of science has one contribution covered a subject with such depth and thoroughness as to set the enduring standard for years, perhaps even decades, to come. This contribution covers all aspects of lightning, including lightning physics, lightning protection, and the interaction of lightning with a variety of objects and systems as well as the environment. The style of writing is well within the ability of the technical non-expert and anyone interested in lightning and its effects. Potential readers will include physicists; engineers working in the power industry, communications, computer, and aviation industries; atmospheric scientists; geophysicists; meteorologists; atmospheric chemists; foresters; ecologists; physicians working in the area of electrical trauma; and, lastly, architects. This comprehensive reference volume contains over 300 illustrations, 70 tables with quantitative information, and over 6000 reference and bibliography entries.

  3. Updated Lightning Safety Recommendations.

    ERIC Educational Resources Information Center

    Vavrek, R. James; Holle, Ronald L.; Lopez, Raul E.

    1999-01-01

    Summarizes the recommendations of the Lightning Safety Group (LSG), which was first convened during the 1998 American Meteorological Society Conference. Findings outline appropriate actions under various circumstances when lightning threatens. (WRM)

  4. The Lightning Discharge

    ERIC Educational Resources Information Center

    Orville, Richard E.

    1976-01-01

    Correspondence of Benjamin Franklin provides authenticity to a historical account of early work in the field of lightning. Present-day theories concerning the formation and propagation of lightning are expressed and photographic evidence provided. (CP)

  5. Lightning safety of animals.

    PubMed

    Gomes, Chandima

    2012-11-01

    This paper addresses a concurrent multidisciplinary problem: animal safety against lightning hazards. In regions where lightning is prevalent, either seasonally or throughout the year, a considerable number of wild, captive and tame animals are injured due to lightning generated effects. The paper discusses all possible injury mechanisms, focusing mainly on animals with commercial value. A large number of cases from several countries have been analyzed. Economically and practically viable engineering solutions are proposed to address the issues related to the lightning threats discussed.

  6. Efficient gene transfer into normal human B lymphocytes with the chimeric adenoviral vector Ad5/F35.

    PubMed

    Jung, Daniel; Néron, Sonia; Drouin, Mathieu; Jacques, Annie

    2005-09-01

    The failure to efficiently introduce genes into normal cells such as human B lymphocytes limits the characterization of their function on cellular growth, differentiation and survival. Recent studies have shown that a new adenoviral vector Ad5/F35 can efficiently transduce human haematopoietic CD34+ progenitor cells. In this study, we compared the gene transfer efficiencies of the Ad5/F35 vector to that of the parental vector Ad5 in human B lymphocytes. Peripheral blood B cells obtained from healthy individuals were cultured in vitro using CD40-CD154 system. Normal B lymphocytes were infected with replication-defectives Ad5 and Ad5/F35, both containing the GFP reporter gene, and transduction efficiencies were monitored by flow cytometry. Ad5 was highly ineffective, infecting only about 5% of human B lymphocytes. In contrast, Ad5/F35 transduced up to 60% of human B lymphocytes and GFP expression could be detected for up to 5 days post infection. Importantly, physiology of B lymphocytes such as proliferation, viability and antibodies secretion were unaffected following Ad5/F35 transduction. Finally, we observed that memory B lymphocytes were more susceptible to Ad5/F35 infection than naïve B lymphocytes. Thus, our results demonstrate that the adenoviral vector Ad5/F35 is an efficient tool for the functional characterization of genes in B lymphopoiesis.

  7. Thunderclouds and Lightning Conductors

    ERIC Educational Resources Information Center

    Martin, P. F.

    1973-01-01

    Discusses the historical background of the development of lightning conductors, describes the nature of thunderclouds and the lightning flash, and provides a calculation of the electric field under a thundercloud. Also discussed are point discharge currents and the attraction theory of the lightning conductor. (JR)

  8. Living with lightning

    SciTech Connect

    Lamarre, L.

    1994-01-01

    As many as 100 lightning flashes occur around the world each second. Electric utilities know well the impact of lightning in terms of dollars, lost productivity, and lives. EPRI research, which began with a study of lightning`s natural characteristics, has resulted in tools utilities can use to better track and prepare for thunderstorms. Recently the institute completed a series of tests using small rockets to trigger and direct lightning strikes. Now EPRI-sponsored researchers are developing a laser-based technology they believe will be able to guide thunderbolts safely to the ground and ultimately even to discharge thunderclouds.

  9. MSFC shuttle lightning research

    NASA Technical Reports Server (NTRS)

    Vaughan, Otha H., Jr.

    1993-01-01

    The shuttle mesoscale lightning experiment (MLE), flown on earlier shuttle flights, and most recently flown on the following space transportation systems (STS's), STS-31, -32, -35, -37, -38, -40, -41, and -48, has continued to focus on obtaining additional quantitative measurements of lightning characteristics and to create a data base for use in demonstrating observation simulations for future spaceborne lightning mapping systems. These flights are also providing design criteria data for the design of a proposed shuttle MLE-type lightning research instrument called mesoscale lightning observational sensors (MELOS), which are currently under development here at MSFC.

  10. 75 FR 12519 - Notice of Intent To Prepare an Environmental Impact Statement for Beddown of Training F-35A Aircraft

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... Training F-35A Aircraft AGENCY: Air Education and Training Command and Air National Guard, United States..., 266 F Street West, Randolph AFB, TX 78150-4319, telephone 210/652-1961. Bao-Anh Trinh, Air...

  11. Lightning in superconductors

    PubMed Central

    Vestgården, J. I.; Shantsev, D. V.; Galperin, Y. M.; Johansen, T. H.

    2012-01-01

    Crucially important for application of type-II superconductor films is the stability of the vortex matter – magnetic flux lines penetrating the material. If some vortices get detached from pinning centres, the energy dissipated by their motion will facilitate further depinning, and may trigger a massive electromagnetic breakdown. Up to now, the time-resolved behaviour of these ultra-fast events was essentially unknown. We report numerical simulation results revealing the detailed dynamics during breakdown as within nanoseconds it develops branching structures in the electromagnetic fields and temperature, with striking resemblance of atmospheric lightning. During a dendritic avalanche the superconductor is locally heated above its critical temperature, while electrical fields rise to several kV/m as the front propagates at instant speeds near up to 100 km/s. The numerical approach provides an efficient framework for understanding the ultra-fast coupled non-local dynamics of electromagnetic fields and dissipation in superconductor films. PMID:23185691

  12. A Lightning Safety Primer for Camps.

    ERIC Educational Resources Information Center

    Attarian, Aram

    1992-01-01

    Provides the following information about lightning, which is necessary for camp administrators and staff: (1) warning signs of lightning; (2) dangers of lightning; (3) types of lightning injuries; (4) prevention of lightning injury; and (5) helpful training tips. (KS)

  13. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey

    2015-01-01

    . 2011) to monitor lightning trends and to anticipate/forecast severe weather (hail > or =2.5 cm, winds > or =25 m/s, tornadoes). The result will be a time-continuous algorithm that uses GOES satellite, radar fields, and HRRR model fields to nowcast first-flash LI and QL, and subsequently monitors lightning trends on a perstorm basis within the LJ algorithm for possible severe weather occurrence out to > or =3 hours. The LI-QL-LJ product will also help prepare the operational forecast community for Geostationary Lightning Mapper (GLM) data expected in late 2015, as these data are monitored for ongoing convective storms. The LI-QL-LJ product will first predict where new lightning is highly probable using GOES imagery of developing cumulus clouds, followed by n analysis of NWS (dual-polarization) radar indicators (reflectivity at the -10 C altitude) of lightning occurrence, to increase confidence that LI is immanent. Once lightning is observed, time-continuous lightning mapping array and Pseudo-GLM observations will be analyzed to assess trends and the severe weather threat as identified by trends in lightning (i.e. LJs). Additionally, 5- and 15-min GOES imagery will then be evaluated on a per-storm basis for overshooting and other cloud-top features known to be associated with severe storms. For the processing framework, the GOES-R 0-1 hour convective initiation algorithm's output will be developed within the Warning Decision Support System - Integrated Information (WDSS-II) tracking tool, and merged with radar and lightning (LMA/Psuedo-GLM) datasets for active storms. The initial focus of system development will be over North Alabama for select lightning-active days in summer 2014, yet will be formed in an expandable manner. The lightning alert tool will also be developed in concert with National Weather Service (NWS) forecasters to meet their needs for real-time, accurate first-flash LI and timing, as well as anticipated lightning trends, amounts, continuation and

  14. Lightning Activities and Earthquakes

    NASA Astrophysics Data System (ADS)

    Liu, Jann-Yenq

    2016-04-01

    The lightning activity is one of the key parameters to understand the atmospheric electric fields and/or currents near the Earth's surface as well as the lithosphere-atmosphere coupling during the earthquake preparation period. In this study, to see whether or not lightning activities are related to earthquakes, we statistically examine lightning activities 30 days before and after 78 land and 230 sea M>5.0 earthquakes in Taiwan during the 12-year period of 1993-2004. Lightning activities versus the location, depth, and magnitude of earthquakes are investigated. Results show that lightning activities tend to appear around the forthcoming epicenter and are significantly enhanced a few, especially 17-19, days before the M>6.0 shallow (depth D< 20 km) land earthquakes. Moreover, the size of the area around the epicenter with the statistical significance of lightning activity enhancement is proportional to the earthquake magnitude.

  15. Polar Lightning on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Images taken by the New Horizons Long-Range Reconnaissance Imager (LORRI) of Jupiter's night side showed lightning strikes. Each 'strike' is probably the cumulative brightness of multiple strikes. This is the first lightning seen at high latitudes on Jupiter; it demonstrates that convection is not confined to lower latitudes, implying an internal driving heat source. Their power is consistent with previous lightning measurements at Jupiter's lower latitudes, equivalent to extremely bright terrestrial 'super bolts.'

  16. Lightning safety of animals.

    PubMed

    Gomes, Chandima

    2012-11-01

    This paper addresses a concurrent multidisciplinary problem: animal safety against lightning hazards. In regions where lightning is prevalent, either seasonally or throughout the year, a considerable number of wild, captive and tame animals are injured due to lightning generated effects. The paper discusses all possible injury mechanisms, focusing mainly on animals with commercial value. A large number of cases from several countries have been analyzed. Economically and practically viable engineering solutions are proposed to address the issues related to the lightning threats discussed. PMID:22215021

  17. Influence of cell physiological state on gene delivery to T lymphocytes by chimeric adenovirus Ad5F35.

    PubMed

    Zhang, Wen-feng; Shao, Hong-wei; Wu, Feng-lin; Xie, Xin; Li, Zhu-ming; Bo, Hua-ben; Shen, Han; Wang, Teng; Huang, Shu-lin

    2016-01-01

    Adoptive transfer of genetically-modified T cells is a promising approach for treatment of both human malignancies and viral infections. Due to its ability to efficiently infect lymphocytes, the chimeric adenovirus Ad5F35 is potentially useful as an immunotherapeutic for the genetic modification of T cells. In previous studies, it was found that the infection efficiency of Ad5F35 was significantly increased without enhanced expression of the viral receptor after T cell stimulation; however, little is known about the underlying mechanism. Nonetheless, cell physiology has long been thought to affect viral infection. Therefore, we aimed to uncover the physiologic changes responsible for the increased infection efficiency of Ad5F35 following T cell stimulation. Given the complexity of intracellular transport we analyzed viral binding, entry, and escape using a Jurkat T cell model and found that both cell membrane fluidity and endosomal escape of Ad5F35 were altered under different physiological states. This, in turn, resulted in differences in the amount of virus entering cells and reaching the cytoplasm. These results provide additional insight into the molecular mechanisms underlying Ad5F35 infection of T cells and consequently, will help further the clinical application of genetically-modified T cells for immunotherapy. PMID:26972139

  18. Influence of cell physiological state on gene delivery to T lymphocytes by chimeric adenovirus Ad5F35

    PubMed Central

    Zhang, Wen-feng; Shao, Hong-wei; Wu, Feng-lin; Xie, Xin; Li, Zhu-Ming; Bo, Hua-Ben; Shen, Han; Wang, Teng; Huang, Shu-lin

    2016-01-01

    Adoptive transfer of genetically-modified T cells is a promising approach for treatment of both human malignancies and viral infections. Due to its ability to efficiently infect lymphocytes, the chimeric adenovirus Ad5F35 is potentially useful as an immunotherapeutic for the genetic modification of T cells. In previous studies, it was found that the infection efficiency of Ad5F35 was significantly increased without enhanced expression of the viral receptor after T cell stimulation; however, little is known about the underlying mechanism. Nonetheless, cell physiology has long been thought to affect viral infection. Therefore, we aimed to uncover the physiologic changes responsible for the increased infection efficiency of Ad5F35 following T cell stimulation. Given the complexity of intracellular transport we analyzed viral binding, entry, and escape using a Jurkat T cell model and found that both cell membrane fluidity and endosomal escape of Ad5F35 were altered under different physiological states. This, in turn, resulted in differences in the amount of virus entering cells and reaching the cytoplasm. These results provide additional insight into the molecular mechanisms underlying Ad5F35 infection of T cells and consequently, will help further the clinical application of genetically-modified T cells for immunotherapy. PMID:26972139

  19. The physics of lightning

    NASA Astrophysics Data System (ADS)

    Dwyer, Joseph R.; Uman, Martin A.

    2014-01-01

    Despite being one of the most familiar and widely recognized natural phenomena, lightning remains relatively poorly understood. Even the most basic questions of how lightning is initiated inside thunderclouds and how it then propagates for many tens of kilometers have only begun to be addressed. In the past, progress was hampered by the unpredictable and transient nature of lightning and the difficulties in making direct measurements inside thunderstorms, but advances in instrumentation, remote sensing methods, and rocket-triggered lightning experiments are now providing new insights into the physics of lightning. Furthermore, the recent discoveries of intense bursts of X-rays and gamma-rays associated with thunderstorms and lightning illustrate that new and interesting physics is still being discovered in our atmosphere. The study of lightning and related phenomena involves the synthesis of many branches of physics, from atmospheric physics to plasma physics to quantum electrodynamics, and provides a plethora of challenging unsolved problems. In this review, we provide an introduction to the physics of lightning with the goal of providing interested researchers a useful resource for starting work in this fascinating field. By what physical mechanism or mechanisms is lightning initiated in the thundercloud? What is the maximum cloud electric field magnitude and over what volume of the cloud? What, if any, high energy processes (runaway electrons, X-rays, gamma rays) are involved in lightning initiation and how? What is the role of various forms of ice and water in lightning initiation? What physical mechanisms govern the propagation of the different types of lightning leaders (negative stepped, first positive, negative dart, negative dart-stepped, negative dart-chaotic) between cloud and ground and the leaders inside the cloud? What is the physical mechanism of leader attachment to elevated objects on the ground and to the flat ground? What are the characteristics

  20. [Neurological diseases after lightning strike : Lightning strikes twice].

    PubMed

    Gruhn, K M; Knossalla, Frauke; Schwenkreis, Peter; Hamsen, Uwe; Schildhauer, Thomas A; Tegenthoff, Martin; Sczesny-Kaiser, Matthias

    2016-06-01

    Lightning strikes rarely occur but 85 % of patients have lightning-related neurological complications. This report provides an overview about different modes of energy transfer and neurological conditions related to lightning strikes. Moreover, two case reports demonstrate the importance of interdisciplinary treatment and the spectrum of neurological complications after lightning strikes. PMID:26873252

  1. [Neurological diseases after lightning strike : Lightning strikes twice].

    PubMed

    Gruhn, K M; Knossalla, Frauke; Schwenkreis, Peter; Hamsen, Uwe; Schildhauer, Thomas A; Tegenthoff, Martin; Sczesny-Kaiser, Matthias

    2016-06-01

    Lightning strikes rarely occur but 85 % of patients have lightning-related neurological complications. This report provides an overview about different modes of energy transfer and neurological conditions related to lightning strikes. Moreover, two case reports demonstrate the importance of interdisciplinary treatment and the spectrum of neurological complications after lightning strikes.

  2. Lightning Often Strikes Twice

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Contrary to popular misconception, lightning often strikes the same place twice. Certain conditions are just ripe for a bolt of electricity to come zapping down; and a lightning strike is powerful enough to do a lot of damage wherever it hits. NASA created the Accurate Location of Lightning Strikes technology to determine the ground strike point of lightning and prevent electrical damage in the immediate vicinity of the Space Shuttle launch pads at Kennedy Space Center. The area surrounding the launch pads is enmeshed in a network of electrical wires and components, and electronic equipment is highly susceptible to lightning strike damage. The accurate knowledge of the striking point is important so that crews can determine which equipment or system needs to be retested following a strike. Accurate to within a few yards, this technology can locate a lightning strike in the perimeter of the launch pad. As an added bonus, the engineers, then knowing where the lightning struck, can adjust the variables that may be attracting the lightning, to create a zone that will be less susceptible to future strikes.

  3. Birth of ball lightning

    NASA Astrophysics Data System (ADS)

    Lowke, J. J.; Smith, D.; Nelson, K. E.; Crompton, R. W.; Murphy, A. B.

    2012-10-01

    Many observations of ball lightning report a ball of light, about 10 cm in diameter, moving at about walking speed, lasting up to 20 s and frequently existing inside of houses and even aeroplanes. The present paper reports detailed observations of the initiation or birth of ball lightning. In two cases, navigation crew of aircraft saw ball lightning form at the windscreen inside the cockpit of their planes. In the first case, the ball lightning occurred during a thunderstorm, with much lightning activity outside of the plane. In the second case, large "horns" of electrical corona were seen outside of the plane at the surface of the radome, just prior to the formation of the ball lightning. A third case reports ball lightning formed inside of a house, during a thunderstorm, at a closed glass window. It is proposed, based on two-dimensional calculations of electron and ion transport, that ball lightning in these cases is driven and formed by atmospheric ions impinging and collecting on the insulating surface of the glass or Perspex windows. This surface charge can produce electric fields inside of the cockpit or room sufficient to sustain an electric discharge. Charges of opposite sign to those outside of the window accumulate on the inside surface of the glass, leaving a ball of net charge moving inside of the cockpit or room to produce a pulsed discharge on a microsecond time scale.

  4. Future Jet Technologies. Part B. F-35 Future Risks v. JS-Education of Pilots & Engineers

    NASA Astrophysics Data System (ADS)

    Gal-Or, Benjamin

    2011-09-01

    Design of “Next-Generation” airframes based on supermarket-jet-engine-components is nowadays passé. A novel integration methodology [Gal-Or, “Editorial-Review, Part A”, 2011, Gal-Or, “Vectored Propulsion, Supermaneuverability and Robot Aircraft”, Springer Verlag, Gal-Or, Int'l. J. of Thermal and Fluid Sciences 7: 1-6, 1998, “Introduction”, 2011] is nowadays in. For advanced fighter aircraft it begins with JS-based powerplant, which takes up to three times longer to mature vis-à-vis the airframe, unless “committee's design” enforces a dormant catastrophe. Jet Steering (JS) or Thrust Vectoring Flight Control, is a classified, integrated engine-airframe technology aimed at maximizing post-stall-maneuverability, flight safety, efficiency and flight envelopes of manned and unmanned air vehicles, especially in the “impossible-to-fly”, post-stall flight domains where the 100+ years old, stall-spin-limited, Conventional Flight Control fails. Worldwide success in adopting the post-stall, JS-revolution, opens a new era in aviation, with unprecedented design variables identified here for a critical review of F-35 future risks v. future fleets of jet-steered, pilotless vehicles, like the X-47B/C. From the educational point of view, it is also instructive to comprehend the causes of long, intensive opposition to adopt post-stall, JS ideas. A review of such debates may also curb a future opposition to adopt more advanced, JS-based technologies, tests, strategies, tactics and missions within the evolving air, marine and land applications of JS. Most important, re-education of pilots and engineers requires adding post-stall, JS-based studies to curriculum & R&D.

  5. 75 FR 3715 - Notice of Intent To Prepare an Environmental Impact Statement for Basing F-35a Operational Aircraft

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-22

    ... identified that potential environmental impacts at Shaw AFB/ McEntire JNGB would be analyzed for no action... Department of the Air Force Notice of Intent To Prepare an Environmental Impact Statement for Basing F-35a... description of the alternative is as follows, ``Shaw AFB/McEntire JNGB would be analyzed for no action and...

  6. Using the VAHIRR Radar Algorithm to Investigate Lightning Cessation

    NASA Technical Reports Server (NTRS)

    Stano, Geoffrey T.; Schultz, Elise V.; Petersen, Walter A.

    2012-01-01

    Accurately determining the threat posed by lightning is a major area for improved operational forecasts. Most efforts have focused on the initiation of lightning within a storm, with far less effort spent investigating lightning cessation. Understanding both components, initiation and cessation, are vital to improving lightning safety. Few organizations actively forecast lightning onset or cessation. One such organization is the 45th Weather Squadron (45WS) for the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45WS has identified that charged anvil clouds remain a major threat of continued lightning and can greatly extend the window of a potential lightning strike. Furthermore, no discernable trend of total lightning activity has been observed consistently for all storms. This highlights the need for more research to find a robust method of knowing when a storm will cease producing lightning. Previous lightning cessation work has primarily focused on forecasting the cessation of cloud-to -ground lightning only. A more recent, statistical study involved total lightning (both cloud-to-ground and intracloud). Each of these previous works has helped the 45WS take steps forward in creating improved and ultimately safer lightning cessation forecasts. Each study has either relied on radar data or recommended increased use of radar data to improve cessation forecasts. The reasoning is that radar data is able to either directly or by proxy infer more about dynamical environment leading to cloud electrification and eventually lightning cessation. The authors of this project are focusing on a two ]step approach to better incorporate radar data and total lightning to improve cessation forecasts. This project will utilize the Volume Averaged Height Integrated Radar Reflectivity (VAHIRR) algorithm originally developed during the Airborne Field Mill II (ABFM II) research project. During the project, the VAHIRR product showed a trend of increasing

  7. Lightning in aeronautics

    NASA Astrophysics Data System (ADS)

    Lago, F.

    2014-11-01

    It is generally accepted that a civilian aircraft is struck, on average, once or twice per year. This number tends to indicate that a lightning strike risk is far from being marginal and so requires that aircraft manufacturers have to demonstrate that their aircraft is protected against lightning. The first generation of aircrafts, which were manufactured mainly in aluminium alloy and had electromechanical and pneumatic controls, had a natural immunity to the effects of lightning. Nowadays, aircraft structures are made primarily with composite materials and flight controls are mostly electronic. This aspect of the "more composite and more electric" aircraft demands to aircraft manufacturers to pay a particular attention to the lightning protection and to its certification by testing and/or analysis. It is therefore essential to take this risk into account when designing the aircraft. Nevertheless, it is currently impossible to reproduce the entire lightning phenomenon in testing laboratories and the best way to analyse the lightning protection is to reproduce its effects. In this context, a number of standards and guides are produced by standards committees to help laboratories and aircraft manufacturers to perform realistic tests. Although the environment of a laboratory is quite different from those of a storm cloud, the rules of aircraft design, the know-how of aircraft manufacturers, the existence of international work leading to a better understanding of the lightning phenomenon and standards more precise, permit, today, to consider the risk as properly controlled.

  8. Lightning Technology: Proceedings of a Technical Symposium

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Several facets of lightning technology are considered including phenomenology, measurement, detection, protection, interaction, and testing. Lightning electromagnetics, protection of ground systems, and simulated lightning testing are emphasized. The lightning-instrumented F-106 aircraft is described.

  9. Lightning hazards to aircraft

    NASA Technical Reports Server (NTRS)

    Corn, P. B.

    1978-01-01

    Lightning hazards and, more generally, aircraft static electricity are discussed by a representative for the Air Force Flight Dynamics Laboratory. An overview of these atmospheric electricity hazards to aircraft and their systems is presented with emphasis on electrical and electronic subsystems. The discussion includes reviewing some of the characteristics of lightning and static electrification, trends in weather and lightning-related mishaps, some specific threat mechanisms and susceptible aircraft subsystems and some of the present technology gaps. A roadmap (flow chart) is presented to show the direction needed to address these problems.

  10. Note on lightning temperature

    SciTech Connect

    Alanakyan, Yu. R.

    2015-10-15

    In this paper, some features of the dynamics of a lightning channel that emerges after the leader-streamer process, are theoretically studied. It is shown that the dynamic pinch effect in the channel becomes possible if a discharge current before the main (quasi-steady) stage of a lightning discharge increases rapidly. The ensuing magnetic compression of the channel increases plasma temperature to several million degrees leading to a soft x-ray flash within the highly ionized plasma. The relation between the plasma temperature and the channel radius during the main stage of a lightning discharge is derived.

  11. Medical Aspects of Lightning

    MedlinePlus

    ... FORECAST Local Graphical Aviation Marine Rivers and Lakes Hurricanes Severe Weather Fire Weather Sun/Moon Long Range ... Safety Campaigns Air Quality Drought Floods Fog Heat Hurricanes Lightning Rip Currents Safe Boating Space Weather Tornadoes, ...

  12. Lightning Protection for Explosive Facilities

    SciTech Connect

    Ong, M

    2001-12-01

    Lawrence Livermore National Laboratory funds construction of lightning protection systems to protect explosive processing and storage facilities. This paper provides an intuitive understanding of the lighting risks and types of lightning protection available. Managers can use this information to decide if limited funds should be spent constructing a lightning protection system for their own facilities. This paper answers the following questions: (1) Why do you need lightning protection systems? (2) How do lightning protection systems work? and (3) Why are there no documented cases of lightning problems at existing explosive facilities?

  13. Lightning effects on aircraft

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Direct and indirect effects of lightning on aircraft were examined in relation to aircraft design. Specific trends in design leading to more frequent lightning strikes were individually investigated. These trends included the increasing use of miniaturized, solid state components in aircraft electronics and electric power systems. A second trend studied was the increasing use of reinforced plastics and other nonconducting materials in place of aluminum skins, a practice that reduces the electromagnetic shielding furnished by a conductive skin.

  14. Upward Lightning in Brazil

    NASA Astrophysics Data System (ADS)

    Schumann, C.; Saba, M. M.; Alves, J.; Warner, T. A.; Albrecht, R. I.; Bie, L. L.

    2012-12-01

    Observations of upward lightning from tall objects have been reported since 1939. Interest in this subject has grown recently, some of it because of the rapid expansion of wind power generation. Also, with the increasing number of tall buildings and towers, there will be a corresponding increase in the number of upward lightning flashes from these structures. Reports from recent field observations are beginning to address the nature of upward lightning initiation, but much still needs to be learned. Examples are studies of upward lightning from towers in winter thunderstorms in Japan (Wang and Takagi, 2010; and Lu et al., 2009) and summer thunderstorms in Europe (Miki et al., 2005; Flache et al., 2008; and Diendorfer et al., 2009; Zhou et al., 2011) and in North America (Mazur and Ruhnke, 2011; Hussein et al., 2011; Warner, 2011, and Warner et al., 2011). Up to January 2012, no upward flash had ever been registered in Brazil. With the help of some video cameras, we recorded 15 upward lightning which started from one of the towers located on Peak Jaraguá in the city of São Paulo. This paper describes the first results of this field campaign. A combination of high-speed video and standard definition video were used to record upward lightning flashes from multiple towers in Sao Paulo, Brazil, a city located in southeastern Brazil with a population over 10 million people, an average elevation of around 800 meters above sea level, and a flash density of 15 flashes/km2/year. Observations of 15 upward flashes made with these assets were analyzed along with BrasilDAT Lightning Detection Network and a lightning mapping array (LMA) and electric field sensors.

  15. The Sandia Lightning Simulator.

    SciTech Connect

    Martinez, Leonard E.; Caldwell, Michele

    2005-01-01

    The Sandia Lightning Simulator at Sandia National Laboratories can provide up to 200 kA for a simulated single lightning stroke, 100 kA for a subsequent stroke, and hundreds of Amperes of continuing current. It has recently been recommissioned after a decade of inactivity and the single-stroke capability demonstrated. The simulator capabilities, basic design components, upgrades, and diagnostic capabilities are discussed in this paper.

  16. Ball lightning burn.

    PubMed

    Selvaggi, Gennaro; Monstrey, Stan; von Heimburg, Dennis; Hamdi, Mustapha; Van Landuyt, Koen; Blondeel, Phillip

    2003-05-01

    Ball lightning is a rare physical phenomenon, which is not yet completely explained. It is similar to lightning but with different, peculiar characteristics. It can be considered a mix of fire and electricity, concentrated in a fireball with a diameter of 20-cm that most commonly appears suddenly, even in indoor conditions, during a thunderstorm. It moves quickly for several meters, can change direction, and ultimately disappears. During a great storm, a 28-year-old man and his 5-year-old daughter sustained burn wounds after ball lightning came from the outdoors through a chimney. These two patients demonstrated signs of fire and electrical injuries. The father, who lost consciousness, sustained superficial second-degree burn wounds bilaterally on the zygomatic area and deep second-degree burn wounds on his right hand (total body surface area, 4%). His daughter demonstrated superficial second-degree burn wounds on the left part of the face and deep second-degree and third-degree burn wounds (total body surface area, 30%) on the left neck, both upper arms, and the back. In this article, the authors report the first two cases of burn injuries resulting from ball lightning contact indoors. The literature on this rare phenomenon is reviewed to elucidate the nature of ball lightning. Emphasis is placed on the nature of injuries after ball lightning contact, the therapy used, and the long-term complications.

  17. The physics of lightning

    NASA Astrophysics Data System (ADS)

    Dwyer, Joseph R.; Uman, Martin A.

    2014-01-01

    Despite being one of the most familiar and widely recognized natural phenomena, lightning remains relatively poorly understood. Even the most basic questions of how lightning is initiated inside thunderclouds and how it then propagates for many tens of kilometers have only begun to be addressed. In the past, progress was hampered by the unpredictable and transient nature of lightning and the difficulties in making direct measurements inside thunderstorms, but advances in instrumentation, remote sensing methods, and rocket-triggered lightning experiments are now providing new insights into the physics of lightning. Furthermore, the recent discoveries of intense bursts of X-rays and gamma-rays associated with thunderstorms and lightning illustrate that new and interesting physics is still being discovered in our atmosphere. The study of lightning and related phenomena involves the synthesis of many branches of physics, from atmospheric physics to plasma physics to quantum electrodynamics, and provides a plethora of challenging unsolved problems. In this review, we provide an introduction to the physics of lightning with the goal of providing interested researchers a useful resource for starting work in this fascinating field. By what physical mechanism or mechanisms is lightning initiated in the thundercloud? What is the maximum cloud electric field magnitude and over what volume of the cloud? What, if any, high energy processes (runaway electrons, X-rays, gamma rays) are involved in lightning initiation and how? What is the role of various forms of ice and water in lightning initiation? What physical mechanisms govern the propagation of the different types of lightning leaders (negative stepped, first positive, negative dart, negative dart-stepped, negative dart-chaotic) between cloud and ground and the leaders inside the cloud? What is the physical mechanism of leader attachment to elevated objects on the ground and to the flat ground? What are the characteristics

  18. Ball lightning burn.

    PubMed

    Selvaggi, Gennaro; Monstrey, Stan; von Heimburg, Dennis; Hamdi, Mustapha; Van Landuyt, Koen; Blondeel, Phillip

    2003-05-01

    Ball lightning is a rare physical phenomenon, which is not yet completely explained. It is similar to lightning but with different, peculiar characteristics. It can be considered a mix of fire and electricity, concentrated in a fireball with a diameter of 20-cm that most commonly appears suddenly, even in indoor conditions, during a thunderstorm. It moves quickly for several meters, can change direction, and ultimately disappears. During a great storm, a 28-year-old man and his 5-year-old daughter sustained burn wounds after ball lightning came from the outdoors through a chimney. These two patients demonstrated signs of fire and electrical injuries. The father, who lost consciousness, sustained superficial second-degree burn wounds bilaterally on the zygomatic area and deep second-degree burn wounds on his right hand (total body surface area, 4%). His daughter demonstrated superficial second-degree burn wounds on the left part of the face and deep second-degree and third-degree burn wounds (total body surface area, 30%) on the left neck, both upper arms, and the back. In this article, the authors report the first two cases of burn injuries resulting from ball lightning contact indoors. The literature on this rare phenomenon is reviewed to elucidate the nature of ball lightning. Emphasis is placed on the nature of injuries after ball lightning contact, the therapy used, and the long-term complications. PMID:12792547

  19. Situational Lightning Climatologies

    NASA Technical Reports Server (NTRS)

    Bauman, William; Crawford, Winifred

    2010-01-01

    Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. It was believed there were two flow systems, but it has been discovered that actually there are seven distinct flow regimes. The Applied Meteorology Unit (AMU) has recalculated the lightning climatologies for the Shuttle Landing Facility (SLF), and the eight airfields in the National Weather Service in Melbourne (NWS MLB) County Warning Area (CWA) using individual lightning strike data to improve the accuracy of the climatologies. The software determines the location of each CG lightning strike with 5-, 10-, 20-, and 30-nmi (.9.3-, 18.5-, 37-, 55.6-km) radii from each airfield. Each CG lightning strike is binned at 1-, 3-, and 6-hour intervals at each specified radius. The software merges the CG lightning strike time intervals and distance with each wind flow regime and creates probability statistics for each time interval, radii, and flow regime, and stratifies them by month and warm season. The AMU also updated the graphical user interface (GUI) with the new data.

  20. Lightning detection technology and applications of lightning data

    NASA Astrophysics Data System (ADS)

    Nag, Amitabh; Holle, Ronald L.

    2012-08-01

    International Lightning Detection Conference/International Lightning Meteorology Conference; Broomfield, Colorado, 2-5 April 2012 More than 100 lightning scientists, meteorologists, and engineers attended the 22nd International Lightning Detection Conference (ILDC) and the 4th International Lightning Meteorology Conference (ILMC) sponsored by Vaisala Inc., in Broomfeld, Colo., this spring. Nearly half of the attendees were from outside the United States, making this event a truly international forum for discussing the science of lightning detection and its applications. ILDC has been held every other year for the past 17 years and took place annually before then. Traditionally, ILDC/ILMC has been a forum for designers and operators of lightning detection networks and users of network data to discuss the latest advances in technology and applications of lightning data for research and operational purposes, as well as technological innovations required to meet future operational challenges.

  1. Evidence for lightning on Venus

    NASA Technical Reports Server (NTRS)

    Strangeway, R. J.

    1992-01-01

    Lightning is an interesting phenomenon both for atmospheric and ionospheric science. At the Earth lightning is generated in regions where there is strong convection. Lightning also requires the generation of large charge-separation electric fields. The energy dissipated in a lightning discharge can, for example, result in chemical reactions that would not normally occur. From an ionospheric point of view, lightning generates a broad spectrum of electromagnetic radiation. This radiation can propagate through the ionosphere as whistler mode waves, and at the Earth the waves propagate to high altitudes in the plasmasphere where they can cause energetic particle precipitation. The atmosphere and ionosphere of Venus are quite different from those on the Earth, and the presence of lightning at Venus has important consequences for our knowledge of why lightning occurs and how the energy is dissipated in the atmosphere and ionosphere. As discussed here, it now appears that lightning occurs in the dusk local time sector at Venus.

  2. 75 FR 78229 - Record of Decision for the U.S. Marine Corps West Coast Basing of the F-35B Aircraft

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-15

    ... Range, to accommodate Field Carrier Landing Practice for the F-35B. The F-35B aircraft will replace 126 legacy F/A-18A/B/C/D Hornet and 56 AV-8B Harrier aircraft in the Third Marine Air Wing (3D MAW) and...

  3. Evidence for solar wind modulation of lightning

    NASA Astrophysics Data System (ADS)

    Scott, C. J.; Harrison, R. G.; Owens, M. J.; Lockwood, M.; Barnard, L.

    2014-05-01

    The response of lightning rates over Europe to arrival of high speed solar wind streams at Earth is investigated using a superposed epoch analysis. Fast solar wind stream arrival is determined from modulation of the solar wind V y component, measured by the Advanced Composition Explorer spacecraft. Lightning rate changes around these event times are determined from the very low frequency arrival time difference (ATD) system of the UK Met Office. Arrival of high speed streams at Earth is found to be preceded by a decrease in total solar irradiance and an increase in sunspot number and Mg II emissions. These are consistent with the high speed stream’s source being co-located with an active region appearing on the Eastern solar limb and rotating at the 27 d period of the Sun. Arrival of the high speed stream at Earth also coincides with a small (˜1%) but rapid decrease in galactic cosmic ray flux, a moderate (˜6%) increase in lower energy solar energetic protons (SEPs), and a substantial, statistically significant increase in lightning rates. These changes persist for around 40 d in all three quantities. The lightning rate increase is corroborated by an increase in the total number of thunder days observed by UK Met stations, again persisting for around 40 d after the arrival of a high speed solar wind stream. This result appears to contradict earlier studies that found an anti-correlation between sunspot number and thunder days over solar cycle timescales. The increase in lightning rates and thunder days that we observe coincides with an increased flux of SEPs which, while not being detected at ground level, nevertheless penetrate the atmosphere to tropospheric altitudes. This effect could be further amplified by an increase in mean lightning stroke intensity that brings more strokes above the detection threshold of the ATD system. In order to remove any potential seasonal bias the analysis was repeated for daily solar wind triggers occurring during the summer

  4. Plotting Lightning-Stroke Data

    NASA Technical Reports Server (NTRS)

    Tatom, F. B.; Garst, R. A.

    1986-01-01

    Data on lightning-stroke locations become easier to correlate with cloudcover maps with aid of new graphical treatment. Geographic region divided by grid into array of cells. Number of lightning strokes in each cell tabulated, and value representing density of lightning strokes assigned to each cell. With contour-plotting routine, computer draws contours of lightning-stroke density for region. Shapes of contours compared directly with shapes of storm cells.

  5. Exploring Lightning Jump Characteristics

    NASA Technical Reports Server (NTRS)

    Chronis, Themis; Carey, Larry D.; Schultz, Christopher J.; Schultz, Elise; Calhoun, Kristin; Goodman, Steven J.

    2014-01-01

    This study is concerned with the characteristics of storms exhibiting an abrupt temporal increase in the total lightning flash rate (i.e., lightning jump, LJ). An automated storm tracking method is used to identify storm "clusters" and total lightning activity from three different lightning detection systems over Oklahoma, northern Alabama and Washington, D.C. On average and for different employed thresholds, the clusters that encompass at least one LJ (LJ1) last longer, relate to higher Maximum Expected Size of Hail, Vertical Integrated Liquid and lightning flash rates (area-normalized) than the clusters that did not exhibit any LJ (LJ0). The respective mean values for LJ1 (LJ0) clusters are 80 min (35 min), 14 mm (8 mm), 25 kg per square meter (18 kg per square meter) and 0.05 flash per min per square kilometer (0.01 flash per min per square kilometer). Furthermore, the LJ1 clusters are also characterized by slower decaying autocorrelation functions, a result that implies a less "random" behavior in the temporal flash rate evolution. In addition, the temporal occurrence of the last LJ provides an estimate of the time remaining to the storm's dissipation. Depending of the LJ strength (i.e., varying thresholds), these values typically range between 20-60 min, with stronger jumps indicating more time until storm decay. This study's results support the hypothesis that the LJ is a proxy for the storm's kinematic and microphysical state rather than a coincidental value.

  6. The start of lightning: Evidence of bidirectional lightning initiation

    PubMed Central

    Montanyà, Joan; van der Velde, Oscar; Williams, Earle R.

    2015-01-01

    Lightning flashes are known to initiate in regions of strong electric fields inside thunderstorms, between layers of positively and negatively charged precipitation particles. For that reason, lightning inception is typically hidden from sight of camera systems used in research. Other technology such as lightning mapping systems based on radio waves can typically detect only some aspects of the lightning initiation process and subsequent development of positive and negative leaders. We report here a serendipitous recording of bidirectional lightning initiation in virgin air under the cloud base at ~11,000 images per second, and the differences in characteristics of opposite polarity leader sections during the earliest stages of the discharge. This case reveals natural lightning initiation, propagation and a return stroke as in negative cloud-to-ground flashes, upon connection to another lightning channel – without any masking by cloud. PMID:26471123

  7. The start of lightning: Evidence of bidirectional lightning initiation.

    PubMed

    Montanyà, Joan; van der Velde, Oscar; Williams, Earle R

    2015-01-01

    Lightning flashes are known to initiate in regions of strong electric fields inside thunderstorms, between layers of positively and negatively charged precipitation particles. For that reason, lightning inception is typically hidden from sight of camera systems used in research. Other technology such as lightning mapping systems based on radio waves can typically detect only some aspects of the lightning initiation process and subsequent development of positive and negative leaders. We report here a serendipitous recording of bidirectional lightning initiation in virgin air under the cloud base at ~11,000 images per second, and the differences in characteristics of opposite polarity leader sections during the earliest stages of the discharge. This case reveals natural lightning initiation, propagation and a return stroke as in negative cloud-to-ground flashes, upon connection to another lightning channel - without any masking by cloud. PMID:26471123

  8. The start of lightning: Evidence of bidirectional lightning initiation.

    PubMed

    Montanyà, Joan; van der Velde, Oscar; Williams, Earle R

    2015-10-16

    Lightning flashes are known to initiate in regions of strong electric fields inside thunderstorms, between layers of positively and negatively charged precipitation particles. For that reason, lightning inception is typically hidden from sight of camera systems used in research. Other technology such as lightning mapping systems based on radio waves can typically detect only some aspects of the lightning initiation process and subsequent development of positive and negative leaders. We report here a serendipitous recording of bidirectional lightning initiation in virgin air under the cloud base at ~11,000 images per second, and the differences in characteristics of opposite polarity leader sections during the earliest stages of the discharge. This case reveals natural lightning initiation, propagation and a return stroke as in negative cloud-to-ground flashes, upon connection to another lightning channel - without any masking by cloud.

  9. Lightning protection technology for small general aviation composite material aircraft

    NASA Technical Reports Server (NTRS)

    Plumer, J. A.; Setzer, T. E.; Siddiqi, S.

    1993-01-01

    An on going NASA (Small Business Innovative Research) SBIR Phase II design and development program will produce the first lightning protected, fiberglass, General Aviation aircraft that is available as a kit. The results obtained so far in development testing of typical components of the aircraft kit, such as the wing and fuselage panels indicate that the lightning protection design methodology and materials chosen are capable of protecting such small composite airframes from lightning puncture and structural damage associated with severe threat lightning strikes. The primary objective of the program has been to develop a lightening protection design for full scale test airframe and verify its adequacy with full scale laboratory testing, thus enabling production and sale of owner-built, lightning-protected, Stoddard-Hamilton Aircraft, Inc. Glasair II airplanes. A second objective has been to provide lightning protection design guidelines for the General Aviation industry, and to enable these airplanes to meet lightening protection requirements for certification of small airplanes. This paper describes the protection design approaches and development testing results obtained thus far in the program, together with design methodology which can achieve the design goals listed above. The presentation of this paper will also include results of some of the full scale verification tests, which will have been completed by the time of this conference.

  10. First images of thunder: Acoustic imaging of triggered lightning

    NASA Astrophysics Data System (ADS)

    Dayeh, M. A.; Evans, N. D.; Fuselier, S. A.; Trevino, J.; Ramaekers, J.; Dwyer, J. R.; Lucia, R.; Rassoul, H. K.; Kotovsky, D. A.; Jordan, D. M.; Uman, M. A.

    2015-07-01

    An acoustic camera comprising a linear microphone array is used to image the thunder signature of triggered lightning. Measurements were taken at the International Center for Lightning Research and Testing in Camp Blanding, FL, during the summer of 2014. The array was positioned in an end-fire orientation thus enabling the peak acoustic reception pattern to be steered vertically with a frequency-dependent spatial resolution. On 14 July 2014, a lightning event with nine return strokes was successfully triggered. We present the first acoustic images of individual return strokes at high frequencies (>1 kHz) and compare the acoustically inferred profile with optical images. We find (i) a strong correlation between the return stroke peak current and the radiated acoustic pressure and (ii) an acoustic signature from an M component current pulse with an unusual fast rise time. These results show that acoustic imaging enables clear identification and quantification of thunder sources as a function of lightning channel altitude.

  11. Lightning mapping sensor study

    NASA Technical Reports Server (NTRS)

    Norwood, V.

    1983-01-01

    A technology assessment to determine how a world-wide, continuous measurement of lightning could be achieved from a geostationary platform is provided. Various approaches to the detector sensors are presented. It was first determined that any existing detector chips would require some degree of modification in order to meet the lightning mapper sensor requirements. The elements of the system were then analyzed, categorized, and graded for study emphasis. The recommended approach for the lightning mapper sensor is to develop a monolithic array in which each detector cell has circuitry that implements a two-step photon-collecting method for a very high dynamic range with good measurement accuracy. The efficiency of the array is compatible with the use of a conventional refractive optics design having an aperture in the neighborhood of 7 to 10 cm.

  12. Lightning in Western Patagonia

    NASA Astrophysics Data System (ADS)

    Garreaud, René D.; Gabriela Nicora, M.; Bürgesser, Rodrigo E.; Ávila, Eldo E.

    2014-04-01

    On the basis of 8 years (2005-2012) of stroke data from the World Wide Lightning Location Network we describe the spatial distribution and temporal variability of lightning activity over Western Patagonia. This region extends from ~40°S to 55°S along the west coast of South America, is limited to the east by the austral Andes, and features a hyper-humid, maritime climate. Stroke density exhibits a sharp maximum along the coast of southern Chile. Although precipitation there is largely produced by cold nimbostratus, days with more than one stroke occur up to a third of the time somewhere along the coastal strip. Disperse strokes are also observed off southern Chile. In contrast, strokes are virtually nonexistent over the austral Andes—where precipitation is maximum—and farther east over the dry lowlands of Argentina. Atmospheric reanalysis and satellite imagery are used to characterize the synoptic environment of lightning-producing storms, exemplified by a case study and generalized by a compositing analysis. Lightning activity tends to occur when Western Patagonia is immersed in a pool of cold air behind a front that has reached the coast at ~40°S. Under these circumstances, midlevel cooling occurs before and is more prominent than near-surface cooling, leading to a weakly unstable postfrontal condition. Forced uplift of the strong westerlies impinging on the coastal mountains can trigger convection and produces significant lightning activity in this zone. Farther offshore, large-scale ascent near the cyclone's center may lift near-surface air parcels, fostering shallow convection and dispersing lightning activity.

  13. Produce documents and media information. [on lightning

    NASA Technical Reports Server (NTRS)

    Alzmann, Melanie A.; Miller, G.A.

    1994-01-01

    Lightning data and information were collected from the United States, Germany, France, Brazil, China, and Australia for the dual purposes of compiling a global lightning data base and producing publications on the Marshall Space Flight Center's lightning program. Research covers the history of lightning, the characteristics of a storm, types of lightningdischarges, observations from airplanes and spacecraft, the future fole of planes and spacecraft in lightning studies, lightning detection networks, and the relationships between lightning and rainfall. Descriptions of the Optical Transient Dectector, the Lightning Imaging Sensor, and the Lightning Mapper Sensor are included.

  14. Functional effects of mutations at F35 in the NH2-terminus of Kir6.2 (KCNJ11), causing neonatal diabetes, and response to sulfonylurea therapy.

    PubMed

    Proks, Peter; Girard, Christophe; Baevre, Halvor; Njølstad, Pål R; Ashcroft, Frances M

    2006-06-01

    Heterozygous mutations in the human Kir6.2 gene (KCNJ11), the pore-forming subunit of the ATP-sensitive K(+) channel (K(ATP) channel), cause neonatal diabetes. To date, all mutations increase whole-cell K(ATP) channel currents by reducing channel inhibition by MgATP. Here, we provide functional characterization of two mutations (F35L and F35V) at residue F35 of Kir6.2, which lies within the NH(2)-terminus. We further show that the F35V patient can be successfully transferred from insulin to sulfonylurea therapy. The patient has been off insulin for 24 months and shows improved metabolic control (mean HbA(1c) 7.58 before and 6.18% after sulfonylurea treatment; P < 0.007). Wild-type and mutant Kir6.2 were heterologously coexpressed with SUR1 in Xenopus oocytes. Whole-cell K(ATP) channel currents through homomeric and heterozygous F35V and F35L channels were increased due to a reduced sensitivity to inhibition by MgATP. The mutation also increased the open probability (P(O)) of homomeric F35 mutant channels in the absence of ATP. These effects on P(O) and ATP sensitivity were abolished in the absence of SUR1. Our results suggest that mutations at F35 cause permanent neonatal diabetes by affecting K(ATP) channel gating and thereby, indirectly, ATP inhibition. Heterozygous F35V channels were markedly inhibited by the sulfonylurea tolbutamide, accounting for the efficacy of sulfonylurea therapy in the patient.

  15. Development of a lightning activity nowcasting tool

    NASA Astrophysics Data System (ADS)

    Karagiannidis, Athanassios; Lagouvardos, Kostas; Kotroni, Vassiliki

    2015-04-01

    Electrical phenomena inside thunderstorm clouds are a significant threat to numerous activities. Summertime convective activity is usually associated to local thermal instability, which is hard to predict using numerical weather prediction models. Despite their relatively small areal extend, these thunderstorms can be violent, resulting to infrastructure damage and loss of life. In the frame of TALOS project the National Observatory of Athens has developed a lightning activity nowcasting tool. This tool uses as sole inputs: (i) real time infrared Meteosat Second Generation (MSG) imagery and (ii) real time flashes provided by the VLF lightning detection system ZEUS, which is operated by the National Observatory of Athens. The MSG SEVIRI 10.8 and 6.2μm channels data are utilized to produce 3 Interest Fields (IFs). These fields are the TB10.8 brightness temperature (indicative of the cloud top glaciation), the TB6.2-TB10.8 difference (indicative of the cloud depth) and the TB10.8 15 minute trend, which will be referenced as "TB10.8trend" (indicative of the cloud growth rate). The latter is defined as the difference between two successive 15 minutes images of the TB10.8. When a predefined threshold value is surpassed, the delimited area is considered to be favorable for lightning activity. A statistical procedure is employed to identify the optimum threshold values for the three IFs, based on the performance of each one. The assessment of their efficiency showed that these three IFs can be used independently as predictors of lightning activity. However, in an effort to improve the tool's efficiency a combined estimation is performed. When all three IFs agree that lightning activity is expected over an area, then a Warning Level 3 (WL3) is issued. When 2 or 1 IFs indicate upcoming activity then a WL2 or WL1 is issued. The assessment of the efficiency of the combined IF tool showed that the combined estimation is more skillful than the individual IFs estimations. In a

  16. Lightning protection of aircraft

    NASA Technical Reports Server (NTRS)

    Fisher, F. A.; Plumer, J. A.

    1977-01-01

    The current knowledge concerning potential lightning effects on aircraft and the means that are available to designers and operators to protect against these effects are summarized. The increased use of nonmetallic materials in the structure of aircraft and the constant trend toward using electronic equipment to handle flight-critical control and navigation functions have served as impetus for this study.

  17. Optical characteristics of lightning

    NASA Technical Reports Server (NTRS)

    Goodman, S. J.

    1985-01-01

    A study of the optical characteristics of cloud-to-ground dischargers and how they compare with intracloud flashes was completed. Time resolved optical (7774A) and electric field-change waveforms were measured above clouds from a U2 airplane coincident with ground-based measurements of lightning. The optical pulse trains are studied for within and between flash variability. Specifically, for each flash researchers examine the 10, 50 (full width half maximum), and 90 percent pulse widths; the 10-10, 10-50, 10-90, and 10-peak percent amplitude rise times; the radiances (optical power densities); radiant energy densities; and pulse intervals. The optical pulse characteristics of first strokes, subsequent strokes, the intracloud components of cloud-to-ground flashes and intracloud flashes as viewed from above cloud are shown to exhibit very similar waveshapes, radiances and radiant energy densities. Descriptive statistics on these pulse categories were tabulated for 25 visually confirmed cloud-to-ground flashes (229 optical pulses) and 232 intracloud flashes (3126 optical pulses). A companion study of lightning observations above and below cloud in storms, storm complexes, and mesoscale convective systems has also been completed. Researchers compared the mapping of total lightning activity from above clouds with ground-based measurements and storm evolution. Although the total (IC + CG) lightning activity is the more representative indication of thunderstorm growth and decay, the ground strike data can be used to locate, diagnose, and track storm evolution in a number of instances.

  18. Bead lightning formation

    SciTech Connect

    Ludwig, G.O.; Saba, M.M.F.

    2005-09-15

    Formation of beaded structures in triggered lightning discharges is considered in the framework of both magnetohydrodynamic (MHD) and hydrodynamic instabilities. It is shown that the space periodicity of the structures can be explained in terms of the kink and sausage type instabilities in a cylindrical discharge with anomalous viscosity. In particular, the fast growth rate of the hydrodynamic Rayleigh-Taylor instability, which is driven by the backflow of air into the channel of the decaying return stroke, dominates the initial evolution of perturbations during the decay of the return current. This instability is responsible for a significant enhancement of the anomalous viscosity above the classical level. Eventually, the damping introduced at the current channel edge by the high level of anomalous viscous stresses defines the final length scale of bead lightning. Later, during the continuing current stage of the lightning flash, the MHD pinch instability persists, although with a much smaller growth rate that can be enhanced in a M-component event. The combined effect of these instabilities may explain various aspects of bead lightning.

  19. The Origin of Lightning.

    ERIC Educational Resources Information Center

    Weewish Tree, 1979

    1979-01-01

    A heavenly source gives an orphaned Cherokee boy 12 silver arrows and directs him to kill the chief of the cruel Manitos (spirits). When the boy fails in his mission, the angry Manitos turn him into lightning, condemning him to flash like his silver arrows across the skies forever. (DS)

  20. Transonic Free-To-Roll Analysis of the F/A-18E and F-35 Configurations

    NASA Technical Reports Server (NTRS)

    Owens, D. Bruce; McConnell, Jeffrey K.; Brandon, Jay M.; Hall, Robert M.

    2004-01-01

    The free-to-roll technique is used as a tool for predicting areas of uncommanded lateral motions. Recently, the NASA/Navy/Air Force Abrupt Wing Stall Program extended the use of this technique to the transonic speed regime. Using this technique, this paper evaluates various wing configurations on the pre-production F/A-18E aircraft and the Joint Strike Fighter (F-35) aircraft. The configurations investigated include leading and trailing edge flap deflections, fences, leading edge flap gap seals, and vortex generators. These tests were conducted in the NASA Langley 16-Foot Transonic Tunnel. The analysis used a modification of a figure-of-merit developed during the Abrupt Wing Stall Program to discern configuration effects. The results showed how the figure-of-merit can be used to schedule wing flap deflections to avoid areas of uncommanded lateral motion. The analysis also used both static and dynamic wind tunnel data to provide insight into the uncommanded lateral behavior. The dynamic data was extracted from the time history data using parameter identification techniques. In general, modifications to the pre-production F/A-18E resulted in shifts in angle-of-attack where uncommanded lateral activity occurred. Sealing the gap between the inboard and outboard leading-edge flaps on the Navy version of the F-35 eliminated uncommanded lateral activity or delayed the activity to a higher angle-of-attack.

  1. Science of Ball Lightning (Fire Ball)

    NASA Astrophysics Data System (ADS)

    Ohtsuki, Yoshi-Hiko

    1989-08-01

    The Table of Contents for the full book PDF is as follows: * Organizing Committee * Preface * Ball Lightning -- The Continuing Challenge * Hungarian Ball Lightning Observations in 1987 * Nature of Ball Lightning in Japan * Phenomenological and Psychological Analysis of 150 Austrian Ball Lightning Reports * Physical Problems and Physical Properties of Ball Lightning * Statistical Analysis of the Ball Lightning Properties * A Fluid-Dynamical Model for Ball Lightning and Bead Lightning * The Lifetime of Hill's Vortex * Electrical and Radiative Properties of Ball Lightning * The Candle Flame as a Model of Ball Lightning * A Model for Ball Lightning * The High-Temperature Physico-Chemical Processes in the Lightning Storm Atmosphere (A Physico-Chemical Model of Ball Lightning) * New Approach to Ball Lightning * A Calculation of Electric Field of Ball Lightning * The Physical Explanation to the UFO over Xinjiang, Northern West China * Electric Reconnection, Critical Ionization Velocity, Ponderomotive Force, and Their Applications to Triggered and Ball Lightning * The PLASMAK™ Configuration and Ball Lightning * Experimental Research on Ball Lightning * Performance of High-Voltage Test Facility Designed for Investigation of Ball Lightning * List of Participants

  2. Situational Lightning Climatologies for Central Florida: Phase IV

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III

    2009-01-01

    The threat of lightning is a daily concern during the warm season in Florida. Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. Previously, the Applied Meteorology Unit (AMU) calculated the gridded lightning climatologies based on seven flow regimes over Florida for 1-, 3- and 6-hr intervals in 5-, 10-,20-, and 30-NM diameter range rings around the Shuttle Landing Facility (SLF) and eight other airfields in the National Weather Service in Melbourne (NWS MLB) county warning area (CWA). In this update to the work, the AMU recalculated the lightning climatologies for using individual lightning strike data to improve the accuracy of the climatologies. The AMU included all data regardless of flow regime as one of the stratifications, added monthly stratifications, added three years of data to the period of record and used modified flow regimes based work from the AMU's Objective Lightning Probability Forecast Tool, Phase II. The AMU made changes so the 5- and 10-NM radius range rings are consistent with the aviation forecast requirements at NWS MLB, while the 20- and 30-NM radius range rings at the SLF assist the Spaceflight Meteorology Group in making forecasts for weather Flight Rule violations during Shuttle landings. The AMU also updated the graphical user interface with the new data.

  3. Inhibitory activity of monoclonal antibody F35.25 on the interaction between hepatocytes (HepG2 cells) and preS1-specific ligands.

    PubMed

    Petit, M A; Strick, N; Dubanchet, S; Capel, F; Neurath, A R

    1991-01-01

    The capacity of a preS1-specific monoclonal antibody (McAb) F35.25 to block the attachment of preS1-specific ligands to human hepatoma HepG2 cells was studied. In order to define more precisely the fine epitope specificity of McAb F35.25, its reaction with synthetic peptides derived from the preS1 sequence (12-53) was investigated. McAb F35.25 was found to recognize better synthetic peptide preS(21-47) from the adw 2 and ayw sequences than the synthetic peptide preS(32-53) adw 2. The shortest sequence recognized by McAb F35.25 among the peptide sequence studied was preS(32-47). The corresponding amino acid sequence (for HBV subtype adw 2) is PAFGANSNNPDWDFNP. As expected, it was found that McAb F35.25 inhibited the attachment of HepG2 cells to HBsAg-cellulose, as well as to preS(21-47)-cellulose, corresponding to two HBV subtypes adw 2 and ayw. Finally, the inhibitory effect of different peptides on the interaction of McAb F35.25 with HBsAg particles containing the preS1 sequence was also studied. The peptide preS(12-47) appeared to be the most effective inhibitor. Therefore, the McAb F35.25 is specific for the sequence preS1(X to 47), where (12 less than or equal to X less than 32). These results indicate that McAb F35.25 is probably virus-neutralizing and represents a reagent of great value to study the interaction between HBV and hepatocytes independently of d/y subtype changes.

  4. Situational Lightning Climatologies for Central Florida: Phase IV: Central Florida Flow Regime Based Climatologies of Lightning Probabilities

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III

    2009-01-01

    The threat of lightning is a daily concern during the warm season in Florida. Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. Previously, the Applied Meteorology Unit (AMU) calculated the gridded lightning climatologies based on seven flow regimes over Florida for 1-, 3- and 6-hr intervals in 5-, 10-, 20-, and 30-NM diameter range rings around the Shuttle Landing Facility (SLF) and eight other airfields in the National Weather Service in Melbourne (NWS MLB) county warning area (CWA). In this update to the work, the AMU recalculated the lightning climatologies for using individual lightning strike data to improve the accuracy of the climatologies. The AMU included all data regardless of flow regime as one of the stratifications, added monthly stratifications, added three years of data to the period of record and used modified flow regimes based work from the AMU's Objective Lightning Probability Forecast Tool, Phase II. The AMU made changes so the 5- and 10-NM radius range rings are consistent with the aviation forecast requirements at NWS MLB, while the 20- and 30-NM radius range rings at the SLF assist the Spaceflight Meteorology Group in making forecasts for weather Flight Rule violations during Shuttle landings. The AMU also updated the graphical user interface with the new data.

  5. Lightning hazards overview: Aviation requirements and interests

    NASA Technical Reports Server (NTRS)

    Corn, P. B.

    1979-01-01

    A ten-year history of USAF lightning incidents is presented along with a discussion of the problems posed by lightning to current aircraft, and the hazards it constitutes to the electrical and electronic subsystems of new technology aircraft. Lightning technical protection technical needs, both engineering and operational, include: (1) in-flight data on lightning electrical parameters; (2) tech base and guidelines for protection of advanced systems and structures; (3) improved laboratory test techniques; (4) analysis techniques for predicting induced effects; (5) lightning strike incident data from general aviation; (6) lightning detection systems; (7) pilot reports on lightning strikes; and (8) better training in lightning awareness.

  6. Lightning mapper sensor design study

    NASA Technical Reports Server (NTRS)

    Eaton, L. R.; Poon, C. W.; Shelton, J. C.; Laverty, N. P.; Cook, R. D.

    1983-01-01

    World-wide continuous measurement of lightning location, intensity, and time during both day and night is to be provided by the Lightning Mapper (LITMAP) instrument. A technology assessment to determine if the LITMAP requirements can be met using existing sensor and electronic technologies is presented. The baseline concept discussed in this report is a compromise among a number of opposing requirements (e.g., ground resolution versus array size; large field of view versus narrow bandpass filter). The concept provides coverage for more than 80 percent of the lightning events as based on recent above-cloud NASA/U2 lightning measurements.

  7. Ball lightning risk to aircraft

    NASA Astrophysics Data System (ADS)

    Doe, R.; Keul, A.

    2009-04-01

    Lightning is a rare but regular phenomenon for air traffic. Aircraft are designed to withstand lightning strikes. Research on lightning and aircraft can be called detailed and effective. In the last 57 years, 18 reported lightning aviation disasters with a fatality figure of at least 714 persons occurred. For comparison, the last JACDEC ten-year average fatality figure was 857. The majority encountered lightning in the climb, descent, approach and/or landing phase. Ball lightning, a metastable, rare lightning type, is also seen from and even within aircraft, but former research only reported individual incidents and did not generate a more detailed picture to ascertain whether it constitutes a significant threat to passenger and aircraft safety. Lacking established incident report channels, observations were often only passed on as "air-travel lore". In an effort to change this unsatisfactory condition, the authors have collected a first international dataset of 38 documented ball lightning aircraft incidents from 1938 to 2001 involving 13 reports over Europe, 13 over USA/Canada, and 7 over Russia. 18 (47%) reported ball lightning outside the aircraft, 18 (47%) inside, 2 cases lacked data. 8 objects caused minor damage, 8 major damage (total: 42%), only one a crash. No damage was reported in 18 cases. 3 objects caused minor crew injury. In most cases, ball lightning lasted several seconds. 11 (29%) incidents ended with an explosion of the object. A cloud-aircraft lightning flash was seen in only 9 cases (24%) of the data set. From the detailed accounts of air personnel in the last 70 years, it is evident that ball lightning is rarely, but consistently observed in connection with aircraft and can also occur inside the airframe. Reports often came from multiple professional witnesses and in several cases, damages were investigated by civil or military authorities. Although ball lightning is no main air traffic risk, the authors suggest that incident and accident

  8. FNAS lightning detection

    NASA Technical Reports Server (NTRS)

    Miller, George P.; Alzmann, Melanie A.

    1993-01-01

    A review of past and future investigations into lightning detection from space was incorporated into a brochure. Following the collection of background information, a meeting was held to discuss the format and contents of the proposed documentation. An initial outline was produced and decided upon. Photographs to be included in the brochure were selected. Quotations with respect to printing the document were requested. In the period between 28 March and June 1993, work continued on compiling the text. Towards the end of this contract, a review of the brochure was undertaken by the technical monitor. Photographs were being revised and additional areas of lightning research were being considered for inclusion into the brochure. Included is a copy of the draft (and photographs) which is still being edited by the technical monitor at the time of this report.

  9. Ball Lightning Investigations

    NASA Astrophysics Data System (ADS)

    Bychkov, V. L.; Nikitin, A. I.; Dijkhuis, G. C.

    Ball lightning (BL) researches' review and theoretical models of three different authors are presented. The general review covers investigations from 1838 until the present day, and includes a discussion on observation data, experimental modeling, and theoretical approaches. Section 6.1 is written by Bychkov and Nikitin; authors of the sections 6.2, 6.3 and 6.4 are, respectively, Bychkov, Nikitin and Dijkhuis.

  10. Update Direct-Strike Lightning Environment for Stockpile-to-Target Sequence

    SciTech Connect

    Uman, M A; Rakov, V A; Elisme, J O; Jordan, D M; Biagi, C J; Hill, J D

    2008-10-01

    The University of Florida has surveyed all relevant publications reporting lightning characteristics and presents here an up-to-date version of the direct-strike lightning environment specifications for nuclear weapons published in 1989 by R. J. Fisher and M. A. Uman. Further, we present functional expressions for current vs. time, current derivative vs. time, second current derivative vs. time, charge transfer vs. time, and action integral (specific energy) vs. time for first return strokes, for subsequent return strokes, and for continuing currents; and we give sets of constants for these expressions so that they yield approximately the median and extreme negative lightning parameters presented in this report. Expressions for the median negative lightning waveforms are plotted. Finally, we provide information on direct-strike lightning damage to metals such as stainless steel, which could be used as components of storage containers for nuclear waste materials; and we describe UF's new experimental research program to add to the sparse data base on the properties of positive lightning. Our literature survey, referred to above, is included in four Appendices. The following four sections (II, III, IV, and V) of this final report deal with related aspects of the research: Section II. Recommended Direct-Strike Median and Extreme Parameters; Section III. Time-Domain Waveforms for First Strokes, Subsequent Strokes, and Continuing Currents; Section IV. Damage to Metal Surfaces by Lightning Currents; and Section V. Measurement of the Characteristics of Positive Lightning. Results of the literature search used to derive the material in Section II and Section IV are found in the Appendices: Appendix 1. Return Stroke Current, Appendix 2. Continuing Current, Appendix 3. Positive Lightning, and Appendix 4. Lightning Damage to Metal Surfaces.

  11. Chimeric adenoviral vector Ad5/F35-mediated APE1 siRNA enhances sensitivity of human colorectal cancer cells to radiotherapy in vitro and in vivo.

    PubMed

    Xiang, D-B; Chen, Z-T; Wang, D; Li, M-X; Xie, J-Y; Zhang, Y-S; Qing, Y; Li, Z-P; Xie, J

    2008-10-01

    Apurinic/apyrimidinic endonuclease (APE1), a bifunctional AP endonuclease/redox factor, is important in DNA repair and redox signaling, may be associated with radioresistance. Here we investigate whether targeted inhibition of APE1 can sensitize tumor cells to irradiation in vitro and in vivo. We first constructed chimeric adenoviral vector Ad5/F35 carrying human APE1 siRNA (Ad5/F35-APE1 siRNA). The infectivity of chimeric Ad5/F35 to LOVO colon cancer cells was greater than that of Ad5. APE1 was strongly expressed and nuclear factor kappaB (NF-kappaB), a downstream molecule of APE1, known as a radioresistance factor, was constitutively active in LOVO cells. Infection of LOVO cells with Ad5/F35-APE1 siRNA resulted in a dose-dependent decrease of APE1 protein and AP endonuclease activity in vitro. Ad5/F35-APE1 siRNA significantly enhanced sensitivity of LOVO cells to irradiation in clonogenic survival assays, associated with increased cell apoptosis. The APE1 expression in LOVO cells was induced by irradiation in a dose-dependent manner, accompanied with the enhancement of DNA-binding activity of NF-kappaB and Ad5/F35-APE1 siRNA effectively inhibited constitutive and irradiation-induced APE1 expression and NF-kappaB activation. In a subcutaneous nude mouse colon cancer model, Ad5/F35-APE1 siRNA (5 x 10(8) IU, intratumoral injection) inhibited the expression of APE1 protein in LOVO xenografts, and significantly enhanced inhibition of tumor growth by irradiation. In conclusion, APE1 may be involved as one of the radioresistance factors, and targeted inhibition of APE1 shows an effective means of enhancing tumor sensitivity to radiotherapy.

  12. Lightning injuries during snowy conditions.

    PubMed

    Cherington, M; Breed, D W; Yarnell, P R; Smith, W E

    1998-12-01

    Skiers and other snow sports enthusiasts can become lightning casualties. Two such accidents are reported, one being fatal. There are fewer warning signals of impending lightning strikes in winter-like conditions. However, outdoor activists should be aware of at least two suspicious clues: the appearance of convective clouds, and the presence of graupel (snow pellets) during precipitation.

  13. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Lightning protection. 25.581 Section 25.581... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Lightning Protection § 25.581 Lightning protection. (a) The airplane must be protected against catastrophic effects from lightning. (b) For...

  14. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Lightning protection. 25.581 Section 25.581... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Lightning Protection § 25.581 Lightning protection. (a) The airplane must be protected against catastrophic effects from lightning. (b) For...

  15. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Lightning protection. 25.581 Section 25.581... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Lightning Protection § 25.581 Lightning protection. (a) The airplane must be protected against catastrophic effects from lightning. (b) For...

  16. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Lightning protection. 25.581 Section 25.581... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Lightning Protection § 25.581 Lightning protection. (a) The airplane must be protected against catastrophic effects from lightning. (b) For...

  17. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Lightning protection. 25.581 Section 25.581... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Lightning Protection § 25.581 Lightning protection. (a) The airplane must be protected against catastrophic effects from lightning. (b) For...

  18. Lightning research: A user's lament

    NASA Technical Reports Server (NTRS)

    Golub, C. N.

    1984-01-01

    As a user of devices and procedures for lightning protection, the author is asking the lightning research community for cookbook recipes to help him solve his problems. He is lamenting that realistic devices are scarce and that his mission does not allow him the time nor the wherewithal to bridge the gap between research and applications. A few case histories are presented. In return for their help he is offering researchers a key to lightning technology--the use of the Eastern Test Range and its extensive resources as a proving ground for their experiment in the lightning capital of the United States. A current example is given--a joint lightning characterization project to take place there. Typical resources are listed.

  19. Lightning protection of a modern wind energy system

    NASA Astrophysics Data System (ADS)

    Jaeger, D.

    Due to their considerable height and frequent location above flat terrain, wind energy systems may be struck by lightning, with two types of severe effects: the physical destruction of structurally and/or mechanically important elements, such as a rotor blade, or the damage or interruption of system electrical and electronic equipment. The GROWIAN II DEMO lightning protection program has undertaken the development of measures which in their sophistication and complexity approximate those for aircraft. These protective measures are applied to the carbon fiber-reinforced plastic composite rotor blades, the rotor bearing, and electrical circuitry installed within the wind turbine's nacelle.

  20. The CHUVA Lightning Mapping Campaign

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.; Blakeslee, Richard J.; Bailey, Jeffrey C.; Carey, Lawrence D.; Hoeller, Hartmut; Albrecht, Rachel I.; Morales, Carlos; Pinto, Osmar; Saba, Marcelo M.; Naccarato, Kleber; Hembury, Nikki; Nag, Amitabh; Heckman, Stan; Holzworth, Robert H.; Rudlosky, Scott D.; Betz, Hans-Dieter; Said, Ryan; Rauenzahn, Kim

    2011-01-01

    The primary science objective for the CHUVA lightning mapping campaign is to combine measurements of total lightning activity, lightning channel mapping, and detailed information on the locations of cloud charge regions of thunderstorms with the planned observations of the CHUVA (Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GPM (GlobAl Precipitation Measurement) field campaign. The lightning campaign takes place during the CHUVA intensive observation period October-December 2011 in the vicinity of S o Luiz do Paraitinga with Brazilian, US, and European government, university and industry participants. Total lightning measurements that can be provided by ground-based regional 2-D and 3-D total lightning mapping networks coincident with overpasses of the Tropical Rainfall Measuring Mission Lightning Imaging Sensor (LIS) and the SEVIRI (Spinning Enhanced Visible and Infrared Imager) on the Meteosat Second Generation satellite in geostationary earth orbit will be used to generate proxy data sets for the next generation US and European geostationary satellites. Proxy data, which play an important role in the pre-launch mission development and in user readiness preparation, are used to develop and validate algorithms so that they will be ready for operational use quickly following the planned launch of the GOES-R Geostationary Lightning Mapper (GLM) in 2015 and the Meteosat Third Generation Lightning Imager (LI) in 2017. To date there is no well-characterized total lightning data set coincident with the imagers. Therefore, to take the greatest advantage of this opportunity to collect detailed and comprehensive total lightning data sets, test and validate multi-sensor nowcasting applications for the monitoring, tracking, warning, and prediction of severe and high impact weather, and to advance our knowledge of thunderstorm physics, extensive measurements from lightning mapping networks will be collected

  1. The effectiveness of the oncolytic activity induced by Ad5/F35 adenoviral vector is dependent on the cumulative cellular conditions of survival and autophagy.

    PubMed

    Kim, So Y; Kang, Sujin; Song, Jae J; Kim, Joo-Hang

    2013-04-01

    To overcome the poor tumor transduction efficiency of adenovirus serotype 5 (Ad5) observed in several types of cancer, the fiber region of Ad5, apart from its tail, was replaced by adenovirus serotype 35 (Ad35). The chimeric Ad5/F35 adenoviral vector did not exhibit any significant enhancement of transduction efficiency. CD46, a receptor for Ad35, was expressed in relatively small amounts in most of the cancer cells examined. Therefore, we investigated the pivotal factor(s) that render cancer cells susceptible to transduction. We discovered that the tumor transduction efficiency of Ad5/F35 was enhanced in the presence of rapamycin, an autophagy inducer, in some cancer cells. Analysis of survival potential and cell proliferation rates revealed that Ad5/F35 exerted a more pronounced oncolytic effect in cancer cells with higher survival potential in the presence of rapamycin.

  2. Lightning return stroke models

    NASA Technical Reports Server (NTRS)

    Lin, Y. T.; Uman, M. A.; Standler, R. B.

    1980-01-01

    We test the two most commonly used lightning return stroke models, Bruce-Golde and transmission line, against subsequent stroke electric and magnetic field wave forms measured simultaneously at near and distant stations and show that these models are inadequate to describe the experimental data. We then propose a new return stroke model that is physically plausible and that yields good approximations to the measured two-station fields. Using the new model, we derive return stroke charge and current statistics for about 100 subsequent strokes.

  3. Using Total Lightning Observations to Enhance Lightning Safety

    NASA Technical Reports Server (NTRS)

    Stano, Geoffrey T.

    2012-01-01

    Lightning is often the underrated threat faced by the public when it comes to dangerous weather phenomena. Typically, larger scale events such as floods, hurricanes, and tornadoes receive the vast majority of attention by both the general population and the media. This comes from the fact that these phenomena are large, longer lasting, can impact a large swath of society at one time, and are dangerous events. The threat of lightning is far more isolated on a case by case basis, although millions of cloud-to-ground lightning strikes hit this United States each year. While attention is given to larger meteorological events, lightning is the second leading cause of weather related deaths in the United States. This information raises the question of what steps can be taken to improve lightning safety. Already, the meteorological community s understanding of lightning has increased over the last 20 years. Lightning safety is now better addressed with the National Weather Service s access to the National Lightning Detection Network data and enhanced wording in their severe weather warnings. Also, local groups and organizations are working to improve public awareness of lightning safety with easy phrases to remember, such as "When Thunder Roars, Go Indoors." The impacts can be seen in the greater array of contingency plans, from airports to sports stadiums, addressing the threat of lightning. Improvements can still be made and newer technologies may offer new tools as we look towards the future. One of these tools is a network of sensors called a lightning mapping array (LMA). Several of these networks exist across the United States. NASA s Short-term Prediction Research and Transition Center (SPoRT), part of the Marshall Spaceflight Center, has access to three of these networks from Huntsville, Alabama, the Kennedy Space Center, and Washington D.C. The SPoRT program s mission is to help transition unique products and observations into the operational forecast environment

  4. Unsolved Mystery of Ball Lightning

    NASA Astrophysics Data System (ADS)

    Bychkov, V. L.

    Ball lightning is an unusual phenomenon always drawing attention of people. There are still questions about its origination, features, interaction with environment, and phenomena related to it. On a way of studying this phenomenon, there are a lot of difficulties, the basic of them is insufficiency of authentic, scientific data. The chapter sets as the purpose to interest the reader in the problem, to describe conditions of ball lightning occurrence, theories, and its hypotheses explanation, to include readers in a circle of experimental searches in creation of a ball lightning and its analogues, and to describe fascination of a problem and difficulty of its solution.

  5. Lightning Observations with the Upgraded Lanmguir Lab Lightning Mapping Array

    NASA Astrophysics Data System (ADS)

    Rison, W.; Krehbiel, P. R.; Hunyady, S.; Edens, H. E.; Aulich, G. D.

    2010-12-01

    The Langmuir Lab Lightning Mapping Array (LMA) is located on and around the Magdalena Mountains in central New Mexico. Recently there have been several improvements to the LMA which have dramatically increased its sensitivity. By switching most stations to solar power (which allows us to place them far from buildings and power lines) and reducing the noise of the power supply, the station-generated and local environmental noise has been reduced to levels near the theoretical thermal value. Because of the recent switch to digital television, the LMA is no longer degraded by the anthropogenic noise of distant VHF television transmitters, due to the stations mostly being switched to UHF. The distant interference was a particularly bad problem for the stations located high in the Magdalena Mountains. The combination of lower threshold values and increasing the number of stations to 16 enables lower-power sources to be detected above the local noise levels and hence located by the system. We are now able to observe the positive leaders (which produce a much lower level of VHF radiation than negative leaders) which propagate upward from a triggering rocket. Lightning channels in natural lightning discharges are also much more clearly defined than in the past. Minor discharges (with one or a few LMA-detected sources) between larger lightning flashes are routinely observed. Much more detail is observed from distant lightning discharges. (However, the increased sensitivity does not reduce the vertical and radial errors for lightning observed outside the array.) In addition to the more sensitive LMA, we continue to improve our array of high-resolution electrostatic field change stations, which provides considerable information on lightning-induced charge transfer. We will present examples of observations of natural and triggered lightning, showing the increased detail now available from the recent improvements to the Langmuir Lab LMA.

  6. Variation in Regional and Global Lightning

    NASA Astrophysics Data System (ADS)

    Holzworth, R. H., II; Brundell, J. B.; McCarthy, M.; Virts, K.; Hutchins, M. L.; Jacobson, A. R.; Heckman, S.

    2015-12-01

    Daily global lightning variation over oceans and orography, caused by major weather patterns such as typhoons and seasonal weather oscillations, are determined with high time resolution. Observations of strong variations in global lightning are used to study possible variations in magnetospheric particle densities. Strong lightning patterns associated with ocean currents are demonstrated with a study of the Gulf Stream. We located all major lightning producing storms, using a clustering algorithm on 10 years of World Wide Lightning Location Network (WWLLN) data to reduce the influence of rapidly increasing lightning network detection efficiency on temporal studies. The clustered storms are used to study the variations and patterns of global and regional lightning activity. WWLLN and Earth Networks lightning detection networks have been used to show the energy per flash of lightning over the oceans is higher than over land, and the sharp contrast at the coasts will be examined.

  7. Lightning observations using Hitachi Lightning Monitoring System (HLMS)

    NASA Astrophysics Data System (ADS)

    Takayanagi, Y.; Takashi, A.

    2013-12-01

    We have been observed lightning discharges using Hitachi Lightning Monitoring System (HLMS) in Singapore. HLMS detect electromagnetic (EM) waves associated with cloud-to-ground and intracloud discharges, and locate the EM wave sources in 3D. HLMS is consisted of VHF broadband digital interferometer (DITF) and Broadband Observation network for Lightning and Thunderstorm (BOLT). VHF DITF enables us to visualize leader developments associated with lightning discharges in real-time. The BOLT is able to locate lightning discharges such as return strokes, K events, and Narrow Bipolar Pulse (NBP), which are energetic breakdowns within thunderclouds several hundred kilometers away from the system. We examined the features of lightning in Singapore using HLMS. In Japan, normal thunderstorm has a tendency to move toward east. On the other hand, observation results using HLMS show several thunderstorm in Singapore remain in the same place for several ten minutes. We will introduce the outline of an observation in Singapore and show and discuss the observation results located by the HLMS.

  8. Multifractal analysis of lightning channel for different categories of lightning

    NASA Astrophysics Data System (ADS)

    Miranda, F. J.; Sharma, S. R.

    2016-07-01

    A study from the point of view of complex systems is done for lightning occurred at Diamantina, Sete Lagoas and São José dos Campos, during the summer from September 2009 to April 2010. For the first time, multifractal analyses were performed for different lightning categories: two-dimensional, three-dimensional, non-branched, branched, cloud, cloud-to-ground, single and multiple. We found that when using two-dimensional images of natural lightning embedded in three dimensions to perform multifractal analysis, the interpretation of the multifractal spectrum must be restricted to identification of the multi (mono) fractal character of lightning channel and to estimation of fractal dimension. We have also observed that, on the average, each category has a specific value of fractal dimension. Categories in which branches and tortuosity are more usual, like branched and cloud categories, exhibited largest fractal dimensions due to more complexity of lightning channels. The results suggest that single and multiple lightning have similar complexities in their channels, leading to the same average values of fractal, information and correlation dimensions for both categories.

  9. Lightning in the Protoplanetary Nebula?

    NASA Technical Reports Server (NTRS)

    Love, Stanley G.

    1997-01-01

    Lightning in the protoplanetary nebula has been proposed as a mechanism for creating meteoritic chondrules: enigmatic mm-sized silicate spheres formed in the nebula by the brief melting of cold precursors.

  10. Venus lightning: PROS and cons

    NASA Astrophysics Data System (ADS)

    Hunten, D. M.

    1995-04-01

    The evidence concerning the presence of lightning on Venus is summarized. There are several observations of electromagnetic pulses, but the only claimed optical detection is ambiguous. Another optical search, making use of an unusual mode of the Pioneer Venus star sensor, set an upper limit on the flash rate, 1.6% of the corresponding Earth rate. Given these difficulties and the unfavorable environment for charge separation, it is concluded that the presence of lightning at anything like the Earth rate is doubtful.

  11. Lightning Imaging via VHF Emission

    NASA Astrophysics Data System (ADS)

    Kawasaki, Z.

    2015-12-01

    Osaka University has been developing interferometric lightning mapping systems for some time, first with narrow band VHF interferometers, and then with broadband digital VHF interferometers (DITF). Recently, a collaboration between New Mexico Tech and Osaka University resulted in the development of the NMT INTF. All of these interferometric lightning mapping systems have added greatly to our understanding of lightning physics. The next generation of digital broadband VHF interferometer is now being developed in Osaka, called the Lightning Imaging via VHF Emission (LIVE) interferometer. LIVE is capable of mapping lightning in real-time with sub-millisecond time resolution, or through post processing with sub-microsecond time resolution. Near-field corrections have been developed, so that sources very close to the array can be located accurately, and so that the baselines can lengthened for improved angular resolution. LIVE is capable of locating lighting over more than a 75 dB range of brightnesses, allowing the system to be extremely sensitive, and the long baselines allow for location uncertainties as low as tens of meters. Presented are observations of lightning recorded in the Kasai area of Japan, as well as the Pengerang region of Malaysia showing the capabilities of the LIVE interferometer.

  12. NOx production in lightning

    NASA Technical Reports Server (NTRS)

    Chameides, W. L.; Stedman, D. H.; Dickerson, R. R.; Rusch, D. W.; Cicerone, R. J.

    1977-01-01

    The rate of odd nitrogen (NOx) production by electrical discharge through air was theoretically and experimentally estimated to be about 60,000 trillion NOx molecules per joule. The theoretical treatment employed a cylindrical shock-wave solution to calculate the rate of NOx production in high temperature reactions. The limits obtained were experimentally verified by subjecting a regulated air flow to electrical discharges followed by a measurement of NOx production using chemiluminescence. These measurements also indicated that water vapor content has no detectable effect on the NOx production rate. The results imply that lightning is a significant source of NOx, producing about 30-40 megatons NOx-N per year and possibly accounting for as much as 50% of the total atmospheric NOx source.

  13. Lightning and thermal injuries.

    PubMed

    Sanford, Arthur; Gamelli, Richard L

    2014-01-01

    Electrical burns are classified as either high voltage (1000 volts and higher) or low voltage (<1000 volts). The typical injury with a high-voltage electrical contact is one where subcutaneous fat, muscles, and even bones are injured. Lower voltages may have lesser injuries. The electrical current has the potential to injure via three mechanisms: injury caused by current flow, an arc injury as the current passes from source to an object, and a flame injury caused by ignition of material in the local environment. Different tissues also have different resistance to the conduction of electricity. Voltage, current (amperage), type of current (alternating or direct), path of current flow across the body, duration of contact, and individual susceptibility all determine what final injury will occur. Devitalized tissue must be evaluated and debrided. Ocular cataracts may develop over time following electrical injury. Lightning strikes may conduct millions of volts of electricity, yet the effects can range from minimal cutaneous injuries to significant injury comparable to a high-voltage industrial accident. Lightning strikes commonly result in cardiorespiratory arrest, for which CPR is effective when begun promptly. Neurologic complications from electrical and lightning injuries are highly variable and may present early or late (up to 2 years) after the injury. The prognosis for electricity-related neurologic injuries is generally better than for other types of traumatic causes, suggesting a conservative approach with serial neurologic examinations after an initial CT scan to rule out correctable causes. One of the most common complications of electrical injury is a cardiac dysrhythmia. Because of the potential for large volumes of muscle loss and the release of myoglobin, the presence of heme pigments in the urine must be evaluated promptly. Presence of these products of breakdown of myoglobin and hemoglobin puts the injured at risk for acute renal failure and must be

  14. Lightning and thermal injuries.

    PubMed

    Sanford, Arthur; Gamelli, Richard L

    2014-01-01

    Electrical burns are classified as either high voltage (1000 volts and higher) or low voltage (<1000 volts). The typical injury with a high-voltage electrical contact is one where subcutaneous fat, muscles, and even bones are injured. Lower voltages may have lesser injuries. The electrical current has the potential to injure via three mechanisms: injury caused by current flow, an arc injury as the current passes from source to an object, and a flame injury caused by ignition of material in the local environment. Different tissues also have different resistance to the conduction of electricity. Voltage, current (amperage), type of current (alternating or direct), path of current flow across the body, duration of contact, and individual susceptibility all determine what final injury will occur. Devitalized tissue must be evaluated and debrided. Ocular cataracts may develop over time following electrical injury. Lightning strikes may conduct millions of volts of electricity, yet the effects can range from minimal cutaneous injuries to significant injury comparable to a high-voltage industrial accident. Lightning strikes commonly result in cardiorespiratory arrest, for which CPR is effective when begun promptly. Neurologic complications from electrical and lightning injuries are highly variable and may present early or late (up to 2 years) after the injury. The prognosis for electricity-related neurologic injuries is generally better than for other types of traumatic causes, suggesting a conservative approach with serial neurologic examinations after an initial CT scan to rule out correctable causes. One of the most common complications of electrical injury is a cardiac dysrhythmia. Because of the potential for large volumes of muscle loss and the release of myoglobin, the presence of heme pigments in the urine must be evaluated promptly. Presence of these products of breakdown of myoglobin and hemoglobin puts the injured at risk for acute renal failure and must be

  15. Suppression of protein phosphatase 2A activity enhances Ad5/F35 adenovirus transduction efficiency in normal human B lymphocytes and in Raji cells.

    PubMed

    Cayer, Marie-Pierre; Samson, Mélanie; Bertrand, Claudia; Dumont, Nellie; Drouin, Mathieu; Jung, Daniel

    2012-02-28

    Investigation of the molecular processes which control the development and function of lymphocytes is essential for our understanding of humoral immunity, as well as lymphocyte associated pathogenesis. Adenovirus-mediated gene transfer provided a powerful tool to investigate these processes. We have previously demonstrated that adenoviral vector Ad5/F35 transduces plasma cell lines at a higher efficiency than primary B cells, owing to differences in intracellular trafficking. Given that phosphatases are effectors of intracellular trafficking, here we have analyzed the effects of a panel of phosphatase inhibitors on Ad5/F35 transduction efficiency in B lymphocytes in the present study. FACS analysis was conducted to determine Ad5/F35-EYFP transduction efficiency in lymphoid cells, including human primary B cells, following serine/threonine phosphatase (PSP) inhibitor treatment. We further used confocal microscopy to analyze intracellular trafficking and fate of CY3 labeled Ad5/F35 vectors, in PSP treated lymphoid cell. Finally, we analyzed the MAPK pathway by Western blot in PSP treated cells. Adenoviral transduction efficiency was unresponsive to inhibition of PP1 whereas inhibition of PP2A by cantharidic acid, or PP1 and PP2A by okadaic acid, substantially increased transduction efficiency. Importantly, confocal microscopy analyses revealed that inhibition of PP2A shut down adenovirus recycling. Moreover, inhibition of PP2A resulted in increased phosphorylation of AKT, ERK1/2 and MEK1/2. Taken together, these results suggest that Ad5/F35 is more efficiently transduced in cells following PP2A inhibition. Our results are in agreement with reports indicating that PP2A is involved in the formation of recycling vesicles and might be of interest for gene therapy applications.

  16. Measuring Method for Lightning Channel Temperature

    PubMed Central

    Li, X.; Zhang, J.; Chen, L.; Xue, Q.; Zhu, R.

    2016-01-01

    In this paper, we demonstrate the temperature of lightning channel utilizing the theory of lightning spectra and the model of local thermodynamic equilibrium (LTE). The impulse current generator platform (ICGS) was used to simulate the lightning discharge channel, and the spectral energy of infrared spectroscopy (930 nm) and the visible spectroscopy (648.2 nm) of the simulated lightning has been calculated. Results indicate that the peaks of luminous intensity of both infrared and visible spectra increase with the lightning current intensity in range of 5–50 kA. Based on the results, the temperature of the lightning channel is derived to be 6140.8–10424 K. Moreover, the temperature of the channel is approximately exponential to the lightning current intensity, which shows good agreement with that of the natural lightning cases. PMID:27665937

  17. Lightning NOx and Impacts on Air Quality

    NASA Technical Reports Server (NTRS)

    Murray, Lee T.

    2016-01-01

    Lightning generates relatively large but uncertain quantities of nitrogen oxides, critical precursors for ozone and hydroxyl radical (OH), the primary tropospheric oxidants. Lightning nitrogen oxide strongly influences background ozone and OH due to high ozone production efficiencies in the free troposphere, effecting small but non-negligible contributions to surface pollutant concentrations. Lightning globally contributes 3-4 ppbv of simulated annual-mean policy-relevant background (PRB) surface ozone, comprised of local, regional, and hemispheric components, and up to 18 ppbv during individual events. Feedbacks via methane may counter some of these effects on decadal time scales. Lightning contributes approximately 1 percent to annual-mean surface particulate matter, as a direct precursor and by promoting faster oxidation of other precursors. Lightning also ignites wildfires and contributes to nitrogen deposition. Urban pollution influences lightning itself, with implications for regional lightning-nitrogen oxide production and feedbacks on downwind surface pollution. How lightning emissions will change in a warming world remains uncertain.

  18. Volcanic Lightning: in nature and in the lab.

    NASA Astrophysics Data System (ADS)

    Cimarelli, Corrado; Alatorre-Ibargüengoitia, Miguel A.; Aizawa, Koki; Díaz Marina, Ana I.; Yokoo, Akihiko; Kueppers, Ulrich; Mueller, Sebastian; Scheu, Bettina; Dingwell, Donald B.

    2015-04-01

    Ash-rich volcanic plumes that are responsible for injecting large quantities of aerosols into the atmosphere are often associated with intense electrical activity and the generation of volcanic lightning. Although the hazard of volcanic lightning is mostly confined to the area proximal to the vent, monitoring electrical discharges associated with explosive eruptions can provide crucial information on the dynamics and structure of the plume as well as on the mass eruption rate and cargo of erupted fine ash. Nevertheless, our understanding of volcanic lightning is still limited due to lacking of both i) systematic instrumental observation of electric activity in volcanic plumes and ii) the limited number of experimental investigations on the electrical properties of volcanic materials and the opportunity of replicating volcanic plume conditions in the lab. We recently contributed to the understanding of both these aspects by performing multi-parametric observation of volcanic lightning at Sakurajima volcano in Japan and by achieving volcanic lightning in particle-laden jets generated in the lab. At Sakurajima volcano we combined high-speed imaging with magnetotelluric and acoustic measurements of ash-rich plumes generating electrical discharges and compare our observation with maximum plume height measurement and atmospheric soundings. Our observations at Sakurajima allow the measurement of flash properties with respect to the plume evolution as well as magnetic and electric field variation and associated transferred current. In addition, weather-balloon soundings rule out the contribution of hydrometeors in the electrification of the plume. We complement the field observation by performing rapid decompression experiments of well-constrained (composition and granulometry) ash samples and analogue materials (micrometric glass beads). The experiments have a similar character to the cannon-like vulcanian explosions observed at Sakurajima and show many similarities with

  19. Infrasonic Observations from Triggered Lightning

    NASA Astrophysics Data System (ADS)

    Arechiga, R. O.; Johnson, J. B.; Edens, H. E.; Rison, W.; Thomas, R. J.; Eack, K.; Eastvedt, E. M.

    2009-12-01

    We measured acoustic signals during both triggered and natural lightning. A comparative analysis of simultaneous data from the Lightning Mapping Array (LMA), acoustic measurements and digital high-speed photography operating in the same area was made. Acoustic emissions, providing quantitative estimates of acoustic power and spectral content, will complement coincident investigations, such as X-ray emissions. Most cloud-to-ground lightning flashes lower negative charge to ground, but flashes that lower positive charge to ground are often unusually destructive and are less understood. The New Mexico Tech Lightning Mapping Array (LMA) locates the sources of impulsive RF radiation produced by lightning flashes in three spatial dimensions and time, operating in the 60 - 66 MHz television band. However, positive breakdown is rarely detected by the LMA and positive leader channels are outlined only by recoil events. Positive cloud-to-ground (CG) channels are usually not mapped (or partially mapped because they may have recoil events). Acoustic and electric field instruments are a good complement to the LMA, since they can detect both negative and positive leaders. An array of five stations was deployed during the Summer of 2009 (July 20 to August 13) in the Magdalena mountains of New Mexico, to monitor infrasound (below 20 Hz) and audio range sources due to natural and triggered lightning. The stations were located at close (57 m), medium (303 and 537 m) and far (1403 and 2556 m) distances surrounding the triggering site. Each station consisted of five sensors, one infrasonic and one in the audio range at the center, and three infrasonic in a triangular configuration. This research will provide a more complete picture, and provide further insight into the nature of lightning.

  20. Detection of VHF lightning from GPS orbit

    SciTech Connect

    Suszcynsky, D. M.

    2003-01-01

    Satellite-based VHF' lightning detection is characterized at GPS orbit by using a VHF receiver system recently launched on the GPS SVN 54 satellite. Collected lightning triggers consist of Narrow Bipolar Events (80%) and strong negative return strokes (20%). The results are used to evaluate the performance of a future GPS-satellite-based VHF global lightning monitor.

  1. Lightning activity and aerosols over the Mediterranean

    NASA Astrophysics Data System (ADS)

    Proestakis, Emmanouil; Kazadzis, Stelios; Kotroni, Vassiliki; Lagouvardos, Kostas; Kazantzidis, Andreas

    2015-04-01

    Lightning activity has received extended scientific attention over the past decades. Several international studies on lightning activity and initiation mechanisms have related the increased aerosol concentrations to lightning enhancement. In the frame of TALOS project, we investigated the effect of aerosols on lightning activity over the Mediterranean Sea. Cloud to ground lightning activity data from ZEUS lightning detection network operated and maintained by the National Observatory of Athens, were used along with atmospheric optical depth (AOD) data retrieved by MODIS, on board Aqua satellite. The analysis covers a period of nine years, spanning from 2005 up to 2013. The results show the importance of aerosols in lightning initiation and enhancement. It is shown that the mean AOD of the days with lightning activity per season is larger than the mean seasonal AOD in 90% of the under study domain. Furthermore, lightning activity increase with increasing aerosol loading was found to be more pronounced during summertime and for atmospheric optical depth values up to 0.4. Additionally, during summertime, the spatial analysis showed that the percentage of days with lightning activity is increasing with increasing aerosol loading. Finally, time series for the period 2005-2013 of the days with lightning activity and AOD differences showed similar temporal behavior. Overall, both the spatial and temporal analysis showed that lightning activity is correlated to aerosol loading and that this characteristic is consistent for all seasons.

  2. 49 CFR 176.120 - Lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Lightning protection. 176.120 Section 176.120 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 1 (Explosive) Materials Stowage § 176.120 Lightning protection. A lightning...

  3. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Lightning protection. 420.71 Section 420.71... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.71 Lightning protection. (a) Lightning protection. A licensee shall ensure that the public is not exposed to hazards...

  4. 49 CFR 176.120 - Lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Lightning protection. 176.120 Section 176.120 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 1 (Explosive) Materials Stowage § 176.120 Lightning protection. A lightning...

  5. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Lightning protection. 420.71 Section 420.71... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.71 Lightning protection. (a) Lightning protection. A licensee shall ensure that the public is not exposed to hazards...

  6. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Lightning protection. 420.71 Section 420.71... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.71 Lightning protection. (a) Lightning protection. A licensee shall ensure that the public is not exposed to hazards...

  7. 49 CFR 176.120 - Lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Lightning protection. 176.120 Section 176.120 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 1 (Explosive) Materials Stowage § 176.120 Lightning protection. A lightning...

  8. 49 CFR 176.120 - Lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Lightning protection. 176.120 Section 176.120 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 1 (Explosive) Materials Stowage § 176.120 Lightning protection. A lightning...

  9. 49 CFR 176.120 - Lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Lightning protection. 176.120 Section 176.120 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 1 (Explosive) Materials Stowage § 176.120 Lightning protection. A lightning...

  10. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Lightning protection. 420.71 Section 420.71... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.71 Lightning protection. (a) Lightning protection. A licensee shall ensure that the public is not exposed to hazards...

  11. Attempts to create ball lightning with triggered lightning

    NASA Astrophysics Data System (ADS)

    Hill, Jonathan D.; Uman, Martin A.; Stapleton, Michael; Jordan, Douglas M.; Chebaro, Alexander M.; Biagi, Christopher J.

    2010-08-01

    We describe attempts to create ball lightning by directing lightning, triggered from natural thunderclouds using the rocket-and-wire technique, through a variety of materials. Some of the observed phenomena have features in common with natural ball lightning or with laboratory attempts to create it: flame-like luminosity for up to 0.5 s above salt water; constant-luminosity silicon fragments falling for about 1 s under the influence of gravity; a 0.7 m region of stationary luminosity whose bottom was 0.3 m above a stainless steel surface to which arcing had occurred; and a glow for about 0.5 s above pine tree sections.

  12. Experimental generation of volcanic lightning

    NASA Astrophysics Data System (ADS)

    Cimarelli, Corrado; Alatorre-Ibargüengoitia, Miguel; Kueppers, Ulrich; Scheu, Bettina; Dingwell, Donald B.

    2014-05-01

    Ash-rich volcanic plumes that are responsible for injecting large quantities of aerosols into the atmosphere are often associated with intense electrical activity. Direct measurement of the electric potential at the crater, where the electric activity in the volcanic plume is first observed, is severely impeded, limiting progress in its investigation. We have achieved volcanic lightning in the laboratory during rapid decompression experiments of gas-particle mixtures under controlled conditions. Upon decompression (from ~100 bar argon pressure to atmospheric pressure), loose particles are vertically accelerated and ejected through a nozzle of 2.8 cm diameter into a large tank filled with air at atmospheric conditions. Because of their impulsive character, our experiments most closely represent the conditions encountered in the gas-thrust region of the plume, when ash is first ejected from the crater. We used sieved natural ash with different grain sizes from Popocatépetl (Mexico), Eyjafjallajökull (Iceland), and Soufrière Hills (Montserrat) volcanoes, as well as micrometric glass beads to constrain the influence of material properties on lightning. We monitored the dynamics of the particle-laden jets with a high-speed camera and the pressure and electric potential at the nozzle using a pressure transducer and two copper ring antennas connected to a high-impedance data acquisition system, respectively. We find that lightning is controlled by the dynamics of the particle-laden jet and by the abundance of fine particles. Two main conditions are required to generate lightning: 1) self-electrification of the particles and 2) clustering of the particles driven by the jet fluid dynamics. The relative movement of clusters of charged particles within the plume generates the gradient in electrical potential, which is necessary for lightning. In this manner it is the gas-particle dynamics together with the evolving particle-density distribution within different regions of

  13. Tropic lightning: myth or menace?

    PubMed

    McCarthy, John

    2014-11-01

    Lightning is one of the leading causes of death related to environmental disaster. Of all lightning fatalities documented between 2006 and 2012, leisure activities contributed the largest proportion of deaths, with water-associated, sports, and camping being the most common. Despite the prevalence of these activities throughout the islands, Hawai'i has had zero documented lightning fatalities since weather data tracking was initiated in 1959. There is a common misconception that lightning does not strike the ground in Hawai'i. This myth may contribute to a potentially dangerous false sense of security, and recognition of warning signs and risk factor modification remain the most important prevention strategies. Lightning damage occurs on a spectrum, from minor burns to multi-organ dysfunction. After injury, initial treatment should focus on "reverse triage" and immediate cardiopulmonary resuscitation when indicated, followed by transfer to a healthcare facility. Definitive treatment entails monitoring and management of potential sequelae, to include cardiovascular, neurologic, dermatologic, ophthalmologic, audiovestibular, and psychiatric complications. PMID:25478304

  14. Tropic Lightning: Myth or Menace?

    PubMed Central

    2014-01-01

    Lightning is one of the leading causes of death related to environmental disaster. Of all lightning fatalities documented between 2006 and 2012, leisure activities contributed the largest proportion of deaths, with water-associated, sports, and camping being the most common. Despite the prevalence of these activities throughout the islands, Hawai‘i has had zero documented lightning fatalities since weather data tracking was initiated in 1959. There is a common misconception that lightning does not strike the ground in Hawai‘i. This myth may contribute to a potentially dangerous false sense of security, and recognition of warning signs and risk factor modification remain the most important prevention strategies. Lightning damage occurs on a spectrum, from minor burns to multi-organ dysfunction. After injury, initial treatment should focus on “reverse triage” and immediate cardiopulmonary resuscitation when indicated, followed by transfer to a healthcare facility. Definitive treatment entails monitoring and management of potential sequelae, to include cardiovascular, neurologic, dermatologic, ophthalmologic, audiovestibular, and psychiatric complications. PMID:25478304

  15. Positive lightning and severe weather

    NASA Astrophysics Data System (ADS)

    Price, C.; Murphy, B.

    2003-04-01

    In recent years researchers have noticed that severe weather (tornados, hail and damaging winds) are closely related to the amount of positive lightning occurring in thunderstorms. On 4 July 1999, a severe derecho (wind storm) caused extensive damage to forested regions along the United States/Canada border, west of Lake Superior. There were 665,000 acres of forest destroyed in the Boundary Waters Canoe Area Wilderness (BWCAW) in Minnesota and Quetico Provincial Park in Canada, with approximately 12.5 million trees blown down. This storm resulted in additional severe weather before and after the occurrence of the derecho, with continuous cloud-to-ground (CG) lightning occurring for more than 34 hours during its path across North America. At the time of the derecho the percentage of positive cloud-to-ground (+CG) lightning measured by the Canadian Lightning Detection Network (CLDN) was greater than 70% for more than three hours, with peak values reaching 97% positive CG lightning. Such high ratios of +CG are rare, and may be useful indicators for short-term forecasts of severe weather.

  16. Modern Protection Against Lightning Strikes

    NASA Astrophysics Data System (ADS)

    Moore, C.

    2005-05-01

    The application of science to provide protection against lightning strikes began around 1750 when Benjamin Franklin who invented the lightning rod in an effort to discharge thunderclouds. Instead of preventing lightning as he expected, his rods have been quite successful as strike receptors, intercepting cloud-to ground discharges and conducting them to Earth without damage to the structures on which they are mounted. In the years since Franklin's invention there has been little attention paid to the rod configuration that best serves as a strike receptor but Franklin's original ideas continue to be rediscovered and promoted. Recent measurements of the responses of variously configured rods to nearby strikes indicate that sharp-tipped rods are not the optimum configuration to serve as strike receptors since the ionization of the air around their tips limits the strength of the local electric fields created by an approaching lightning leader. In these experiments, fourteen blunt-tipped rods exposed in strike-reception competitions with nearby sharp-tipped rods were struck by lightning but none of the sharp-tipped rods were struck.

  17. Tropic lightning: myth or menace?

    PubMed

    McCarthy, John

    2014-11-01

    Lightning is one of the leading causes of death related to environmental disaster. Of all lightning fatalities documented between 2006 and 2012, leisure activities contributed the largest proportion of deaths, with water-associated, sports, and camping being the most common. Despite the prevalence of these activities throughout the islands, Hawai'i has had zero documented lightning fatalities since weather data tracking was initiated in 1959. There is a common misconception that lightning does not strike the ground in Hawai'i. This myth may contribute to a potentially dangerous false sense of security, and recognition of warning signs and risk factor modification remain the most important prevention strategies. Lightning damage occurs on a spectrum, from minor burns to multi-organ dysfunction. After injury, initial treatment should focus on "reverse triage" and immediate cardiopulmonary resuscitation when indicated, followed by transfer to a healthcare facility. Definitive treatment entails monitoring and management of potential sequelae, to include cardiovascular, neurologic, dermatologic, ophthalmologic, audiovestibular, and psychiatric complications.

  18. Lightning at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Gibbons, W. C.; Boyd, B. F.; Jafferis, W.

    1986-01-01

    Kennedy Space Center (KSC) is situated in an area that experiences one of the world's highest rates of cloud-ground lightning strikes, about 600-2000 strikes per summer. Two lightning detection systems have been implemented, the Launch Pad Lightning Warning System (LPLWS) and the Lightning Location and Protection system (LLP). The LPLWS consists of field mills of eight vertically oriented stator sections mounted 10 in. above ground and alternately covered and uncovered as the rotor turns. Differential voltages between covered and uncovered sections furnish electric field amplitude and polarity data. Ten samples per second are telemetered to a central processing facility. The system is used during launch and landing. The LLP has high and low gain components, the former being two direction finder antennas with 100 m strike position finding accuracy, the latter featuring medium gain antennas for 500 m accuracy in locating strikes. The LLP system is used primarily to warn personnel of strike conditions and to lift warnings to avoid lost work time. Several experimental programs have been initiated for triggering lightning strikes and controlling their locations.

  19. The Anthropogenic/Lightning Effects Around Houston: The Houston Environmental Aerosol Thunderstorm (HEAT) Project - 2005

    NASA Astrophysics Data System (ADS)

    Orville, R. E.

    2004-12-01

    A major field program will occur in summer 2005 to determine the sources and causes for the enhanced cloud-to-ground lightning over Houston, Texas. This program will be in association with simultaneous experiments supported by the Environmental Protection Agency (EPA) and the Texas Commission on Environmental Quality (TCEQ), formally the Texas Natural Resource Conservation Commission (TNRCC). Recent studies covering the period 1989-2002 document a 60 percent increase of cloud-to-ground lightning in the Houston area as compared to surrounding background values, which is second in flash density only to the Tampa Bay, Florida area. We suggest that the elevated flash densities could result from several factors, including 1) the convergence due to the urban heat island effect and complex sea breeze (thermal hypothesis), and 2) the increasing levels of air pollution from anthropogenic sources producing numerous small cloud droplets and thereby suppressing mean droplet size (aerosol hypothesis). The latter effect would enable more cloud water to reach the mixed phase region where it is involved in the formation of precipitation and the separation of electric charge, leading to an enhancement of lightning. The primary goals of HEAT are to examine the effects of (1) pollution, (2) the urban heat island, and (3) the complex coastline on storms and lightning characteristics in the Houston area. The transport of air pollutants by Houston thunderstorms will be investigated. In particular, the relative amounts of lightning-produced and convectively transported NOx into the upper troposphere will be determined, and a comparison of the different NOx sources in the urban area of Houston will be developed. The HEAT project is based on the observation that there is an enhancement in cloud-to-ground (CG) lightning. Total lightning (intracloud (IC) and CG) will be measured using a lightning mapping system (LDAR II) to observe if there is an enhancement in intracloud lightning as well.

  20. Somatic cell genetic analysis of human cell surface antigens 5.1H11 and F35/9 (gp45).

    PubMed

    Rettig, W J; Triche, T J; Bander, N H

    1990-01-01

    Serologic analysis of rodent-human somatic cell hybrids has permitted the assignment of loci coding for cell surface differentiation antigens 5.1H11 (gene symbol MSK39) and F35/9 (MSK40) to human chromosomes 11q13-qter and 22, respectively. Both antigens are expressed in hybrids constructed with antigen-positive human cells and certain hybrids constructed with antigen-negative human cells, indicating that the coding genes are not irreversibly silenced in human nonexpressor cells. Antigens 5.1H11 and F35/9, and at least six additional cell surface antigens encoded by chromosomes 11 and 22, are expressed on human Ewing sarcoma and peripheral neuroepithelioma cells, providing selectable markers for isolating and characterizing the specific t(11;22)(q24;q12) marker chromosomes of these tumors in interspecies hybrids.

  1. Adenovirus 5 and chimeric adenovirus 5/F35 employ distinct B-lymphocyte intracellular trafficking routes that are independent of their cognate cell surface receptor.

    PubMed

    Drouin, Mathieu; Cayer, Marie-Pierre; Jung, Daniel

    2010-06-01

    Gene transfer applications with adenovirus (Ad) type 5 are limited by its native tropism, hampering their use in several cell types. To address this limitation, several Ad vectors bearing chimeric fiber have been produced to take advantage of the different cellular receptors used by other subgroups of Ads. In this study, we have compared the transduction efficiency of Ad5 and the chimeric Ad5/F35 in primary human B lymphocytes and B-cell lines as a function of the developmental stage. We found that transduction efficiencies of the two Ads differ independently of their targeted cellular receptor but are related to the intracellular localization of the virus. In efficiently transduced cells, Ads were localized in early endosomes or cytosol, whereas in poorly transduced cells they were localized within late endosomes/lysosomes. Finally, we demonstrate that treatment of cells with phosphatase inhibitors known to redirect endocytosis towards caveolae, increased Ad5/F35 transduction efficiency.

  2. Recent Lightning Experiments at the International Center for Lightning Research and Testing: From Ball Lightning to Gamma Rays

    NASA Astrophysics Data System (ADS)

    Uman, M. A.

    2008-12-01

    Recent lightning data and the instrumentation used to acquire it at the UF-FIT International Center for Lightning Research and Testing, located on about 1 square kilometer of flat ground at the Camp Blanding Army National Guard Base in north-central Florida, are discussed. The progress of several on-going studies is reviewed: (1) understanding the physics of the "classical" rocket-and-wire triggering of lightning from natural overhead thunderclouds, (2) attempting to generate ball lightning by allowing triggered-lightning to strike various materials and objects (e.g., tree-trunk sections, pools of salt water, silicon powder), (3) measuring the very close (100 m to 1 km) electric and magnetic fields of natural cloud-to-ground lightning, and (4) probing the relationship between lightning processes and the x-rays and gamma-rays associated with them.

  3. Electro-optic lightning detector.

    PubMed

    Koshak, W J; Solakiewicz, R J

    1999-07-20

    The design, alignment, calibration, and field deployment of a solid-state lightning detector is described. The primary sensing component of the detector is a potassium dihydrogen phosphate electro-optic crystal that is attached in series to a flat-plate aluminum antenna; the antenna is exposed to the ambient thundercloud electric field. A semiconductor laser diode (lambda = 685 nm), polarizing optics, and the crystal are arranged in a Pockels cell configuration. Lightning-caused electric field changes are related to small changes in the transmission of laser light through the optical cell. Several hundred lightning electric field change excursions were recorded during five thunderstorms that occurred in the summer of 1998 at the NASA Marshall Space Flight Center in northern Alabama. PMID:18323949

  4. Structure of laboratory ball lightning.

    PubMed

    Ito, Tsuyohito; Tamura, Tomoya; Cappelli, Mark A; Hamaguchi, Satoshi

    2009-12-01

    Trajectories of self-sustained laboratory ball lightning, generated by arc discharges with silicon, are investigated for understanding the possibility of buoyant flight. Extremely low apparent densities are found, nearly approaching that of standard air. The freely buoyant balls are observed to survive for about 0.1 s, with significantly buoyant balls surviving for several seconds. These ball lightning objects are found to have a density and size that can easily allow them to be carried by a gentle breeze of a few meters per second. The results are interpreted by a model that is an extension of that first proposed by Abrahamson and Dinniss [J. Abrahamson and J. Dinniss, Nature (London) 403, 519 (2000)]. The buoyant behavior of ball lightning seen in our experiments is believed to arise as a result of the formation of a nanoparticle oxide network growing from a molten silicon core.

  5. Structure of laboratory ball lightning

    NASA Astrophysics Data System (ADS)

    Ito, Tsuyohito; Tamura, Tomoya; Cappelli, Mark A.; Hamaguchi, Satoshi

    2009-12-01

    Trajectories of self-sustained laboratory ball lightning, generated by arc discharges with silicon, are investigated for understanding the possibility of buoyant flight. Extremely low apparent densities are found, nearly approaching that of standard air. The freely buoyant balls are observed to survive for about 0.1 s, with significantly buoyant balls surviving for several seconds. These ball lightning objects are found to have a density and size that can easily allow them to be carried by a gentle breeze of a few meters per second. The results are interpreted by a model that is an extension of that first proposed by Abrahamson and Dinniss [J. Abrahamson and J. Dinniss, Nature (London) 403, 519 (2000)]. The buoyant behavior of ball lightning seen in our experiments is believed to arise as a result of the formation of a nanoparticle oxide network growing from a molten silicon core.

  6. Structure of laboratory ball lightning.

    PubMed

    Ito, Tsuyohito; Tamura, Tomoya; Cappelli, Mark A; Hamaguchi, Satoshi

    2009-12-01

    Trajectories of self-sustained laboratory ball lightning, generated by arc discharges with silicon, are investigated for understanding the possibility of buoyant flight. Extremely low apparent densities are found, nearly approaching that of standard air. The freely buoyant balls are observed to survive for about 0.1 s, with significantly buoyant balls surviving for several seconds. These ball lightning objects are found to have a density and size that can easily allow them to be carried by a gentle breeze of a few meters per second. The results are interpreted by a model that is an extension of that first proposed by Abrahamson and Dinniss [J. Abrahamson and J. Dinniss, Nature (London) 403, 519 (2000)]. The buoyant behavior of ball lightning seen in our experiments is believed to arise as a result of the formation of a nanoparticle oxide network growing from a molten silicon core. PMID:20365306

  7. Electro-optic Lightning Detector

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Solakiewicz, Richard J.

    1996-01-01

    The design, alignment, calibration, and field deployment of a solid-state lightning detector is described. The primary sensing component of the detector is a potassium dihydrogen phosphate (KDP) electro-optic crystal that is attached in series to a flat plate aluminum antenna; the antenna is exposed to the ambient thundercloud electric field. A semiconductor laser diode (lambda = 685 nm), polarizing optics, and the crystal are arranged in a Pockels cell configuration. Lightning-caused electric field changes are related to small changes in the transmission of laser light through the optical cell. Several hundred lightning electric field change excursions were recorded during five thunderstorms that occurred in the summer of 1998 at the NASA Marshall Space Flight Center (MSFC) in northern Alabama.

  8. Lightning Effects in the Payload Changeout Room

    NASA Technical Reports Server (NTRS)

    Thomas, Garland L.; Fisher, Franklin A.; Collier, Richard S.; Medelius, Pedro J.

    1997-01-01

    Analytical and empirical studies have been performed to provide better understanding of the electromagnetic environment inside the Payload Changeout Room and Orbiter payload bay resulting from lightning strikes to the launch pad lightning protection system. The analytical studies consisted of physical and mathematical modeling of the pad structure and the Payload Changeout Room. Empirical testing was performed using a lightning simulator to simulate controlled (8 kA) lightning strikes to the catenary wire lightning protection system. In addition to the analyses and testing listed above, an analysis of the configuration with the vehicle present was conducted, in lieu of testing, by the Finite Difference, Time Domain method.

  9. NASA Manned Launch Vehicle Lightning Protection Development

    NASA Technical Reports Server (NTRS)

    McCollum, Matthew B.; Jones, Steven R.; Mack, Jonathan D.

    2009-01-01

    Historically, the National Aeronautics and Space Administration (NASA) relied heavily on lightning avoidance to protect launch vehicles and crew from lightning effects. As NASA transitions from the Space Shuttle to the new Constellation family of launch vehicles and spacecraft, NASA engineers are imposing design and construction standards on the spacecraft and launch vehicles to withstand both the direct and indirect effects of lightning. A review of current Space Shuttle lightning constraints and protection methodology will be presented, as well as a historical review of Space Shuttle lightning requirements and design. The Space Shuttle lightning requirements document, NSTS 07636, Lightning Protection, Test and Analysis Requirements, (originally published as document number JSC 07636, Lightning Protection Criteria Document) was developed in response to the Apollo 12 lightning event and other experiences with NASA and the Department of Defense launch vehicles. This document defined the lightning environment, vehicle protection requirements, and design guidelines for meeting the requirements. The criteria developed in JSC 07636 were a precursor to the Society of Automotive Engineers (SAE) lightning standards. These SAE standards, along with Radio Technical Commission for Aeronautics (RTCA) DO-160, Environmental Conditions and Test Procedures for Airborne Equipment, are the basis for the current Constellation lightning design requirements. The development and derivation of these requirements will be presented. As budget and schedule constraints hampered lightning protection design and verification efforts, the Space Shuttle elements waived the design requirements and relied on lightning avoidance in the form of launch commit criteria (LCC) constraints and a catenary wire system for lightning protection at the launch pads. A better understanding of the lightning environment has highlighted the vulnerability of the protection schemes and associated risk to the vehicle

  10. Filigree burn of lightning: two case reports.

    PubMed

    Kumar, Virendra

    2007-04-01

    Lightning is a powerful natural electrostatic discharge produced during a thunderstorm. The electric current passing through the discharge channels is direct with a potential of 1000 million volts or more. Lightning can kill or injure a person by a direct strike, a side-flash, or conduction through another object. Lightning can cause a variety of injuries in the skin and the cardiovascular, neurological and ophthalmic systems. Filigree burn of lightning is a superficial burn and very rare. Two cases of death from lightning which have this rare finding are reported and discussed. PMID:17520964

  11. Electromagnetic sensors for general lightning application

    NASA Technical Reports Server (NTRS)

    Baum, C. E.; Breen, E. L.; Onell, J. P.; Moore, C. B.; Sower, G. D.

    1980-01-01

    Electromagnetic sensors for general lightning applications in measuring environment are discussed as well as system response to the environment. This includes electric and magnetic fields, surface current and charge densities, and currents on conductors. Many EMP sensors are directly applicable to lightning measurements, but there are some special cases of lightning measurements involving direct strikes which require special design considerations for the sensors. The sensors and instrumentation used by NMIMT in collecting data on lightning at South Baldy peak in central New Mexico during the 1978 and 1979 lightning seasons are also discussed. The Langmuir Laboratory facilities and details of the underground shielded instrumentation room and recording equipment are presented.

  12. Filigree burn of lightning: two case reports.

    PubMed

    Kumar, Virendra

    2007-04-01

    Lightning is a powerful natural electrostatic discharge produced during a thunderstorm. The electric current passing through the discharge channels is direct with a potential of 1000 million volts or more. Lightning can kill or injure a person by a direct strike, a side-flash, or conduction through another object. Lightning can cause a variety of injuries in the skin and the cardiovascular, neurological and ophthalmic systems. Filigree burn of lightning is a superficial burn and very rare. Two cases of death from lightning which have this rare finding are reported and discussed.

  13. Lightning injury: a case report.

    PubMed

    Moollaor, P; Annoppetch, C

    1993-07-01

    A 40-year-old Thai male was struck by lightning while he was riding his motorcycle during a day of gathering clouds and threatening rain. There were third degree burns around the mastoid areas corresponding to the metal arms of the spectacles, also around the neck where a silver chain with pendant (Buddha image) hung, as well as a full thickness vertical lesion down the center of the chest and abdomen where the zip of the jacket made its mark. Fern-like skin erythema was also seen around the later wound. These are stigmas of lightning skin injuries and the patient survived with no memory of the event.

  14. Lightning and Life on Exoplanets

    NASA Astrophysics Data System (ADS)

    Rimmer, Paul; Ardaseva, Aleksandra; Hodosan, Gabriella; Helling, Christiane

    2016-07-01

    Miller and Urey performed a ground-breaking experiment, in which they discovered that electric discharges through a low redox ratio gas of methane, ammonia, water vapor and hydrogen produced a variety of amino acids, the building blocks of proteins. Since this experiment, there has been significant interest on the connection between lightning chemistry and the origin of life. Investigation into the atmosphere of the Early Earth has generated a serious challenge for this project, as it has been determined both that Earth's early atmosphere was likely dominated by carbon dioxide and molecular nitrogen with only small amounts of hydrogen, having a very high redox ratio, and that discharges in gases with high redox ratios fail to yield more than trace amounts of biologically relevant products. This challenge has motivated several origin of life researchers to abandon lightning chemistry, and to concentrate on other pathways for prebiotic synthesis. The discovery of over 2000 exoplanets includes a handful of rocky planets within the habitable zones around their host stars. These planets can be viewed as remote laboratories in which efficient lightning driven prebiotic synthesis may take place. This is because many of these rocky exoplanets, called super-Earths, have masses significantly greater than that of Earth. This higher mass would allow them to more retain greater amounts hydrogen within their atmosphere, reducing the redox ratio. Discharges in super-Earth atmospheres can therefore result in a significant yield of amino acids. In this talk, I will discuss new work on what lightning might look like on exoplanets, and on lightning driven chemistry on super-Earths. Using a chemical kinetics model for a super-Earth atmosphere with smaller redox ratios, I will show that in the presence of lightning, the production of the amino acid glycine is enhanced up to a certain point, but with very low redox ratios, the production of glycine is again inhibited. I will conclude

  15. Lightning hazard reduction at wind farms

    SciTech Connect

    Kithil, R.

    1997-12-31

    The USA wind farm industry (WFI) largely is centered in low-lightning areas of the State of California. While some evidence of lightning incidents is reported here, the problem is not regarded as serious by most participants. The USA WFI now is moving eastward, into higher areas of lightning activity. The European WFI has had many years experience with lightning problems. One 1995 German study estimated that 80% of wind turbine insurance claims paid for damage compensation were caused by lightning strikes. The European and USA WFI have not adopted site criteria, design fundamentals, or certification techniques aimed at lightning safety. Sufficient evidence about lightning at wind farms is available to confirm that serious potential problems exist.

  16. Future Expansion of the Lightning Surveillance System at the Kennedy Space Center and the Cape Canaveral Air Force Station, Florida, USA

    NASA Technical Reports Server (NTRS)

    Mata, C. T.; Wilson, J. G.

    2012-01-01

    The NASA Kennedy Space Center (KSC) and the Air Force Eastern Range (ER) use data from two cloud-to-ground (CG) lightning detection networks, the Cloud-to-Ground Lightning Surveillance System (CGLSS) and the U.S. National Lightning Detection Network (NLDN), and a volumetric mapping array, the lightning detection and ranging II (LDAR II) system: These systems are used to monitor and characterize lightning that is potentially hazardous to launch or ground operations and hardware. These systems are not perfect and both have documented missed lightning events when compared to the existing lightning surveillance system at Launch Complex 39B (LC39B). Because of this finding it is NASA's plan to install a lightning surveillance system around each of the active launch pads sharing site locations and triggering capabilities when possible. This paper shows how the existing lightning surveillance system at LC39B has performed in 2011 as well as the plan for the expansion around all active pads.

  17. Total Lightning as an Indicator of Mesocyclone Behavior

    NASA Technical Reports Server (NTRS)

    Stough, Sarah M.; Carey, Lawrence D.; Schultz, Christopher J.

    2014-01-01

    Apparent relationship between total lightning (in-cloud and cloud to ground) and severe weather suggests its operational utility. Goal of fusion of total lightning with proven tools (i.e., radar lightning algorithms. Preliminary work here investigates circulation from Weather Suveilance Radar- 1988 Doppler (WSR-88D) coupled with total lightning data from Lightning Mapping Arrays.

  18. Can volcanic lightning be observed in space?

    NASA Astrophysics Data System (ADS)

    Martinez, J. M., Jr.; Thomas, R. J.

    2014-12-01

    Lightning, a phenomenon widely known to occur in thunderstorms, is also present in major volcanic eruptions. Although volcanic lightning is not apparently different, its occurrence within ash clouds increase the difficulty to detect and measure it optically with remote instruments. Major volcanic eruptions, those with Volcanic Explosive Index (VEI) > 3 or with ash plume heights greater than 10 km are likely to have lightning. This lightning should be seen from space by LIS and OTD (Lightning Imaging Sensor, Optical Transient Detector). Ash clouds however absorb much more light than regular clouds which results in lower or no radiance measured for lightning in the ash plume. The LIS/OTD satellite data was studied for a small region centered on different volcanoes during reportedly active periods (3 days or more). This volcanic lightning should be distinguished from thunderstorm lightning according to specific criteria. All relevant eruptions that have occurred since LIS was launched in 1997 aboard TRMM (Tropical Rainfall Measurement Mission) Observatory need to be studied. LIS and OTD are in low orbits and do not cover the entire globe. Since any volcano is observed only a few minutes each day the likelihood of observing lightning events during a volcanic eruption is low. Inter comparison of lightning data from several eruptions, at different dates and places all over the world helps set a criteria to distinguish volcanic lightning from thunderstorm related lightning. LIS datasets, typically structured in four different levels - events,groups,flashes, areas - are plotted separately using conventional IDL algorithms to retrieve orbit data from individual HDF files. Events associated to volcanic lightning are distributed in fewer groups, which in turn are structured in less flashes than "regular" lightning.

  19. Nadir Observations of Lightning and TLEs by JEM-GLIMS

    NASA Astrophysics Data System (ADS)

    Sato, Mitsuteru; Ushio, Tomoo; Morimoto, Takeshi; Suzuki, Makoto; Yamazaki, Atsushi; Kikuchi, Masayuki; Takahashi, Yukihiro; Inan, Umran; Linscott, Ivan; Hobara, Yasuhide

    2013-04-01

    JEM-GLIMS is a space mission to observe lightning and lightning-associated Transient Luminous Events (TLEs) from the Exposed Facility (EF) of the Japanese Experiment Module (JEM) at the International Space Station (ISS). The main purpose of this mission is to carry out the nadir observations of these phenomena and to identify temporal and spatial evolutions of lightning and TLEs and to clarify the occurrence conditions of TLEs and global occurrence locations and rates of TLEs. JEM-GLIMS consists of two optical instruments, two radio receivers, and one onboard computer. The optical instruments are two CMOS cameras (LSI-1, LSI-2) and six-channel spectrophotometers (PH1 - PH6). The FOV of LSI is 28.3 deg. x 28.3 deg., and LSI-1 (LSI-2) equips a 766-832 nm wide band filter (a 762+/-7 nm narrow band filter). Each PH channel equips the optical band-pass filter, and these photometers measure the N2 1P, N2 2P, N2 LBH, and N2+ 1N emissions of lightning and TLEs. The radio receivers consist of one VLF receiver (VLFR) and two sets of VHF receivers (VITF). In order to detect TLE-associated whistler waves, VLFR employs a nadir-directing monopole antenna and an electronics unit recording waveform data with a sampling frequency of 100 kHz with 14-bit resolution. VITF consists of two patch-type antennas separated by 1.5 m and an electronics unit, and VITF mainly observes VHF pulses in the frequency range of 70-100 MHz excited by lightning discharges with a sampling frequency of 200 MHz with 8-bit resolution. JEM-GIMS was successfully launched and transported to the ISS by the H-II Transfer Vehicle (HTV) No.3 cargo transporter at the end of July 2012, and was installed at JEM-EF on August 9. For the period from September 15 to November 12 we have carried out the initial checkout operation and confirmed that the functions of all the instruments are normal and that the performance of all the science instruments is identical with that before launch. Finally, we have started the

  20. Volcanic Lightning: in nature and in the lab.

    NASA Astrophysics Data System (ADS)

    Cimarelli, C.

    2015-12-01

    Ash-rich volcanic plumes are often associated with intense electrical activity and the generation of volcanic lightning. Monitoring electrical discharges associated with explosive eruptions can provide crucial information on the dynamics and structure of the plume as well as on the mass eruption rate and cargo of erupted fine ash. Nevertheless, our understanding of volcanic lightning is still limited due to lacking of i) systematic instrumental observations and ii) the limited number of experimental investigations on the electrical properties of volcanic materials and the opportunity of replicating volcanic plume conditions in the lab.We recently contributed to the understanding of both these aspects by performing multi-parametric observation of volcanic lightning at Sakurajima volcano in Japan and by achieving volcanic lightning in particle-laden jets generated in the lab.At Sakurajima volcano we combined high-speed imaging with magnetotelluric and acoustic measurements of ash-rich plumes and compared our observation with maximum plume height measurement and atmospheric soundings. Our observations at Sakurajima allow the measurement of flash properties with respect to the plume evolution as well as magnetic and electric field variation and associated transferred current. In addition, weather-balloon soundings rule out the contribution of hydrometeors in the electrification of the plume.We complement the field observation by performing rapid decompression experiments of well-constrained (composition and granulometry) ash samples and analogue materials. The experiments show many similarities with the vulcanian explosions at Sakurajima and, most importantly, they highlight how lightning is controlled by the dynamics of the rapidly expanding particle-laden jet. Two main conditions are required to generate lightning: 1) triboelectrification of the particles and 2) clustering of the particles driven by the jet fluid dynamics. As observed in nature, the size of the

  1. Laboratory-produced ball lightning

    NASA Astrophysics Data System (ADS)

    Golka, Robert K., Jr.

    1994-05-01

    For 25 years I have actively been searching for the true nature of ball lightning and attempting to reproduce it at will in the laboratory. As one might expect, many unidentified lights in the atmosphere have been called ball lightning, including Texas Maffa lights (automobile headlights), flying saucers (UFOs), swamp gas in Ann Arbor, Michigan, etc. For 15 years I thought ball lightning was strictly a high-voltage phenomenon. It was not until 1984 when I was short-circuiting the electrical output of a diesel electric railroad locomotive that I realized that the phenomenon was related more to a high current. Although I am hoping for some other types of ball lightning to emerge such as strictly electrostatic-electromagnetic manifestations, I have been unlucky in finding laboratory provable evidence. Cavity-formed plasmodes can be made by putting a 2-inch burning candle in a home kitchen microwave oven. The plasmodes float around for as long as the microwave energy is present.

  2. Aircraft Lightning Electromagnetic Environment Measurement

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.

    2011-01-01

    This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.

  3. Jovian Lightning and Moonlit Clouds

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Jovian lightning and moonlit clouds. These two images, taken 75 minutes apart, show lightning storms on the night side of Jupiter along with clouds dimly lit by moonlight from Io, Jupiter's closest moon. The images were taken in visible light and are displayed in shades of red. The images used an exposure time of about one minute, and were taken when the spacecraft was on the opposite side of Jupiter from the Earth and Sun. Bright storms are present at two latitudes in the left image, and at three latitudes in the right image. Each storm was made visible by multiple lightning strikes during the exposure. Other Galileo images were deliberately scanned from east to west in order to separate individual flashes. The images show that Jovian and terrestrial lightning storms have similar flash rates, but that Jovian lightning strikes are a few orders of magnitude brighter in visible light.

    The moonlight from Io allows the lightning storms to be correlated with visible cloud features. The latitude bands where the storms are seen seem to coincide with the 'disturbed regions' in daylight images, where short-lived chaotic motions push clouds to high altitudes, much like thunderstorms on Earth. The storms in these images are roughly one to two thousand kilometers across, while individual flashes appear hundreds of kilometer across. The lightning probably originates from the deep water cloud layer and illuminates a large region of the visible ammonia cloud layer from 100 kilometers below it.

    There are several small light and dark patches that are artifacts of data compression. North is at the top of the picture. The images span approximately 50 degrees in latitude and longitude. The lower edges of the images are aligned with the equator. The images were taken on October 5th and 6th, 1997 at a range of 6.6 million kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for

  4. Modern concepts of treatment and prevention of lightning injuries.

    PubMed

    Edlich, Richard F; Farinholt, Heidi-Marie A; Winters, Kathryne L; Britt, L D; Long, William B

    2005-01-01

    Lightning is the second most common cause of weather-related death in the United States. Lightning is a natural atmospheric discharge that occurs between regions of net positive and net negative electric charges. There are several types of lightning, including streak lightning, sheet lightning, ribbon lightning, bead lightning, and ball lightning. Lightning causes injury through five basic mechanisms: direct strike, flash discharge (splash), contact, ground current (step voltage), and blunt trauma. While persons struck by lightning show evidence of multisystem derangement, the most dramatic effects involve the cardiovascular and central nervous systems. Cardiopulmonary arrest is the most common cause of death in lightning victims. Immediate resuscitation of people struck by lightning greatly affects the prognosis. Electrocardiographic changes observed following lightning accidents are probably from primary electric injury or burns of the myocardium without coronary artery occlusion. Lightning induces vasomotor spasm from direct sympathetic stimulation resulting in severe loss of pulses in the extremities. This vasoconstriction may be associated with transient paralysis. Damage to the central nervous system accounts for the second most debilitating group of injuries. Central nervous system injuries from lightning include amnesia and confusion, immediate loss of consciousness, weakness, intracranial injuries, and even brief aphasia. Other organ systems injured by lightning include the eye, ear, gastrointestinal system, skin, and musculoskeletal system. The best treatment of lightning injuries is prevention. The Lightning Safety Guidelines devised by the Lightning Safety Group should be instituted in the United States and other nations to prevent these devastating injuries.

  5. Modern concepts of treatment and prevention of lightning injuries.

    PubMed

    Edlich, Richard F; Farinholt, Heidi-Marie A; Winters, Kathryne L; Britt, L D; Long, William B

    2005-01-01

    Lightning is the second most common cause of weather-related death in the United States. Lightning is a natural atmospheric discharge that occurs between regions of net positive and net negative electric charges. There are several types of lightning, including streak lightning, sheet lightning, ribbon lightning, bead lightning, and ball lightning. Lightning causes injury through five basic mechanisms: direct strike, flash discharge (splash), contact, ground current (step voltage), and blunt trauma. While persons struck by lightning show evidence of multisystem derangement, the most dramatic effects involve the cardiovascular and central nervous systems. Cardiopulmonary arrest is the most common cause of death in lightning victims. Immediate resuscitation of people struck by lightning greatly affects the prognosis. Electrocardiographic changes observed following lightning accidents are probably from primary electric injury or burns of the myocardium without coronary artery occlusion. Lightning induces vasomotor spasm from direct sympathetic stimulation resulting in severe loss of pulses in the extremities. This vasoconstriction may be associated with transient paralysis. Damage to the central nervous system accounts for the second most debilitating group of injuries. Central nervous system injuries from lightning include amnesia and confusion, immediate loss of consciousness, weakness, intracranial injuries, and even brief aphasia. Other organ systems injured by lightning include the eye, ear, gastrointestinal system, skin, and musculoskeletal system. The best treatment of lightning injuries is prevention. The Lightning Safety Guidelines devised by the Lightning Safety Group should be instituted in the United States and other nations to prevent these devastating injuries. PMID:15777170

  6. Lightning climatology over the eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Galanaki, Elissavet; Lagouvardos, Kostas; Kotroni, Vassiliki; Argyriou, Athanassios

    2015-04-01

    In the frame of TALOS project, the lightning activity for a 10-year period (2005-2014) over the eastern Mediterranean (16-320E, 34-460N) is analysed. The study is based on the use of cloud-to-ground lightning activity data from ZEUS system, a Very-Low-Frequency Lightning detection network operated by the National Observatory of Athens. The spatial and temporal (seasonal and diurnal) variability of the lightning activity is examined. Lightning is modulated by the diurnal cycle of insolation and the underlying topographic features of the region. CG lightning activity is dominant over land and coastal areas during summer and spring, while during the cold period of the year is dominant over the sea and is significantly stronger over the mainland than over the sea. The maximum of the lightning activity is observed in June and mostly in the afternoon. The CG variability is consistent with the global lightning activity observations. The effect of elevation, terrain slope and vegetation on the distribution of the CG flashes is also investigated. The orography and the terrain slope favour the lightning activity. Throughout the year, the potential of producing CG flashes ("lightning yield") over bareground is low while during the warm period of the year, the forested areas have increased "lightning yield". Additional analysis focuses on the links of CG lightning with indices related with the atmospheric instability such as the Convective Available Potential Energy (CAPE). CAPE is known as the driving force for thunderstorm development. The analysis showed that the lightning density increases with increasing values of CAPE.

  7. TRMM-Based Lightning Climatology

    NASA Technical Reports Server (NTRS)

    Cecil, Daniel J.; Buechler, Dennis E.; Blakeslee, Richard J.

    2011-01-01

    Gridded climatologies of total lightning flash rates seen by the spaceborne Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) have been updated. OTD collected data from May 1995 to March 2000. LIS data (equatorward of about 38 deg) has been added for 1998-2010. Flash counts from each instrument are scaled by the best available estimates of detection efficiency. The long LIS record makes the merged climatology most robust in the tropics and subtropics, while the high latitude data is entirely from OTD. The mean global flash rate from the merged climatology is 46 flashes per second. The peak annual flash rate at 0.5 deg scale is 160 fl/square km/yr in eastern Congo. The peak monthly average flash rate at 2.5 scale is 18 fl/square km/mo, from early April to early May in the Brahmaputra Valley of far eastern India. Lightning decreases in this region during the monsoon season, but increases further north and west. A monthly average peak from early August to early September in northern Pakistan also exceeds any monthly averages from Africa, despite central Africa having the greatest yearly average. Most continental regions away from the equator have an annual cycle with lightning flash rates peaking in late spring or summer. The main exceptions are India and southeast Asia, with springtime peaks in April and May. For landmasses near the equator, flash rates peak near the equinoxes. For many oceanic regions, the peak flash rates occur in autumn. This is particularly noticeable for the Mediterranean and North Atlantic. Landmasses have a strong diurnal cycle of lightning, with flash rates generally peaking between 3-5 pm local solar time. The central United States flash rates peak later, in late evening or early night. Flash rates peak after midnight in northern Argentina. These regions are known for large, intense, long-lived mesoscale convective systems.

  8. Where are the lightning hotspots on Earth?

    NASA Astrophysics Data System (ADS)

    Albrecht, R. I.; Goodman, S. J.; Buechler, D. E.; Blakeslee, R. J.; Christian, H. J., Jr.

    2015-12-01

    The first lightning observations from space date from the early 1960s and more than a dozen spacecraft orbiting the Earth have flown instruments that recorded lightning signals from thunderstorms over the past 45 years. In this respect, the Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS), having just completed its mission (1997-2015), provides the longest and best total (intracloud and cloud-to-ground) lightning data base over the tropics.We present a 16 year (1998-2013) reprocessed data set to create very high resolution (0.1°) TRMM LIS total lightning climatology. This detailed very high resolution climatology is used to identify the Earth's lightning hotspots and other regional features. Earlier studies located the lightning hotspot within the Congo Basin in Africa, but our very high resolution lightning climatology found that the highest lightning flash rate on Earth actually occurs in Venezuela over Lake Maracaibo, with a distinct maximum during the night. The higher resolution dataset clearly shows that similar phenomenon also occurs over other inland lakes with similar conditions, i.e., locally forced convergent flow over a warm lake surface which drives deep nocturnal convection. Although Africa does not have the top lightning hotspot, it comes in a close second and it is the continent with the highest number of lightning hotspots, followed by Asia, South America, North America, and Oceania. We also present climatological maps for local hour and month of lightning maxima, along with a ranking of the highest five hundred lightning maxima, focusing discussion on each continent's 10 highest lightning maxima. Most of the highest continental maxima are located near major mountain ranges, revealing the importance of local topography in thunderstorm development. These results are especially relevant in anticipation of the upcoming availability of continuous total lightning observations from the Geostationary Lightning Mapping (GLM

  9. High current lightning test of space shuttle external tank lightning protection system

    NASA Technical Reports Server (NTRS)

    Mumme, E.; Anderson, A.; Schulte, E. H.

    1977-01-01

    During lift-off, the shuttle launch vehicle (external tank, solid rocket booster and orbiter) may be subjected to a lightning strike. Tests of a proposed lightning protection method for the external tank and development materials which were subjected to simulated lightning strikes are described. Results show that certain of the high resistant paint strips performed remarkably well in diverting the 50 kA lightning strikes.

  10. Relativistic-microwave theory of ball lightning.

    PubMed

    Wu, H-C

    2016-06-22

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.

  11. Relativistic-microwave theory of ball lightning.

    PubMed

    Wu, H-C

    2016-01-01

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics. PMID:27328835

  12. Electric charge of a lightning ball

    NASA Astrophysics Data System (ADS)

    Grigor'ev, A. I.; Shiryaeva, S. O.; Petrushov, N. A.

    2016-09-01

    The electric charge of a lightning ball is found by comparing the electrohydrodynamic stabilities of a charged drop in an electrostatic suspension and a lightning ball floating in a superposition of the gravitational field and the surface electric field. It has been assumed that the electric field strength at the surface is limited by a breakdown value. For a lightning ball radius of 15 cm, its charge is estimated as several microcoulombs. Accordingly, the density of electrostatic energy accumulated in the lightning ball is on the order of one-hundredth of a joule per square centimeter. The density of the material that constitutes the lightning ball has been estimated for the case when the electric field strength at the site of its origination is several times higher than that in fine weather. The density of the lightning ball turns out to differ from that of air by only a few percents.

  13. Relativistic-microwave theory of ball lightning

    NASA Astrophysics Data System (ADS)

    Wu, H.-C.

    2016-06-01

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.

  14. Relativistic-microwave theory of ball lightning

    PubMed Central

    Wu, H.-C.

    2016-01-01

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics. PMID:27328835

  15. Myocardial infarction due to lightning strike.

    PubMed

    Karadas, Sevdegul; Vuruskan, Ertan; Dursun, Recep; Sincer, Isa; Gonullu, Hayriye; Akkaya, Emre

    2013-09-01

    Cardiac events due to lightning strike and their severity vary according to the strength of the electric current and the duration of exposure. The electrophysiological effects of lightning on the heart can result in ventricular fibrillation, asystole, QT prolongation, supraventricular tachycardia, and non-specific ST-T wave changes. In this report, a case of a patient who suffered myocardial infarction due to lightning strike is presented, which is a rare complication. PMID:24601203

  16. Myocardial infarction due to lightning strike.

    PubMed

    Karadas, Sevdegul; Vuruskan, Ertan; Dursun, Recep; Sincer, Isa; Gonullu, Hayriye; Akkaya, Emre

    2013-09-01

    Cardiac events due to lightning strike and their severity vary according to the strength of the electric current and the duration of exposure. The electrophysiological effects of lightning on the heart can result in ventricular fibrillation, asystole, QT prolongation, supraventricular tachycardia, and non-specific ST-T wave changes. In this report, a case of a patient who suffered myocardial infarction due to lightning strike is presented, which is a rare complication.

  17. Lightning attachment processes of three natural lightning discharges

    NASA Astrophysics Data System (ADS)

    Wang, D.; Takagi, N.; Gamerota, W. R.; Uman, M. A.; Jordan, D. M.

    2015-10-01

    Using a high-speed optical imaging system specifically designed for observing the lightning attachment process, we have documented the attachment process for six strokes in three natural lightning flashes. All strokes initiate at a height above ground and propagate bidirectionally from that height, similar to the return strokes of artificially initiated (triggered) lightning previously reported by Wang et al. (2013, 2014). Though the data are quite limited, these natural return strokes suggest a correlation between larger peak current and greater initiation height. Initiation heights determined here span 12-60 m with a typical uncertainty of less than 10 m. The initial upward return stroke luminosity speeds range from (0.8 ± 0.2) to (2.0 ± 0.4) × 108 m/s. Two first return strokes downward luminosity speeds are assessed as (1.6 ± 0.3) × 107 m/s and (1.4 ± 0.3) × 108 m/s. One of the first return strokes appeared to be initiated with a stepping pulse discharge of its leader as an inseparable part of the return stroke.

  18. Lightning Protection Guidelines for Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Goodloe, C. C.

    1999-01-01

    This technical memorandum provides lightning protection engineering guidelines and technical procedures used by the George C. Marshall Space Flight Center (MSFC) Electromagnetics and Aerospace Environments Branch for aerospace vehicles. The overviews illustrate the technical support available to project managers, chief engineers, and design engineers to ensure that aerospace vehicles managed by MSFC are adequately protected from direct and indirect effects of lightning. Generic descriptions of the lightning environment and vehicle protection technical processes are presented. More specific aerospace vehicle requirements for lightning protection design, performance, and interface characteristics are available upon request to the MSFC Electromagnetics and Aerospace Environments Branch, mail code EL23.

  19. Lightning Protection of Wind Turbine Generation System

    NASA Astrophysics Data System (ADS)

    Yokoyama, Shigeru; Sekioka, Shozo

    The rapid increase of wind power plants and enlargement of capacity makes the lightning problem of the wind power plants including blades serious. This report summarizes the result of the comprehensive surveillance study carried out for these several years. The contents lightning outages, the lightning phenomena and the result of the electric discharge experiment in connection with the measure against lightning of a windmill blades. Furthermore, the state of the present condition of the protective measures in the blades of windmill, mechanical parts, connecting power lines and communication lines was also considered. Especially grounding methods for wind power plants are considered.

  20. Lightning Strike in Pregnancy With Fetal Injury.

    PubMed

    Galster, Kellen; Hodnick, Ryan; Berkeley, Ross P

    2016-06-01

    Injuries from lightning strikes are an infrequent occurrence, and are only rarely noted to involve pregnant victims. Only 13 cases of lightning strike in pregnancy have been previously described in the medical literature, along with 7 additional cases discovered within news media reports. This case report presents a novel case of lightning-associated injury in a patient in the third trimester of pregnancy, resulting in fetal ischemic brain injury and long-term morbidity, and reviews the mechanics of lightning strikes along with common injury patterns of which emergency providers should be aware. PMID:27116922

  1. Lightning Studies Using VHF Waveform Data

    NASA Technical Reports Server (NTRS)

    Moldwin, Mark; Lennon, Carl

    1996-01-01

    Several atmospheric electricity studies were begun utilizing VHF lightning data obtained with the lightning detection and ranging system (LDAR) at the Kennedy Space Center (KSC). The LDAR system uses differences in the time of arrival of electromagnetic noise generated by the lightning process to seven antennas to calculate very accurate three dimensional locations of lightning. New software was developed to obtain the source location of multiple, simultaneous, and spatially separate lightning signatures. Three studies utilizing these data were begun this summer: (1) VHF observations of simultaneous lightning, (2) ground based VHF observations of transionospheric pulse pairs (TIPPs), and (3) properties of intra-cloud recoil streamers. The principal result of each of these studies are: (1) lightning commonly occurs in well separated (2-50 km) regions simultaneously, (2) large amplitude pairs of VHF pulses are commonly observed on the ground but had not been previously identified due to the large number of signals usually observed in the VHF noise of close lightning, and (3) the VHF Q-noise and pulse signatures associated with K-changes within intra-cloud lightning propagate at velocities of more than 10(exp 8) m/s. The interim results of these three studies are reviewed in this brief report.

  2. A three-station lightning detection system

    NASA Technical Reports Server (NTRS)

    Ruhnke, L. H.

    1972-01-01

    A three-station network is described which senses magnetic and electric fields of lightning. Directional and distance information derived from the data are used to redundantly determine lightning position. This redundancy is used to correct consistent propagation errors. A comparison is made of the relative accuracy of VLF direction finders with a newer method to determine distance to and location of lightning by the ratio of magnetic-to-electric field as observed at 400 Hz. It was found that VLF direction finders can determine lightning positions with only one-half the accuracy of the method that uses the ratio of magnetic-to-electric field.

  3. Lightning studies using LDAR and LLP data

    NASA Technical Reports Server (NTRS)

    Forbes, Gregory S.

    1993-01-01

    This study intercompared lightning data from LDAR and LLP systems in order to learn more about the spatial relationships between thunderstorm electrical discharges aloft and lightning strikes to the surface. The ultimate goal of the study is to provide information that can be used to improve the process of real-time detection and warning of lightning by weather forecasters who issue lightning advisories. The Lightning Detection and Ranging (LDAR) System provides data on electrical discharges from thunderstorms that includes cloud-ground flashes as well as lightning aloft (within cloud, cloud-to-cloud, and sometimes emanating from cloud to clear air outside or above cloud). The Lightning Location and Protection (LLP) system detects primarily ground strikes from lightning. Thunderstorms typically produce LDAR signals aloft prior to the first ground strike, so that knowledge of preferred positions of ground strikes relative to the LDAR data pattern from a thunderstorm could allow advance estimates of enhanced ground strike threat. Studies described in the report examine the position of LLP-detected ground strikes relative to the LDAR data pattern from the thunderstorms. The report also describes other potential approaches to the use of LDAR data in the detection and forecasting of lightning ground strikes.

  4. Lightning Strike in Pregnancy With Fetal Injury.

    PubMed

    Galster, Kellen; Hodnick, Ryan; Berkeley, Ross P

    2016-06-01

    Injuries from lightning strikes are an infrequent occurrence, and are only rarely noted to involve pregnant victims. Only 13 cases of lightning strike in pregnancy have been previously described in the medical literature, along with 7 additional cases discovered within news media reports. This case report presents a novel case of lightning-associated injury in a patient in the third trimester of pregnancy, resulting in fetal ischemic brain injury and long-term morbidity, and reviews the mechanics of lightning strikes along with common injury patterns of which emergency providers should be aware.

  5. Polymer-composite ball lightning.

    PubMed

    Bychkov, V L

    2002-01-15

    Investigations into the state of ball lightning (BL) have been made, and both theory and experiments, related to so-called "polymer-composite" ball lightning, are presented. The properties of such a polymeric BL have been described and are that of a long-lived object capable of storing high energy. Results of experiments, starting with polymeric components in erosive gas discharge experiments, are described and discussed. The model of BL as a highly charged polymer-dielectric structure is described. According to this model BL appears as the result of the aggregation of natural polymers, such as lignin and cellulose, soot, polymeric silica and other natural dust particles. Its ability to glow is explained by the appearance over its perimeter of gas discharges near the highly charged BL surface, and electrical breakdown of some regions on the surface, consisting of polymerized and aggregated threads.

  6. Indirect Lightning Safety Assessment Methodology

    SciTech Connect

    Ong, M M; Perkins, M P; Brown, C G; Crull, E W; Streit, R D

    2009-04-24

    Lightning is a safety hazard for high-explosives (HE) and their detonators. In the However, the current flowing from the strike point through the rebar of the building The methodology for estimating the risk from indirect lighting effects will be presented. It has two parts: a method to determine the likelihood of a detonation given a lightning strike, and an approach for estimating the likelihood of a strike. The results of these two parts produce an overall probability of a detonation. The probability calculations are complex for five reasons: (1) lightning strikes are stochastic and relatively rare, (2) the quality of the Faraday cage varies from one facility to the next, (3) RF coupling is inherently a complex subject, (4) performance data for abnormally stressed detonators is scarce, and (5) the arc plasma physics is not well understood. Therefore, a rigorous mathematical analysis would be too complex. Instead, our methodology takes a more practical approach combining rigorous mathematical calculations where possible with empirical data when necessary. Where there is uncertainty, we compensate with conservative approximations. The goal is to determine a conservative estimate of the odds of a detonation. In Section 2, the methodology will be explained. This report will discuss topics at a high-level. The reasons for selecting an approach will be justified. For those interested in technical details, references will be provided. In Section 3, a simple hypothetical example will be given to reinforce the concepts. While the methodology will touch on all the items shown in Figure 1, the focus of this report is the indirect effect, i.e., determining the odds of a detonation from given EM fields. Professor Martin Uman from the University of Florida has been characterizing and defining extreme lightning strikes. Using Professor Uman's research, Dr. Kimball Merewether at Sandia National Laboratory in Albuquerque calculated the EM fields inside a Faraday-cage type

  7. Lightning strike in golf practice.

    PubMed

    Elena-Sorando, E; Galeano-Ricaño, N; Agulló-Domingo, A; Cimorra-Moreno, G; Gil-Castillo, C

    2006-03-31

    The case is presented of a golfer who was struck by lightning while playing golf during a thunderstorm. The patient was found lying unconscious on wet grass with his clothes scorched and his spiked golf shoes torn. He had suffered dermal burns affecting the neck, thorax, abdomen, and upper and lower limbs (10% total body surface area), without any cardiovascular or respiratory disturbances. It may be hypothesized that the lightning current went over the outside of the patient, causing ignition of his clothes. Treatment included monitoring, adequate fluid management, debridement, and topical treatment (silver sulphadiazine). Complete healing of the wounds was achieved in two weeks. After three years' follow-up, the patient had no sequelae. PMID:21991022

  8. Polymer-composite ball lightning.

    PubMed

    Bychkov, V L

    2002-01-15

    Investigations into the state of ball lightning (BL) have been made, and both theory and experiments, related to so-called "polymer-composite" ball lightning, are presented. The properties of such a polymeric BL have been described and are that of a long-lived object capable of storing high energy. Results of experiments, starting with polymeric components in erosive gas discharge experiments, are described and discussed. The model of BL as a highly charged polymer-dielectric structure is described. According to this model BL appears as the result of the aggregation of natural polymers, such as lignin and cellulose, soot, polymeric silica and other natural dust particles. Its ability to glow is explained by the appearance over its perimeter of gas discharges near the highly charged BL surface, and electrical breakdown of some regions on the surface, consisting of polymerized and aggregated threads. PMID:16210170

  9. Interferometric Observations of Lightning Initiation

    NASA Astrophysics Data System (ADS)

    Rison, W.; Krehbiel, P. R.; Stock, M.; Edens, H. E.; Shao, X. M.; Thomas, R. J.; Stanley, M. A.

    2014-12-01

    Observations of the initial parts of lightning flashes close to Langmuir Laboratory in central New Mexico appear to show the lightning initiation process. The observations were made on August 5, 2013, from a number of flashes within 5 km of the New Mexico Tech broadband VHF interferometer (INTF). In addition to the INTF, the flashes were observed by the Langmuir Laboratory Lightning Mapping Array (LMA), and by close fast and slow antennas. For those flashes where the powers of the initial sources detected by the LMA were stronger than about 5 dBW (4 watts), the INTF observations showed that the initial LMA source was associated with a previously unidentified form of fast positive breakdown. No activity was detected prior to the positive breakdown, either by the sensitive INTF or fast electric measurements. The VHF radiation and electric field changes develop simultaneously, and the INTF shows a positive breakdown which propagates about one hundred meters. This and other features of the observations indicate that the breakdown occurs in virgin air and is produced by dielectric streamer processes in localized regions of strong electric fields. We observed both normal intracloud and cloud-to-ground discharges to be initiated by such breakdown. After the fast positive breakdown died out, the INTF showed continuous negative breakdown at the start of the positive channel, which subsequently developed into a negative leader propagating in the opposite direction of the initial positive breakdown. The results are fundamentally consistent with those obtained from modelling studies by Liu et al. (Phys. Rev. Lett.109, 025002, 2012), in which positive sprite streamers were shown to be initiated by purely dielectric breakdown, without the need of an initiating event such as a cosmic ray or energetic electron avalanches. We speculate that all lightning flashes are initiated by the fast positive events.

  10. Takotsubo cardiomyopathy following lightning strike.

    PubMed

    Dundon, B K; Puri, R; Leong, D P; Worthley, M I

    2008-07-01

    Lightning strike is the most common environmental cause of sudden cardiac death, but may also be associated with a myriad of injuries to various organ systems. Direct myocardial injury may be manifest as electrocardiographic alterations or elevation in cardiac-specific isoenzymes; however, significant electrical cardiac trauma appears uncommon. A case is presented of severe acute cardiomyopathy in a "Takotsubo" distribution causing cardiogenic shock following lightning strike in a previously healthy 37-year-old woman. Although rarely identified in this context, Takotsubo cardiomyopathy (also known as "transient left ventricular apical ballooning syndrome") is characterised by transient cardiac dysfunction, electrocardiographic changes that may mimic acute myocardial infarction and minimal release of cardiac-specific enzymes in the absence of obstructive coronary artery disease. The condition is associated with a substantial female bias (up to 90% of cases) in reported series, and despite occasionally dramatic presentations recovery of left ventricular function is almost universal over days to weeks. In rare instances, however, the syndrome has been associated with more catastrophic complications such as papillary muscle or cardiac free wall rupture, necessitating emergency surgical intervention to preserve life. In clinical practice, non-lethal lightning strike-induced cardiac injury is frequently associated with small elevations of cardiac isoenzymes without overt clinical sequelae; however, the incidence of silent myocardial mechanical dysfunction remains unknown. Cases such as the one presented highlight the potential for serious, albeit usually transient, cardiac sequelae from lightning strike injury and remind us that our mothers' advice to remain indoors during thunderstorms is probably worth heeding. PMID:18573973

  11. Takotsubo cardiomyopathy following lightning strike.

    PubMed

    Dundon, Benjamin K; Puri, Rishi; Leong, Darryl P; Worthley, Matthew Ian

    2009-01-01

    Lightning strike is the most common environmental cause of sudden cardiac death, but it may also be associated with a myriad of injuries to various organ systems. Direct myocardial injury may be manifest as electrocardiographic alterations or elevation in cardiac-specific isoenzymes; however, significant electrical cardiac trauma appears uncommon. A case is presented of severe acute cardiomyopathy in a "Takotsubo" distribution causing cardiogenic shock following lightning strike in a previously healthy 37-year-old woman. Although rarely identified in this context, Takotsubo cardiomyopathy (also known as "transient left ventricular apical ballooning syndrome") is characterised by transient cardiac dysfunction, electrocardiographic changes that may mimic acute myocardial infarction and minimal release of cardiac-specific enzymes in the absence of obstructive coronary artery disease. The condition is associated with a substantial female bias (up to 90% of cases) in reported series, and despite occasionally dramatic presentations recovery of left ventricular function is almost universal over days to weeks. In rare instances, however, the syndrome has been associated with more catastrophic complications such as papillary muscle or cardiac free wall rupture, necessitating emergency surgical intervention to preserve life. In clinical practice, non-lethal lightning strike-induced cardiac injury is frequently associated with small elevations of cardiac isoenzymes without overt clinical sequelae; however, the incidence of silent myocardial mechanical dysfunction remains unknown. Cases such as the one presented highlight the potential for serious, albeit usually transient, cardiac sequelae from lightning strike injury and remind us that our mothers' advice to remain indoors during thunderstorms is probably worth heeding. PMID:21686980

  12. How to create ball lightning

    NASA Technical Reports Server (NTRS)

    Golka, Robert K., Jr.

    1991-01-01

    Procedures are given on how to produce ball lightning. Necessary equipment includes a transformer of 150,000 watts capable of providing approximately 10,000 amperes at 15 volts, 60 cycles; thick one inch cables of stranded wire leading into a 3 by 4 by 1 foot plastic tank; a quarter inch thick 4 by 6 inch aluminum plate to be used as one of the discharge electrodes; and another electrode of heavy copper wire with the insulation stripped back 6 inches.

  13. Launch pad lightning protection effectiveness

    NASA Technical Reports Server (NTRS)

    Stahmann, James R.

    1991-01-01

    Using the striking distance theory that lightning leaders will strike the nearest grounded point on their last jump to earth corresponding to the striking distance, the probability of striking a point on a structure in the presence of other points can be estimated. The lightning strokes are divided into deciles having an average peak current and striking distance. The striking distances are used as radii from the points to generate windows of approach through which the leader must pass to reach a designated point. The projections of the windows on a horizontal plane as they are rotated through all possible angles of approach define an area that can be multiplied by the decile stroke density to arrive at the probability of strokes with the window average striking distance. The sum of all decile probabilities gives the cumulative probability for all strokes. The techniques can be applied to NASA-Kennedy launch pad structures to estimate the lightning protection effectiveness for the crane, gaseous oxygen vent arm, and other points. Streamers from sharp points on the structure provide protection for surfaces having large radii of curvature. The effects of nearby structures can also be estimated.

  14. Slow Lightning in Water Plasmoids

    NASA Astrophysics Data System (ADS)

    Stephan, Karl; Dumas, Shelby; McMinn, Jonathan

    2012-10-01

    Water plasmoids are produced when a capacitor is discharged into a cathode at the surface of a weakly conducting water electrolyte. The resulting plasma jet forms a glowing spherical plasmoid which persists in air for up to 0.3 s and resembles ball lightning in some respects. This study shows that during the plasmoid's formation stage, surface discharges with unusual characteristics carry the large instantaneous discharge current. The liquid-surface discharges have some characteristics of both conventional solid-surface discharges (branching, fractal structure) and glow discharges (approximately constant current density from the discharge plasma to the water surface over a wide range of current). Dynamically, the surface discharge resembles a two-dimensional version of a lightning leader, but develops at much lower speeds: a maximum of about 0.3 m/s for the surface discharges in this study, compared to lightning leader speeds of 100 to 100,000 m/s. The low conductivity of the water used (about 20 mS/m) means that the surface discharges are interacting with a resistive barrier, which allows a significant tangential electric field on the surface. High-speed photography of the discharges is supplemented by spectroscopic and other experimental studies.

  15. Total Lightning Activity as Observed from Space

    NASA Technical Reports Server (NTRS)

    Christian, Hugh J.

    2004-01-01

    Our knowledge of the global distribution of lightning has improved dramatically since the 1995 launch of the Optical Transient Detector (OTD), followed in 1997 by the launch of the Lightning Imaging Sensor (LIS). Together, these instruments have generated a continuous seven-year record of global lightning activity. These lightning observations have provided a new global perspective on total lightning activity. For the first time, total lightning activity (CG and IC) has been observed over large regions with high detection efficiencies and accurate geographic location. This has produced new insights into lightning distributions, times of occurrence and variability. It has produced a revised global flash rate estimate (44 flashes per second) and has lead to a new realization of the significance of total ligh&g activity in severe weather. Accurate flash rate estimates are now available for areas of the earth (+/- 72 deg. latitude). Ocean-land contrasts as a function of season are clearly reveled, as are orographic effects and seasonal and interannual variability. The data set indicates that air mass thunderstorms, not large storm system dominate global activity. The ability of LIS and OTD to detect total lightning has lead to improved insight into the correlation between lightning and storm development. The relationship between updraft development and lightning activity is now well established and presents an opportunity for providing a new mechanism for remotely monitoring storm development. In this concept, lightning would serve as a surrogate for updraft velocity. It is anticipated that this capability could lead to significantly improved severe weather warning times and reduced false warning rates.

  16. Total Lightning Activity as Observed from Space

    NASA Technical Reports Server (NTRS)

    Christian, Hugh J.

    2004-01-01

    ABSTRACT: Our knowledge of the global distribution of lightning has improved dramatically since the 1995 launch of the Optical Transient Detector (OTD), followed in 1997 by the launch of the Lightning Imaging Sensor (LIS). Together, these instruments have generated a continuous seven-year record of global lightning activity. These lightning observations have provided a new global perspective on total lightning activity. For the first time, total lightning activity (CG and IC) has been observed over large regions with high detection efficiencies and accurate geographic location. This has produced new insights into lightning distributions, times of occurrence and variability. It has produced a revised global flash rate estimate (44 flashes per second) and has lead to a new realization of the significance of total ligh&g activity in severe weather. Accurate flash rate estimates are now available for areas of the earth (+/- 72 deg. latitude). Ocean-land contrasts as a function of season are clearly reveled, as are orographic effects and seasonal and interannual variability. The data set indicates that air mass thunderstorms, not large storm system dominate global activity. The ability of LIS and OTD to detect total lightning has lead to improved insight into the correlation between lightning and storm development. The relationship between updraft development and lightning activity is now well established and presents an opportunity for providing a new mechanism for remotely monitoring storm development. In this concept, lightning would serve as a surrogate for updraft velocity. It is anticipated that this capability could lead to significantly improved severe weather warning times and reduced false warning rates.

  17. Infrasound from lightning measured in Ivory Coast

    NASA Astrophysics Data System (ADS)

    Farges, T.; Matoza, R. S.

    2011-12-01

    It is well established that more than 2,000 thunderstorms occur continuously around the world and that about 45 lightning flashes are produced per second over the globe. More than two thirds (42) of the infrasound stations of the International Monitoring System (IMS) of the CTBTO (Comprehensive nuclear Test Ban Treaty Organisation) are now certified and routinely measure signals due to natural activity (e.g., airflow over mountains, aurora, microbaroms, surf, volcanoes, severe weather including lightning flashes, ...). Some of the IMS stations are located where worldwide lightning detection networks (e.g. WWLLN) have a weak detection capability but lightning activity is high (e.g. Africa, South America). These infrasound stations are well localised to study lightning flash activity and its disparity, which is a good proxy for global warming. Progress in infrasound array data processing over the past ten years makes such lightning studies possible. For example, Farges and Blanc (2010) show clearly that it is possible to measure lightning infrasound from thunderstorms within a range of distances from the infrasound station. Infrasound from lightning can be detected when the thunderstorm is within about 75 km from the station. The motion of the squall zone is very well measured inside this zone. Up to 25% of lightning flashes can be detected with this technique, giving better results locally than worldwide lightning detection networks. An IMS infrasound station has been installed in Ivory Coast for 8 years. The optical space-based instrument OTD measured a rate of 10-20 flashes/km^2/year in that country and showed strong seasonal variations (Christian et al., 2003). Ivory Coast is therefore a good place to study infrasound data associated with lightning activity and its temporal variation. First statistical results will be presented in this paper based on 3 years of data (2005-2008).

  18. [Lightning strikes and lightning injuries in prehospital emergency medicine. Relevance, results, and practical implications].

    PubMed

    Hinkelbein, J; Spelten, O; Wetsch, W A

    2013-01-01

    Up to 32.2% of patients in a burn center suffer from electrical injuries. Of these patients, 2-4% present with lightning injuries. In Germany, approximately 50 people per year are injured by a lightning strike and 3-7 fatally. Typically, people involved in outdoor activities are endangered and affected. A lightning strike usually produces significantly higher energy doses as compared to those in common electrical injuries. Therefore, injury patterns vary significantly. Especially in high voltage injuries and lightning injuries, internal injuries are of special importance. Mortality ranges between 10 and 30% after a lightning strike. Emergency medical treatment is similar to common electrical injuries. Patients with lightning injuries should be transported to a regional or supraregional trauma center. In 15% of all cases multiple people may be injured. Therefore, it is of outstanding importance to create emergency plans and evacuation plans in good time for mass gatherings endangered by possible lightning. PMID:21909737

  19. [Lightning strikes and lightning injuries in prehospital emergency medicine. Relevance, results, and practical implications].

    PubMed

    Hinkelbein, J; Spelten, O; Wetsch, W A

    2013-01-01

    Up to 32.2% of patients in a burn center suffer from electrical injuries. Of these patients, 2-4% present with lightning injuries. In Germany, approximately 50 people per year are injured by a lightning strike and 3-7 fatally. Typically, people involved in outdoor activities are endangered and affected. A lightning strike usually produces significantly higher energy doses as compared to those in common electrical injuries. Therefore, injury patterns vary significantly. Especially in high voltage injuries and lightning injuries, internal injuries are of special importance. Mortality ranges between 10 and 30% after a lightning strike. Emergency medical treatment is similar to common electrical injuries. Patients with lightning injuries should be transported to a regional or supraregional trauma center. In 15% of all cases multiple people may be injured. Therefore, it is of outstanding importance to create emergency plans and evacuation plans in good time for mass gatherings endangered by possible lightning.

  20. On the proportion of upward flashes to lightning research towers

    NASA Astrophysics Data System (ADS)

    Smorgonskiy, Alexander; Rachidi, Farhad; Rubinstein, Marcos; Diendorfer, Gerhard; Schulz, Wolfgang

    2013-07-01

    We compare in this paper direct measurements obtained on the towers on San Salvatore Mountain (Switzerland) and on the Gaisberg Mountain (Austria). They are situated in similar topographical environments but in different lightning activity zones. Direct measurements of lightning currents on these towers have revealed a major difference in terms of the number of downward flashes. While measurements made by Berger and co-workers revealed a significant number of downward flashes on the two towers on San Salvatore Mountain, more recent observations on the Gaisberg and Peissenberg towers were essentially composed of upward flashes. We use in this paper a new method to estimate the proportion of upward/downward flashes to a given tower, based on the data from lightning location systems. The analysis using the proposed method explains the discrepancy in terms of the measured number of downward flashes in the Gaisberg and San Salvatore towers. The analysis presented reveals also that in the evaluation of the percentage of upward flashes initiated from a tall structure, different parameters should be carefully examined, namely (i) the value of the ground flash density, (ii) the topographical conditions, and (iii) the presence of other tall structures in the region from which upward flashes might be initiated.

  1. Combined use of adenoviral vector Ad5/F35-mediated APE1 siRNA enhances the therapeutic efficacy of adenoviral-mediated p53 gene transfer in hepatoma cells in vitro and in vivo.

    PubMed

    Cun, Yanping; Zhang, Qinhong; Xiong, Chengjie; Li, Mengxia; Dai, Nan; Zhang, Shiheng; Wang, Dong

    2013-06-01

    Gene therapy has emerged as a novel therapeutic approach for the treatment of cancer. In order to establish a more effective therapeutic strategy against unresectable hepatocellular carcinoma (HCC), we evaluated, in the present study, the effects of combined treatment with adenoviral vector Ad5/F35-mediated APE1 siRNA (Ad5/F35-siAPE1) and adenoviral-mediated p53 gene transfer (Ad-p53) in hepatoma cells in vitro and in vivo. Infection of SMMC-7721 cells with Ad5/F35-siAPE1 resulted in a time- and dose-dependent decrease of APE1 protein, while Ad-p53 treatment led to a time- and dose-dependent increase of p53 protein expression. Ad5/F35-siAPE1 significantly enhanced the cytotoxic effect of SMMC-7721 cells to Ad-p53 in cell survival assays, associated with increased cell apoptosis. Moreover, administration of Ad5/F35-siAPE1 and Ad-p53 into nude mice resulted in tumor growth inhibition and apoptosis induction in SMMC-7721 xenografts compared to administration of either agent alone. These results suggest that combination of Ad5/F35-siAPE1 and Ad-p53 could be a promising gene therapeutic approach against human HCC.

  2. ER-2 investigations of lightning and thunderstorms

    NASA Technical Reports Server (NTRS)

    Blakeslee, Richard

    1993-01-01

    The primary objective of the ER-2 lightning program is to investigate relationships between lightning and storm electrification and a number of underlying and interrelated phenomena including the structure, dynamics, and evolution of thunderstorms and thunderstorm systems, precipitation distribution and amounts, atmospheric chemistry processes, and the global electric circuit. This research is motivated by the desire to develop an understanding needed for the effective utilization and interpretation of data from the Lighting Imaging Sensor (LIS), the Lightning Mapper Sensor (LMS), and other satellite-based lightning detectors planned for the late 1900's and early 2000's. These satellite lightning detection systems will be characterized by high detection efficiencies (i.e., 90 percent) and the capability to detect both intracloud and cloud-to-ground discharges during day and night. The Lightning Imaging Sensor (LIS) is being developed by NASA for the Tropical Rainfall Measuring Mission (TRMM) satellite. In the ER-2 and related investigations, the emphasis is on establishing quantitative relationships and developing practical algorithms that employ lightning data, such as could be derived from satellite observations of optical lightning emissions, as the independent variable. Significant accomplishments made during the past year are presented.

  3. Space shuttle program: Lightning protection criteria document

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The lightning environment for space shuttle design is defined and requirements that the design must satisfy to insure protection of the vehicle system from direct and indirect effects of lightning are imposed. Specifications, criteria, and guidelines included provide a practical and logical approach to protection problems.

  4. Protecting Your Park When Lightning Strikes.

    ERIC Educational Resources Information Center

    Frydenlund, Marvin M.

    1987-01-01

    A formula for assessing specific risk of lightning strikes is provided. Recent legal cases are used to illustrate potential liability. Six actions park managers can take to minimize danger from lightning are presented, and commonsense rules which should be publicly posted are listed. (MT)

  5. The Importance of Venus Lightning Investigations

    NASA Astrophysics Data System (ADS)

    Hart, R. A.; Russell, C. T.; Wei, H.; Zhang, T.

    2013-12-01

    Lightning in planetary atmospheres arises due to the separation of electric charges in convective cloud systems. We expect that Venus should have strong thermally driven winds at its location of 0.72 AU from the Sun. Observations of the cloud tops and the vertical motions of the atmosphere by the VEGA balloons confirm this expectation. We have made extensive surveys for lightning on Venus with spacecraft in the Venusian ionosphere. However, as yet we do not have a complete mapping of the occurrence of lightning because at the low frequencies at which measurements have been made it is difficult for the waves generated to penetrate the ionosphere. We expect the lightning to be intense as it generates nitric oxide and nitric oxide as is abundant on Venus as on Earth. We have surveyed almost all the Venus Express 128 Hz magnetometer data recorded to date. These data reveal that lightning is extensive on Venus but still do not reveal its true occurrence rate or altitude of generation. This requires observations from multipoint monitors at frequencies that penetrate into the ionosphere and will allow us to determine the energy released by lightning in the Venusian atmosphere. Finally, it is essential for us to study similar planetary processes in different settings in order to fully understand the process itself. Lightning is an important terrestrial process. Venus gives us the opportunity to understand the process more deeply. In this presentation we review the present state of knowledge of Venus lightning.

  6. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  7. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  8. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  9. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  10. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  11. A Total Lightning Climatology for the Tennessee Valley Region

    NASA Technical Reports Server (NTRS)

    McCaul, E. W.; Goodman, S. J.; Buechler, D. E.; Blakeslee, R.; Christian, H.; Boccippio, D.; Koshak, W.; Bailey, J.; Hallm, J.; Bateman, M.

    2003-01-01

    Total flash counts derived from the North Alabama Lightning Mapping Array are being processed for 2002 to form a climatology of total lightning for the Tennessee Valley region. The data from this active and interesting period will be compared to data fiom the National Lightning Detection Network, space-based lightning sensors, and weather radars.

  12. Mathematical physics approaches to lightning discharge problems

    NASA Technical Reports Server (NTRS)

    Kyrala, A.

    1985-01-01

    Mathematical physics arguments useful for lightning discharge and generation problems are pursued. A soliton Ansatz for the lightning stroke is treated including a charge generation term which is the ultimate source for the phenomena. Equations are established for a partially ionized plasma inding the effects of pressure, magnetic field, electric field, gravitation, viscosity, and temperature. From these equations is then derived the non-stationary generalized Ohm's Law essential for describing field/current density relationships in the horizon channel of the lightning stroke. The discharge initiation problem is discussed. It is argued that the ionization rate drives both the convective current and electric displacement current to increase exponentially. The statistical distributions of charge in the thundercloud preceding a lightning dischage are considered. The stability of the pre-lightning charge distributions and the use of Boltzmann relaxational equations to determine them are discussed along with a covered impedance path provided by the aircraft.

  13. Lightning injuries in sports and recreation.

    PubMed

    Thomson, Eric M; Howard, Thomas M

    2013-01-01

    The powers of lightning have been worshiped and feared by all known human cultures. While the chance of being struck by lightning is statistically very low, that risk becomes much greater in those who frequently work or play outdoors. Over the past 2 yr, there have been nearly 50 lightning-related deaths reported within the United States, with a majority of them associated with outdoor recreational activities. Recent publications primarily have been case studies, review articles, and a discussion of a sixth method of injury. The challenge in reducing lightning-related injuries in organized sports has been addressed well by both the National Athletic Trainers' Association and the National Collegiate Athletic Association in their guidelines on lightning safety. Challenges remain in educating the general population involved in recreational outdoor activities that do not fall under the guidelines of organized sports.

  14. The Lightning Nitrogen Oxides Model (LNOM): Status and Recent Applications

    NASA Technical Reports Server (NTRS)

    Koshak, William; Khan, Maudood; Peterson, Harold

    2011-01-01

    Improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) are discussed. Recent results from an August 2006 run of the Community Multiscale Air Quality (CMAQ) modeling system that employs LNOM lightning NOx (= NO + NO2) estimates are provided. The LNOM analyzes Lightning Mapping Array (LMA) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NOx. The latest LNOM estimates of (a) lightning channel length distributions, (b) lightning 1-m segment altitude distributions, and (c) the vertical profile of NOx are presented. The impact of including LNOM-estimates of lightning NOx on CMAQ output is discussed.

  15. Global optical lightning flash rates determined with the Forte satellite

    SciTech Connect

    Light, T.; Davis, S. M.; Boeck, W. L.; Jacobson, A. R.; Suszcynsky, D. M.

    2003-01-01

    Using FORTE photodiode detector (PDD) observations of lightning, we have determined the geographic distribution of nighttime flash rate density. We estimate the PDD flash detection efficiency to be 62% for total lightning through comparison to lightning observations by the TRMM satellite's Lightning Imaging Sensor (LIS), using cases in which FORTE and TRMM viewed the same storm. We present here both seasonal and l,ot,al flash rate maps. We examine some characteristics of the optical emissions of lightning in both high and low flash rate environments, and find that while lightning occurs less frequently over ocean, oceanic lightning flashes are somewhat more powerful, on average, than those over land.

  16. Acoustic Manifestations of Natural versus Triggered Lightning

    NASA Astrophysics Data System (ADS)

    Arechiga, R. O.; Johnson, J. B.; Edens, H. E.; Rison, W.; Thomas, R. J.; Eack, K.; Eastvedt, E. M.; Aulich, G. D.; Trueblood, J.

    2010-12-01

    Positive leaders are rarely detected by VHF lightning detection systems; positive leader channels are usually outlined only by recoil events. Positive cloud-to-ground (CG) channels are usually not mapped. The goal of this work is to study the types of thunder produced by natural versus triggered lightning and to assess which types of thunder signals have electromagnetic activity detected by the lightning mapping array (LMA). Towards this end we are investigating the lightning detection capabilities of acoustic techniques, and comparing them with the LMA. In a previous study we used array beam forming and time of flight information to locate acoustic sources associated with lightning. Even though there was some mismatch, generally LMA and acoustic techniques saw the same phenomena. To increase the database of acoustic data from lightning, we deployed a network of three infrasound arrays (30 m aperture) during the summer of 2010 (August 3 to present) in the Magdalena mountains of New Mexico, to monitor infrasound (below 20 Hz) and audio range sources due to natural and triggered lightning. The arrays were located at a range of distances (60 to 1400 m) surrounding the triggering site, called the Kiva, used by Langmuir Laboratory to launch rockets. We have continuous acoustic measurements of lightning data from July 20 to September 18 of 2009, and from August 3 to September 1 of 2010. So far, lightning activity around the Kiva was higher during the summer of 2009. We will present acoustic data from several interesting lightning flashes including a comparison between a natural and a triggered one.

  17. Global lightning activity and climate change

    SciTech Connect

    Price, C.G.

    1993-12-31

    The relationship between global lightning frequencies and global climate change is examined in this thesis. In order to study global impacts of climate change, global climate models or General Circulations Models (GCMs) need to be utilized. Since these models have coarse resolutions many atmospheric phenomena that occur at subgrid scales, such as lightning, need to be parameterized whenever possible. We begin with a simple parameterization used to Simulate total (intracloud and cloud-to-ground) lightning frequencies. The parameterization uses convective cloud top height to approximate lightning frequencies. Then we consider a parameterization for simulating cloud-to-ground (CG) lightning around the globe. This parameterization uses the thickness of the cold cloud sector in thunderstorms (0{degrees}C to cloud top) to calculate the proportion of CG flashes in a particular thunderstorm. We model lightning in the Goddard Institute for Space Studies (GISS) GCM. We present two climate change scenarios. One for a climate where the solar constant is reduced by 2% (5.9{degrees}C global cooling), and one for a climate with twice the present concentration of CO{sub 2} in the atmosphere (4.2{degrees}C global warming). The results imply a 24%/30% decrease/increase in global lightning frequencies for the cooler/warmer climate. The possibility of using the above findings to monitor future global warming is discussed. The earth`s ionospheric potential, which is regulated by global thunderstorm activity, could supply valuable information regarding global surface temperature fluctuations. Finally, we look at the implications of changes in both lightning frequencies and the hydrological cycle, as a result of global warming, on natural forest fires. In the U.S. the annual mean number of lightning fires could increase by 40% while the area burned may increase by 65% in a 2{times}CO{sub 2} climate. On a global scale the largest increase in lightning fires can be expected in the tropics.

  18. Estimates of the Lightning NOx Profile in the Vicinity of the North Alabama Lightning Mapping Array

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Peterson, Harold S.; McCaul, Eugene W.; Blazar, Arastoo

    2010-01-01

    The NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) is applied to August 2006 North Alabama Lightning Mapping Array (NALMA) data to estimate the (unmixed and otherwise environmentally unmodified) vertical source profile of lightning nitrogen oxides, NOx = NO + NO2. Data from the National Lightning Detection Network (Trademark) (NLDN) is also employed. This is part of a larger effort aimed at building a more realistic lightning NOx emissions inventory for use by the U.S. Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) modeling system. Overall, special attention is given to several important lightning variables including: the frequency and geographical distribution of lightning in the vicinity of the NALMA network, lightning type (ground or cloud flash), lightning channel length, channel altitude, channel peak current, and the number of strokes per flash. Laboratory spark chamber results from the literature are used to convert 1-meter channel segments (that are located at a particular known altitude; i.e., air density) to NOx concentration. The resulting lightning NOx source profiles are discussed.

  19. Ball lightning as a force-free magnetic knot

    PubMed

    Ranada; Soler; Trueba

    2000-11-01

    The stability of fireballs in a recent model of ball lightning is studied. It is shown that the balls shine while relaxing in an almost quiescent expansion, and that three effects contribute to their stability: (i) the formation in each one during a process of Taylor relaxation of a force-free magnetic field, a concept introduced in 1954 in order to explain the existence of large magnetic fields and currents in stable configurations of astrophysical plasmas; (ii) the so called Alfven conditions in magnetohydrodynamics; and (iii) the approximate conservation of the helicity integral. The force-free fields that appear are termed "knots" because their magnetic lines are closed and linked.

  20. Giant elves: Lightning-generated electromagnetic pulses in giant planets.

    NASA Astrophysics Data System (ADS)

    Luque Estepa, Alejandro; Dubrovin, Daria; José Gordillo-Vázquez, Francisco; Ebert, Ute; Parra-Rojas, Francisco Carlos; Yair, Yoav; Price, Colin

    2015-04-01

    We currently have direct optical observations of atmospheric electricity in the two giant gaseous planets of our Solar System [1-5] as well as radio signatures that are possibly generated by lightning from the two icy planets Uranus and Neptune [6,7]. On Earth, the electrical activity of the troposphere is associated with secondary electrical phenomena called Transient Luminous Events (TLEs) that occur in the mesosphere and lower ionosphere. This led some researchers to ask if similar processes may also exist in other planets, focusing first on the quasi-static coupling mechanism [8], which on Earth is responsible for halos and sprites and then including also the induction field, which is negligible in our planet but dominant in Saturn [9]. However, one can show that, according to the best available estimation for lightning parameters, in giant planets such as Saturn and Jupiter the effect of the electromagnetic pulse (EMP) dominates the effect that a lightning discharge has on the lower ionosphere above it. Using a Finite-Differences, Time-Domain (FDTD) solver for the EMP we found [10] that electrically active storms may create a localized but long-lasting layer of enhanced ionization of up to 103 cm-3 free electrons below the ionosphere, thus extending the ionosphere downward. We also estimate that the electromagnetic pulse transports 107 J to 1010 J toward the ionosphere. There emissions of light of up to 108 J would create a transient luminous event analogous to a terrestrial elve. Although these emissions are about 10 times fainter than the emissions coming from the lightning itself, it may be possible to target them for detection by filtering the appropiate wavelengths. [1] Cook, A. F., II, T. C. Duxbury, and G. E. Hunt (1979), First results on Jovian lightning, Nature, 280, 794, doi:10.1038/280794a0. [2] Little, B., C. D. Anger, A. P. Ingersoll, A. R. Vasavada, D. A. Senske, H. H. Breneman, W. J. Borucki, and The Galileo SSI Team (1999), Galileo images of

  1. Cable coupling lightning transient qualification

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    Simulated lightning strike testing of instrumentation cabling on the redesigned solid rocket motor was performed. Testing consisted of subjecting the lightning evaluation test article to simulated lightning strikes and evaluating the effects of instrumentation cable transients on cables within the system tunnel. The maximum short-circuit current induced onto a United Space Boosters, Inc., operational flight cable within the systems tunnel was 92 A, and the maximum induced open-circuit voltage was 316 V. These levels were extrapolated to the worst-case (200 kA) condition of NASA specification NSTS 07636 and were also scaled to full-scale redesigned solid rocket motor dimensions. Testing showed that voltage coupling to cables within the systems tunnel can be reduced 40 to 90 dB and that current coupling to cables within the systems tunnel can be reduced 30 to 70 dB with the use of braided metallic sock shields around cables that are external to the systems tunnel. Testing also showed that current and voltage levels induced onto cables within the systems tunnel are partially dependant on the cables' relative locations within the systems tunnel. Results of current injections to the systems tunnel indicate that the dominant coupling mode on cables within the systems tunnel is not from instrumentation cables but from coupling through the systems tunnel cover seam apertures. It is recommended that methods of improving the electrical bonding between individual sections of the systems tunnel covers be evaluated. Further testing to better characterize redesigned solid rocket motor cable coupling effects as an aid in developing methods to reduce coupling levels, particularly with respect to cable placement within the systems tunnel, is also recommended.

  2. Lightning strike at Bryan, Ohio

    SciTech Connect

    Nichols, B. E.

    1980-02-01

    A week before the 29 August 1979 dedication of the photovoltaic power system at daytime AM radio station WBNO, in Bryan, Ohio, a lightning superbolt struck the FM radio tower, one of two towers at the station. Minor damage to the station and to components of the photovoltaic system, the latter designed by MIT Lincoln Laboratory under US Department of Energy sponsorship, is described. This rare strike suggested the need for increased protection and more voltage-transient suppressors were added to those already in place as a preventive measure in the event that such a phenomenon reoccurs.

  3. Structural and erosive Effects of Lightning on Sandstone: An Experimental Investigation

    NASA Astrophysics Data System (ADS)

    Haddad, Houssam; Ebert, Matthias; Kenkmann, Thomas; Thoma, Klaus; Nau, Siegfried; Schäfer, Frank

    2016-04-01

    Recent prognoses predict an average temperature increase of the world's climate of about 1.5 to 2 °C until the end of 21st century. This change leads not only to a rise of the sea level but also to an increase of thunderstorms and therefore to a ~25 percent increase of cloud-to-ground lightning events (Romps et al., 2014). It is known that (i) lightning strikes are able to fragment surface rocks, which probably influences the erosion rates at exposed mountain areas (Knight and Grab, 2014), and (ii) the efficiency of the process increases due to the predicted climate change. However, our knowledge about the electro-mechanical destruction of rocks caused by high energetic lightning is incomplete. In this study, laboratory experiments of lightning strikes were performed in order to understand the fragmentation of rocks and changes to landforms by lightning. The artificial lightning with known electric current was simulated by a high-current generator in the laboratories of the Fraunhofer Ernst-Mach Institute for High-Speed Dynamics (Freiburg, Germany). Different currents were transferred over a distance of ~2mm onto water-saturated sandstones by using a copper cathode (3 experiments; U, I, E, Δt: 6 kV, 200 kA, 0.1 MJ, 0.7 ms; 9 kV, 300 kA, 0.19 MJ, 0.9 ms; 12 kV, 400 kA, 0.35 MJ, 0.5 ms). The damaged sandstones were investigated by means of optical and electron-optical methods as well as by X-ray computed tomography to determine the modes and dimensions of melting and fragmentation. Digital elevation models of craters formed by ejection were obtained by white-light interferometry. The lightning experiments produced small craters (~1 cm in diameter, ~0.5 cm depth) which surfaces and sub-surfaces consist of silicate melts (molten quartz and phyllosilicates). The silicate melts reach several hundred micrometers into the sub-surface and resemble the appearance of natural fulgurites. Melting of quartz indicate temperatures of at least 1650 °C. In addition, the

  4. Some of the ball lightning observations could be phosphenes induced by energetic radiation from thunderstorms and lightning

    NASA Astrophysics Data System (ADS)

    Cooray, G. K.; Cooray, G. V.; Dwyer, J. R.

    2011-12-01

    phosphenes. The study shows that: (i) X-rays and relativistic electrons generated by the lightning leaders are strong enough to induce phosphenes in a person located indoors during a direct lightning strike to a building. (ii) Strong gamma ray busts at ground level produced by thunderstorms could release sufficient energy in the eye to induce phosphenes. (iii) If an air plane encounters the source of an ongoing gamma ray burst in a cloud, the energetic electrons penetrating the airplane during the encounter is strong enough to induce phosphenes in the passengers. It is suggested that some of the ball lightning observations are phosphenes induced by energetic radiation from thunderstorms and lightning. [1] Lipetz, L. E. (1955), The X-ray and radium phosphenes, British Journal of Ophthalmology, 39, pp. 577-598. [2] Fuglesang, C. (2007), Using the human eye to image space radiation or the history and status of the light flash phenomena, Nuclear Instruments and Physics Research A, vol. 580, pp. 861 - 865.

  5. Infrasound from lightning measured in Ivory Coast

    NASA Astrophysics Data System (ADS)

    Farges, T.; Millet, C.; Matoza, R. S.

    2012-04-01

    It is well established that more than 2,000 thunderstorms occur continuously around the world and that about 45 lightning flashes are produced per second over the globe. More than two thirds (42) of the infrasound stations of the International Monitoring System (IMS) of the CTBTO (Comprehensive nuclear Test Ban Treaty Organisation) are now certified and routinely measure signals due to natural activity (e.g., airflow over mountains, aurora, microbaroms, surf, volcanoes, severe weather including lightning flashes, …). Some of the IMS stations are located where worldwide lightning detection networks (e.g. WWLLN) have a weak detection capability but lightning activity is high (e.g. Africa, South America). These infrasound stations are well localised to study lightning flash activity and its disparity, which is a good proxy for global warming. Progress in infrasound array data processing over the past ten years makes such lightning studies possible. For example, Farges and Blanc (2010) show clearly that it is possible to measure lightning infrasound from thunderstorms within a range of distances from the infrasound station. Infrasound from lightning can be detected when the thunderstorm is within about 75 km from the station. The motion of the squall zone is very well measured inside this zone. Up to 25% of lightning flashes can be detected with this technique, giving better results locally than worldwide lightning detection networks. An IMS infrasound station has been installed in Ivory Coast for 9 years. The lightning rate of this region is 10-20 flashes/km2/year from space-based instrument OTD (Christian et al., 2003). Ivory Coast is therefore a good place to study infrasound data associated with lightning activity and its temporal variation. First statistical results will be presented in this paper based on 4 years of data (2005-2009). For short lightning distances (less than 20 km), up to 60 % of lightning detected by WWLLN has been one-to-one correlated

  6. An Approach to the Lightning Overvoltage Protection of Medium Voltage Lines in Severe Lightning Areas

    SciTech Connect

    Omidiora, M. A.; Lehtonen, M.

    2008-05-08

    This paper deals with the effect of shield wires on lightning overvoltage reduction and the energy relief of MOV (Metal Oxide Varistor) arresters from direct strokes to distribution lines. The subject of discussion is the enhancement of lightning protection in Finnish distribution networks where lightning is most severe. The true index of lightning severity in these areas is based on the ground flash densities and return stroke data collected from the Finnish meteorological institute. The presented test case is the IEEE 34-node test feeder injected with multiple lightning strokes and simulated with the Alternative Transients Program/Electromagnetic Transients program (ATP/EMTP). The response of the distribution line to lightning strokes was modeled with three different cases: no protection, protection with surge arresters and protection with a combination of shield wire and arresters. Simulations were made to compare the resulting overvoltages on the line for all the analyzed cases.

  7. Total Lightning Activity Associated with Tornadic Storms

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.; Buechler, Dennis; Hodanish, Stephen; Sharp, David; Williams, Earle; Boldi, Bob; Matlin, Anne; Weber, Mark

    1999-01-01

    Severe storms often have high flash rates (in excess of one flash per second) and are dominated by intracloud lightning activity. In addition to the extraordinary flash rates, there is a second distinguishing lightning characteristic of severe storms that seems to be important. When the total lightning history is examined, one finds sudden increases in the lightning rate, which we refer to as lightning "jumps," that precede the occurrence of severe weather by ten or more minutes. These jumps are typically 30-60 flashes/min, and are easily identified as anomalously large derivatives in the flash rate. This relationship is associated with updraft intensification and updraft strength is an important factor in storm severity (through the accumulation of condensate aloft and the stretching of vorticity). In several cases, evidence for diminishment of midlevel rotation and the descent of angular momentum from aloft is present prior to the appearance of the surface tornado. Based on our experience with severe and tornadic storms in Central Florida, we believe the total lightning may augment the more traditional use of NEXRAD radars and storm spotters. However, a more rigorous relation of these jumps to storm kinematics is needed if we are to apply total lightning in a decision tree that leads to improved warning lead times and decreased false alarm rates.

  8. Recent Advancements in Lightning Jump Algorithm Work

    NASA Technical Reports Server (NTRS)

    Schultz, Christopher J.; Petersen, Walter A.; Carey, Lawrence D.

    2010-01-01

    In the past year, the primary objectives were to show the usefulness of total lightning as compared to traditional cloud-to-ground (CG) networks, test the lightning jump algorithm configurations in other regions of the country, increase the number of thunderstorms within our thunderstorm database, and to pinpoint environments that could prove difficult for any lightning jump configuration. A total of 561 thunderstorms have been examined in the past year (409 non-severe, 152 severe) from four regions of the country (North Alabama, Washington D.C., High Plains of CO/KS, and Oklahoma). Results continue to indicate that the 2 lightning jump algorithm configuration holds the most promise in terms of prospective operational lightning jump algorithms, with a probability of detection (POD) at 81%, a false alarm rate (FAR) of 45%, a critical success index (CSI) of 49% and a Heidke Skill Score (HSS) of 0.66. The second best performing algorithm configuration was the Threshold 4 algorithm, which had a POD of 72%, FAR of 51%, a CSI of 41% and an HSS of 0.58. Because a more complex algorithm configuration shows the most promise in terms of prospective operational lightning jump algorithms, accurate thunderstorm cell tracking work must be undertaken to track lightning trends on an individual thunderstorm basis over time. While these numbers for the 2 configuration are impressive, the algorithm does have its weaknesses. Specifically, low-topped and tropical cyclone thunderstorm environments are present issues for the 2 lightning jump algorithm, because of the suppressed vertical depth impact on overall flash counts (i.e., a relative dearth in lightning). For example, in a sample of 120 thunderstorms from northern Alabama that contained 72 missed events by the 2 algorithm 36% of the misses were associated with these two environments (17 storms).

  9. New mechanism for lightning initiation

    SciTech Connect

    Roussel-Dupre, R.; Buchwald, M.; Gurevich, A.

    1996-10-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). To distinguish radio-frequency (rf) signals generated by lightning from the electromagnetic pulse produced by a nuclear explosion, it is necessary to understand the fundamental nature of thunderstorm discharges. The recent debate surrounding the origin of transionospheric pulse pairs (TIPPs) detected by the BLACKBEARD experiment aboard the ALEXIS satellite illustrates this point. We have argued that TIPP events could originate from the upward propagating discharges recently identified by optical images taken from the ground, from airplanes, and from the space shuttle. In addition, the Gamma Ray Observatory (GRO) measurements of x-ray bursts originating from thunderstorms are almost certainly associated with these upward propagating discharges. When taken together, these three measurements point directly to the runaway electron mechanism as the source of the upward discharges. The primary goal of this research effort was to identify the specific role played by the runaway-air-breakdown mechanism in the general area of thunderstorm electricity and in so doing develop lightning models that predict the optical, rf, and x-ray emissions that are observable from space.

  10. Lightning energy conversion using lasers

    NASA Astrophysics Data System (ADS)

    Khan, Nasrullah; Mariun, Norman

    2000-01-01

    Potential energy sources are being investigated for the socioeconomic needs and increased power demand. Systems employing nuclear, thermal, hydro, solar, volcano, MHD, tidal and wind power generation techniques already exist. This work describes our attempt to utilize the off-planet lightning charge to store super electrolytic batteries or super capacitors. The electrostatic charge on clouds can be shifted to earth through a conducive air plasma channel created by appropriate high power Q-switched and mode-locked laser. The pulsed laser may create a conducting path consisting of ionized air particles from earth to some upper atmosphere. An antenna connected to anode of super cell or positive terminal of the super capacitor will accumulate and store this charge for future use. The anode of battery or positive terminal of capacitor may be connected to earth to complete the circuit. Due to extremely loud thundering and tropical weather severity a detailed work was done on lightning regarding its temporal and spatial profiles to develop a reasonable model to explore transient charging characteristics. Experimental work in respect of laser inducted plasma wire creation and charging capabilities of super storage batteries or super capacitors is optimized. Latest experimental results are reported.

  11. Explaining unusual winter lightning in Japan

    NASA Astrophysics Data System (ADS)

    Shindo, Takatoshi; Ishii, Masaru; Williams, Earle

    2011-11-01

    Third International Symposium on Winter Lightning; Sapporo, Japan, 15-16 June 2011 Japan's meteorological setting in winter is unusual: It is an island in a relatively warm sea frequently overswept by colder air from Siberia. This sets up appreciable atmospheric instability in the fringe of the land adjacent to the Sea of Japan. Heavy snowstorms overlap the edge of the island and produce extraordinarily energetic lightning flashes that initiate from points on the ground (known as ground-to-cloud (GC) strokes) and wreak havoc on power lines and, more recently, wind turbines. These troublesome and costly conditions set the stage for the third in a series of conferences on winter lightning.

  12. Lightning strike-induced brachial plexopathy.

    PubMed

    Bhargava, Amita N; Kasundra, Gaurav M; Khichar, Subhakaran; Bhushan, Bharat S K

    2014-10-01

    We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered. PMID:25288846

  13. Lightning strike-induced brachial plexopathy.

    PubMed

    Bhargava, Amita N; Kasundra, Gaurav M; Khichar, Subhakaran; Bhushan, Bharat S K

    2014-10-01

    We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered.

  14. Lightning induced brightening in the airglow layer

    SciTech Connect

    Boeck, W.L. ); Vaughan, O.H. Jr.; Blakeslee, R. ); Vonnegut, B. ); Brook, M. )

    1992-01-24

    This report describes a transient luminosity observed at the altitude of the airglow layer (about 95 km) in coincidence with a lightning flash in a tropical oceanic thunderstorm directly beneath it. This event provides new evidence of direct coupling between lightning and ionospheric events. This luminous event in the ionosphere was the only one of its kind observed during an examination of several thousand images of lightning recorded under suitable viewing conditions with Space Shuttle cameras. Several possible mechanisms and interpretations are discussed briefly.

  15. Estimates of the Lightning NOx Profile in the Vicinity of the North Alabama Lightning Mapping Array

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Peterson, Harold

    2010-01-01

    The NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) is applied to August 2006 North Alabama Lightning Mapping Array (LMA) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning nitrogen oxides, NOx = NO + NO 2 . This is part of a larger effort aimed at building a more realistic lightning NOx emissions inventory for use by the U.S. Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) modeling system. Data from the National Lightning Detection Network TM (NLDN) is also employed. Overall, special attention is given to several important lightning variables including: the frequency and geographical distribution of lightning in the vicinity of the LMA network, lightning type (ground or cloud flash), lightning channel length, channel altitude, channel peak current, and the number of strokes per flash. Laboratory spark chamber results from the literature are used to convert 1-meter channel segments (that are located at a particular known altitude; i.e., air density) to NOx concentration. The resulting raw NOx profiles are discussed.

  16. Combined Aircraft and Satellite-Derived Storm Electric Current and Lightning Rates Measurements and Implications for the Global Electric Circuit

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Blakeslee, Richard J.; Bateman, Monte G.

    2010-01-01

    Using rotating vane electric field mills and Gerdien capacitors, we measured the electric field profile and conductivity during 850 overflights of electrified shower clouds and thunderstorms spanning regions including the Southeastern United States, the Western Atlantic Ocean, the Gulf of Mexico, Central America and adjacent oceans, Central Brazil, and the South Pacific. The overflights include storms over land and ocean, with and without lightning, and with positive and negative fields above the storms. The measurements were made with the NASA ER-2 and the Altus-II high altitude aircrafts. Peak electric fields, with lightning transients removed, ranged from -1.0 kV/m to 16 kV/m, with a mean value of 0.9 kV/m. The median peak field was 0.29 kV/m. Integrating our electric field and conductivity data, we determined total conduction currents and flash rates for each overpass. With knowledge of the storm location (land or ocean) and type (with or without lightning), we determine the mean currents by location and type. The mean current for ocean storms with lightning is 1.6 A while the mean current for land storms with lightning is 1.0 A. The mean current for oceanic storms without lightning (i.e., electrified shower clouds) is 0.39 A and the mean current for land storms without lightning is 0.13 A. Thus, on average, land storms with or without lightning have about half the mean current as their corresponding oceanic storm counterparts. Over three-quarters (78%) of the land storms had detectable lightning, while less than half (43%) of the oceanic storms had lightning. We did not find any significant regional or latitudinal based patterns in our total conduction currents. By combining the aircraft derived storm currents and flash rates with diurnal lightning statistics derived from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) low Earth orbiting satellites, we reproduce the diurnal variation in the global electric circuit (i.e., the Carnegie

  17. A solid state lightning propagation speed sensor

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Rust, W. David

    1989-01-01

    A device to measure the propagation speeds of cloud-to-ground lightning has been developed. The lightning propagation speed (LPS) device consists of eight solid state silicon photodetectors mounted behind precision horizontal slits in the focal plane of a 50-mm lens on a 35-mm camera. Although the LPS device produces results similar to those obtained from a streaking camera, the LPS device has the advantages of smaller size, lower cost, mobile use, and easier data collection and analysis. The maximum accuracy for the LPS is 0.2 microsec, compared with about 0.8 microsecs for the streaking camera. It is found that the return stroke propagation speed for triggered lightning is different than that for natural lightning if measurements are taken over channel segments less than 500 m. It is suggested that there are no significant differences between the propagation speeds of positive and negative flashes. Also, differences between natural and triggered dart leaders are discussed.

  18. Lightning activity during the 1999 Superior derecho

    NASA Astrophysics Data System (ADS)

    Price, Colin G.; Murphy, Brian P.

    2002-12-01

    On 4 July 1999, a severe convective windstorm, known as a derecho, caused extensive damage to forested regions along the United States/Canada border, west of Lake Superior. There were 665,000 acres of forest destroyed in the Boundary Waters Canoe Area Wilderness (BWCAW) in Minnesota and Quetico Provincial Park in Canada, with approximately 12.5 million trees blown down. This storm resulted in additional severe weather before and after the occurrence of the derecho, with continuous cloud-to-ground (CG) lightning occurring for more than 34 hours during its path across North America. At the time of the derecho the percentage of positive cloud-to-ground (+CG) lightning measured by the Canadian Lightning Detection Network (CLDN) was greater than 70% for more than three hours, with peak values reaching 97% positive CG lightning. Such high ratios of +CG are rare, and may be useful indicators of severe weather.

  19. Lightning Activity During the 1999 Superior Derecho

    NASA Astrophysics Data System (ADS)

    Price, C. G.; Murphy, B. P.

    2002-12-01

    On 4 July 1999, a severe convective windstorm, known as a derecho, caused extensive damage to forested regions along the United States/Canada border, west of Lake Superior. There were 665,000 acres of forest destroyed in the Boundary Waters Canoe Area Wilderness (BWCAW) in Minnesota and Quetico Provincial Park in Canada, with approximately 12.5 million trees blown down. This storm resulted in additional severe weather before and after the occurrence of the derecho, with continuous cloud-to-ground (CG) lightning occurring for more than 34 hours during its path across North America. At the time of the derecho the percentage of positive cloud-to-ground (+CG) lightning measured by the Canadian Lightning Detection Network (CLDN) was greater than 70% for more than three hours, with peak values reaching 97% positive CG lightning. Such high ratios of +CG are rare, and may be useful indicators of severe weather.

  20. Correlated observations of three triggered lightning flashes

    NASA Technical Reports Server (NTRS)

    Idone, V. P.; Orville, R. E.; Hubert, P.; Barret, L.; Eybert-Berard, A.

    1984-01-01

    Three triggered lightning flashes, initiated during the Thunderstorm Research International Program (1981) at Langmuir Laboratory, New Mexico, are examined on the basis of three-dimensional return stroke propagation speeds and peak currents. Nonlinear relationships result between return stroke propagation speed and stroke peak current for 56 strokes, and between return stroke propagation speed and dart leader propagation speed for 32 strokes. Calculated linear correlation coefficients include dart leader propagation speed and ensuing return stroke peak current (32 strokes; r = 0.84); and stroke peak current and interstroke interval (69 strokes; r = 0.57). Earlier natural lightning data do not concur with the weak positive correlation between dart leader propagation speed and interstroke interval. Therefore, application of triggered lightning results to natural lightning phenomena must be made with certain caveats. Mean values are included for the three-dimensional return stroke propagation speed and for the three-dimensional dart leader propagation speed.

  1. Protection against lightning at a geomagnetic observatory

    NASA Astrophysics Data System (ADS)

    Čop, R.; Milev, G.; Deželjin, D.; Kosmač, J.

    2014-08-01

    The Sinji Vrh Geomagnetic Observatory was built on the brow of Gora, the mountain above Ajdovščina, which is a part of Trnovo plateau, and all over Europe one can hardly find an area which is more often struck by lightning than this southwestern part of Slovenia. When the humid air masses of a storm front hit the edge of Gora, they rise up more than 1000 m in a very short time, and this causes an additional electrical charge of stormy clouds. The reliability of operations performed in every section of the observatory could be increased by understanding the formation of lightning in a thunderstorm cloud and the application of already-proven methods of protection against a stroke of lightning and against its secondary effects. To reach this goal the following groups of experts have to cooperate: experts in the field of protection against lightning, constructors and manufacturers of equipment and observatory managers.

  2. Lightning Safety and Outdoor Sports Activities

    MedlinePlus

    ... FORECAST Local Graphical Aviation Marine Rivers and Lakes Hurricanes Severe Weather Fire Weather Sun/Moon Long Range ... Safety Campaigns Air Quality Drought Floods Fog Heat Hurricanes Lightning Rip Currents Safe Boating Space Weather Tornadoes, ...

  3. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... operations and withdrawal of the public to public area distance prior to an electrical storm, or for an... prior to an electrical storm. (4) Testing and inspection. Lightning protection systems shall be...

  4. A Simple Lightning Flash Polarity Discriminating Counter.

    ERIC Educational Resources Information Center

    Devan, K. R. S.; Jayaratne, E. R.

    1990-01-01

    Described are the apparatus and procedures needed for a demonstration of a determination of the polarity of charges carried by individual ground flashes of lightning. Discussed are materials, apparatus construction, and experimental results. (CW)

  5. Central Hyperadrenergic State After Lightning Strike

    PubMed Central

    Parsaik, Ajay K.; Ahlskog, J. Eric; Singer, Wolfgang; Gelfman, Russell; Sheldon, Seth H.; Seime, Richard J.; Craft, Jennifer M.; Staab, Jeffrey P.; Kantor, Birgit; Low, Phillip A.

    2013-01-01

    Objective To describe and review autonomic complications of lightning strike. Methods Case report and laboratory data including autonomic function tests in a subject who was struck by lightning. Results A 24-year-old man was struck by lightning. Following that, he developed dysautonomia, with persistent inappropriate sinus tachycardia and autonomic storms, as well as posttraumatic stress disorder (PTSD) and functional neurologic problems. Interpretation The combination of persistent sinus tachycardia and episodic exacerbations associated with hypertension, diaphoresis, and agitation were highly suggestive of a central hyperadrenergic state with superimposed autonomic storms. Whether the additional PTSD and functional neurologic deficits were due to a direct effect of the lightning strike on the CNS or a secondary response is open to speculation. PMID:23761114

  6. Correlation of DIAL Ozone Observations with Lightning

    NASA Technical Reports Server (NTRS)

    Peterson, Harold S.; Kuang, Shi; Koshak, William J.; Newchurch, Mike

    2014-01-01

    The purpose of this project is to see whether ozone maxima measured by the DIfferential Absorption Lidar (DIAL) instrument in Huntsville, AL may be traced back to lightning events occurring 24-48 hours beforehand. The methodology is to start with lidar measurements of ozone from DIAL. The HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model is then used to determine the origin of these ozone maxima 24-48 hours prior. Data from the National Lightning Detection Network (NLDN) are used to examine the presence/absence of lightning along the trajectory. This type of analysis suggests that lightning-produced NOx may be responsible for some of the ozone maxima over Huntsville.

  7. Correlation of DIAL Ozone Observations with Lightning

    NASA Technical Reports Server (NTRS)

    Peterson, Harold; Kuang, Shi; Koshak, William; Newchurch, Michael

    2013-01-01

    The purpose of this project is to see whether ozone maxima measured by the DIfferential Absorption Lidar (DIAL) instrument in Huntsville, AL may be traced back to lightning events occurring 24- 48 hours beforehand. The methodology is to start with lidar measurements of ozone from DIAL as well as ozonesonde measurements. The HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model is then used to determine the origin of these ozone maxima 24-48 hours prior. Data from the National Lightning Detection Network (NLDN) are used to examine the presence/absence of lightning along the trajectory. This type of analysis suggests that lightning-produced NOx may be responsible for some of the ozone maxima over Huntsville.

  8. How Lightning Works Inside Thunderstorms: A Half-Century of Lightning Studies

    NASA Astrophysics Data System (ADS)

    Krehbiel, P. R.

    2015-12-01

    Lightning is a fascinating and intriguing natural phenomenon, but the most interesting parts of lightning discharges are inside storms where they are obscured from view by the storm cloud. Although clouds are essentially opaque at optical frequencies, they are fully transparent at radio frequencies (RF). This, coupled with the fact that lightning produces prodigious RF emissions, has allowed us to image and study lightning inside storms using various RF and lower-frequency remote sensing techniques. As in all other scientific disciplines, the technology for conducting the studies has evolved to an incredible extent over the past 50 years. During this time, we have gone from having very little or no knowledge of how lightning operates inside storms, to being able to 'see' its detailed structure and development with an increasing degree of spatial and temporal resolution. In addition to studying the discharge processes themselves, lightning mapping observations provide valuable information on the electrical charge structure of storms, and on the mechanisms by which storms become strongly electrified. In this presentation we briefly review highlights of previous observations, focussing primarily on the long string of remote-sensing studies I have been involved in. We begin with the study of lightning charge centers of cloud-to-ground discharges in central New Mexico in the late 1960s and continue up to the present day with interferometric and 3-dimensional time-of-arrival VHF mapping observations of lightning in normally- and anomalously electrified storms. A particularly important aspect of the investigations has been comparative studies of lightning in different climatological regimes. We conclude with observations being obtained by a high-speed broadband VHF interferometer, which show in unprecedented detail how individual lightning discharges develop inside storms. From combined interferometer and 3-D mapping data, we are beginning to unlock nature's secrets

  9. Summary report of the Lightning and Static Electricity Committee

    NASA Technical Reports Server (NTRS)

    Plumer, J. A.

    1979-01-01

    Lightning protection technology as applied to aviation and identifying these technology needs are presented. The flight areas of technical needs include; (1) the need for In-Flight data on lightning electrical parameters; (2) technology base and guidelines for protection of advanced systems and structures; (3) improved laboratory test techniques; (4) analysis techniques for predicting induced effects; (5) lightning strike incident data from General Aviation; (6) lightning detection systems; (7) obtain pilot reports of lightning strikes; and (8) better training in lightning awareness. The nature of each problem, timeliness, impact of solutions, degree of effort required, and the roles of government and industry in achieving solutions are discussed.

  10. Scientific Lightning Detection Network for Kazakhstan

    NASA Astrophysics Data System (ADS)

    Streltsov, A. V.; Lozbin, A.; Inchin, A.; Shpadi, Y.; Inchin, P.; Shpadi, M.; Ayazbayev, G.; Bykayev, R.; Mailibayeva, L.

    2015-12-01

    In the frame of grant financing of the scientific research in 2015-2017 the project "To Develop Electromagnetic System for lightning location and atmosphere-lithosphere coupling research" was found. The project was start in January, 2015 and should be done during 3 years. The purpose is to create a system of electromagnetic measurements for lightning location and atmosphere-lithosphere coupling research consisting of a network of electric and magnetic sensors and the dedicated complex for data processing and transfer to the end user. The main tasks are to set several points for electromagnetic measurements with 100-200 km distance between them, to develop equipment for these points, to develop the techniques and software for lightning location (Time-of-arrival and Direction Finding (TOA+DF)) and provide a lightning activity research in North Tien-Shan region with respect to seismicity and other natural and manmade activities. Also, it is planned to use lightning data for Global Electric Circuit (GEC) investigation. Currently, there are lightning detection networks in many countries. In Kazakhstan we have only separate units in airports. So, we don't have full lightning information for our region. It is planned, to setup 8-10 measurement points with magnetic and electric filed antennas for VLF range. The final data set should be including each stroke location, time, type (CG+, CG-, CC+ or CC-) and waveform from each station. As the magnetic field lightning antenna the ferrite rod VLF antenna will be used. As the electric field antenna the wide range antenna with specific frequencies filters will be used. For true event detection TOA and DF methods needs detected stroke from minimum 4 stations. In this case we can get location accuracy about 2-3 km and better.

  11. Lightning, whistlers, and hiss - A possible relationship

    NASA Technical Reports Server (NTRS)

    Sonwalkar, Vikas S.

    1990-01-01

    While it has been established that whistlers originate in terrestrial lightning, the generation mechanism remains unclear and is intractable by means of quasi-linear theory, which does not account for the generation of hiss from the background thermal noise. Observational data are presently discussed which indicate that the wave energy introduced in the magnetosphere by atmospheric lightning discharges may play an important role both in the loss of particles through wave-induced precipitation and in the embrionic generation of hiss.

  12. Lightning protection system for a wind turbine

    DOEpatents

    Costin, Daniel P.; Petter, Jeffrey K.

    2008-05-27

    In a wind turbine (104, 500, 704) having a plurality of blades (132, 404, 516, 744) and a blade rotor hub (120, 712), a lightning protection system (100, 504, 700) for conducting lightning strikes to any one of the blades and the region surrounding the blade hub along a path around the blade hub and critical components of the wind turbine, such as the generator (112, 716), gearbox (708) and main turbine bearings (176, 724).

  13. Volcanic Lightning in Eruptions of Sakurajima Volcano

    NASA Astrophysics Data System (ADS)

    Edens, Harald; Thomas, Ronald; Behnke, Sonja; McNutt, Stephen; Smith, Cassandra; Farrell, Alexandra; Van Eaton, Alexa; Cimarelli, Corrado; Cigala, Valeria; Eack, Ken; Aulich, Graydon; Michel, Christopher; Miki, Daisuke; Iguchi, Masato

    2016-04-01

    In May 2015 a field program was undertaken to study volcanic lightning at the Sakurajima volcano in southern Japan. One of the main goals of the study was to gain a better understanding of small electrical discharges in volcanic eruptions, expanding on our earlier studies of volcanic lightning at Augustine and Redoubt volcanoes in Alaska, USA, and Eyjafjallajökull in Iceland. In typical volcanic eruptions, electrical activity occurs at the onset of an eruption as a near-continual production of VHF emissions at or near to the volcanic vent. These emissions can occur at rates of up to tens of thousands of emissions per second, and are referred to as continuous RF. As the ash cloud expands, small-scale lightning flashes of several hundred meters length begin to occur while the continuous RF ceases. Later on during the eruption larger-scale lightning flashes may occur within the ash cloud that are reminiscent of regular atmospheric lightning. Whereas volcanic lightning flashes are readily observed and reasonably well understood, the nature and morphology of the events producing continuous RF are unknown. During the 2015 field program we deployed a comprehensive set of instrumentation, including a 10-station 3-D Lightning Mapping Array (LMA) that operated in 10 μs high time resolution mode, slow and fast ΔE antennas, a VHF flat-plate antenna operating in the 20-80 MHz band, log-RF waveforms within the 60-66 MHz band, an infra-red video camera, a high-sensitivity Watec video camera, two high-speed video cameras, and still cameras. We give an overview of the Sakurajima field program and present preliminary results using correlated LMA, waveforms, photographs and video recordings of volcanic lightning at Sakurajima volcano.

  14. The Sandia Lightning Simulator Recommissioning and upgrades.

    SciTech Connect

    Martinez, Leonard E.; Caldwell, Michele

    2005-08-01

    The Sandia lightning simulator at Sandia National Laboratories can provide up to 200 kA for a simulated single lightning stroke, 100 kA for a subsequent stroke, and hundreds of Amperes of continuing current. It has recently been recommissioned after a decade of inactivity and the single-stroke capability demonstrated. The simulator capabilities, basic design components, upgrades, and diagnostic capabilities are discussed in this paper.

  15. Lightning protection design external tank /Space Shuttle/

    NASA Technical Reports Server (NTRS)

    Anderson, A.; Mumme, E.

    1979-01-01

    The possibility of lightning striking the Space Shuttle during liftoff is considered and the lightning protection system designed by the Martin Marietta Corporation for the external tank (ET) portion of the Shuttle is discussed. The protection system is based on diverting and/or directing a lightning strike to an area of the spacecraft which can sustain the strike. The ET lightning protection theory and some test analyses of the system's design are reviewed including studies of conductivity and thermal/stress properties in materials, belly band feasibility, and burn-through plug grounding and puncture voltage. The ET lightning protection system design is shown to be comprised of the following: (1) a lightning rod on the forward most point of the ET, (2) a continually grounded, one inch wide conductive strip applied circumferentially at station 371 (belly band), (3) a three inch wide conductive belly band applied over the TPS (i.e. the insulating surface of the ET) and grounded to a structure with eight conductive plugs at station 536, and (4) a two inch thick TPS between the belly bands which are located over the weld lands.

  16. Generation of lightning in Jupiter's water cloud.

    PubMed

    Gibbard, S; Levy, E H; Lunine, J I

    1995-12-01

    Lightning is a familiar feature of storms on the Earth, and has also been seen on Jupiter and inferred indirectly to occur on Venus and Neptune. On Jupiter, lightning may be important as a source of energy to drive chemical reactions in the atmosphere, perhaps determining the abundances of molecules such as CO, HCN and C2H2. Lightning may be generated in Jupiter's water clouds by a mechanism similar to that which operates in terrestrial thunderstorms. Here we investigate the development of lightning by modelling the thunderstorm separation of electrical charge on precipitating ice particles at varying depths in Jupiter's atmosphere. We find that lightning can indeed be generated in the jovian water clouds, and that--in agreement with estimates from the analysis of Voyager images--it is most likely to occur at the 3- or 4-bar pressure level. Our model also predicts that a condensed-water abundance in the range of at least 1-2 g m-3 is required for lightning to occur in jovian thunderstorms--a prediction that may be tested when the Galileo probe arrives at Jupiter on 7 December 1995.

  17. A Fossilized Energy Distribution of Lightning

    NASA Astrophysics Data System (ADS)

    Pasek, Matthew A.; Hurst, Marc

    2016-07-01

    When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per length and frequency. Energy per length is determined from fulgurites as a function of diameter, and frequency is determined both by cumulative number and by cumulative length. This distribution parallels those determined for a number of lightning parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating lightning energy and damage potential of strikes.

  18. Generation of lightning in Jupiter's water cloud.

    PubMed

    Gibbard, S; Levy, E H; Lunine, J I

    1995-12-01

    Lightning is a familiar feature of storms on the Earth, and has also been seen on Jupiter and inferred indirectly to occur on Venus and Neptune. On Jupiter, lightning may be important as a source of energy to drive chemical reactions in the atmosphere, perhaps determining the abundances of molecules such as CO, HCN and C2H2. Lightning may be generated in Jupiter's water clouds by a mechanism similar to that which operates in terrestrial thunderstorms. Here we investigate the development of lightning by modelling the thunderstorm separation of electrical charge on precipitating ice particles at varying depths in Jupiter's atmosphere. We find that lightning can indeed be generated in the jovian water clouds, and that--in agreement with estimates from the analysis of Voyager images--it is most likely to occur at the 3- or 4-bar pressure level. Our model also predicts that a condensed-water abundance in the range of at least 1-2 g m-3 is required for lightning to occur in jovian thunderstorms--a prediction that may be tested when the Galileo probe arrives at Jupiter on 7 December 1995. PMID:8524392

  19. Safety in the presence of lightning.

    PubMed

    Holle, R L; López, R E; Howard, K W; Vavrek, J; Allsopp, J

    1995-12-01

    Not enough emphasis is usually placed on the proactive ability to recognize the lightning hazard. Instead, most literature and training materials treat the reactive mode. The latter approach emphasizes the posture to take when a person is caught by surprise in the open by a thunderstorm when the lightning threat is at its greatest; in other words, it is too late for precautions. The same reactive approach concentrates on what a person is wearing or holding when lightning is overhead instead of how the person came to be in this situation in the first place. Rather than focusing on these last-minute factors, the primary issue must be on the ability of a person, whether in a baseball game, riding a bike, or on a golf course, to recognize in advance the existence of a major lightning threat. This proactive approach emphasizes advance planning and recognition of a potential threat from lightning. A complete plan involves a sequence of decisions on a time scale from days to seconds. Although most of the available information in pamphlets and safety guidelines is correct concerning the reactive phase of lightning safety, the hazard remains important because of the lack of emphasis on planning and awareness.

  20. Lightning Location Using Electric Field Change Meters

    NASA Astrophysics Data System (ADS)

    Bitzer, P. M.; Christian, H.; Burchfield, J.

    2010-12-01

    Briefly introduced last year, the Huntsville Alabama Field Change Array (HAFCA) is a collection of electric field change meters deployed in and around Huntsville. Armed with accurate GPS timing, the array is able to sample electric field changes due to lightning strokes simultaneously at several locations. For the first time, different components of the lightning flash can be located in three dimensions using only electric field change records. In particular, this research will show spacetime locations throughout entire lightning strokes, from preliminary breakdown pulses to the return stroke and later processes that may be related to charge neutralization. To find the spacetime locations, standard time of arrival methods will be used: finding the parameters that best fit the model using the Marquardt method. However, we will also discuss using Markov Chain Monte Carlo methods which yield a better estimation of errors. With this information, we will discuss selected cases from the array to date. In particular, we will discuss the inter-comparison of HAFCA with two other well known lightning location arrays, NLDN and NALMA. Specifically, we will explore the relationship between the first LMA pulse in a lightning stroke and the locations of preliminary breakdown pulses and the implications on lightning initiation. Further, the return stroke locations will be shown to agree reasonably well with NLDN locations. We will also locate compact intracloud discharges (CIDs) and compare with NLDN locations.

  1. A Fossilized Energy Distribution of Lightning

    PubMed Central

    Pasek, Matthew A.; Hurst, Marc

    2016-01-01

    When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per length and frequency. Energy per length is determined from fulgurites as a function of diameter, and frequency is determined both by cumulative number and by cumulative length. This distribution parallels those determined for a number of lightning parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating lightning energy and damage potential of strikes. PMID:27466230

  2. A Fossilized Energy Distribution of Lightning.

    PubMed

    Pasek, Matthew A; Hurst, Marc

    2016-01-01

    When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per length and frequency. Energy per length is determined from fulgurites as a function of diameter, and frequency is determined both by cumulative number and by cumulative length. This distribution parallels those determined for a number of lightning parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating lightning energy and damage potential of strikes. PMID:27466230

  3. JPS heater and sensor lightning qualification

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    Simulated lightning strike testing of the Redesigned Solid Rocket Motor (RSRM) field joint protection system heater assembly was performed at Thiokol Corp., Wendover Lightning Facility. Testing consisted of subjecting the lightning evaluation test article to simulated lightning strikes and evaluating the effects of heater cable transients on cables within the systems tunnel. The maximum short circuit current coupled onto a United Space Boosters, Inc. operational flight cable within the systems tunnel, induced by transients from all cables external to the systems tunnel, was 92 amperes. The maximum open-circuit voltage coupled was 316 volts. The maximum short circuit current coupled onto a United Space Boosters, Inc. operational flight cable within the systems tunnel, induced by heater power cable transients only, was 2.7 amperes; the maximum open-circuit voltage coupled was 39 volts. All heater power cable induced coupling was due to simulated lightning discharges only, no heater operating power was applied during the test. The results showed that, for a worst-case lightning discharge, the heater power cable is responsible for a 3.9 decibel increase in voltage coupling to operational flight cables within the systems tunnel. Testing also showed that current and voltage levels coupled onto cables within the systems tunnel are partially dependant on the relative locations of the cables within the systems tunnel.

  4. A Fossilized Energy Distribution of Lightning.

    PubMed

    Pasek, Matthew A; Hurst, Marc

    2016-07-28

    When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per length and frequency. Energy per length is determined from fulgurites as a function of diameter, and frequency is determined both by cumulative number and by cumulative length. This distribution parallels those determined for a number of lightning parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating lightning energy and damage potential of strikes.

  5. Lightning Arrestor Connectors Production Readiness

    SciTech Connect

    Marten, Steve; Linder, Kim; Emmons, Jim; Gomez, Antonio; Hasam, Dawud; Maurer, Michelle

    2008-10-20

    The Lightning Arrestor Connector (LAC), part “M”, presented opportunities to improve the processes used to fabricate LACs. The A## LACs were the first production LACs produced at the KCP, after the product was transferred from Pinnellas. The new LAC relied on the lessons learned from the A## LACs; however, additional improvements were needed to meet the required budget, yield, and schedule requirements. Improvement projects completed since 2001 include Hermetic Connector Sealing Improvement, Contact Assembly molding Improvement, development of a second vendor for LAC shells, general process improvement, tooling improvement, reduction of the LAC production cycle time, and documention of the LAC granule fabrication process. This report summarizes the accomplishments achieved in improving the LAC Production Readiness.

  6. Characteristics of Winter Lightning that Occurred on a Windmill and its Lightning Protection Tower in Japan

    NASA Astrophysics Data System (ADS)

    Wang, Daohong; Takagi, Nobuyuki

    We have observed lightning that struck a wind turbine and its neighboring lightning-protection tower during the past six winter seasons (2005 to 2010) using various lightning observation instruments. Our results show that the upward lightning from high structures can be classified into self-initiated and other-triggered types according to whether there is a discharge activity prior to the upward lightning. Furthermore, we found that although other-triggered upward lightning can start at a relatively low wind speed, self-initiated upward lightning always started either from the stationary tower under a larger wind speeds or from a rotating wind turbine blade. It appears that the wind does have considerable effect in assisting the initiation of an upward leader. In addition, we found that the self-initiated upward positive leaders from structures with different effective heights exhibited remarkably different initial speeds. Higher structures tend to initiate faster upward leaders. Finally, we discussed the pulse discharges observed in the very initial stages of positive upward leaders and how to protect structures from upward lightning as well.

  7. Washington D.C. Lightning Mapping Array Demonstration Project Risk Reduction for GOES Lightning Mapper Data

    NASA Technical Reports Server (NTRS)

    Smith, Stephan B.; Goodman, Steven; Krehbiel, Paul

    2007-01-01

    A 10-site, ground-based total lightning mapping array (LMA) has been installed in the Washington D.C. metropolitan area in 2006. The total lightning data from DC LMA are being processed in real-time and derived products are being provided to the forecasters of the National Weather Service (NWS) forecast office in Sterling, Virginia. The NWS forecasters are using the products to monitor convective activity along with conventional radar and satellite products. Operational experience with these products is intended to inform decision making in how to best utilize in NWS operations similar data available from the GOES Lightning Mapper. The paper will discuss specifics of the LMA as well as proposed research into use of total lightning data in predicting and warning for cloud-to-ground lightning.

  8. A NASA Lightning Parameterization for CMAQ

    NASA Technical Reports Server (NTRS)

    Koshak, William; Khan, Maudood; Biazar, Arastoo; Newchurch, Mike; McNider, Richard

    2009-01-01

    Many state and local air quality agencies use the U.S. Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) modeling system to determine compliance with the National Ambient Air Quality Standards (NAAQS). Because emission reduction scenarios are tested using CMAQ with an aim of determining the most efficient and cost effective strategies for attaining the NAAQS, it is very important that trace gas concentrations derived by CMAQ are accurate. Overestimating concentrations can literally translate into billions of dollars lost by commercial and government industries forced to comply with the standards. Costly health, environmental and socioeconomic problems can result from concentration underestimates. Unfortunately, lightning modeling for CMAQ is highly oversimplified. This leads to very poor estimates of lightning-produced nitrogen oxides "NOx" (= NO + NO2) which directly reduces the accuracy of the concentrations of important CMAQ trace gases linked to NOx concentrations such as ozone and methane. Today it is known that lightning is the most important NOx source in the upper troposphere with a global production rate estimated to vary between 2-20 Tg(N)/yr. In addition, NOx indirectly influences our climate since it controls the concentration of ozone and hydroxyl radicals (OH) in the atmosphere. Ozone is an important greenhouse gas and OH controls the oxidation of various greenhouse gases. We describe a robust NASA lightning model, called the Lightning Nitrogen Oxides Model (LNOM) that combines state-of-the-art lightning measurements, empirical results from field studies, and beneficial laboratory results to arrive at a realistic representation of lightning NOx production for CMAQ. NASA satellite lightning data is used in conjunction with ground-based lightning detection systems to assure that the best representation of lightning frequency, geographic location, channel length, channel altitude, strength (i.e., channel peak current), and

  9. Lightning: Nature's Probe of Severe Weather for Research and Operations

    NASA Technical Reports Server (NTRS)

    Blakeslee, R.J.

    2007-01-01

    Lightning, the energetic and broadband electrical discharge produced by thunderstorms, provides a natural remote sensing signal for the study of severe storms and related phenomena on global, regional and local scales. Using this strong signal- one of nature's own probes of severe weather -lightning measurements prove to be straightforward and take advantage of a variety of measurement techniques that have advanced considerably in recent years. We briefly review some of the leading lightning detection systems including satellite-based optical detectors such as the Lightning Imaging Sensor, and ground-based radio frequency systems such as Vaisala's National Lightning Detection Network (NLDN), long range lightning detection systems, and the Lightning Mapping Array (LMA) networks. In addition, we examine some of the exciting new research results and operational capabilities (e.g., shortened tornado warning lead times) derived from these observations. Finally we look forward to the next measurement advance - lightning observations from geostationary orbit.

  10. 14 CFR 27.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... within the system by— (a) Direct lightning strikes to areas having a high probability of stroke attachment; (b) Swept lightning strokes to areas where swept strokes are highly probable; or (c) Corona...

  11. 14 CFR 25.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... within the system by— (a) Direct lightning strikes to areas having a high probability of stroke attachment; (b) Swept lightning strokes to areas where swept strokes are highly probable; and (c) Corona...

  12. 14 CFR 29.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... within the system by— (a) Direct lightning strikes to areas having a high probability of stroke attachment; (b) Swept lightning strokes to areas where swept strokes are highly probable; and (c) Corona...

  13. Lightning vulnerability of fiber-optic cables.

    SciTech Connect

    Martinez, Leonard E.; Caldwell, Michele

    2008-06-01

    One reason to use optical fibers to transmit data is for isolation from unintended electrical energy. Using fiber optics in an application where the fiber cable/system penetrates the aperture of a grounded enclosure serves two purposes: first, it allows for control signals to be transmitted where they are required, and second, the insulating properties of the fiber system help to electrically isolate the fiber terminations on the inside of the grounded enclosure. A fundamental question is whether fiber optic cables can allow electrical energy to pass through a grounded enclosure, with a lightning strike representing an extreme but very important case. A DC test bed capable of producing voltages up to 200 kV was used to characterize electrical properties of a variety of fiber optic cable samples. Leakage current in the samples were measured with a micro-Ammeter. In addition to the leakage current measurements, samples were also tested to DC voltage breakdown. After the fiber optic cables samples were tested with DC methods, they were tested under representative lightning conditions at the Sandia Lightning Simulator (SLS). Simulated lightning currents of 30 kA and 200 kA were selected for this test series. This paper documents measurement methods and test results for DC high voltage and simulated lightning tests performed at the Sandia Lightning Simulator on fiber optic cables. The tests performed at the SLS evaluated whether electrical energy can be conducted inside or along the surface of a fiber optic cable into a grounded enclosure under representative lightning conditions.

  14. An Operational Perspective of Total Lightning Information

    NASA Technical Reports Server (NTRS)

    Nadler, David J.; Darden, Christopher B.; Stano, Geoffrey; Buechler, Dennis E.

    2009-01-01

    The close and productive collaborations between the NWS Warning and Forecast Office, the Short Term Prediction and Research Transition Center at NASA Marshall Space Flight Center and the University of Alabama in Huntsville have provided a unique opportunity for science sharing and technology transfer. One significant technology transfer that has provided immediate benefits to NWS forecast and warning operations is the use of data from the North Alabama Lightning Mapping Array. This network consists of ten VHF receivers deployed across northern Alabama and a base station located at the National Space Science and Technology Center. Preliminary investigations done at WFO Huntsville, along with other similar total lightning networks across the country, have shown distinct correlations between the time rate-of-change of total lightning and trends in intensity/severity of the parent convective cell. Since May 2003 when WFO HUN began receiving these data - in conjunction with other more traditional remotely sensed data (radar, satellite, and surface observations) -- have improved the situational awareness of the WFO staff. The use of total lightning information, either from current ground based systems or future space borne instrumentation, may substantially contribute to the NWS mission, by enhancing severe weather warning and decision-making processes. Operational use of the data has been maximized at WFO Huntsville through a process that includes forecaster training, product implementation, and post event analysis and assessments. Since receiving these data, over 50 surveys have been completed highlighting the use of total lightning information during significant events across the Tennessee Valley. In addition, around 150 specific cases of interest have been archived for collaborative post storm analysis. From these datasets, detailed trending information from radar and total lightning can be compared to corresponding damage reports. This presentation will emphasize

  15. "Thunderstruck": penetrating thoracic injury from lightning strike.

    PubMed

    van Waes, Oscar J F; van de Woestijne, Pieter C; Halm, Jens A

    2014-04-01

    Lightning strike victims are rarely presented at an emergency department. Burns are often the primary focus. This case report describes the improvised explosive device like-injury to the thorax due to lightning strike and its treatment, which has not been described prior in (kerauno)medicine. Penetrating injury due to blast from lightning strike is extremely rare. These "shrapnel" injuries should however be ruled out in all patients struck by lightning. PMID:24054789

  16. "Thunderstruck": penetrating thoracic injury from lightning strike.

    PubMed

    van Waes, Oscar J F; van de Woestijne, Pieter C; Halm, Jens A

    2014-04-01

    Lightning strike victims are rarely presented at an emergency department. Burns are often the primary focus. This case report describes the improvised explosive device like-injury to the thorax due to lightning strike and its treatment, which has not been described prior in (kerauno)medicine. Penetrating injury due to blast from lightning strike is extremely rare. These "shrapnel" injuries should however be ruled out in all patients struck by lightning.

  17. North Alabama Total Lightning Climatology in Support of Lightning Safety Operations

    NASA Astrophysics Data System (ADS)

    Stano, G. T.; Schultz, C. J.; Koshak, W. J.

    2015-12-01

    The North Alabama Lightning Mapping Array (NALMA) was installed in 2001 to observe total lightning (cloud-to-ground and intra-cloud) and study its relationship to convective activity. NALMA has served as ground-truth for the Tropical Rainfall Measuring Mission Lightning Imager (TRMM-LIS) and will again for the GOES-R Geostationary Lightning Mapper (GLM). Also, NASA's Short-term Prediction Research and Transition Center (SPoRT) has transitioned these data to National Weather Service Weather Forecast Offices to evaluate the impact in operations since 2003. This study focuses on seasonal and diurnal observations from NALMA's 14 year history. This is initially intended to improve lightning safety at Marshall Space Flight Center, but has other potential applications. Improvements will be made by creating a dataset to investigate temporal, spatial, and seasonal patterns in total lightning over the Tennessee Valley, compare these observations to background environmental parameters and the TRMM-LIS climatology, and investigate applying these data to specific points of interest. Unique characteristics, such as flash extent density and length of flashes can be investigated, which are unavailable from other lightning networks like the National Lightning Detection Network (NLDN). The NALMA and NLDN data can be combined such that end users can use total lightning to gain lead time on the initial cloud-to-ground flash of a storm and identify if lightning is extending far from the storm's core. This spatial extent can be analyzed to determine how often intra-cloud activity may impinge on a region of interest and how often a cloud-to-ground strike may occur in the region. The seasonal and diurnal lightning maps can aid with planning of various experiments or tests that often require some knowledge about future weather patterns months in advance. The main goal is to develop a protocol to enhance lightning safety everywhere once the Geostationary Lightning Mapper (GLM) is on orbit

  18. Explosive spread F caused by lightning-induced electromagnetic effects

    NASA Technical Reports Server (NTRS)

    Liao, C. P.; Freidberg, J. P.; Lee, M. C.

    1989-01-01

    Lightning-produced electromagnetic effects may produce significant modifications in the ionospheric plasmas. An outstanding phenomenon investigated in this paper is the so-called explosive spread F, whose close link with lightning has been identified (Woodman and Kudeki, 1984). Parametric instability excited by the lightning-induced whistler waves is proposed as a potential source mechanism causing the explosive spread F.

  19. Interrelation between ball lightning and optically induced forces

    NASA Astrophysics Data System (ADS)

    Torchigin, V. P.; Torchigin, A. V.

    2013-09-01

    Optically induced forces are considered as a key factor for explaining the phenomenon of ball lightning. They can provide not only the existence of ball lightning in the form of self-confined intense white light circulating in a spherical shell of air strongly compressed by the light but also the anomalous motion of ball lightning in the terrestrial atmosphere.

  20. Lightning: Understanding it and protecting systems from its effects

    SciTech Connect

    Hasbrouck, R.T.

    1989-04-10

    This tutorial will raise the reader's level of lightning consciousness by providing an overview of the atmospheric electrification process and by discussing the development and characteristics of a lightning discharge. Next, techniques and instrumentation for lightning threat warning, detection and tracking will be presented. Finally, the principles of protection will be discussed, along with several methods for testing that protection. 15 refs., 16 figs.

  1. How to protect a wind turbine from lightning

    NASA Technical Reports Server (NTRS)

    Dodd, C. W.; Mccalla, T., Jr.; Smith, J. G.

    1983-01-01

    Techniques for reducing the chances of lightning damage to wind turbines are discussed. The methods of providing a ground for a lightning strike are discussed. Then details are given on ways to protect electronic systems, generating and power equipment, blades, and mechanical components from direct and nearby lightning strikes.

  2. 30 CFR 57.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Short circuit and lightning protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  3. 30 CFR 56.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit and lightning protection. 56... Electricity § 56.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  4. 30 CFR 57.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit and lightning protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  5. 30 CFR 57.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Short circuit and lightning protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  6. 30 CFR 56.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Short circuit and lightning protection. 56... Electricity § 56.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  7. 30 CFR 56.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Short circuit and lightning protection. 56... Electricity § 56.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  8. 14 CFR 29.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system lightning protection. 29.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  9. 14 CFR 29.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system lightning protection. 29.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  10. 30 CFR 57.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Short circuit and lightning protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  11. 14 CFR 25.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system lightning protection. 25.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  12. 14 CFR 25.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system lightning protection. 25.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  13. 14 CFR 27.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system lightning protection. 27.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  14. 14 CFR 23.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system lightning protection. 23.954... Fuel System § 23.954 Fuel system lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having...

  15. 14 CFR 27.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system lightning protection. 27.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  16. 14 CFR 27.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system lightning protection. 27.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  17. 30 CFR 56.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Short circuit and lightning protection. 56... Electricity § 56.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  18. 14 CFR 29.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system lightning protection. 29.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  19. 14 CFR 25.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system lightning protection. 25.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  20. 14 CFR 25.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system lightning protection. 25.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  1. 30 CFR 56.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Short circuit and lightning protection. 56... Electricity § 56.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  2. 14 CFR 23.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system lightning protection. 23.954... Fuel System § 23.954 Fuel system lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having...

  3. 30 CFR 57.12065 - Short circuit and lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Short circuit and lightning protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning....

  4. 14 CFR 23.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system lightning protection. 23.954... Fuel System § 23.954 Fuel system lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having...

  5. 14 CFR 27.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system lightning protection. 27.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  6. 14 CFR 23.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system lightning protection. 23.954... Fuel System § 23.954 Fuel system lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having...

  7. 14 CFR 29.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system lightning protection. 29.954... lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having a high probability of...

  8. 14 CFR 23.954 - Fuel system lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system lightning protection. 23.954... Fuel System § 23.954 Fuel system lightning protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct lightning strikes to areas having...

  9. Lightning Launch Commit Criteria for America's Space Program

    NASA Technical Reports Server (NTRS)

    Roeder, W. P.; Sardonia, J. E.; Jacobs, S. C.; Hinson, M. S.; Harms, D. E.; Madura, J. T.; DeSordi, S. P.

    1999-01-01

    The danger of natural and triggered lightning significantly impacts space launch operations supported by the USAF. The lightning Launch Commit Criteria (LCC) are used by the USAF to avoid these lightning threats to space launches. This paper presents a brief overview of the LCC.

  10. Production of Artificial Lightning in An Ordinary Clear Light Bulb.

    ERIC Educational Resources Information Center

    Zaffo, Peter Alfred

    1981-01-01

    Reported is a method of producing artificial lightning in an ordinary clear lightbulb. The appearance of sparks produced is that of a miniature stroke of forked lightning seen in natural thunderstorms. The sparks also show the intricate branching patterns often seen in natural lightning. (JT)

  11. The Sandia transportable triggered lightning instrumentation facility

    NASA Technical Reports Server (NTRS)

    Schnetzer, George H.; Fisher, Richard J.

    1991-01-01

    Development of the Sandia Transportable Triggered Lightning Instrumentation Facility (SATTLIF) was motivated by a requirement for the in situ testing of a munitions storage bunker. Transfer functions relating the incident flash currents to voltages, currents, and electromagnetic field values throughout the structure will be obtained for use in refining and validating a lightning response computer model of this type of structure. A preliminary shakedown trial of the facility under actual operational conditions was performed during summer of 1990 at the Kennedy Space Center's (KSC) rocket-triggered lightning test site. A description is given of the SATTLIF, which is readily transportable on a single flatbed truck of by aircraft, and its instrumentation for measuring incident lightning channel currents and the responses of the systems under test. Measurements of return-stroke current peaks obtained with the SATTLIF are presented. Agreement with data acquired on the same flashes with existing KSC instrumentation is, on average, to within approximately 7 percent. Continuing currents were measured with a resolution of approximately 2.5 A. This field trial demonstrated the practicality of using a transportable triggered lightning facility for specialized test applications.

  12. Characteristics of Winter Lightning that Occurred on a Windmill and its Lightning Protection Tower

    NASA Astrophysics Data System (ADS)

    Takagi, Nobuyuki; Wang, Daohong

    We have obtained the electric current, electric field change, and optical image data or several tens of lightning that hit on a wind turbine and its lightning-protection tower during the past6 non-stop winter seasons from 2005 to 2010. By analyzing the data, we found that the upward lightning hitting on the high structures can be classified into self-initiated and other-triggered types according to whether there is a discharge activity prior to the upward lightning. We also found that although other-triggered upward lightning can start at a relatively lower wind speed, self-initiated upward lightning always started either from the stationary tower under a larger wind speed or from a rotating wind turbine blade. It appears that the wind and by inference the corona discharge shielding do have considerable effect in the initiation of an upward leader. Regarding the initial progression of a positive leader, we found a systematic difference in the speeds of the leaders from the structures that have remarkably different heights. Finally, we discussed the pulse discharges observed in the very initial stages of positive upward leaders and also how to forecast direct strike of upward lightning.

  13. Lightning NOx Statistics Derived by NASA Lightning Nitrogen Oxides Model (LNOM) Data Analyses

    NASA Technical Reports Server (NTRS)

    Koshak, William; Peterson, Harold

    2013-01-01

    What is the LNOM? The NASA Marshall Space Flight Center (MSFC) Lightning Nitrogen Oxides Model (LNOM) [Koshak et al., 2009, 2010, 2011; Koshak and Peterson 2011, 2013] analyzes VHF Lightning Mapping Array (LMA) and National Lightning Detection Network(TradeMark) (NLDN) data to estimate the lightning nitrogen oxides (LNOx) produced by individual flashes. Figure 1 provides an overview of LNOM functionality. Benefits of LNOM: (1) Does away with unrealistic "vertical stick" lightning channel models for estimating LNOx; (2) Uses ground-based VHF data that maps out the true channel in space and time to < 100 m accuracy; (3) Therefore, true channel segment height (ambient air density) is used to compute LNOx; (4) True channel length is used! (typically tens of kilometers since channel has many branches and "wiggles"); (5) Distinction between ground and cloud flashes are made; (6) For ground flashes, actual peak current from NLDN used to compute NOx from lightning return stroke; (7) NOx computed for several other lightning discharge processes (based on Cooray et al., 2009 theory): (a) Hot core of stepped leaders and dart leaders, (b) Corona sheath of stepped leader, (c) K-change, (d) Continuing Currents, and (e) M-components; and (8) LNOM statistics (see later) can be used to parameterize LNOx production for regional air quality models (like CMAQ), and for global chemical transport models (like GEOS-Chem).

  14. Lightning and severe thunderstorms in event management.

    PubMed

    Walsh, Katie M

    2012-01-01

    There are a few national position stands/guidelines that address environmental conditions in athletics, yet they do not govern all outdoor sports. Extreme heat and cold, lightning, and severe wind can all be fatal, yet the majority of outdoor sports have no published guidelines addressing these conditions in relation to activity. Available research on extreme heat and cold conditions in athletics provides prevention strategies, to include acclimatization. Lightning and severe wind are two environmental conditions to which humans cannot accommodate, and they both can be deadly. There are strong positions on extreme heat/cold and lightning safety in athletics, but none affiliated with severe winds. Medical personnel involved in planning large outdoor sporting events must know of the presence of nationally published weather-related documents and apply them to their event. In addition, research needs to be expanded in the realm of establishing guidelines for safety to participants and spectators in severe wind conditions. PMID:22580490

  15. Electrostatic charge bounds for ball lightning models

    NASA Astrophysics Data System (ADS)

    Stephan, Karl D.

    2008-03-01

    Several current theories concerning the nature of ball lightning predict a substantial electrostatic charge in order to account for its observed motion and shape (Turner 1998 Phys. Rep. 293 1; Abrahamson and Dinniss 2000 Nature 403 519). Using charged soap bubbles as a physical model for ball lightning, we show that the magnitude of charge predicted by some of these theories is too high to allow for the types of motion commonly observed in natural ball lightning, which includes horizontal motion above the ground and movement near grounded conductors. Experiments show that at charge levels of only 10-15 nC, 3-cm-diameter soap bubbles tend to be attracted by induced charges to the nearest grounded conductor and rupture. We conclude with a scaling rule that can be used to extrapolate these results to larger objects and surroundings.

  16. On the energy characteristics of ball lightning.

    PubMed

    Bychkov, A V; Bychkov, V L; Abrahamson, John

    2002-01-15

    A compilation of 17 observations of ball lightning showing the most energetic effects is presented along with estimates of their energy content. These observations were chosen from several thousand for the much stronger interaction of each ball lightning on its surroundings, and the method of energy estimation outlined. The case is put that some of the observations show a higher energy than self-contained chemical energy could provide. Comments have been added to the paper, arguing that the energy estimations themselves should be consistent with whatever model is used for ball lightning. For example, the presence of reacting nanoparticles releasing chemical energy may bring about the same observed effects with lower estimated energy.

  17. Augmenting Satellite Precipitation Estimation with Lightning Information

    SciTech Connect

    Mahrooghy, Majid; Anantharaj, Valentine G; Younan, Nicolas H.; Petersen, Walter A.; Hsu, Kuo-Lin; Behrangi, Ali; Aanstoos, James

    2013-01-01

    We have used lightning information to augment the Precipitation Estimation from Remotely Sensed Imagery using an Artificial Neural Network - Cloud Classification System (PERSIANN-CCS). Co-located lightning data are used to segregate cloud patches, segmented from GOES-12 infrared data, into either electrified (EL) or non-electrified (NEL) patches. A set of features is extracted separately for the EL and NEL cloud patches. The features for the EL cloud patches include new features based on the lightning information. The cloud patches are classified and clustered using self-organizing maps (SOM). Then brightness temperature and rain rate (T-R) relationships are derived for the different clusters. Rain rates are estimated for the cloud patches based on their representative T-R relationship. The Equitable Threat Score (ETS) for daily precipitation estimates is improved by almost 12% for the winter season. In the summer, no significant improvements in ETS are noted.

  18. The response of aeroshells to lightning

    SciTech Connect

    Loescher, D.H.; Dinallo, M.A.

    1994-06-01

    Electrical discharges from a lightning simulator were directed at Mk12 aeroshells. Buckling of the aluminum substrate was observed after some 100-kA shots, and severe damage consisting of tearing of the aluminum and the production of inward flying aluminum shrapnel was observed after some 200-kA peak-current shots. Some shots resulted in severe damage to both the aluminum and the carbon-phenolic ablative material. It is reasonable to conclude from the experimental results that a lightning stroke with very high-peak current could, by itself, produce an opening in an Mk12 aeroshell. Because the aeroshell is part of the nuclear explosive safety exclusion region for the Mk12/W62 nuclear weapon, an opening would significantly reduce the assured safety of the weapon. It is unlikely that the observed interaction between lightning and the aeroshells would have been predicted by any form of computer simulation.

  19. On the energy characteristics of ball lightning.

    PubMed

    Bychkov, A V; Bychkov, V L; Abrahamson, John

    2002-01-15

    A compilation of 17 observations of ball lightning showing the most energetic effects is presented along with estimates of their energy content. These observations were chosen from several thousand for the much stronger interaction of each ball lightning on its surroundings, and the method of energy estimation outlined. The case is put that some of the observations show a higher energy than self-contained chemical energy could provide. Comments have been added to the paper, arguing that the energy estimations themselves should be consistent with whatever model is used for ball lightning. For example, the presence of reacting nanoparticles releasing chemical energy may bring about the same observed effects with lower estimated energy. PMID:16210173

  20. Investigating Dunedin whistlers using volcanic lightning

    NASA Astrophysics Data System (ADS)

    Antel, Claire; Collier, Andrew B.; Lichtenberger, János; Rodger, Craig J.

    2014-07-01

    Whistlers detected at Dunedin, New Zealand are an anomaly: there is little lightning around Dunedin's conjugate point yet whistlers appear in relatively large numbers. These surplus whistlers have consequently inspired investigations into their origins. Dunedin's lightning-sparse conjugate point lies in the Aleutian Islands, a region populated with active volcanoes. Their presence has allowed us to perform a novel analysis: the correlation of whistlers to volcanic lightning. We report on our investigation, which successfully yielded the first observations of "volcanic whistlers." It was found that the single July 2008 Mount Okmok eruption had an impressive effect on the number of whistlers at Dunedin. The eruptions at Mount Redoubt in 2009 also caused a sporadic flow of whistlers in Dunedin.

  1. Further evidence for lightning on Venus

    NASA Technical Reports Server (NTRS)

    Singh, R. N.; Russell, C. T.

    1986-01-01

    Impulsive electrical signals at all frequencies recorded by the plasma wave instrument on Pioneer Venus are found to cluster around periapsis. The signals are strongest at 100 Hz and have a secondary peak at 5.4 kHz. These characteristics are consistent with generation by lightning in the Venus atmosphere and the direct propagation of whistler mode signals below the electron gyro frequency and the partial transmission of electromagnetic waves in the presence of electron density inhomogeneities above the electron gyro frequency. The scattering by electron density inhomogeneities may also weaken any correlation with surface topographical features. Thus, the source of these signals may either be intercloud lightning at high altitudes or lightning in volcanic plumes near the ground, despite the large scatter in inferred source locations.

  2. Lightning and severe thunderstorms in event management.

    PubMed

    Walsh, Katie M

    2012-01-01

    There are a few national position stands/guidelines that address environmental conditions in athletics, yet they do not govern all outdoor sports. Extreme heat and cold, lightning, and severe wind can all be fatal, yet the majority of outdoor sports have no published guidelines addressing these conditions in relation to activity. Available research on extreme heat and cold conditions in athletics provides prevention strategies, to include acclimatization. Lightning and severe wind are two environmental conditions to which humans cannot accommodate, and they both can be deadly. There are strong positions on extreme heat/cold and lightning safety in athletics, but none affiliated with severe winds. Medical personnel involved in planning large outdoor sporting events must know of the presence of nationally published weather-related documents and apply them to their event. In addition, research needs to be expanded in the realm of establishing guidelines for safety to participants and spectators in severe wind conditions.

  3. The effect of global warming on lightning frequencies

    NASA Technical Reports Server (NTRS)

    Price, Colin; Rind, David

    1990-01-01

    The first attempt to model global lightning distributions by using the Goddard Institute for Space Studies (GISS) GCM is reported. Three sets of observations showing the relationship between lightning frequency and cloud top height are shown. Zonally averaged lightning frequency observed by satellite are compared with those calculated using the GISS GCM, and fair agreement is found. The change in lightning frequency for a double CO2 climate is calculated and found to be nearly 2.23 x 10 exp 6 extra lightning flashes per day.

  4. a Critical Review of Nonconventional Approaches to Lightning Protection.

    NASA Astrophysics Data System (ADS)

    Uman, M. A.; Rakov, V. A.

    2002-12-01

    The conventional technique for the lightning protection of structures is described in the U.S. National Standard, NFPA 780, and in many other national and international lightning protection standards. Two nonconventional techniques, known generically as "lightning elimination" and "early streamer emission," are claimed by their proponents to be superior to the conventional lightning protection technique. We review the literature on these nonconventional approaches as well as the pertinent lightning literature and conclude that the suggested superiority of the nonconventional techniques over the conventional method is not supported by the available experimental data or by theory.

  5. Earthquake-Lightning Signature Probed by Tropical Rainfall Measuring Mission

    NASA Astrophysics Data System (ADS)

    Lee, Hao; Liu, Jann-Yenq Tiger

    2016-04-01

    The lightning activity is one of the key parameters to understand the atmospheric electric fields near the Earth's surface and the lithosphere-atmosphere-ionosphere coupling during the earthquake preparation period. A statistical study shows more lightning before magnitude M>=5.0 earthquakes in Taiwan during 1993-2004. In this paper, the Lightning Imaging Sensor (LIS) onboard Tropical Rainfall Measuring Mission (TRMM) is used to statistically exam the lightning activity 30 days before and after 198 M>=7.0 earthquakes in the tropical area of the globe during the 17-year period of 1988-2014. The statistical results show that lightning activities over epicenter significantly enhance before the earthquakes.

  6. Study of the transport parameters of cloud lightning plasmas

    SciTech Connect

    Chang, Z. S.; Yuan, P.; Zhao, N.

    2010-11-15

    Three spectra of cloud lightning have been acquired in Tibet (China) using a slitless grating spectrograph. The electrical conductivity, the electron thermal conductivity, and the electron thermal diffusivity of the cloud lightning, for the first time, are calculated by applying the transport theory of air plasma. In addition, we investigate the change behaviors of parameters (the temperature, the electron density, the electrical conductivity, the electron thermal conductivity, and the electron thermal diffusivity) in one of the cloud lightning channels. The result shows that these parameters decrease slightly along developing direction of the cloud lightning channel. Moreover, they represent similar sudden change behavior in tortuous positions and the branch of the cloud lightning channel.

  7. System and Method of Locating Lightning Strikes

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro J. (Inventor); Starr, Stanley O. (Inventor)

    2002-01-01

    A system and method of determining locations of lightning strikes has been described. The system includes multiple receivers located around an area of interest, such as a space center or airport. Each receiver monitors both sound and electric fields. The detection of an electric field pulse and a sound wave are used to calculate an area around each receiver in which the lighting is detected. A processor is coupled to the receivers to accurately determine the location of the lighting strike. The processor can manipulate the receiver data to compensate for environmental variables such as wind, temperature, and humidity. Further, each receiver processor can discriminate between distant and local lightning strikes.

  8. Lightning trends as a precursor to microbursts

    NASA Technical Reports Server (NTRS)

    Buechler, Dennis E.; Goodman, Steven J.; Meyer, Paul J.

    1989-01-01

    The feasibility of using lightning-rate data to aid in the early warning of microburst occurrence in moist environments is illustrated. Convective tendency images were generated for a small microburst-producing storm that developed in northern Alabama on July 20, 1986 during the Cooperative Huntsville Meteorological Experiment. Radar observations were obtained from the NCAR CP2 10-cm dual-polarization Doppler radar, while the measurements of total lightning activity were provided by the National Severe Storm Laboratory, a mobile laboratory that was located under the storm throughout its lifetime. The scenario for the evolution of wet microburst producing thunderstorms is described.

  9. Lightning parameterization in a storm electrification model

    NASA Technical Reports Server (NTRS)

    Helsdon, John H., Jr.; Farley, Richard D.; Wu, Gang

    1988-01-01

    The parameterization of an intracloud lightning discharge has been implemented in our Storm Electrification Model. The initiation, propagation direction, termination and charge redistribution of the discharge are approximated assuming overall charge neutrality. Various simulations involving differing amounts of charge transferred have been done. The effects of the lightning-produced ions on the hydrometeor charges, electric field components and electrical energy depend strongly on the charge transferred. A comparison between the measured electric field change of an actual intracloud flash and the field change due to the simulated discharge show favorable agreement.

  10. Automatic lightning detection and photographic system

    NASA Technical Reports Server (NTRS)

    Wojtasinski, R. J.; Holley, L. D.; Gray, J. L.; Hoover, R. B. (Inventor)

    1972-01-01

    A system is presented for monitoring and recording lightning strokes within a predetermined area with a camera having an electrically operated shutter with means for advancing the film in the camera after activating the shutter. The system includes an antenna for sensing lightning strikes which, in turn, generates a signal that is fed to an electronic circuit which generates signals for operating the shutter of the camera. Circuitry is provided for preventing activation of the shutter as the film in the camera is being advanced.

  11. Acoustic vs VHF Lightning Location Systems

    NASA Astrophysics Data System (ADS)

    Arechiga, R. O.; Lapierre, J. L.; Stock, M.; Erives, H.; Edens, H. E.; Stringer, A.; Rison, W.; Thomas, R. J.

    2013-12-01

    A single acoustic array can determine the 3-D location of lightning sources by using time of arrival differences arriving at the microphones and ranging techniques. The range is obtained from the time difference between the electromagnetic emission (detected by the acoustic data logger) and the acoustic signal produced by lightning. Audio frequency acoustic location systems are sensitive to the gas dynamic expansion of portions of a rapidly heating lightning channel, and so acoustic signatures are produced by a wide variety of different lightning discharge processes including: return strokes, K changes, M components, leader stepping and more. Infrasonic frequency range acoustic sensors are also sensitive to gas dynamic expansion, and in addition are also sensitive to processes which are electro-static in nature. RF location systems such as the Lightning Mapping Array (LMA) and the Continuous Sampling Broadband VHF Digital Interferometer (DITF) from New Mexico Tech (NMT) produce high quality maps of lightning discharges; however, they are sensitive to breakdown processes only and can not locate sources originating in already well conducting channels. During the summer of 2013 an acoustic audio-range array and an infrasound array were co-located with the NMT DITF in the Magdalena mountains of central New Mexico, where an LMA is also operating. The audio-range acoustic array consists of custom-designed GPS-synced data loggers with a 50 kHz sampling rate and audio range omnidirectional dynamic microphones. The infrasound array uses GPS time-synced data logger and custom-designed broadband microphones with flat response in the band of 0.01 to 500 Hz. The DITF uses flat plate dE/dt antennas bandpass filtered to 20 to 80 MHz, providing 2D maps of lightning emissions with very high (sub-microsecond) timing resolution. Both acoustic and interferometric arrays of antennas determine location of sources by coherently comparing the signals arriving at the antennas (or

  12. Artificial Neural Network applied to lightning flashes

    NASA Astrophysics Data System (ADS)

    Gin, R. B.; Guedes, D.; Bianchi, R.

    2013-05-01

    The development of video cameras enabled cientists to study lightning discharges comportment with more precision. The main goal of this project is to create a system able to detect images of lightning discharges stored in videos and classify them using an Artificial Neural Network (ANN)using C Language and OpenCV libraries. The developed system, can be split in two different modules: detection module and classification module. The detection module uses OpenCV`s computer vision libraries and image processing techniques to detect if there are significant differences between frames in a sequence, indicating that something, still not classified, occurred. Whenever there is a significant difference between two consecutive frames, two main algorithms are used to analyze the frame image: brightness and shape algorithms. These algorithms detect both shape and brightness of the event, removing irrelevant events like birds, as well as detecting the relevant events exact position, allowing the system to track it over time. The classification module uses a neural network to classify the relevant events as horizontal or vertical lightning, save the event`s images and calculates his number of discharges. The Neural Network was implemented using the backpropagation algorithm, and was trained with 42 training images , containing 57 lightning events (one image can have more than one lightning). TheANN was tested with one to five hidden layers, with up to 50 neurons each. The best configuration achieved a success rate of 95%, with one layer containing 20 neurons (33 test images with 42 events were used in this phase). This configuration was implemented in the developed system to analyze 20 video files, containing 63 lightning discharges previously manually detected. Results showed that all the lightning discharges were detected, many irrelevant events were unconsidered, and the event's number of discharges was correctly computed. The neural network used in this project achieved a

  13. Nowcasting and forecasting of lightning activity: the Talos project.

    NASA Astrophysics Data System (ADS)

    Lagouvardos, Kostas; Kotroni, Vassiliki; Kazadzis, Stelios; Giannaros, Theodore; Karagiannidis, Athanassios; Galanaki, Elissavet; Proestakis, Emmanouil

    2015-04-01

    Thunder And Lightning Observing System (TALOS) is a research program funded by the Greek Ministry of Education with the aim to promote excellence in the field of lightning meteorology. The study focuses on exploring the real-time observations provided by the ZEUS lightning detection system, operated by the National Observatory of Athens since 2005, as well as the 10-year long database of the same system. More precisely the main research issues explored are: - lightning climatology over the Mediterranean focusing on lightning spatial and temporal distribution, on the relation of lightning with topographical features and instability and on the importance of aerosols in lightning initiation and enhancement. - nowcasting of lightning activity over Greece, with emphasis on the operational aspects of this endeavour. The nowcasting tool is based on the use of lightning data complemented by high-time resolution METEOSAT imagery. - forecasting of lightning activity over Greece based on the use of WRF numerical weather prediction model. - assimilation of lightning with the aim to improve the model precipitation forecast skill. In the frame of this presentation the main findings of each of the aforementioned issues are highlighted.

  14. Harmful effects of lightning surge discharge on communications terminal equipments

    NASA Astrophysics Data System (ADS)

    Liang, Sisi; Xu, Xiaoying; Tao, Zhigang; Dai, Yanling

    2013-03-01

    The interference problem of lightning surges on electronic and telecommunication products were examined, and a series of experiments were conducted to analyze the failure situations to find out the mechanisms of failures caused by the lightning surge. In addition, the ways in which lightning surges damaged equipment were deduced. It was found that failure positions were scattered and appeared in groups, and most of them were ground discharge. Internet access transformer had high withstand-voltage under the lightning pulse, and the lightning surge seldom passed through the internet access transformer. The lightning current can release to the ground via the computer network adapter of the terminal user. The study will help to improve the performance of lightning surge protection circuit and protection level.

  15. Lightning criteria relative to space shuttles: Currents and electric field intensity in Florida lightning

    NASA Technical Reports Server (NTRS)

    Uman, M. A.; Mclain, D. K.

    1972-01-01

    The measured electric field intensities of 161 lightning strokes in 39 flashes which occurred between 1 and 35 km from an observation point at Kennedy Space Center, Florida during June and July of 1971 have been analyzed to determine the lightning channel currents which produced the fields. In addition, typical channel currents are derived and from these typical electric fields at distances between 0.5 and 100 km are computed and presented. On the basis of the results recommendations are made for changes in the specification of lightning properties relative to space vehicle design as given in NASA TMX-64589 (Daniels, 1971). The small sample of lightning analyzed yielded several peak currents in the 100 kA range. Several current rise-times from zero to peak of 0.5 microsec or faster were found; and the fastest observed current rate-of-rise was near 200 kA/microsec. The various sources of error are discussed.

  16. Thunderstorm and Lightning Studies using the FORTE Optical Lightning System (FORTE/OLS)

    SciTech Connect

    Argo, P.; Franz, R.; Green, J.; Guillen, J.L.; Jacobson, A.R.; Kirkland, M.; Knox, S.; Spalding, R.; Suszcynsky, D.M.

    1999-02-01

    Preliminary observations of simultaneous RF and optical emissions from lightning as seen by the FORTE spacecraft are presented. RF/optical pairs of waveforms are routinely collected both as individual lightning events and as sequences of events associated with cloud-to-ground (CG) and intra-cloud (IC) flashes. CG pulses can be distinguished from IC pulses based on the properties of the RF and optical waveforms, but mostly based on the associated RF spectrograms. The RF spectrograms are very similar to previous ground-based VHF observations of lightning and show signatures associated with return strokes, stepped and dart leaders, and attachment processes,. RF emissions are observed to precede the arrival of optical emissions at the satellite by a mean value of 280 microseconds. The dual phenomenology nature of these observations are discussed in terms of their ability to contribute to a satellite-based lightning monitoring mission.

  17. Ball lightning as a force-free magnetic knot

    PubMed

    Ranada; Soler; Trueba

    2000-11-01

    The stability of fireballs in a recent model of ball lightning is studied. It is shown that the balls shine while relaxing in an almost quiescent expansion, and that three effects contribute to their stability: (i) the formation in each one during a process of Taylor relaxation of a force-free magnetic field, a concept introduced in 1954 in order to explain the existence of large magnetic fields and currents in stable configurations of astrophysical plasmas; (ii) the so called Alfven conditions in magnetohydrodynamics; and (iii) the approximate conservation of the helicity integral. The force-free fields that appear are termed "knots" because their magnetic lines are closed and linked. PMID:11102074

  18. Model Study of Conditions for Red Sprite Onset Determined by Lightning Discharge and Atmospheric Parameters

    NASA Astrophysics Data System (ADS)

    Tonev, Peter; Velinov, Peter

    We study the conditions of onset of red sprites produced by positive cloud-to-ground (+CG) lightning discharges at night by means of modeling. Sprites appear as consequence of two events: hallo for about one millisecond at altitudes 85-90 km, followed by formation close below it of a net of downward positive and, sometimes, upward negative streamers. It is believed that these two events always occur together, although any of them can be sometimes unobservable. Here conditions of initiation of streamers are studied, which represent the essential phase of a sprite. These conditions are determined by three groups of factors: i) +CG discharge characterized by the time distribution of the lightning current moment; ii) ambient electron and ion densities, conductivity, etc.; and iii) factors responsible for creation of small-scale irregularities of electron density at altitudes ~80-85 km which play a key role in streamer initiation. We study first the quasi-static (QS) electric field generated by a +CG lightning discharge in lower ionosphere above the discharge (mainly, its peak value and the time interval of the peak) as function of the lightning current moment and the ionospheric conductivity. For this goal, the QS electric field is obtained as solution of continuity equation for the Maxwell current. Approximations are obtained which analytically represents the considered dependences. Self-consistent changes of this field in the lower ionosphere due to electron heating and ionization are approximately taken into account. Then, we study the conditions for streamer initiation by the post-lightning peak QS electric field when a small region of ionospheric irregularity is present, depending on its shape and electron density. The possible role of the cosmic rays (galactic and solar) is discussed.

  19. Lightning Jump Algorithm Development for the GOES·R Geostationary Lightning Mapper

    NASA Technical Reports Server (NTRS)

    Schultz. E.; Schultz. C.; Chronis, T.; Stough, S.; Carey, L.; Calhoun, K.; Ortega, K.; Stano, G.; Cecil, D.; Bateman, M.; Goodman, S.

    2014-01-01

    Current work on the lightning jump algorithm to be used in GOES-R Geostationary Lightning Mapper (GLM)'s data stream is multifaceted due to the intricate interplay between the storm tracking, GLM proxy data, and the performance of the lightning jump itself. This work outlines the progress of the last year, where analysis and performance of the lightning jump algorithm with automated storm tracking and GLM proxy data were assessed using over 700 storms from North Alabama. The cases analyzed coincide with previous semi-objective work performed using total lightning mapping array (LMA) measurements in Schultz et al. (2011). Analysis shows that key components of the algorithm (flash rate and sigma thresholds) have the greatest influence on the performance of the algorithm when validating using severe storm reports. Automated objective analysis using the GLM proxy data has shown probability of detection (POD) values around 60% with false alarm rates (FAR) around 73% using similar methodology to Schultz et al. (2011). However, when applying verification methods similar to those employed by the National Weather Service, POD values increase slightly (69%) and FAR values decrease (63%). The relationship between storm tracking and lightning jump has also been tested in a real-time framework at NSSL. This system includes fully automated tracking by radar alone, real-time LMA and radar observations and the lightning jump. Results indicate that the POD is strong at 65%. However, the FAR is significantly higher than in Schultz et al. (2011) (50-80% depending on various tracking/lightning jump parameters) when using storm reports for verification. Given known issues with Storm Data, the performance of the real-time jump algorithm is also being tested with high density radar and surface observations from the NSSL Severe Hazards Analysis & Verification Experiment (SHAVE).

  20. Combining satellite-based fire observations and ground-based lightning detections to identify lightning fires across the conterminous USA

    USGS Publications Warehouse

    Bar-Massada, A.; Hawbaker, T.J.; Stewart, S.I.; Radeloff, V.C.

    2012-01-01

    Lightning fires are a common natural disturbance in North America, and account for the largest proportion of the area burned by wildfires each year. Yet, the spatiotemporal patterns of lightning fires in the conterminous US are not well understood due to limitations of existing fire databases. Our goal here was to develop and test an algorithm that combined MODIS fire detections with lightning detections from the National Lightning Detection Network to identify lightning fires across the conterminous US from 2000 to 2008. The algorithm searches for spatiotemporal conjunctions of MODIS fire clusters and NLDN detected lightning strikes, given a spatiotemporal lag between lightning strike and fire ignition. The algorithm revealed distinctive spatial patterns of lightning fires in the conterminous US While a sensitivity analysis revealed that the algorithm is highly sensitive to the two thresholds that are used to determine conjunction, the density of fires it detected was moderately correlated with ground based fire records. When only fires larger than 0.4 km2 were considered, correlations were higher and the root-mean-square error between datasets was less than five fires per 625 km2 for the entire study period. Our algorithm is thus suitable for detecting broad scale spatial patterns of lightning fire occurrence, and especially lightning fire hotspots, but has limited detection capability of smaller fires because these cannot be consistently detected by MODIS. These results may enhance our understanding of large scale patterns of lightning fire activity, and can be used to identify the broad scale factors controlling fire occurrence.

  1. Number of lightning discharges causing damage to lightning arrester cables for aerial transmission lines in power systems

    SciTech Connect

    Nikiforov, E. P.

    2009-07-15

    Damage by lightning discharges to lightning arrester cables for 110-175 kV aerial transmission lines is analyzed using data from power systems on incidents with aerial transmission lines over a ten year operating period (1997-2006). It is found that failures of lightning arrester cables occur when a tensile force acts on a cable heated to the melting point by a lightning current. The lightning currents required to heat a cable to this extent are greater for larger cable cross sections. The probability that a lightning discharge will develop decreases as the amplitude of the lightning current increases, which greatly reduces the number of lightning discharges which damage TK-70 cables compared to TK-50 cables. In order to increase the reliability of lightning arrester cables for 110 kV aerial transmission lines, TK-70 cables should be used in place of TK-50 cables. The number of lightning discharges per year which damage lightning arrester cables is lowered when the density of aerial transmission lines is reduced within the territory of electrical power systems. An approximate relationship between these two parameters is obtained.

  2. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. The ACES lightning study used the Altus II twin turbo uninhabited aerial vehicle, built by General Atomics Aeronautical Systems, Inc. of San Diego. The Altus II was chosen for its slow flight speed of 75 to 100 knots (80 to 115 mph), long endurance, and high-altitude flight (up to 65,000 feet). These qualities gave the Altus II the ability to fly near and around thunderstorms for long periods of time, allowing investigations to be conducted over the entire life cycle of storms. The vehicle has a wing span of 55 feet and a payload capacity of over 300 lbs. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  3. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely-piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. The ACES lightning study used the Altus II twin turbo uninhabited aerial vehicle, built by General Atomics Aeronautical Systems, Inc. of San Diego. The Altus II was chosen for its slow flight speed of 75 to 100 knots (80 to 115 mph), long endurance, and high-altitude flight (up to 65,000 feet). These qualities gave the Altus II the ability to fly near and around thunderstorms for long periods of time, allowing investigations to be to be conducted over the entire life cycle of storms. The vehicle has a wing span of 55 feet and a payload capacity of over 300 lbs. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA,s Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  4. Assessment of the Pseudo Geostationary Lightning Mapper Products at the Spring Program and Summer Experiment

    NASA Technical Reports Server (NTRS)

    Stano, Geoffrey T.; Calhoun, Kristin K.; Terborg, Amanda M.

    2014-01-01

    Since 2010, the de facto Geostationary Lightning Mapper (GLM) demonstration product has been the Pseudo-Geostationary Lightning Mapper (PGLM) product suite. Originally prepared for the Hazardous Weather Testbed's Spring Program (specifically the Experimental Warning Program) when only four ground-based lightning mapping arrays were available, the effort now spans collaborations with several institutions and eight collaborative networks. For 2013, NASA's Short-term Prediction Research and Transition (SPoRT) Center and NOAA's National Severe Storms Laboratory have worked to collaborate with each network to obtain data in real-time. This has gone into producing the SPoRT variant of the PGLM that was demonstrated in AWIPS II for the 2013 Spring Program. Alongside the PGLM products, the SPoRT / Meteorological Development Laboratory's total lightning tracking tool also was evaluated to assess not just another visualization of future GLM data but how to best extract more information while in the operational environment. Specifically, this tool addressed the leading request by forecasters during evaluations; provide a time series trend of total lightning in real-time. In addition to the Spring Program, SPoRT is providing the PGLM "mosaic" to the Aviation Weather Center (AWC) and Storm Prediction Center. This is the same as what is used at the Hazardous Weather Testbed, but combines all available networks into one display for use at the national centers. This year, the mosaic was evaluated during the AWC's Summer Experiment. An important distinction between this and the Spring Program is that the Summer Experiment focuses on the national center perspective and not at the local forecast office level. Specifically, the Summer Experiment focuses on aviation needs and concerns and brings together operational forecaster, developers, and FAA representatives. This presentation will focus on the evaluation of SPoRT's pseudo-GLM products in these separate test beds. The emphasis

  5. The verification of lightning location accuracy in Finland deduced from lightning strikes to trees

    NASA Astrophysics Data System (ADS)

    Mäkelä, Antti; Mäkelä, Jakke; Haapalainen, Jussi; Porjo, Niko

    2016-05-01

    We present a new method to determine the ground truth and accuracy of lightning location systems (LLS), using natural lightning strikes to trees. Observations of strikes to trees are being collected with a Web-based survey tool at the Finnish Meteorological Institute. Since the Finnish thunderstorms tend to have on average a low flash rate, it is often possible to identify from the LLS data unambiguously the stroke that caused damage to a given tree. The coordinates of the tree are then the ground truth for that stroke. The technique has clear advantages over other methods used to determine the ground truth. Instrumented towers and rocket launches measure upward-propagating lightning. Video and audio records, even with triangulation, are rarely capable of high accuracy. We present data for 36 quality-controlled tree strikes in the years 2007-2008. We show that the average inaccuracy of the lightning location network for that period was 600 m. In addition, we show that the 50% confidence ellipse calculated by the lightning location network and used operationally for describing the location accuracy is physically meaningful: half of all the strikes were located within the uncertainty ellipse of the nearest recorded stroke. Using tree strike data thus allows not only the accuracy of the LLS to be estimated but also the reliability of the uncertainty ellipse. To our knowledge, this method has not been attempted before for natural lightning.

  6. Lightning detection and exposure algorithms for smartphones

    NASA Astrophysics Data System (ADS)

    Wang, Haixin; Shao, Xiaopeng; Wang, Lin; Su, Laili; Huang, Yining

    2015-05-01

    This study focuses on the key theory of lightning detection, exposure and the experiments. Firstly, the algorithm based on differential operation between two adjacent frames is selected to remove the lightning background information and extract lighting signal, and the threshold detection algorithm is applied to achieve the purpose of precise detection of lightning. Secondly, an algorithm is proposed to obtain scene exposure value, which can automatically detect external illumination status. Subsequently, a look-up table could be built on the basis of the relationships between the exposure value and average image brightness to achieve rapid automatic exposure. Finally, based on a USB 3.0 industrial camera including a CMOS imaging sensor, a set of hardware test platform is established and experiments are carried out on this platform to verify the performances of the proposed algorithms. The algorithms can effectively and fast capture clear lightning pictures such as special nighttime scenes, which will provide beneficial supporting to the smartphone industry, since the current exposure methods in smartphones often lost capture or induce overexposed or underexposed pictures.

  7. Total Lightning Activity Associated with Tornadic Storms

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.; Buechler, Dennis; Hodanish, Stephen; Sharpe, David; Williams, Earle R.; Boldi, Bob; Matlin, Anne; Weber, Mark

    1999-01-01

    Prior studies have examined the association of lightning activity with the occurrence of severe weather. Severe storms often have high flash rates (in excess of one flash per second) and are dominated by intracloud lightning activity. Most recently, we have identified a rapid change (referred to as a "jump") in total flash rate which precedes the occurrence of severe weather by ten or more minutes. This relationship is associated with updraft intensification. In this paper we examine whether there exist unique characteristics of the total lightning and the lightning jumps associated with tornadoes in Florida, and explain how they might relate to the interaction of mesocyclonic shear, the rear flank downdraft and outflow boundaries that can lead to tornadogenesis. In several cases, evidence for diminishment of midlevel rotation and the descent of angular momentum from aloft is present prior to the appearance of the surface tornado. The relatively long lead time between the lighting jump and the occurrence of the tornado is attributed to the time lag between updraft invigoration and the boundary layer spin up of vorticity.

  8. Locating Initial Breakdown Pulses of Lightning Flashes

    NASA Astrophysics Data System (ADS)

    Karunarathne, S.; Marshall, T.; Stolzenburg, M.; Betz, H.; Wieczorek, G.

    2010-12-01

    Lightning flashes often begin with a series of bipolar pulses, 1-5 us in width, called initial breakdown pulses or characteristic pulses. In this presentation we show electric field change data of initial breakdown pulses collected with a network of 5 flat-plate antennas with a bandwidth of 0 - 5 MHz. These pulses were obtained at the NASA/Kennedy Space Center (KSC) during the summer of 2010. The (x, y, z, t) positions of these pulses have been determined using a time of arrival technique [Koshak and Solakiewicz, JGR, 1996] for several lightning flashes. In addition, we also collected magnetic field change data with a LINET system [e.g., Betz et al., GRL, 2004], which consisted of 7 crossed-loop sensors having a bandwidth of 5 - 200 kHz; the pulse locations detected by this system were also determined by time of arrival. The locations of the initial breakdown pulses from both systems will be compared to locations of VHF lightning sources made with the KSC LDAR2 system (with a center frequency of 63 MHz and a bandwidth of 6 MHz). Possible implications of the pulse locations derived from the three different sets of sensors on lightning initiation and propagation will be discussed.

  9. Lightning protection devices for high frequencies equipments

    SciTech Connect

    Pierre, J.

    1983-01-01

    Contents: Mechanism of a Lightning Stroke from Antenna to Ground; Principles of Protection Devices for Feeders; Electrical Characteristics of H.F. Protection Devices; Calculation of H.F. Protection Devices; Catalogue Devices for High Frequency Protection; Some Measurement Results for Tees; Measurement Results for Decoupling Line Devices; Installation of High Frequency Devices.

  10. Systems tunnel linear shaped charge lightning strike

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    Simulated lightning strike testing of the systems tunnel linear shaped charge (LSC) was performed at the Thiokol Lightning Test Complex in Wendover, Utah, on 23 Jun. 1989. The test article consisted of a 160-in. section of the LSC enclosed within a section of the systems tunnel. The systems tunnel was bonded to a section of a solid rocket motor case. All test article components were full scale. The systems tunnel cover of the test article was subjected to three discharges (each discharge was over a different grounding strap) from the high-current generator. The LSC did not detonate. All three grounding straps debonded and violently struck the LSC through the openings in the systems tunnel floor plates. The LSC copper surface was discolored around the areas of grounding strap impact, and arcing occurred at the LSC clamps and LSC ends. This test verified that the present flight configuration of the redesigned solid rocket motor systems tunnel, when subjected to simulated lightning strikes with peak current levels within 71 percent of the worst-case lightning strike condition of NSTS-07636, is adequate to prevent LSC ignition. It is therefore recommended that the design remain unchanged.

  11. The laser lightning rod system: thunderstorm domestication.

    PubMed

    Ball, L M

    1974-10-01

    An unusual application of the laser, namely protection of life and property from lightning, is described. The device relies on multiphoton ionization in mode-locked beams, rather than on collisional (avalanche) electron production. Feasibility is demonstrated numerically, and relevant principles explained. A method of mobile deployment is mentioned, by which economic (as opposed to scientific) feasibility might be achieved. PMID:20134678

  12. Lightning driven EMP in the upper atmosphere

    NASA Technical Reports Server (NTRS)

    Rowland, H. L.; Fernsler, R. F.; Huba, J. D.; Bernhardt, P. A.

    1995-01-01

    Large lightning discharges can drive electromagnetic pulses (EMP) that cause breakdown of the neutral atmosphere between 80 and 95 km leading to order of magnitude increases in the plasma density. The increase in the plasma density leads to increased reflection and absorption, and limits the pulse strength that propagates higher into the ionosphere.

  13. STS-135 Launch Pad Lightning Strike

    NASA Video Gallery

    A pair of lightning strikes occurred near launch pad 39-A at NASA's Kennedy Space Center at 12:31 p.m. and 12:40 p.m. EDT on July 7. The first struck the water tower 515 feet from the pad and the s...

  14. The laser lightning rod system: thunderstorm domestication.

    PubMed

    Ball, L M

    1974-10-01

    An unusual application of the laser, namely protection of life and property from lightning, is described. The device relies on multiphoton ionization in mode-locked beams, rather than on collisional (avalanche) electron production. Feasibility is demonstrated numerically, and relevant principles explained. A method of mobile deployment is mentioned, by which economic (as opposed to scientific) feasibility might be achieved.

  15. Lightning Pin Injection Testing on MOSFETS

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.; Koppen, Sandra V.; Mielnik, John J.; Vaughan, Roger K.; Wysocki, Philip F.; Celaya, Jose R.; Saha, Sankalita

    2009-01-01

    Lightning transients were pin-injected into metal-oxide-semiconductor field-effect transistors (MOSFETs) to induce fault modes. This report documents the test process and results, and provides a basis for subsequent lightning tests. MOSFETs may be present in DC-DC power supplies and electromechanical actuator circuits that may be used on board aircraft. Results show that unprotected MOSFET Gates are susceptible to failure, even when installed in systems in well-shielded and partial-shielded locations. MOSFET Drains and Sources are significantly less susceptible. Device impedance decreased (current increased) after every failure. Such a failure mode may lead to cascading failures, as the damaged MOSFET may allow excessive current to flow through other circuitry. Preliminary assessments on a MOSFET subjected to 20-stroke pin-injection testing demonstrate that Breakdown Voltage, Leakage Current and Threshold Voltage characteristics show damage, while the device continues to meet manufacturer performance specifications. The purpose of this research is to develop validated tools, technologies, and techniques for automated detection, diagnosis and prognosis that enable mitigation of adverse events during flight, such as from lightning transients; and to understand the interplay between lightning-induced surges and aging (i.e. humidity, vibration thermal stress, etc.) on component degradation.

  16. Killing effect of Ad5/F35-APE1 siRNA recombinant adenovirus in combination with hematoporphrphyrin derivative-mediated photodynamic therapy on human nonsmall cell lung cancer.

    PubMed

    Xia, Lei; Guan, Wei; Wang, Dong; Zhang, Yun-Song; Zeng, Lin-Li; Li, Zeng-Peng; Wang, Ge; Yang, Zhen-Zhou

    2013-01-01

    The main goal of this work is to investigate the killing effects and molecular mechanism of photodynamic therapy (PDT) mediated by the Ad5/F35-APE1 siRNA recombinant adenovirus in combination with a hematoporphrphyrin derivative (HpD) in the A549 human lung adenocarcinoma cell line in vitro to provide a theoretical reference for treating lung cancer by HpD-PDT. By using the technologies of MTT, flow cytometry, ELISA, and western blot, we observed that the proliferation inhibition and apoptosis of the A549 cells were significantly higher than the control group (P < 0.05) after HpD-PDT was performed. The inhibitory efficiency is dependent on the HpD concentration and laser intensity dose. The inhibitory effect on the proliferation of A549 cells of Ad5/F35-APE1 siRNA is more significant after combining with PDT, as indicated by a significant elevation of the intracellular ROS level and the expression of inflammatory factors (P < 0.05). The HpD-PDT-induced expression of the APE1 protein reached the peak after 24 h in A549 cells. The inhibition of APE1 expression in A549 cells was most significant after 48 hours of infection by Ad5/F35-APE1 siRNA recombinant adenovirus (10 MOI). In conclusion, the Ad5/F35-APE1 siRNA recombinant adenovirus could efficiently inhibit the HpD-PDT-induced APE1 expression hence could significantly enhance the killing effect of HpD-PDT in lung cancer cells.

  17. Lockheed P-38 Lightning in flight

    NASA Technical Reports Server (NTRS)

    1943-01-01

    The P-38 shown in this photo was one of the fighters built in the late 1930s and early 1940s that experienced compressibility effects. In steep dives, these aircraft could reach speeds above Mach 0.75 (called transonic). At transonic speeds, air in front of the wings became compressed and reached supersonic speeds as it flowed over the wings, forming a shock wave. This resulted in an increase in drag and a decrease in lift. Another result was the movement of the wing's center of lift to the rear, forcing the aircraft to rotate so that the nose moved downward and it went into a steep dive. Pilots found that that their aircraft would not pull out of this dive. When they attempted to pull out, they found the control stick, as one pilot put it, 'was cast in about two feet of concrete.' In some cases, the airplanes crashed or broke up in the denser air as they approached the ground. In other cases, the pilots were able to pull out of the dive. These accidents and near misses reinforced the popular belief in a 'sound barrier.' The need for data at speeds near that of sound and the inability of wind tunnels at the time to provide it would lead to the construction and flight of the X-1 and D-558 research aircraft. The Lockheed P-38 Lightning was one of the best-known Army Air Forces fighters that flew in World War II. It was already in mass production before the war started for the United States, and production lasted until 1945. With a wingspan of 52 feet; a length of 37 feet, 10 inches; and a height of 9 feet, 10 inches, the P-38s had maximum speeds ranging from 390 miles per hour for the basic P-38 to 414 mph for the P-38L. Except for the M model (a two-seater), all the P-38s were single-seat pursuit and long-range escort aircraft.

  18. Lightning and Sprite Detection from Internationa Space Station

    NASA Astrophysics Data System (ADS)

    Ushio, T.; Sato, M.; Morimoto, T.; Suzuki, M.; Yamazaki, A.; Hobara, Y.; Kikuchi, M.; Inan, U.; Linscott, I.; Kikuchi, H.; Takahashi, Y.; Adachi, T.

    2014-12-01

    Lightning and Sprite detection technique from International Space Station (ISS) and its scientific results are presented. Global Lightning and Sprite Measurements from ISS is a mission to observe lightning and sprite from CMOS camera, Photometer, VLF and VHF interferometeric measurements as a part of the multi-mission consolidated equipment on Japanese Exposure Module. In this mission, CMOS cameras measure the optical emissions from sprite at 762 nm and lightning at 740-830 nm in order to discriminate lightning and sprite signals. Photometeric measurements at six channels (150-280 nm , 337+/-5 nm, 762+/-5 nm, 600-900 nm, 316+/-5 nm, 392+/-5 nm) also provide information on the detection and identification of sprite and lightning process. From these measurements, global distribution of sprite has been derived and some implications to discriminate ground and cloud flashes from space borne platforms are presented. VLFR measurements on GLIMS adds information on the charge moment of the parent lightning based on the whistler wave of the VLF waves that the lightning generates. While VLF observation does not locate the sources of the radiation, VLFR serves an important role as a bridge in coupling the occurrence of TLEs to lightning. The VHF measurements consists of two antennas and from this observation with photometric measurements, location of VHF emission from lightning from space station was successful for the first time. In this presentation, mission overview and some scientific results are briefly summarized using these equipments.

  19. Lightning Sensors for Observing, Tracking and Nowcasting Severe Weather

    PubMed Central

    Price, Colin

    2008-01-01

    Severe and extreme weather is a major natural hazard all over the world, often resulting in major natural disasters such as hail storms, tornados, wind storms, flash floods, forest fires and lightning damages. While precipitation, wind, hail, tornados, turbulence, etc. can only be observed at close distances, lightning activity in these damaging storms can be monitored at all spatial scales, from local (using very high frequency [VHF] sensors), to regional (using very low frequency [VLF] sensors), and even global scales (using extremely low frequency [ELF] sensors). Using sensors that detect the radio waves emitted by each lightning discharge, it is now possible to observe and track continuously distant thunderstorms using ground networks of sensors. In addition to the number of lightning discharges, these sensors can also provide information on lightning characteristics such as the ratio between intra-cloud and cloud-to-ground lightning, the polarity of the lightning discharge, peak currents, charge removal, etc. It has been shown that changes in some of these lightning characteristics during thunderstorms are often related to changes in the severity of the storms. In this paper different lightning observing systems are described, and a few examples are provided showing how lightning may be used to monitor storm hazards around the globe, while also providing the possibility of supplying short term forecasts, called nowcasting.

  20. Using lightning observations as a volcanic eruption monitoring tool

    NASA Astrophysics Data System (ADS)

    Behnke, Sonja A.; McNutt, Stephen R.

    2014-08-01

    Lightning commonly occurs in the eruption columns produced by explosive volcanic eruptions. There are several different kinds of lightning detection instruments that could be employed to help monitor volcanoes, each with their own advantages and disadvantages. Very low frequency (VLF) instruments have the ability to detect lightning at long ranges but tend to have low sensitivity due to network geometry and typically can provide only the time and 2-D location of a cloud-to-ground return stroke or similar high-amplitude pulse produced by an intracloud discharge. Low frequency (LF) and medium frequency (MF) instruments typically have more sensitivity than a VLF network but can only be used for detection on a regional scale. Very high frequency (VHF) lightning mapping instruments also provide only regional coverage but detect all lightning within their range. During the 2009 eruption of Redoubt Volcano, Alaska, USA, each of these types of instruments detected lightning from Redoubt's ash plume. The VHF system consistently detected lightning before the other two during each distinct explosive event and also detected more lightning than the others, by one or two orders of magnitude. Lightning observations could be used to confirm, and in some cases, detect explosive volcanic activity. The rapid response provided by lightning monitoring is a valuable tool for fast identification of potentially hazardous ash clouds.

  1. Characteristics of TLE-producing lightning in a coastal thunderstorm

    NASA Astrophysics Data System (ADS)

    Chang, Shu-Chun; Hsu, Rue-Ron; Huang, Sung-Ming; Su, Han-Tzong; Kuo, Cheng-Ling; Chou, Jung-Kung; Lee, Li-Jou; Wu, Yeng-Jung; Chen, Alfred B.

    2014-11-01

    Observing from southern Taiwan on 2 August 2010, a thunderstorm near Luzon Island, Philippines, about 500 km away was found to produce 72 transient luminous events (TLEs). Besides optical images, ULF and VLF sferics of lightning from this thunderstorm were also recorded. This work examines the characteristics of TLE-producing lightning through studying their ULF and VLF sferics. The attenuation of ULF and VLF sferics in the Earth cavity is obtained through analyzing the sferics associated with Imager of Sprite and Upper Atmospheric Lightning elves that occurred within ~1500 km of Taiwan. Amplitudes of the ULF and the VLF sferics are found to vary as D-0.871 and D-1.207, respectively, where D is the source distance from the sferic stations. After normalizing the sferics from the 2 August 2010 storm to 500 km distance, the ratio of the peak ULF and the VLF magnetic fields is found to be distinct for different TLE-producing lightning. The ratio for the halo-producing lightning is nearly 3 times that of the elve-producing lightning, but it is comparable to that of the halo-sprite-producing lightning, although the ULF strength for the halo-sprite lightning is significantly larger than that for the halo lightning. Therefore, it is possible to distinguish between the TLE-types using the ULF to VLF peak ratio or the strength of ULF/VLF band emissions of the parent lightning. Comparison of numerically simulated and the observed lightning radiation fields indicates that the best fit discharge time of the elve lightning is about 100 µs, while that for the halo-producing lightning is between 200 and 500 µs.

  2. Assessing Operational Total Lightning Visualization Products

    NASA Technical Reports Server (NTRS)

    Stano, Geoffrey T.; Darden, Christopher B.; Nadler, David J.

    2010-01-01

    In May 2003, NASA's Short-term Prediction Research and Transition (SPoRT) program successfully provided total lightning data from the North Alabama Lightning Mapping Array (NALMA) to the National Weather Service (NWS) office in Huntsville, Alabama. The major accomplishment was providing the observations in real-time to the NWS in the native Advanced Weather Interactive Processing System (AWIPS) decision support system. Within days, the NALMA data were used to issue a tornado warning initiating seven years of ongoing support to the NWS' severe weather and situational awareness operations. With this success, SPoRT now provides real-time NALMA data to five forecast offices as well as working to transition data from total lightning networks at Kennedy Space Center and the White Sands Missile Range to the surrounding NWS offices. The only NALMA product that has been transitioned to SPoRT's partner NWS offices is the source density product, available at a 2 km resolution in 2 min intervals. However, discussions with users of total lightning data from other networks have shown that other products are available, ranging from spatial and temporal variations of the source density product to the creation of a flash extent density. SPoRT and the Huntsville, Alabama NWS are evaluating the utility of these variations as this has not been addressed since the initial transition in 2003. This preliminary analysis will focus on what products will best support the operational warning decision process. Data from 19 April 2009 are analyzed. On this day, severe thunderstorms formed ahead of an approaching cold front. Widespread severe weather was observed, primarily south of the Tennessee River with multiple, weak tornadoes, numerous severe hail reports, and wind. This preliminary analysis is the first step in evaluation which product(s) are best suited for operations. The ultimate goal is selecting a single product for use with all total lightning networks to streamline training and

  3. Acute transient hemiparesis induced by lightning strike.

    PubMed

    Rahmani, Seyed Hesam; Faridaalaee, Gholamreza; Jahangard, Samira

    2015-07-01

    According to data from the National Oceanic and Atmospheric Administration,in the years from 1959 to 1994, lightning was responsible for more than 3000 deaths and nearly 10,000 casualties. The most important characteristic features of lightning injuries are multisystem involvement and widely variable severity. Lightning strikes are primarily a neurologic injury that affects all 3 components of the nervous system: central, autonomic,and peripheral. Neurologic complications of lightning strikes vary from transient benign symptoms to permanent disability. Many patients experience a temporary paralysis called keraunoparalysis. Here we reported a 22-year-old mountaineer man with complaining of left sided hemiparesis after being hit by a lightning strike in the mountain 3 hours ago. There was no loss of consciousness at hitting time. On arrival the patient was alert, awake and hemodynamically stable. In neurologic examination cranial nerves were intact, left sided upper and lower extremity muscle force was I/V with a combination of complete sensory loss, and right-sided muscle force and sensory examination were normal. There is not any evidence of significant vascular impairment in the affected extremities. Brain MRI and CT scan and cervical MRI were normal. During 2 days of admission, with intravenous hydration, heparin 5000 unit SC q12hr and physical therapy of the affected limbs, motor and sensory function improved and was normal except mild paresthesia. He was discharged 1 day later for outpatient follow up while vitamin B1 100mg orally was prescribed.Paresthesia improved after 3 days without further sequels. PMID:25650360

  4. Acute transient hemiparesis induced by lightning strike.

    PubMed

    Rahmani, Seyed Hesam; Faridaalaee, Gholamreza; Jahangard, Samira

    2015-07-01

    According to data from the National Oceanic and Atmospheric Administration,in the years from 1959 to 1994, lightning was responsible for more than 3000 deaths and nearly 10,000 casualties. The most important characteristic features of lightning injuries are multisystem involvement and widely variable severity. Lightning strikes are primarily a neurologic injury that affects all 3 components of the nervous system: central, autonomic,and peripheral. Neurologic complications of lightning strikes vary from transient benign symptoms to permanent disability. Many patients experience a temporary paralysis called keraunoparalysis. Here we reported a 22-year-old mountaineer man with complaining of left sided hemiparesis after being hit by a lightning strike in the mountain 3 hours ago. There was no loss of consciousness at hitting time. On arrival the patient was alert, awake and hemodynamically stable. In neurologic examination cranial nerves were intact, left sided upper and lower extremity muscle force was I/V with a combination of complete sensory loss, and right-sided muscle force and sensory examination were normal. There is not any evidence of significant vascular impairment in the affected extremities. Brain MRI and CT scan and cervical MRI were normal. During 2 days of admission, with intravenous hydration, heparin 5000 unit SC q12hr and physical therapy of the affected limbs, motor and sensory function improved and was normal except mild paresthesia. He was discharged 1 day later for outpatient follow up while vitamin B1 100mg orally was prescribed.Paresthesia improved after 3 days without further sequels.

  5. Bringing Thunder and Lightning Indoors

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Piezoelectric materials convert mechanical energy into electrical energy and electrical energy into mechanical energy. They generate electrical charges in response to mechanical stress and generate mechanical displacement and/or force when subjected to an electric current. Scientists at Langley Research Center have developed a piezoelectric device that is superior in many ways to those that used to be the only ones commercially available. It is tougher, has far greater displacement and greater mechanical load capacity for a comparative voltage operation, can be easily produced at a relatively low cost, and lends itself well to mass production. The NASA-developed piezoelectric device is also unique in that it is more efficient in extracting electrical energy from the mechanical energy that goes in. It works on a simple principle. A thin ceramic piezoelectric wafer is sandwiched between an aluminum sheet and a steel sheet and held together with LaRC-SI, an amorphous thermoplastic adhesive with special properties created by NASA at Langley. The sandwich is heated in an autoclave, and the adhesive melts. When the sandwich cools, the adhesive bonds the parts together into one piezoelectric element. While they cool, the components of the element contract at different rates, since they are made of different materials. This differential shrinkage causes the element to warp in either a convex or concave shape, depending on which way it is oriented. The shrinking of the outside metal layers places the inside piezoelectric ceramic under mechanical stress. If the element is cantilevered by clamping one side and then plucked, it reverberates like a diving board that has just ejected a diver. This way, a small amount of mechanical energy can result in a relatively long period of electrical generation. When the piezoelectric element is used for the creation of electricity, it is called Lightning. This same sandwiched piezoelectric wafer can also convert electrical energy into

  6. A Field Study of Lightning Surges Propagating through Low-voltage Electric Appliances

    NASA Astrophysics Data System (ADS)

    Ishii, Tsunayoshi; Sakamoto, Yoshiki; Oguchi, Shuichi; Okabe, Shigemitsu

    In today's highly information-based society, lightning damage has a significant impact on an increasing number of electric appliances such as personal computers and facsimile machines. Lightning surge protection devices for electric appliances are on the market and concern for lightning protection has been increasing, but there are still many unknown aspects of lightning surges that propagate into residences. To provide effective lightning protection measures, clarification of surge propagation patterns is needed. The Tokyo Electric Power Company has observed the patterns of lightning surge propagation into houses using lightning surge waveform detectors installed at ordinary residences and obtained data on 30 lightning surge current waveforms between 2008 and 2009. This paper discusses various aspects of lightning surge currents propagating into low-voltage appliances, including home electric appliances, based on the lightning surge current waveform data obtained from lightning observations. The result revealed the patterns of lightning surge currents propagating into the ground and lines of low-voltage appliances.

  7. Velocity and Current of Lightning Sprites

    NASA Astrophysics Data System (ADS)

    Rai, J.; Paras, M. K.

    2010-12-01

    Lightning Sprites are the recently discovered upper atmospheric discharges which occur in the mesospheric region. Sentman et al., [1995], Cummer et al., [1998] and other workers have done experimental studies on lightning sprites from ground based and airborne instruments. Cummer et al. [1998] measured the luminosity and current moment due to lightning sprites. The purpose of the present paper is to find the expressions for velocity and current of lightning sprites from which the current moment, charge moment change and ELF/VLF spectrum can be obtained. From the knowledge of variation of luminosity the temperature of sprites has been estimated. The variation of breakdown electric field above the thundercloud has been taken from Gurevich et al. [2001]. Further, the propagation of lightning in the form of potential gradient waves [Rai, 1978] has been taken into account and the expression for velocity of lightning sprites has been obtained, which is given by V(t)=V0e-b(t-a)2 Where, V0 = 3×107 ms-1; b=5.1×105 s-1; and a=2.04×10-3 s. The double exponential current expression which has been considered here is given by i(t)=i0(e-γt-e-δt) Where, γ and δ are the rising and decaying coefficients and i0 corresponds to the peak value of current. Three cases have been discussed for peak values of sprite current i.e. 3.3, 6 and 8 kA. The calculated values of current moment correspond to the experimental observations of Cummer et al. [1998]. The total charge moment change has also obtained . These values are within the range of values of charge moment change for sprites reported by other workers. Our calculation for deceleration rate (0.9×1010 ms-2) of sprite velocity comes out to be in accordance with the observations (1×1010 ms-2) of Li et al. [2009]. Cummer et al., [1998], Stanley et al. [1999] and other various workers have found from their experimental observation that the peak radiation occurs from lightning sprites only in the ELF region and radiation in VLF

  8. Burning molten metallic spheres: One class of ball lightning?

    NASA Astrophysics Data System (ADS)

    Stephan, Karl D.; Massey, Nathan

    2008-08-01

    Abrahamson and Dinniss [2000. Ball lightning caused by oxidation of nanoparticle networks from normal lightning strikes on soil. Nature 403, 519-521] proposed a theory of ball lighting in which silicon nanoparticles undergo slow oxidation and emit light. Paiva et al. [2007. Production of ball-lightning-like luminous balls by electrical discharges in silicon. Physical Review Letters 98, 048501] reported that an electric arc to silicon produced long-lasting luminous white spheres showing many characteristics of ball lightning. We show experimentally that these consist of burning molten silicon spheres with diameters in the 0.1-1 mm range. The evidence of our experiments leads us to propose that a subset of ball lightning events may consist of macro-scale molten spheres of burning metallic materials likely to be ejected from a conventional lightning strike to earth.

  9. Doppler radar echoes of lightning and precipitation at vertical incidence

    NASA Technical Reports Server (NTRS)

    Zrnic, D. S.; Rust, W. D.; Taylor, W. L.

    1982-01-01

    Digital time series data at 16 heights within two storms were collected at vertical incidence with a 10-cm Doppler radar. On several occasions during data collection, lightning echoes were observed as increased reflectivity on an oscilloscope display. Simultaneously, lightning signals from nearby electric field change antennas were recorded on an analog recorder together with the radar echoes. Reflectivity, mean velocity, and Doppler spectra were examined by means of time series analysis for times during and after lightning discharges. Spectra from locations where lightning occurred show peaks, due to the motion of the lightning channel at the air speed. These peaks are considerably narrower than the ones due to precipitation. Besides indicating the vertical air velocity that can then be used to estimate hydrometeor-size distribution, the lightning spectra provide a convenient means to estimate the radar cross section of the channel. Subsequent to one discharge, we deduce that a rapid change in the orientation of hydrometeors occurred within the resolution volume.

  10. Weekly Cycle of Lightning: Evidence of Storm Invigoration by Pollution

    NASA Technical Reports Server (NTRS)

    Bell, Thomas L.; Rosenfeld, Daniel; Kim, Kyu-Myong

    2009-01-01

    We have examined summertime 1998 2009 U.S. lightning data from the National Lightning Detection Network (NLDN) to look for weekly cycles in lightning activity. As was found by Bell et al. (2008) for rain over the southeast U.S., there is a significant weekly cycle in afternoon lightning activity that peaks in the middle of the week there. The weekly cycle appears to be reduced over population centers. Lightning activity peaks on weekends over waters near the SE U.S. The statistical significance of weekly cycles over the western half of the country is generally small. We found no evidence of a weekly cycle of synoptic-scale forcing that might explain these patterns. The lightning behavior is entirely consistent with the explanation suggested by Bell et al. (2008) for the cycles in rainfall and other atmospheric data from the SE U.S., that aerosols can cause storms to intensify in humid, convectively unstable environments.

  11. Lightning-associated deaths--United States, 1980-1995.

    PubMed

    1998-05-22

    A lightning strike can cause death or various injuries to one or several persons. The mechanism of injury is unique, and the manifestations differ from those of other electrical injuries. In the United States, lightning causes more deaths than do most other natural hazards (e.g., hurricanes and tornadoes), although the incidence of lightning-related deaths has decreased since the 1950s. The cases described in this report illustrate diverse circumstances in which deaths attributable to lightning can occur. This report also summarizes data from the Compressed Mortality File of CDC's National Center for Health Statistics on lightning fatalities in the United States from 1980 through 1995, when 1318 deaths were attributed to lightning.

  12. Objective Lightning Probability Forecasting for Kennedy Space Center and Cape Canaveral Air Force Station, Phase III

    NASA Technical Reports Server (NTRS)

    Crawford, Winifred C.

    2010-01-01

    The AMU created new logistic regression equations in an effort to increase the skill of the Objective Lightning Forecast Tool developed in Phase II (Lambert 2007). One equation was created for each of five sub-seasons based on the daily lightning climatology instead of by month as was done in Phase II. The assumption was that these equations would capture the physical attributes that contribute to thunderstorm formation more so than monthly equations. However, the SS values in Section 5.3.2 showed that the Phase III equations had worse skill than the Phase II equations and, therefore, will not be transitioned into operations. The current Objective Lightning Forecast Tool developed in Phase II will continue to be used operationally in MIDDS. Three warm seasons were added to the Phase II dataset to increase the POR from 17 to 20 years (1989-2008), and data for October were included since the daily climatology showed lightning occurrence extending into that month. None of the three methods tested to determine the start of the subseason in each individual year were able to discern the start dates with consistent accuracy. Therefore, the start dates were determined by the daily climatology shown in Figure 10 and were the same in every year. The procedures used to create the predictors and develop the equations were identical to those in Phase II. The equations were made up of one to three predictors. TI and the flow regime probabilities were the top predictors followed by 1-day persistence, then VT and Ll. Each equation outperformed four other forecast methods by 7-57% using the verification dataset, but the new equations were outperformed by the Phase II equations in every sub-season. The reason for the degradation may be due to the fact that the same sub-season start dates were used in every year. It is likely there was overlap of sub-season days at the beginning and end of each defined sub-season in each individual year, which could very well affect equation

  13. The impact of lightning on tropospheric ozone chemistry using a new global lightning parametrisation

    NASA Astrophysics Data System (ADS)

    Finney, D. L.; Doherty, R. M.; Wild, O.; Abraham, N. L.

    2016-06-01

    A lightning parametrisation based on upward cloud ice flux is implemented in a chemistry-climate model (CCM) for the first time. The UK Chemistry and Aerosols model is used to study the impact of these lightning nitric oxide (NO) emissions on ozone. Comparisons are then made between the new ice flux parametrisation and the commonly used, cloud-top height parametrisation. The ice flux approach improves the simulation of lightning and the temporal correlations with ozone sonde measurements in the middle and upper troposphere. Peak values of ozone in these regions are attributed to high lightning NO emissions. The ice flux approach reduces the overestimation of tropical lightning apparent in this CCM when using the cloud-top approach. This results in less NO emission in the tropical upper troposphere and more in the extratropics when using the ice flux scheme. In the tropical upper troposphere the reduction in ozone concentration is around 5-10 %. Surprisingly, there is only a small reduction in tropospheric ozone burden when using the ice flux approach. The greatest absolute change in ozone burden is found in the lower stratosphere, suggesting that much of the ozone produced in the upper troposphere is transported to higher altitudes. Major differences in the frequency distribution of flash rates for the two approaches are found. The cloud-top height scheme has lower maximum flash rates and more mid-range flash rates than the ice flux scheme. The initial Ox (odd oxygen species) production associated with the frequency distribution of continental lightning is analysed to show that higher flash rates are less efficient at producing Ox; low flash rates initially produce around 10 times more Ox per flash than high-end flash rates. We find that the newly implemented lightning scheme performs favourably compared to the cloud-top scheme with respect to simulation of lightning and tropospheric ozone. This alternative lightning scheme shows spatial and temporal differences in

  14. Chasing Lightning: Sferics, Tweeks and Whistlers

    NASA Astrophysics Data System (ADS)

    Webb, P. A.; Franzen, K.; Garcia, L.; Schou, P.; Rous, P.

    2008-12-01

    We all know what lightning looks like during a thunderstorm, but the visible flash we see is only part of the story. This is because lightning also generates light with other frequencies that we cannot perceive with our eyes, but which are just as real as visible light. Unlike the visible light from lightning, these other frequencies can carry the lightning's energy hundreds or thousands of miles across the surface of the Earth in the form of special signals called "tweeks" and "sferics". Some of these emissions can even travel tens of thousands of miles out into space before returning to the Earth as "whistlers". The INSPIRE Project, Inc is a non-profit scientific and educational corporation whose beginning mission was to bring the excitement of observing these very low frequency (VLF) natural radio waves emissions from lightning to high school students. Since 1989, INSPIRE has provided specially designed radio receiver kits to over 2,600 participants around the world to make observations of signals in the VLF frequency range. Many of these participants are using the VLF data they collect in very creative projects that include fiction, music and art exhibitions. During the Fall 2008 semester, the first INSPIRE based university-level course was taught at University of Maryland Baltimore County (UMBC) as part of its First-Year Seminar (FYS) series. The FYS classes are limited to 20 first-year students per class and are designed to create an active-learning environment that encourages student participation and discussion that might not otherwise occur in larger first-year classes. This presentation will cover the experiences gained from using the INSPIRE kits as the basis of a university course. This will include the lecture material that covers the basic physics of lightning, thunderstorms and the Earth's atmosphere, as well as the electronics required to understand the basic workings of the VLF kit. It will also cover the students assembly of the kit in an

  15. Plume Dynamics, Turbulence and Volcanic Lightning

    NASA Astrophysics Data System (ADS)

    Behnke, S. A.; Bruning, E. C.

    2014-12-01

    Volcanic lightning observations made with the Lightning Mapping Array (LMA) from the 2009 eruption of Redoubt Volcano, Alaska, USA are used to probe the kinematic structure of a volcanic eruption column. Bruning and MacGorman (2013) used lightning flash energy spectra to show that the electrical and kinematic components of a thunderstorm may be coupled. They found that the flash energy spectra showed a 5/3 slope over length scales consistent with the turbulent kinetic energy inertial subrange expected for thunderstorms. They proposed that turbulence may influence the charge distribution in a cloud by advecting charge-bearing precipitation, which would affect flash rate and size. This analysis has now been applied to the lightning storms that occurred during the series of explosive eruptive events in the 2009 Redoubt eruption. Results show that the spectral shape of the volcanic lightning changed over the course of the storms. While volcanic forcing was active the flash energy was concentrated at small flash sizes and the spectra did not have the 5/3 spectral shape at the scales observed by Bruning and MacGorman (2013). 5-10 minutes after the volcanic forcing ended, the spectra transitioned a shape similar to their observations. This delay was inferred to be a relaxation period where the volcanic flow began to equilibrate to and blend with the background atmospheric flow. The lack of a 5/3 spectrum during the period of volcanic forcing could be because the inertial range of the plumes was on scales smaller than the detection limit of the LMA. Alternatively, this may be due to the nature of the forcing. The turbulent volcanic forcing was highly impulsive and short duration compared to the supercell thunderstorms studied by Bruning and MacGorman, which would have been in a quasi-steady state. The 5/3 spectrum represents an equilibrium where energy is transferred from an energy-maximum integral length scale down to the inertial range. Therefore, we would not expect to

  16. GOES-R Geostationary Lightning Mapper Performance Specifications and Algorithms

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Goodman, Steven J.; Blakeslee, Richard J.; Koshak, William J.; Petersen, William A.; Boldi, Robert A.; Carey, Lawrence D.; Bateman, Monte G.; Buchler, Dennis E.; McCaul, E. William, Jr.

    2008-01-01

    The Geostationary Lightning Mapper (GLM) is a single channel, near-IR imager/optical transient event detector, used to detect, locate and measure total lightning activity over the full-disk. The next generation NOAA Geostationary Operational Environmental Satellite (GOES-R) series will carry a GLM that will provide continuous day and night observations of lightning. The mission objectives for the GLM are to: (1) Provide continuous, full-disk lightning measurements for storm warning and nowcasting, (2) Provide early warning of tornadic activity, and (2) Accumulate a long-term database to track decadal changes of lightning. The GLM owes its heritage to the NASA Lightning Imaging Sensor (1997- present) and the Optical Transient Detector (1995-2000), which were developed for the Earth Observing System and have produced a combined 13 year data record of global lightning activity. GOES-R Risk Reduction Team and Algorithm Working Group Lightning Applications Team have begun to develop the Level 2 algorithms and applications. The science data will consist of lightning "events", "groups", and "flashes". The algorithm is being designed to be an efficient user of the computational resources. This may include parallelization of the code and the concept of sub-dividing the GLM FOV into regions to be processed in parallel. Proxy total lightning data from the NASA Lightning Imaging Sensor on the Tropical Rainfall Measuring Mission (TRMM) satellite and regional test beds (e.g., Lightning Mapping Arrays in North Alabama, Oklahoma, Central Florida, and the Washington DC Metropolitan area) are being used to develop the prelaunch algorithms and applications, and also improve our knowledge of thunderstorm initiation and evolution.

  17. Feasibility study for a future Austrian lightning nano-satellite

    NASA Astrophysics Data System (ADS)

    Schwingenschuh, Konrad; Jaffer, Ghulam; Koudelka, O.; Khan, S.; Grant, C.; Unterberger, M.; Lichtenegger, Herbert; Macher, W.; Hausleitner, W.

    A feasibility study for an Austrian lightning nano-satellite is presented. The satellite will carry a radio-frequency receiver payload for the investigation of electromagnetic signatures produced by lightning strokes. A special emphasis will be on the investigation of transient electromagnetic waves in VHF range (20-40MHz) known as sferics. The onboard RF lightning triggering system will be a special capability of the nano-satellite. The lightning experiment will also observe VHF signals of ionospheric and magnetospheric origin. Adaptive filters will be developed to differentiate terrestrial electromagnetic impulsive signals from ionospheric or magnetospheric signals. One of the major problems using a nano-satellite is to integrate the lightning experiment antenna, receiver and data acquisition unit into the nano-satellite structure. Using a gravity gradient boom as a lightning antenna can increase the sensitivity and directional capability. A major part of this study is devoted to the design of a combined gravity-gradient boom and a sferics antenna. The compact structure of a nano-satellite faces special EMC issues e.g., impulsive electromagnetic events from DC converters. The low power and mass budget of a nano-satellite requires merging of the satellite housekeeping and lightning experiment units. The Lightning nano-satellite team has participated in various space missions (HUYGENS, DEMETER, PHOBOS, CLUSTER) investigating electromagnetic phenomena. The data of these missions will be used to test the hardand software of the lightning experiment before the launch. Further tests with a satellite mock-up, high frequency electronics and gravity gradient boom acting as lightning antenna will be carried out in a high voltage chamber, where artificial lightning can be generated. Additionally ground based and balloon-borne tests are planned with the satellite engineering model using terrestrial lightning.

  18. Lightning production of hydrocarbons and HCN on Titan - Laboratory measurements

    NASA Technical Reports Server (NTRS)

    Borucki, W. J.; Giver, L. P.; Mckay, C. P.; Scattergood, T.; Parris, J. E.

    1988-01-01

    Experimental measurements have been obtained for the chemical yields of hydrogen cyanide, acetylene, ethylene, ethane, and propane from simulated lightning discharges, in order to ascertain whether lightning in the troposphere of Titan may be contributing to the hydrocarbon inventory. A comparison of these results with those obtained on the basis of thermodynamic equilibrium considerations shows substantial discrepancies and implies that thermodynamic equilibrium theories are inadequate. The production of ethylene by lightning and its subsequent stratospheric diffusion nevertheless appears to be one reasonable mechanism.

  19. Lightning Injuries-Who Is at Greatest Risk?

    PubMed

    Cherington, M; Vervalin, C

    1990-08-01

    In brief A bicyclist was struck by lightning after he sought shelter under an isolated tree. He suffered spinal cord and peripheral nerve injury, but eventually was able to walk with the aid of a walker. The sports activities that are associated with the highest number of lightning injuries and deaths are water sports, golf, camping, hiking, baseball, and football. Athletes and outdoor recreationists should know how to reduce their risk of injury during a lightning storm.

  20. Engineering work plan tank farm lightning mitigation system

    SciTech Connect

    Jones, F.M., Fluor Daniel Hanford

    1997-02-10

    This Engineering Work Plan defines the scope, function and design criteria, and installation activities that will be provided in support of the Tank Farm Lightning Mitigation System. The Tank Farm Lightning Mitigation System is comprised of two tasks, the light pole air terminal design and the tank riser bonding design. Air terminals, riser and riser flange bonding system will be designed and installed to mitigate the effect of lightning strikes in single shell tank farms with watchlist tanks.

  1. Toward Application of Lightning Observations to Weather Forecasts and Warnings

    NASA Astrophysics Data System (ADS)

    Macgorman, D. R.

    2002-12-01

    Once lightning mapping systems became fast enough to locate lightning in real or near-real time, it became possible to consider applications of lightning data to weather operations. The first system to be used routinely in such a way was the LLP direction-finder network deployed around 1980 by the Bureau of Land Management to help detect range and forest fires started by cloud-to-ground lightning. In 1987, a federal interagency group collaborated with the State University of New York at Albany to put together a trial National Lightning Detection Network for a three-year evaluation of possible applications to weather operations. During this trial, the National Weather Service determined that the lightning ground-strike data are useful for detecting the presence, configuration, and evolution of storms and storm systems, and so subsequently procured lightning strike mapping data for federal use that has continued to the present. Research since then has suggested that detection of positive cloud-to-ground lightning may also be useful, when combined with radar data, to help identify some severe storms, though the conditions under which this is possible are still being investigated. Furthermore, cloud-to-ground flash data can be assimilated into forecast models to improve the initial conditions, and hence the forecasts, of the models. More recently technology has advanced to the point that mapping all types of lightning is feasible. Because typically more than 70% of the lightning flashes produced by a storm do not strike ground, such technologies, at a minimum, would increase sampling rates to identify thunderstorms more quickly and reliably. However, different types of lightning also provide different information about storms. Cloud-to-ground lightning tends to indicate the formation and descent of precipitation, while cloud flash rates appear to be associated more closely with updraft and graupel evolution. Research is underway to determine and quantify these

  2. Lightning Strike Induced Damage Mechanisms of Carbon Fiber Composites

    NASA Astrophysics Data System (ADS)

    Kawakami, Hirohide

    Composite materials have a wide application in aerospace, automotive, and other transportation industries, because of the superior structural and weight performances. Since carbon fiber reinforced polymer composites possess a much lower electrical conductivity as compared to traditional metallic materials utilized for aircraft structures, serious concern about damage resistance/tolerance against lightning has been rising. Main task of this study is to clarify the lightning damage mechanism of carbon fiber reinforced epoxy polymer composites to help further development of lightning strike protection. The research on lightning damage to carbon fiber reinforced polymer composites is quite challenging, and there has been little study available until now. In order to tackle this issue, building block approach was employed. The research was started with the development of supporting technologies such as a current impulse generator to simulate a lightning strike in a laboratory. Then, fundamental electrical properties and fracture behavior of CFRPs exposed to high and low level current impulse were investigated using simple coupon specimens, followed by extensive parametric investigations in terms of different prepreg materials frequently used in aerospace industry, various stacking sequences, different lightning intensity, and lightning current waveforms. It revealed that the thermal resistance capability of polymer matrix was one of the most influential parameters on lightning damage resistance of CFRPs. Based on the experimental findings, the semi-empirical analysis model for predicting the extent of lightning damage was established. The model was fitted through experimental data to determine empirical parameters and, then, showed a good capability to provide reliable predictions for other test conditions and materials. Finally, structural element level lightning tests were performed to explore more practical situations. Specifically, filled-hole CFRP plates and patch

  3. Ball lightning caused by oxidation of nanoparticle networks from normal lightning strikes on soil

    PubMed

    Abrahamson; Dinniss

    2000-02-01

    Observations of ball lightning have been reported for centuries, but the origin of this phenomenon remains an enigma. The 'average' ball lightning appears as a sphere with a diameter of 300 mm, a lifetime of about 10 s, and a luminosity similar to a 100-W lamp. It floats freely in the air, and ends either in an explosion, or by simply fading from view. It almost invariably occurs during stormy weather. Several energy sources have been proposed to explain the light, but none of these models has succeeded in explaining all of the observed characteristics. Here we report a model that potentially accounts for all of those properties, and which has some experimental support. When normal lightning strikes soil, chemical energy is stored in nanoparticles of Si, SiO or SiC, which are ejected into the air as a filamentary network. As the particles are slowly oxidized in air, the stored energy is released as heat and light. We investigated this basic process by exposing soil samples to a lightning-like discharge, which produced chain aggregates of nanoparticles: these particles oxidize at a rate appropriate for explaining the lifetime of ball lightning.

  4. Lightning Radio Source Retrieval Using Advanced Lightning Direction Finder (ALDF) Networks

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Blakeslee, Richard J.; Bailey, J. C.

    1998-01-01

    A linear algebraic solution is provided for the problem of retrieving the location and time of occurrence of lightning ground strikes from an Advanced Lightning Direction Finder (ALDF) network. The ALDF network measures field strength, magnetic bearing and arrival time of lightning radio emissions. Solutions for the plane (i.e., no Earth curvature) are provided that implement all of tile measurements mentioned above. Tests of the retrieval method are provided using computer-simulated data sets. We also introduce a quadratic planar solution that is useful when only three arrival time measurements are available. The algebra of the quadratic root results are examined in detail to clarify what portions of the analysis region lead to fundamental ambiguities in source location. Complex root results are shown to be associated with the presence of measurement errors when the lightning source lies near an outer sensor baseline of the ALDF network. In the absence of measurement errors, quadratic root degeneracy (no source location ambiguity) is shown to exist exactly on the outer sensor baselines for arbitrary non-collinear network geometries. The accuracy of the quadratic planar method is tested with computer generated data sets. The results are generally better than those obtained from the three station linear planar method when bearing errors are about 2 deg. We also note some of the advantages and disadvantages of these methods over the nonlinear method of chi(sup 2) minimization employed by the National Lightning Detection Network (NLDN) and discussed in Cummins et al.(1993, 1995, 1998).

  5. Ball lightning caused by oxidation of nanoparticle networks from normal lightning strikes on soil

    PubMed

    Abrahamson; Dinniss

    2000-02-01

    Observations of ball lightning have been reported for centuries, but the origin of this phenomenon remains an enigma. The 'average' ball lightning appears as a sphere with a diameter of 300 mm, a lifetime of about 10 s, and a luminosity similar to a 100-W lamp. It floats freely in the air, and ends either in an explosion, or by simply fading from view. It almost invariably occurs during stormy weather. Several energy sources have been proposed to explain the light, but none of these models has succeeded in explaining all of the observed characteristics. Here we report a model that potentially accounts for all of those properties, and which has some experimental support. When normal lightning strikes soil, chemical energy is stored in nanoparticles of Si, SiO or SiC, which are ejected into the air as a filamentary network. As the particles are slowly oxidized in air, the stored energy is released as heat and light. We investigated this basic process by exposing soil samples to a lightning-like discharge, which produced chain aggregates of nanoparticles: these particles oxidize at a rate appropriate for explaining the lifetime of ball lightning. PMID:10676954

  6. Nowcasting of Lightning-Related Accidents in Africa

    NASA Astrophysics Data System (ADS)

    Ihrlich, Laura; Price, Colin

    2016-04-01

    Tropical Africa is the world capital of thunderstorm activity with the highest density of strikes per square kilometer per year. As a result it is also the continent with perhaps the highest casualties and injuries from direct lightning strikes. This region of the globe also has little lightning protection of rural homes and schools, while many casualties occur during outdoor activities (e.g. farming, fishing, sports, etc.) In this study we investigated two lightning-caused accidents that got wide press coverage: A lightning strike to a Cheetah Center in Namibia which caused a huge fire and great destruction (16 October 2013), and a plane crash in Mali where 116 people died (24 July 2014). Using data from the World Wide Lightning Location Network (WWLLN) we show that the lightning data alone can provide important early warning information that can be used to reduce risks and damages and loss of life from lightning strikes. We have developed a now-casting scheme that allows for early warnings across Africa with a relatively low false alarm rate. To verify the accuracy of our now-cast, we have performed some statistical analysis showing relatively high skill at providing early warnings (lead time of a few hours) based on lightning alone. Furthermore, our analysis can be used in forensic meteorology for determining if such accidents are caused by lightning strikes.

  7. Inducing Therapeutic Hypothermia in Cardiac Arrest Caused by Lightning Strike.

    PubMed

    Scantling, Dane; Frank, Brian; Pontell, Mathew E; Medinilla, Sandra

    2016-09-01

    Only limited clinical scenarios are grounds for induction of therapeutic hypothermia. Its use in traumatic cardiac arrests, including those from lightning strikes, is not well studied. Nonshockable cardiac arrest rhythms have only recently been included in resuscitation guidelines. We report a case of full neurological recovery with therapeutic hypothermia after a lightning-induced pulseless electrical activity cardiac arrest in an 18-year-old woman. We also review the important pathophysiology of lightning-induced cardiac arrest and neurologic sequelae, elaborate upon the mechanism of therapeutic hypothermia, and add case-based evidence in favor of the use of targeted temperature management in lightning-induced cardiac arrest. PMID:27451005

  8. A review of natural lightning - Experimental data and modeling

    NASA Technical Reports Server (NTRS)

    Uman, M. A.; Krider, E. P.

    1982-01-01

    A critical review is presented of the currents and the electric and magnetic fields characteristic of each of the salient discharge processes which make up cloud-to-ground and intracloud lightning. Emphasis is placed on the more recent work in which measured waveform variation is in the microsecond and submicrosecond range, since it is this time-scale that is of primary importance in lightning/aircraft interactions. The state-of-the-art of the modeling of lightning currents and fields is discussed in detail. A comprehensive bibliography is given of all literature relating to both lightning measurements and models.

  9. BLDG 101, OVERVIEW WITH LIGHTNING POLES Naval Magazine Lualualei, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BLDG 101, OVERVIEW WITH LIGHTNING POLES - Naval Magazine Lualualei, Headquarters Branch, Operational Storage Building, Fifteenth Street near Kolekole Road intersection, Pearl City, Honolulu County, HI

  10. Inducing Therapeutic Hypothermia in Cardiac Arrest Caused by Lightning Strike.

    PubMed

    Scantling, Dane; Frank, Brian; Pontell, Mathew E; Medinilla, Sandra

    2016-09-01

    Only limited clinical scenarios are grounds for induction of therapeutic hypothermia. Its use in traumatic cardiac arrests, including those from lightning strikes, is not well studied. Nonshockable cardiac arrest rhythms have only recently been included in resuscitation guidelines. We report a case of full neurological recovery with therapeutic hypothermia after a lightning-induced pulseless electrical activity cardiac arrest in an 18-year-old woman. We also review the important pathophysiology of lightning-induced cardiac arrest and neurologic sequelae, elaborate upon the mechanism of therapeutic hypothermia, and add case-based evidence in favor of the use of targeted temperature management in lightning-induced cardiac arrest.

  11. Cochlear implantation for severe sensorineural hearing loss caused by lightning.

    PubMed

    Myung, Nam-Suk; Lee, Il-Woo; Goh, Eui-Kyung; Kong, Soo-Keun

    2012-01-01

    Lightning strike can produce an array of clinical symptoms and injuries. It may damage multiple organs and cause auditory injuries ranging from transient hearing loss and vertigo to complete disruption of the auditory system. Tympanic-membrane rupture is relatively common in patients with lightning injury. The exact pathogenetic mechanisms of auditory lesions in lightning survivors have not been fully elucidated. We report the case of a 45-year-old woman with bilateral profound sensorineural hearing loss caused by a lightning strike, who was successfully rehabilitated after a cochlear implantation.

  12. Radar research on thunderstorms and lightning

    NASA Technical Reports Server (NTRS)

    Rust, W. D.; Doviak, R. J.

    1982-01-01

    Applications of Doppler radar to detection of storm hazards are reviewed. Normal radar sweeps reveal data on reflectivity fields of rain drops, ionized lightning paths, and irregularities in humidity and temperature. Doppler radar permits identification of the targets' speed toward or away from the transmitter through interpretation of the shifts in the microwave frequency. Wind velocity fields can be characterized in three dimensions by the use of two radar units, with a Nyquist limit on the highest wind speeds that may be recorded. Comparisons with models numerically derived from Doppler radar data show substantial agreement in storm formation predictions based on information gathered before the storm. Examples are provided of tornado observations with expanded Nyquist limits, gust fronts, turbulence, lightning and storm structures. Obtaining vertical velocities from reflectivity spectra is discussed.

  13. NASA F-106B lightning tests

    NASA Technical Reports Server (NTRS)

    Heady, B. D.; Zeisel, K. S.

    1983-01-01

    Lightning simulation ground tests conducted on the NASA F-106B research aircraft to elicit natural strikes are summarized. The purpose of the test program was to measure the response of the aircraft's electromagnetic sensors and interior wire circuits to a controlled ground test environment that simulates the electromagnetic effects of a lightning strike. Both direct attachment and radiated field tests were conducted. In most cases, the aircraft's engine was running and test data were gathered simultaneously from NASA and MCAIR sensors on both the aircraft's own instrumentation system and the remote MCAIR computer-controlled data acquisition system. During the direct attachment tests, the input inductance, output condition (hard-wired or spark gap), and the output location were varied to provide a wide variety of test conditons. The radiated tests to the isolated aircraft were conducted to excite and measure the natural resonances of the F-106B aircraft.

  14. Runaway breakdown and hydrometeors in lightning initiation.

    PubMed

    Gurevich, A V; Karashtin, A N

    2013-05-01

    The particular electric pulse discharges are observed in thunderclouds during the initiation stage of negative cloud-to-ground lightning. The discharges are quite different from conventional streamers or leaders. A detailed analysis reveals that the shape of the pulses is determined by the runaway breakdown of air in the thundercloud electric field initiated by extensive atmospheric showers (RB-EAS). The high amplitude of the pulse electric current is due to the multiple microdischarges at hydrometeors stimulated and synchronized by the low-energy electrons generated in the RB-EAS process. The series of specific pulse discharges leads to charge reset from hydrometeors to the free ions and creates numerous stretched ion clusters, both positive and negative. As a result, a wide region in the thundercloud with a sufficiently high fractal ion conductivity is formed. The charge transport by ions plays a decisive role in the lightning leader preconditioning. PMID:23683210

  15. Lightning injury: report of a case.

    PubMed

    Tseng, Y L; Tsai, M C; Wu, M H

    1993-08-01

    Lightning injury can cause severe damage to many systems and often results in a high mortality. We report a case of sustained lightning injury in which a 54-year-old woman presented with heart failure, pulmonary edema and consciousness disturbance. The patient was found unconscious, lying face down on the ground of a trash dump on the day of a thunderstorm. No deformities were seen in the extremities, but scattered third degree burns (less than 1%) were found on her neck where her necklace had been. Ventilator and inotropic agents with an adequate fluid supply were used. A Swan-Ganz catheter was inserted for monitoring. The patient was discharged two weeks later with an uneventful clinical course, except for mild neurologic sequelae (amnesia, disorientation).

  16. The detection of lightning from geostationary orbit

    NASA Technical Reports Server (NTRS)

    Christian, Hugh J.; Blakeslee, Richard J.; Goodman, Steven J.

    1989-01-01

    Consideration is given to the development of the Lightning Mapper Sensor (LMS), a space sensor capable of mapping intracloud and cloud-to-ground lightning discharges from geostationary orbit during day and night. The LMS is expected to have a spatial resolution of 10 km and a detection efficiency of 90 percent. The LMS combines modern solid state mosaic focal planes with extensive on-board signal processing to make it possible to detect weak background-contaminated signals. The LMS is planned to have a 10.5 degree field of view covering all of the continental U.S. The characteristics and design of the LMS are described, noting the possible applications of the sensor.

  17. Structure of conducting channel of lightning

    SciTech Connect

    Alanakyan, Yu. R.

    2013-08-15

    The spatial distribution of the plasma density in a lightning channel is studied theoretically. It is shown that the electric-field double layer is formed at the channel boundary. In this case, the electron temperature changes abruptly and ions are accelerated by the electric field of the double layer. The ion momentum flux density is close to the surrounding gas pressure. Cleaning of the channel from heavy particles occurs in particle-exchange processes between the plasma channel and the surrounding air. Hydrogen ions are accumulated inside the expanding channel from the surrounding air, which is enriched by hydrogen-contained molecules. In this case, the plasma channel is unstable and splits to a chain of equidistant bunches of plasma. The hydrogen-enrich bunches burn diffusely after recombination exhibiting the bead lightning behavior.

  18. Comparison of the United States Precision Lightning Network(TM) (USPLN(TM)) and the Cloud-to-Ground Lightning Surveillance System (CGLSS)

    NASA Astrophysics Data System (ADS)

    Jacques, Alexander Andrew

    WSI Corporation requested a performance evaluation of their United States Precision Lightning Network(TM) (USPLN(TM)), which is co-owned by TOA Systems, Inc. The USPLN is a national lightning detection network with over 160 sensors placed across the North American continent. Previous performance evaluations of the network had been limited to simulated lightning events and individual fixed tower case studies. Thus, a longer evaluation of the network had yet to be completed, which this study attempts to achieve. As a validation tool, the second generation of the Cloud-to-Ground Lightning Surveillance System (CGLSS-II) was selected. CGLSS-II is a local detection network used for critical lightning surveillance at Kennedy Space Center and Cape Canaveral Air Force Station (KSC/CCAFS). The network of six sensors has been certified by the U.S. Air Force since 1989, and is constantly monitored and evaluated. CGLSS-II and the USPLN share numerous similarities including: the processing of all lightning strokes, GPS timing, and the time-of-arrival technique for triangulating stroke locations. Stroke data for CGLSS-II and USPLN were acquired and quality controlled for the selected study period of 20 May 2008 to 31 August 2010. The study period was further divided into sub-periods based on changes to CGLSS-II performance, and data were restricted to a region surrounding KSC/CCAFS. A correlation procedure was selected which matched strokes between the two networks using time and distance thresholds, creating a comparative dataset. Data from the Four Dimensional Lightning Surveillance System (4DLSS) was also collected as a means to classify cloud-to-ground (CG) and intra-cloud (IC) strokes. Melbourne (KMLB) composite reflectivity radar imagery was also acquired to further evaluate USPLN performance. Several analyses of USPLN stroke detection efficiency (DE) and location accuracy were conducted to first determine average performance and then to examine specific case studies

  19. Combined Current Measurements and Lightning Mapping Array Observations of Rocket-Triggered Lightning at Langmuir Lab

    NASA Astrophysics Data System (ADS)

    Trueblood, Jacob

    2012-10-01

    Over the 2011 storm season at Langmuir Lab, several rocket-triggered lightning flashes were observed by Langmuir's Lightning Mapping Array (LMA) and by current viewing resistors (CVR). The LMA data allows us to calculate the velocity of the positive leaders from the flashes. The CVR is attached to the wire that is towed behind the rocket allowing us to measure the current at the base of the lightning flash. We are able to compare the current measurements and velocity calculations from the LMA data to provide insights into stages of a triggered flash. We discuss one flash from August 11 as a case study, were we found positive leader velocities to range from 1.4 to 2.4x10^4 m s-1 The faster speeds were found during the initial continuous current (ICC).

  20. Anomalous light output from lightning dart leaders

    NASA Technical Reports Server (NTRS)

    Guo, C.; Krider, E. P.

    1985-01-01

    About 5 percent of the multiple-stroke cloud-to-ground lightning discharges recorded at the NASA Kennedy Space Center during the summer of 1981 contained dart leaders that produced an unusually large light output. An analysis of these cases indicates that the average peak light output per unit length in the leader may be comparable to or even exceed that of the return stroke that follows.

  1. Lightning Protection for the Orion Space Vehicle

    NASA Technical Reports Server (NTRS)

    Scully, Robert

    2015-01-01

    The Orion space vehicle is designed to requirements for both direct attachment and indirect effects of lightning. Both sets of requirements are based on a full threat 200kA strike, in accordance with constraints and guidelines contained in SAE ARP documents applicable to both commercial and military aircraft and space vehicles. This paper describes the requirements as levied against the vehicle, as well as the means whereby the design shows full compliance.

  2. Horizontal electric fields from lightning return strokes

    NASA Technical Reports Server (NTRS)

    Thomson, E. M.; Medelius, P. J.; Rubinstein, M.; Uman, M. A.; Johnson, J.

    1988-01-01

    An experiment to measure simultaneously the wideband horizontal and vertical electric fields from lightning return strokes is described. Typical wave shapes of the measured horizontal and vertical fields are presented, and the horizontal fields are characterized. The measured horizontal fields are compared with calculated horizontal fields obtained by applying the wavetilt formula to the vertical fields. The limitations and sources of error in the measurement technique are discussed.

  3. Acoustic Location of Lightning Using Interferometric Techniques

    NASA Astrophysics Data System (ADS)

    Erives, H.; Arechiga, R. O.; Stock, M.; Lapierre, J. L.; Edens, H. E.; Stringer, A.; Rison, W.; Thomas, R. J.

    2013-12-01

    Acoustic arrays have been used to accurately locate thunder sources in lightning flashes. The acoustic arrays located around the Magdalena mountains of central New Mexico produce locations which compare quite well with source locations provided by the New Mexico Tech Lightning Mapping Array. These arrays utilize 3 outer microphones surrounding a 4th microphone located at the center, The location is computed by band-passing the signal to remove noise, and then computing the cross correlating the outer 3 microphones with respect the center reference microphone. While this method works very well, it works best on signals with high signal to noise ratios; weaker signals are not as well located. Therefore, methods are being explored to improve the location accuracy and detection efficiency of the acoustic location systems. The signal received by acoustic arrays is strikingly similar to th signal received by radio frequency interferometers. Both acoustic location systems and radio frequency interferometers make coherent measurements of a signal arriving at a number of closely spaced antennas. And both acoustic and interferometric systems then correlate these signals between pairs of receivers to determine the direction to the source of the received signal. The primary difference between the two systems is the velocity of propagation of the emission, which is much slower for sound. Therefore, the same frequency based techniques that have been used quite successfully with radio interferometers should be applicable to acoustic based measurements as well. The results presented here are comparisons between the location results obtained with current cross correlation method and techniques developed for radio frequency interferometers applied to acoustic signals. The data were obtained during the summer 2013 storm season using multiple arrays sensitive to both infrasonic frequency and audio frequency acoustic emissions from lightning. Preliminary results show that

  4. Joint voltages resulting from lightning currents.

    SciTech Connect

    Johnson, William Arthur; Warne, Larry Kevin; Merewether, Kimball O.; Chen, Kenneth C.

    2007-03-01

    Simple formulas are given for the interior voltages appearing across bolted joints from exterior lightning currents. External slot and bolt inductances as well as internal slot and bolt diffusion effects are included. Both linear and ferromagnetic wall materials are considered. A useful simplification of the slot current distribution into linear stripline and cylindrical parts (near the bolts) allows the nonlinear voltages to be estimated in closed form.

  5. Effects of a Longer Detection Window in VHF Time-of-Arrival Lightning Detection Systems

    NASA Astrophysics Data System (ADS)

    Murphy, M.; Holle, R.; Demetriades, N.

    2003-12-01

    Lightning detection systems that operate by measuring the times of arrival (TOA) of short bursts of radiation at VHF can produce huge volumes of data. The first automated system of this kind, the NASA Kennedy Space Center LDAR network, is capable of producing one detection every 100 usec from each of seven sensors (Lennon and Maier, 1991), where each detection consists of the time and amplitude of the highest-amplitude peak observed within the 100 usec window. More modern systems have been shown to produce very detailed information with one detection every 10 usec (Rison et al., 2001). Operating such systems in real time, however, can become expensive because of the large data communications rates required. One solution to this problem is to use a longer detection window, say 500 usec. In principle, this has little or no effect on the flash detection efficiency because each flash typically produces a very large number of these VHF bursts (known as sources). By simply taking the largest-amplitude peak from every 500-usec interval instead of every 100-usec interval, we should detect the largest 20{%} of the sources that would have been detected using the 100-usec window. However, questions remain about the exact effect of a longer detection window on the source detection efficiency with distance from the network, its effects on how well flashes are represented in space, and how well the reduced information represents the parent thunderstorm. The latter issue is relevant for automated location and tracking of thunderstorm cells using data from VHF TOA lightning detection networks, as well as for understanding relationships between lightning and severe weather. References Lennon, C.L. and L.M. Maier, Lightning mapping system. Proceedings, Intl. Aerospace and Ground Conf. on Lightning and Static Elec., Cocoa Beach, Fla., NASA Conf. Pub. 3106, vol. II, pp. 89-1 - 89-10, 1991. Rison, W., P. Krehbiel, R. Thomas, T. Hamlin, J. Harlin, High time resolution lightning mapping

  6. An Optical Lightning Simulator in an Electrified Cloud-Resolving Model to Prepare the Future Space Lightning Missions

    NASA Astrophysics Data System (ADS)

    Bovalo, Christophe; Defer, Eric; Pinty, Jean-Pierre

    2016-04-01

    The future decade will see the launch of several space missions designed to monitor the total lightning activity. Among these missions, the American (Geostationary Lightning Mapper - GLM) and European (Lightning Imager - LI) optical detectors will be onboard geostationary satellites (GOES-R and MTG, respectively). For the first time, the total lightning activity will be monitored over the full Earth disk and at a very high temporal resolution (2 and 1 ms, respectively). Missions like the French Tool for the Analysis of Radiation from lightNIng and Sprites (TARANIS) and ISS-LIS will bring complementary information in order to better understand the lightning physics and to improve the weather prediction (nowcasting and forecasting). Such missions will generate a huge volume of new and original observations for the scientific community and weather prediction centers that have to be prepared. Moreover, before the launch of these missions, fundamental questions regarding the interpretation of the optical signal property and its relation to cloud optical thickness and lightning discharge processes need to be further investigated. An innovative approach proposed here is to use the synergy existing in the French MesoNH Cloud-Resolving Model (CRM). Indeed, MesoNH is one of the only CRM able to simulate the lifecycle of electrical charges generated within clouds through non-inductive charging process (dependent of the 1-moment microphysical scheme). The lightning flash geometry is based on a fractal law while the electrical field is diagnosed thanks to the Gauss' law. The lightning optical simulator is linked to the electrical scheme as the lightning radiance at 777.4 nm is a function of the lightning current, approximated by the charges neutralized along the lightning path. Another important part is the scattering of this signal by the hydrometeors (mainly ice particles) that is taken into account. Simulations at 1-km resolution are done over the Langmuir Laboratory (New

  7. Simulation of Meteosat Third Generation-Lightning Imager through tropical rainfall measuring mission: Lightning Imaging Sensor data

    NASA Astrophysics Data System (ADS)

    Biron, Daniele; De Leonibus, Luigi; Laquale, Paolo; Labate, Demetrio; Zauli, Francesco; Melfi, Davide

    2008-08-01

    The Centro Nazionale di Meteorologia e Climatologia Aeronautica recently hosted a fellowship sponsored by Galileo Avionica, with the intent to study and perform a simulation of Meteosat Third Generation - Lightning Imager (MTG-LI) sensor behavior through Tropical Rainfall Measuring Mission - Lightning Imaging Sensor data (TRMM-LIS). For the next generation of earth observation geostationary satellite, major operating agencies are planning to insert an optical imaging mission, that continuously observes lightning pulses in the atmosphere; EUMETSAT has decided in recent years that one of the three candidate mission to be flown on MTG is LI, a Lightning Imager. MTG-LI mission has no Meteosat Second Generation heritage, but users need to evaluate the possible real time data output of the instrument to agree in inserting it on MTG payload. Authors took the expected LI design from MTG Mission Requirement Document, and reprocess real lightning dataset, acquired from space by TRMM-LIS instrument, to produce a simulated MTG-LI lightning dataset. The simulation is performed in several run, varying Minimum Detectable Energy, taking into account processing steps from event detection to final lightning information. A definition of the specific meteorological requirements is given from the potential use in meteorology of lightning final information for convection estimation and numerical cloud modeling. Study results show the range of instrument requirements relaxation which lead to minimal reduction in the final lightning information.

  8. Characterizing the Relationships Among Lightning and Storm Parameters: Lightning as a Proxy Variable

    NASA Technical Reports Server (NTRS)

    Goodman, S. J.; Raghavan, R.; William, E.; Weber, M.; Boldi, B.; Matlin, A.; Wolfson, M.; Hodanish, S.; Sharp. D.

    1997-01-01

    We have gained important insights from prior studies that have suggested relationships between lightning and storm growth, decay, convective rain flux, vertical distribution of storm mass and echo volume in the region, and storm energetics. A study was initiated in the Summer of 1996 to determine how total (in-cloud plus ground) lightning observations might provide added knowledge to the forecaster in the determination and identification of severe thunderstorms and weather hazards in real-time. The Melbourne Weather Office was selected as a primary site to conduct this study because Melbourne is the only site in the world with continuous and open access to total lightning (LDAR) data and a Doppler (WSR-88D) radar. A Lightning Imaging Sensor Data Applications Demonstration (LISDAD) system was integrated into the forecaster's workstation during the Summer 1996 to allow the forecaster to interact in real-time with the multi-sensor data being displayed. LISDAD currently ingests LDAR data, the cloud-to-ground National Lightning Detection Network (NLDN) data, and the Melbourne radar data in f real-time. The interactive features provide the duty forecaster the ability to perform quick diagnostics on storm cells of interest. Upon selection of a storm cell, a pop-up box appears displaying the time-history of various storm parameters (e.g., maximum radar reflectivity, height of maximum reflectivity, echo-top height, NLDN and LDAR lightning flash rates, storm-based vertically integrated liquid water content). This product is archived to aid on detailed post-analysis.

  9. Triggered-Lightning Interaction with a Lightning Protective System: Current Distribution and Electromagnetic Environment

    NASA Technical Reports Server (NTRS)

    Mata, C. T.; Rakov, V. A.; Mata, A. G.

    2010-01-01

    A new comprehensive lightning instrumentation system has been designed for Launch Complex 39B (LC3913) at the Kennedy Space Center, Florida. This new instrumentation system includes the synchronized recording of six high-speed video cameras; currents through the nine downconductors of the new lightning protection system for LC3913; four dH/dt, 3-axis measurement stations; and five dE/dt stations composed of two antennas each. A 20:1 scaled down model of the new Lightning Protection System (LPS) of LC39B was built at the International Center for Lightning Research and Testing, Camp Blanding, FL. This scaled down lightning protection system was instrumented with the transient recorders, digitizers, and sensors to be used in the final instrumentation installation at LC3913. The instrumentation used at the ICLRT is also a scaled-down instrumentation of the LC39B instrumentation. The scaled-down LPS was subjected to seven direct lightning strikes and six (four triggered and two natural nearby flashes) in 2010. The following measurements were acquired at the ICLRT: currents through the nine downconductors; two dl-/dt, 3-axis stations, one at the center of the LPS (underneath the catenary wires), and another 40 meters south from the center of the LPS; ten dE/dt stations, nine of them on the perimeter of the LPS and one at the center of the LPS (underneath the catenary wire system); and the incident current. Data from representative events are presented and analyzed in this paper.

  10. Illumination of mesospheric irregularity by lightning discharge

    NASA Astrophysics Data System (ADS)

    Füllekrug, Martin; Mezentsev, Andrew; Soula, Serge; Velde, Oscar; Evans, Adrian

    2013-12-01

    Theoretical model calculations recently predicted the existence of mesospheric irregularities which assist the initiation of sprites. Here we report the experimental detection of a ˜3-19 km3 large mesospheric irregularity at ˜80-85 km height which is illuminated by the electromagnetic field of an intense positive cloud-to-ground lightning discharge. While the lightning discharge causes a prompt group of four sprites above the lightning discharge, the mesospheric irregularity is found at a horizontal distance at least ˜15-20 km away from the sprite group and it rebrightens ˜40-60 ms after the sprite group occurrence. This rebrightening is driven by a local quasi-static electric field enhancement with a charge moment ˜4-20 Ckm which causes the irregularity to develop a downward descending luminous column from ˜75-85 km height. The quasi-static electric field enhancement is caused by the reorganization of residual charge inside the thundercloud during a high-level activity of intracloud discharges with ˜10-20 pulses per ms. Such mesospheric irregularities might have an effect on the wave propagation of 100 kHz radio waves which are used for atomic time transfer and marine navigation.

  11. Tropospheric sources of NOx: lightning and biology

    NASA Technical Reports Server (NTRS)

    Levine, J. S.; Augustsson, T. R.; Anderson, I. C.; Hoell, J. M. Jr

    1984-01-01

    Laboratory experiments to quantify the global production of NOx (NO + NO2) in the troposphere due to atmospheric lightning and biogenic activity in soil are presented. These laboratory experiments, as well as other studies, suggest that the global production of NOx by lightning probably ranges between 2 and 20 MT(N)y-1 of NO and is strongly dependent on the total energy deposited by lightning, a quantity not well-known. In our laboratory experiments, nitrifying micro-organisms is soil were found to be a significant source of both NO and nitrous oxide (N2O). The measured production ratio of NO to N2O averaged 2-3 for oxygen partial pressures of 0.5-10%. Extrapolating these laboratory measurements to the global scale, which is somewhat risky, suggests that nitrifying micro-organisms in soil may account for as much as 10 MT(N) y-1 of NO. Additional experiments with denitrifying micro-organisms gave an NO to N2O production ratio ranging from 2 to 4 for an oxygen partial pressure of 0.5% and a ratio of less than unity for oxygen partial pressures ranging from 1 to 20%. The production of NO and N2O, normalized with respect to micro-organism number indicates that the production of both NO and N2O by denitrifying micro-organisms is at least an order of magnitude less than production by nitrifying micro-organisms for the micro-organisms studied.

  12. Locating Preliminary Breakdown Pulses in Lightning Flashes

    NASA Astrophysics Data System (ADS)

    Karunarathne, S.; Marshall, T.; Stolzenburg, M.

    2011-12-01

    Lightning flashes often begin with a series of bipolar pulses, 1-5 us in width, called initial breakdown pulses or characteristic pulses. In 2010 we showed that these pulses can be located (find x, y, z, t) using Time of arrival method (TOA) [Koshak and Solakiewicz, JGR, 1996]. Electric field change data was obtained at the NASA/Kennedy Space Center (KSC) during the summer of 2010 at 5 stations with a band width of 0-0.5MHz and time accuracy of 1us. We concluded that in order to increase the accuracy positions; time accuracy, band width and number of stations should be increased. In summer of 2011, we placed electric field change meters with band width of 0-5Mhz and time accuracy of 0.1us at the KSC. We have doubled the number of stations (10 stations). We use TOA technique with different algorithm to locate positions of beginning pulses with greater accuracy. The locations will be compared to locations of VHF lightning sources made with the KSC LDAR2 system (which has a center frequency of 63 MHz and a bandwidth of 6 MHz). A monte-carlo method will be used to calculate the error of the locations. A statistical comparison between our TOA positions and LDAR2 positions will be presented along with possible physical connections between the preliminary breakdown pulses, the LDAD2 sources, and the developing lightning leader.

  13. Analysis of electrical transients created by lightning

    NASA Technical Reports Server (NTRS)

    Nanevicz, J. E.; Vance, E. F.

    1980-01-01

    A series of flight tests was conducted using a specially-instrumented NASA Learjet to study the electrical transients created on an aircraft by nearby lightning. The instrumentation included provisions for the time-domain and frequency-domain recording of the electrical signals induced in sensors located both on the exterior and on the interior of the aircraft. The design and calibration of the sensors and associated measuring systems is described together with the results of the flight test measurements. The results indicate that the concept of providing instrumentation to follow the lightning signal from propagation field, to aircraft skin current, to current on interior wiring is basically sound. The results of the measurement indicate that the high frequency signals associated with lightning stroke precursor activity are important in generating electromagnetic noise on the interior of the aircraft. Indeed, the signals produced by the precursors are often of higher amplitude and of longer duration that the pulse produced by the main return stroke.

  14. Acoustic vs Interferometric Measurements of Lightning

    NASA Astrophysics Data System (ADS)

    Arechiga, R. O.; Erives, H.; Sonnenfeld, R. G.; Stanley, M. A.; Rison, W.; Thomas, R. J.; Edens, H. E.; Lapierre, J. L.; Stock, M.; Jensen, D.; Morris, K.

    2015-12-01

    During the summer of 2015 we acquired acoustic and RF data on severalflashes from thunderstorms over Fort Morgan CO. and Langmuir Laboratoryin the Magdalena mountains of central New Mexico. The acoustic arrayswere located at a distance of roughly 150 m from the interferometers.Lightning mapping array and slow antenna data were also obtained. Theacoustic arrays consist of arrays of five audio-range and six infrasoundmicrophones operating at 50 KHz and 1 KHz respectively. The lightninginterferometer at Fort Morgan CO. consists of three flat-plate, 13" diameterantennas at the vertices of an equilateral 50 m per side triangle. Theinterferometer at Langmuir Laboratory consists of three 13" dishes separatedby about 15 m. Both interferometers, operating at 180 Megasamples persecond, use the analysis software and digitizer hardware pioneered byStanley, Stock et al. The high data rate allows for excellent spatialresolution of high speed (and typically high current) processes such asK-changes, return strokes and dart-leaders. In previous studies, we haveshown the usefulness of acoustic recordings to locate thunder sources aswell as infrasound pulses from lightning. This work will present acomparison of Acoustic and Interferometric measurements from lightning,using some interesting flashes, including a positive cloud to ground,that occurred in these campaigns.

  15. Lightning fatalities and injuries in Turkey

    NASA Astrophysics Data System (ADS)

    Tilev-Tanriover, Ş.; Kahraman, A.; Kadioğlu, M.; Schultz, D. M.

    2015-03-01

    A database of lightning-related fatalities and injuries in Turkey was constructed by collecting data from the Turkish State Meteorological Service, newspaper archives, European Severe Weather Database, and the internet. The database covers January 1930 to June 2014. In total, 742 lightning incidents causing human fatalities and injuries were found. Within these 742 incidents, there were 895 fatalities, 149 serious injuries, and 535 other injuries. Most of the incidents (89%) occurred during April through September, with a peak in May and June (26 and 28 %) followed by July (14%). Lightning-related fatalities and injuries were most frequent in the afternoon. Most of the incidents (86%) occurred in the rural areas, with only 14% in the urban areas. Approximately, two thirds of the victims with known gender were male. Because of the unrepresentativeness of the historical data, determining an average mortality rate over a long period is not possible. Nevertheless, there were 31 fatalities (0.42 per million) in 2012, 26 fatalities (0.35 per million) in 2013, and 25 fatalities (0.34 per million) in 2014 (as of June). There were 36 injuries (0.49 per million) in each of 2012 and 2013, and 62 injuries (0.84 per million) in 2014 (as of June).

  16. Lightning fatalities and injuries in Turkey

    NASA Astrophysics Data System (ADS)

    Tilev-Tanriover, Ş.; Kahraman, A.; Kadioğlu, M.; Schultz, D. M.

    2015-08-01

    A database of lightning-related fatalities and injuries in Turkey was constructed by collecting data from the Turkish State Meteorological Service, newspaper archives, European Severe Weather Database, and the internet. The database covers January 1930 to June 2014. In total, 742 lightning incidents causing human fatalities and injuries were found. Within these 742 incidents, there were 895 fatalities, 149 serious injuries, and 535 other injuries. Most of the incidents (89 %) occurred during April through September, with a peak in May and June (26 and 28 %) followed by July (14 %). Lightning-related fatalities and injuries were most frequent in the afternoon. Most of the incidents (86 %) occurred in rural areas, with only 14 % in the urban areas. Approximately, two thirds of the victims with known gender were male. Because of the unrepresentativeness of the historical data, determining an average mortality rate over a long period is not possible. Nevertheless, there were 31 fatalities (0.42 per million) in 2012, 26 fatalities (0.35 per million) in 2013, and 25 fatalities (0.34 per million) in 2014 (as of June). There were 36 injuries (0.49 per million) in each of 2012 and 2013, and 62 injuries (0.84 per million) in 2014 (as of June).

  17. Advanced lightning location interferometer. Final report

    SciTech Connect

    1995-05-25

    In January, 1994, New Mexico Institute for Mining and Technology (NM Tech) was commissioned by Los Alamos National Laboratories (LANL) to develop a three-axis interferometric lightning mapping system to be used in determining the source of certain frequency-dispersed pulse pairs which had been detected by spaceborne sensors. The existing NM Tech VHF Lightning Interferometer was a two axis system operating at 274 MHz with 6 MHz bandwidth. The third axis was to be added to refine estimates of the elevation angle to distant RF sources in that band. The system was to be initially deployed in support of an Air Force Technical Applications Center (AFTAC) effort planned for the Kennedy Space Center/Cape Canaveral AFS area in June-July of 1994. The project was, however, postponed until September of 1994. The interferometer was set up and operated at KSC near the Lightning Detection and Ranging (LDAR) central station. The initial setup was in two-axis configuration, and the third (vertical) axis was added at about mid-project. Though the storms were reduced in frequency and severity over what one would expect in mid-summer, several good data sets were obtained and delivered to AFTAC.

  18. Lightning flash multiplicity in eastern Mediterranean thunderstorms

    NASA Astrophysics Data System (ADS)

    Yair, Y.; Shalev, S.; Erlich, Z.; Agrachov, A.; Katz, E.; Saaroni, H.; Price, C.; Ziv, B.

    2014-02-01

    Cloud-to-ground lightning flashes usually consist of one or several strokes coming in very short temporal succession and close spatial proximity. A commonly used method for converting stroke data into flashes is using the National Lightning Detection Network (NLDN) thresholds of maximum temporal separation of 0.5 s and maximum lateral distance of 10 km radius between successive strokes. In the present study, we tested a location-based algorithm with several spatial and temporal ranges, and analyzed stroke data obtained by the Israel Lightning Location System (ILLS) during one year (1.8.2009-31.7.2010). We computed the multiplicity, the percentage of single stroke flashes and the geographical distribution of average multiplicity values for thunderstorms in the Eastern Mediterranean region. Results show that for the NLDN thresholds, the percentage of single stroke flashes in Israel was 37% and the average multiplicity was 1.7. We reanalyzed the data with a spatial range that equals twice the ILLS location error and shorter times. For the new thresholds of maximum distance of 2.5 km and maximum allowed temporal separation of 0.2 s we find that the mean multiplicity of negative CGs is lowered to 1.4 and find a percentage of 58% of single stroke flashes. A unique severe storm from 30 October 2009 is analyzed and compared with the annual average of 2009/2010, showing that large deviations from the mean values can occur in specific events.

  19. Initiation and development of first lightning leader: The effects of coronae and position of lightning origin

    NASA Astrophysics Data System (ADS)

    Aleksandrov, N. L.; Bazelyan, E. M.; Raizer, Yu. P.

    2005-07-01

    This paper addresses, by means of numerical simulations, the issues of lightning initiation near tall, grounded objects and lightning development in the cloud-to-ground gap. Taken into account is the effect of coronae on the initiation of an upward leader from the top of a fixed grounded structure that is exposed to the electric field produced by the storm-cloud and approaching downward leader. It is shown that the potential carried by a downward leader to the ground and, consequently, the return stroke current depend greatly on the position of a bi-directional leader origin inside a cloud and on the shape of the leader path.

  20. Lightning current rate of rise in the new lightning flash model for the space shuttle program

    NASA Technical Reports Server (NTRS)

    Bankston, Nathaniel G.

    1991-01-01

    The recently baselined Space Shuttle lightning effects flash model is discussed. The discussion is limited to the current rate(s) of rise. A review of some of the recent data is presented, as well as a discussion of how interaction processes affect the induced voltages and currents which arise from a lightning strike. It is concluded that the multiple pulse components of the new flash model present a more severe threat to complex avionic systems, than is presented by a single pulse having an extremely fast rate of rise.

  1. Time-Correlated High-Speed Video and Lightning Mapping Array Results For Triggered Lightning Flashes

    NASA Astrophysics Data System (ADS)

    Eastvedt, E. M.; Eack, K.; Edens, H. E.; Aulich, G. D.; Hunyady, S.; Winn, W. P.; Murray, C.

    2009-12-01

    Several lightning flashes triggered by the rocket-and-wire technique at Langmuir Laboratory's Kiva facility on South Baldy (approximately 3300 meters above sea level) were captured on high-speed video during the summers of 2008 and 2009. These triggered flashes were also observed with Langmuir Laboratory's Lightning Mapping Array (LMA), a 3-D VHF time-of-arrival system. We analyzed nine flashes (obtained in four different storms) for which the electric field at ground was positive (foul-weather). Each was initiated by an upward positive leader that propagated into the cloud. In all cases observed, the leader exhibited upward branching, and most of the flashes had multiple return strokes.

  2. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely-piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. Using special equipment aboard the Altus II, scientists in ACES will gather electric, magnetic, and optical measurements of the thunderstorms, gauging elements such as lightning activity and the electrical environment in and around the storms. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  3. Lightning climatology in the Congo Basin

    NASA Astrophysics Data System (ADS)

    Soula, S.; Kasereka, J. Kigotsi; Georgis, J. F.; Barthe, C.

    2016-09-01

    The lightning climatology of the Congo Basin including several countries of Central Africa is analysed in detail for the first time. It is based on data from the World Wide Lightning Location Network (WWLLN), for the period from 2005 to 2013. A comparison of these data with Lightning Imaging Sensor (LIS) data for the same period shows the relative detection efficiency of the WWLLN (DE) in the 2500 km × 2500 km region increases from about 1.70% in the beginning of the period to 5.90% in 2013, and it is in agreement with previous results for other regions of the world. However, the increase of DE is not uniform over the whole region. The average monthly flash rate describes an annual cycle with a strong activity from October to March and a low one from June to August, associated with the ITCZ migration but not exactly symmetrical on both sides of the equator. The zonal distribution of the lightning flashes exhibits a maximum between 1°S and 2°S and about 56% of the flashes are located south of the equator in the 10°S-10°N interval. The diurnal evolution of the flash rate has a maximum between 1400 and 1700 UTC, according to the reference year. The annual flash density and number of stormy days show a sharp maximum localized in the eastern part of Democratic Republic of Congo (DRC) regardless of the reference year and the period of the year. These maxima reach 12.86 fl km- 2 and 189 days, respectively, in 2013, and correspond to a very active region located at the rear of the Virunga mountain range at altitudes that exceed 3000 m. The presence of these mountains plays a role in the thunderstorm development along the year. The estimation of this local maximum of the lightning density by taking into account the DE, leads to a value consistent with that of the global climatology by Christian et al. (2003).

  4. Volcanic lightning on Venus and early Earth

    NASA Astrophysics Data System (ADS)

    Airey, Martin; Aplin, Karen

    2016-04-01

    Lightning may have been crucial in the development of life, as it enables key chemical reactions to occur. We cannot directly observe early Earth's hot, CO2-rich, atmosphere; however, similar conditions exist today on Venus, where there may be volcanic and/or meteorological lightning. Recent observations made by ESA's Venus Express satellite have provided evidence for active volcanism [1-3] and lightning discharges [e.g. 4], which may be volcanic in origin. This study uses laboratory experiments to simulate ash generation and to measure its electrical charging under typical atmospheric conditions for Venus and the early Earth (specifically the Hadean eon, up to 4 billion years ago, and the Archean eon, from 4 billion to 2.5 billion years ago). Ultimately the work will address the following questions: (a) is volcanic activity a feasible mechanism for lightning generation on Venus and early Earth, (b) how would these extreme paleo-environmental conditions affect lightning, (c) can the similarities in atmospheric conditions inform us of planetary evolutionary concepts, (d) could volcanic lightning have been important in the emergence of life on Earth, and (e) what are the wider implications for the likelihood of the emergence of life on other planets? A 1-litre atmospheric simulation chamber will be used to simulate the high-pressure, high-temperature, CO2-dominated atmospheres of the surface of early Earth, and Venus at ~10 km altitude (~5 MPa, 650 K) (where ash plume-forming eruptions on Venus are more likely to occur [5]). The chamber contains temperature/pressure monitoring and logging equipment, a collision apparatus to generate the charged rock fragments, and electrodes for charge measurement with an electrometer [6]. The planned experimental programme will measure the effects of varying temperature, pressure, atmospheric, and sample composition under a range of conditions appropriate to Venus and early Earth. Comparative work with present day Earth conditions

  5. Direct Measurements of NOx Produced by Lightning

    NASA Astrophysics Data System (ADS)

    Rahman, M.; Cooray, V.; Rakov, V. A.; Uman, M. A.; Liyanage, P.; Decarlo, B. A.; Jerauld, J.; Olsen, R. C.

    2006-12-01

    We present the first direct measurements of NOx generated by lightning. In July 2005, three negative lightning flashes were triggered using the rocket-and-wire technique at the International Center for Lightning Research and Testing (ICLRT) at Camp Blanding, Florida. The NOx produced by these three rocket- triggered flashes was measured, using the chemiluminescence method, by isolating a 3-cm long section of the lightning channel within a discharge chamber whose volume was 0.77 m3. We measured NOx individually for the first flash, which was triggered on July 15, and cumulatively for the other two flashes, which were triggered within about eleven minutes of each other on July 31. The July 15 flash contained only an initial- stage current and no return strokes. Each of the July 31 flashes contained an initial-stage current and either one or two return strokes. The initial-stage current in each case had a duration in the range from 260 to 360 ms, and one return stroke in each July 31 flash was followed by a continuing current whose duration was greater than 40 ms. The NOx production by the July 15 flash without return strokes (total charge transfer of 77 C) was 2.0×10^{22} molecules per meter of lightning channel, and that by the two July 31 flashes with return strokes (total charge transfer of 108 C) was 2.4×10^{22} molecules per meter. The NOx production per unit charge for these two measurements was similar: 2.6×1020 and 2.2×1020 molecules per meter per coulomb. It appears that the NOx production is primarily from long-duration, steady currents, as opposed to microsecond-scale impulsive return stroke currents. This observation implies that cloud discharges, which transfer, on average, larger charges than ground discharges, but do not contain return strokes (although they do contain typically shorter and presumably smaller amplitude microsecond-scale pulses) may be as effective as (or more effective than) cloud-to-ground discharges in producing NOx in the

  6. Three Years of TRMM Precipitation Features. Part 1; Radar, Radiometric, and Lightning Characteristics

    NASA Technical Reports Server (NTRS)

    Cecil, Daniel J.; Goodman, Steven J.; Boccippio, Dennis J.; Zipser, Edward J.; Nesbitt, Stephen W.

    2004-01-01

    During its first three years, the Tropical Rainfall Measuring Mission (TRMM) satellite observed nearly six million precipitation features. The population of precipitation features is sorted by lightning flash rate, minimum brightness temperature, maximum radar reflectivity, areal extent, and volumetric rainfall. For each of these characteristics, essentially describing the convective intensity or the size of the features, the population is broken into categories consisting of the top 0.001%, top 0.01%, top 0.1%, top 1%, top 2.4%, and remaining 97.6%. The set of 'weakest / smallest' features comprises 97.6% of the population because that fraction does not have detected lightning, with a minimum detectable flash rate 0.7 fl/min. The greatest observed flash rate is 1351 fl/min; the lowest brightness temperatures are 42 K (85-GHz) and 69 K (37- GHz). The largest precipitation feature covers 335,000 sq km and the greatest rainfall from an individual precipitation feature exceeds 2 x 10(exp 12) kg of water. There is considerable overlap between the greatest storms according to different measures of convective intensity. The largest storms are mostly independent of the most intense storms. The set of storms producing the most rainfall is a convolution of the largest and the most intense storms. This analysis is a composite of the global tropics and subtropics. Significant variability is known to exist between locations, seasons, and meteorological regimes. Such variability will be examined in Part II. In Part I, only a crude land / Ocean separation is made. The known differences in bulk lightning flash rates over land and Ocean result from at least two differences in the precipitation feature population: the frequency of occurrence of intense storms, and the magnitude of those intense storms that do occur. Even when restricted to storms with the same brightness temperature, same size, or same radar reflectivity aloft, the storms over water are considerably less likely to

  7. Lightning location system supervising Swedish power transmission network

    NASA Technical Reports Server (NTRS)

    Melin, Stefan A.

    1991-01-01

    For electric utilities, the ability to prevent or minimize lightning damage on personnel and power systems is of great importance. Therefore, the Swedish State Power Board, has been using data since 1983 from a nationwide lightning location system (LLS) for accurately locating lightning ground strikes. Lightning data is distributed and presented on color graphic displays at regional power network control centers as well as at the national power system control center for optimal data use. The main objectives for use of LLS data are: supervising the power system for optimal and safe use of the transmission and generating capacity during periods of thunderstorms; warning service to maintenance and service crews at power line and substations to end operations hazardous when lightning; rapid positioning of emergency crews to locate network damage at areas of detected lightning; and post analysis of power outages and transmission faults in relation to lightning, using archived lightning data for determination of appropriate design and insulation levels of equipment. Staff have found LLS data useful and economically justified since the availability of power system has increased as well as level of personnel safety.

  8. Characteristics of lightning echoes observed with VHF ST radar

    NASA Astrophysics Data System (ADS)

    RöTtger, J.; Liu, C. H.; Pan, C. J.; Su, S. Y.

    1995-07-01

    The development of tropospheric convection was observed with the Chung-Li VHF stratosphere-troposphere (ST) radar in Taiwan, Republic of China. Deep convection evolved into thunderstorms during which radar echoes from lightning were recorded with a particular high time resolution program. These lightning echoes usually exist for only several tens to a few hundred milliseconds. To investigate the fine structure in the amplitude and phase of the lightning returns, the necessary time resolution has to be in the order of a few milliseconds. Such time resolutions are for the first time applied with VHF ST radar and the initial results are presented in this paper. Rapid jumps in the phase path were occurring together with sudden amplitude changes. This indicates that the scattering regions change their position, which could be on different branches of the lightning stroke. Large radial velocities of the lightning scattering regions up to several tens of meters per second were observed. Also, strong velocity shears were noticed in these lightning echo regions. Power peaks in Doppler spectra corresponding to velocities of about 300 m s-1 were occasionally detected. It is contemplated that these are caused by Bragg scattering from sound waves resulting from the lightning shock wave. Also a periodic velocity and amplitude modulation of a thin sheet of radar reflectivity was observed which one could attribute to infra-sound with a frequency of about 6-7 Hz. Preliminary conclusions are drawn finally to confirm that our observations are generally consistent with backscatter from lightning.

  9. Lightning-Strike Disaster: Effects on Children's Fears and Worries.

    ERIC Educational Resources Information Center

    Dollinger, Stephen J.; And Others

    1984-01-01

    Compares fears of lightning-strike victims (N=29) with matched control children (N=58), using fear reports from children and their mothers. Differences between samples were most pronounced for child-reported fears. Correspondence between mothers' and children's reports of intense storm-related fears was markedly larger in the lightning sample than…

  10. 21st Century Lightning Protection for High Altitude Observatories

    NASA Astrophysics Data System (ADS)

    Kithil, Richard

    2013-05-01

    One of the first recorded lightning insults to an observatory was in January 1890 at the Ben Nevis Observatory in Scotland. In more recent times lightning has caused equipment losses and data destruction at the US Air Force Maui Space Surveillance Complex, the Cerro Tololo observatory and the nearby La Serena scientific and technical office, the VLLA, and the Apache Point Observatory. In August 1997 NOAA's Climate Monitoring and Diagnostic Laboratory at Mauna Loa Observatory was out of commission for a month due to lightning outages to data acquisition computers and connected cabling. The University of Arizona has reported "lightning strikes have taken a heavy toll at all Steward Observatory sites." At Kitt Peak, extensive power down protocols are in place where lightning protection for personnel, electrical systems, associated electronics and data are critical. Designstage lightning protection defenses are to be incorporated at NSO's ATST Hawaii facility. For high altitude observatories lightning protection no longer is as simple as Franklin's 1752 invention of a rod in the air, one in the ground and a connecting conductor. This paper discusses selection of engineered lightning protection subsystems in a carefully planned methodology which is specific to each site.

  11. Lightning Over the Technology Test Bed at MSFC

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Multiple lightning bolts struck the Technology Test Bed, formerly the S-IC Static Test Stand, at the Marshall Space Flight Center (MSFC) during a thunderstorm. This spectacular image of lightning was photographed by MSFC photographer Dernis Olive on August 29, 1990.

  12. Lightning characteristics of derecho producing mesoscale convective systems

    NASA Astrophysics Data System (ADS)

    Bentley, Mace L.; Franks, John R.; Suranovic, Katelyn R.; Barbachem, Brent; Cannon, Declan; Cooper, Stonie R.

    2016-06-01

    Derechos, or widespread, convectively induced wind storms, are a common warm season phenomenon in the Central and Eastern United States. These damaging and severe weather events are known to sweep quickly across large spatial regions of more than 400 km and produce wind speeds exceeding 121 km h-1. Although extensive research concerning derechos and their parent mesoscale convective systems already exists, there have been few investigations of the spatial and temporal distribution of associated cloud-to-ground lightning with these events. This study analyzes twenty warm season (May through August) derecho events between 2003 and 2013 in an effort to discern their lightning characteristics. Data used in the study included cloud-to-ground flash data derived from the National Lightning Detection Network, WSR-88D imagery from the University Corporation for Atmospheric Research, and damaging wind report data obtained from the Storm Prediction Center. A spatial and temporal analysis was conducted by incorporating these data into a geographic information system to determine the distribution and lightning characteristics of the environments of derecho producing mesoscale convective systems. Primary foci of this research include: (1) finding the approximate size of the lightning activity region for individual and combined event(s); (2) determining the intensity of each event by examining the density and polarity of lightning flashes; (3) locating areas of highest lightning flash density; and (4) to provide a lightning spatial analysis that outlines the temporal and spatial distribution of flash activity for particularly strong derecho producing thunderstorm episodes.

  13. Upgrade to the Broadband Observation network for Lightning and Thunderstorms

    NASA Astrophysics Data System (ADS)

    Akiyama, Y.; Wu, T.; Stock, M.; Nakamura, Y.; Kikuchi, H.; Yoshida, S.; Ushio, T.; Kawasaki, Z.

    2015-12-01

    Observation sensors for lightning discharges sense electromagnetic waves, mainly in the ELF to UHF range, and especially in the LF and VHF bands. VHF band sensor sensors can observe lightning discharge process in detail but its observation coverage is limited. On the other hand, LF band sensor can observe lightning at much great distances. Therefore, LF sensors are well adapted to observe lightning throughout a thunderstorm's life cycle. Our research group has been designing and developing the Broadband Observation network for Lightning and Thunderstorm (BOLT), which locates radiation sources associated with lightning discharge in three spatial dimensions. BOLT consists of 11 LF band sensors which detect lightning pulses wide frequency range from 5 kHz to 500 kHz. We have been operating BOLT in Kansai area of Japan, locating both cloud-to-ground and intracloud discharges. Currently, the BOLT system observes about 100 to 1000 lightning pulses per flash, but we are striving to improve both the detection efficiency and the location accuracy. Preliminary investigation show that the number of sources located, increases dramatically when only the highest portion of the BLOT frequency band is used far location. So, our research group has proposed improving a new "DDT" antenna sensor design to improve the high frequency sensitivity of the antenna. The DDT antenna consists of a modified charge amplifier circuit. In this research, we present a comparison of the DDT antenna and show the advantages of the DDT antenna.

  14. The 2000 Fire Season: Lightning-Caused Fires.

    NASA Astrophysics Data System (ADS)

    Rorig, Miriam L.; Ferguson, Sue A.

    2002-07-01

    A large number of lightning-caused fires burned across the western United States during the summer of 2000. In a previous study, the authors determined that a simple index of low-level moisture (85-kPa dewpoint depression) and instability (85-50-kPa temperature difference) from the Spokane, Washington, upper-air soundings was very useful for indicating the likelihood of `dry' lightning (occurring without significant concurrent rainfall) in the Pacific Northwest. This same method was applied to the summer-2000 fire season in the Pacific Northwest and northern Rockies. The mean 85-kPa dewpoint depression at Spokane from 1 May through 20 September was 17.7°C on days when lightning-caused fires occurred and was 12.3°C on days with no lightning-caused fires. Likewise, the mean temperature difference between 85 and 50 kPa was 31.3°C on lightning-fire days, as compared with 28.9°C on non-lightning-fire days. The number of lightning-caused fires corresponded more closely to high instability and high dewpoint depression than to the total number of lightning strikes in the region.

  15. Assessments of Total Lightning Data Utility in Weather Forecasting

    NASA Technical Reports Server (NTRS)

    Buechler, Dennis E.; Goodman, Steve; LaCasse, Katherine; Blakeslee, Richard; Darden, Chris

    2005-01-01

    National Weather Service forecasters in Huntsville, Alabama have had access to total lightning data from the North Alabama Lightning Mapping Array (LMA) since 2003. Forecasters can monitor real-time total lightning observations on their AWIPS (Advanced Weather Interactive Processing System (AWIPS) workstations. The lightning data is used to supplement other observations such as radar and satellite data. The lightning data is updated every 2 min, providing more timely evidence of storm growth or decay than is available from 5 min radar scans. Total lightning observations have been used to positively impact warning decisions in a number of instances. A number of approaches are being pursued to assess the usefulness of total lightning measurements to the operational forecasting community in the warning decision process. These approaches, which include both qualitative and quantitative assessment methods, will be discussed. submitted to the American Meteorological Society (AMS) Conference on Meteorological Applications of Lightning Data to be held in San Diego, CA January 9-13,2005. This will be a presentation and an extended abstract will be published on a CD available from the AMS.

  16. State of technology in optical systems. [applicable to lightning experiments

    NASA Technical Reports Server (NTRS)

    Edgar, B. C.

    1979-01-01

    The use of silicon photodiode sensors and locator systems for lightning experiments is discussed. Tables are presented on: (1) satellite optical lightning experiments (silicon detectors); (2) reticon photodiode linear arrays; and (3) locator systems (grey code and reticon). An illustration of a grey code locator system for a low altitude satellite is also given.

  17. 14 CFR 25.1316 - System lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false System lightning protection. 25.1316... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment General § 25.1316 System lightning... systems to perform these functions are not adversely affected when the airplane is exposed to...

  18. 14 CFR 25.1316 - System lightning protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false System lightning protection. 25.1316... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment General § 25.1316 System lightning... systems to perform these functions are not adversely affected when the airplane is exposed to...

  19. 30 CFR 56.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Lightning protection for telephone wires and... NONMETAL MINES Electricity § 56.12069 Lightning protection for telephone wires and ungrounded conductors... lightning shall be equipped with suitable lightning arrestors of approved type within 100 feet of the...

  20. 30 CFR 57.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Lightning protection for telephone wires and... AND NONMETAL MINES Electricity Surface Only § 57.12069 Lightning protection for telephone wires and... exposed to lightning shall be equipped with suitable lightning arrestors of approved type within 100...

  1. 30 CFR 56.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Lightning protection for telephone wires and... NONMETAL MINES Electricity § 56.12069 Lightning protection for telephone wires and ungrounded conductors... lightning shall be equipped with suitable lightning arrestors of approved type within 100 feet of the...

  2. 30 CFR 56.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Lightning protection for telephone wires and... NONMETAL MINES Electricity § 56.12069 Lightning protection for telephone wires and ungrounded conductors... lightning shall be equipped with suitable lightning arrestors of approved type within 100 feet of the...

  3. 30 CFR 56.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lightning protection for telephone wires and... NONMETAL MINES Electricity § 56.12069 Lightning protection for telephone wires and ungrounded conductors... lightning shall be equipped with suitable lightning arrestors of approved type within 100 feet of the...

  4. 30 CFR 57.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Lightning protection for telephone wires and... AND NONMETAL MINES Electricity Surface Only § 57.12069 Lightning protection for telephone wires and... exposed to lightning shall be equipped with suitable lightning arrestors of approved type within 100...

  5. 30 CFR 57.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lightning protection for telephone wires and... AND NONMETAL MINES Electricity Surface Only § 57.12069 Lightning protection for telephone wires and... exposed to lightning shall be equipped with suitable lightning arrestors of approved type within 100...

  6. 30 CFR 57.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Lightning protection for telephone wires and... AND NONMETAL MINES Electricity Surface Only § 57.12069 Lightning protection for telephone wires and... exposed to lightning shall be equipped with suitable lightning arrestors of approved type within 100...

  7. Lightning Jump Algorithm and Relation to Thunderstorm Cell Tracking, GLM Proxy and other Meteorological Measurements

    NASA Technical Reports Server (NTRS)

    Schultz, Christopher J.; Carey, Larry; Cecil, Dan; Bateman, Monte; Stano, Geoffrey; Goodman, Steve

    2012-01-01

    Objective of project is to refine, adapt and demonstrate the Lightning Jump Algorithm (LJA) for transition to GOES -R GLM (Geostationary Lightning Mapper) readiness and to establish a path to operations Ongoing work . reducing risk in GLM lightning proxy, cell tracking, LJA algorithm automation, and data fusion (e.g., radar + lightning).

  8. Global Validation of Single-Station Schumann Resonance Lightning Location

    NASA Technical Reports Server (NTRS)

    Boccippio, Dennis; Wong, C.; Williams, E. R.; Boldi, R.; Christian, H. J.; Goodman, S. J.

    1998-01-01

    Global measurements of large, optically bright lightning events from the Optical Transient Detector (OTD) satellite are used to validate estimates of lightning location from single-station Schumann resonance (SR) data. Bearing estimates are obtained through conventional magnetic direction-finding techniques, while source range is estimated from the range-dependent impedance spectrum of individual SR transients. An analysis of 40 such transients suggests that single-station techniques can locate lightning globally with an accuracy of 1-2mm. This is confirmed by further validation at close ranges from flashes detected by the National Lightning Detection-Network (NLDN). Observations with both OTD and SR systems may be useful for globally locating lightning with necessary, if not sufficient, characteristics to trigger mesospheric sprites.

  9. Lightning Protection and Instrumentation at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Colon, Jose L.

    2005-01-01

    Lightning is a natural phenomenon, but can be dangerous. Prevention of lightning is a physical impossibility and total protection requires compromises on costs and effects, therefore prediction and measurements of the effects that might be produced by iightn:ing is a most at locat:ions where people or sensitive systems and equipment are exposed. This is the case of the launching pads for the Space Shuttle at Kennedy Space Center (KSC) of the National Aeronautics and Space Administration. This report summarizes lightring phenomena with a brief explanation of lightning generation and lightning activity as related to KSC. An analysis of the instrumentation used at the launching pads for measurements of lightning effects with alternatives to improve the protection system and up-grade the actual instrumentation system is indicated.

  10. Noise and interference study for satellite lightning sensor

    NASA Technical Reports Server (NTRS)

    Herman, J. R.

    1981-01-01

    The use of radio frequency techniques for the detection and monitoring of terrestrial thunderstorms from space are discussed. Three major points are assessed: (1) lightning and noise source characteristics; (2) propagation effects imposed by the atmosphere and ionosphere; and (3) the electromagnetic environment in near space within which lightning RF signatures must be detected. A composite frequency spectrum of the peak of amplitude from lightning flashes is developed. Propagation effects (ionospheric cutoff, refraction, absorption, dispersion and scintillation) are considered to modify the lightning spectrum to the geosynchronous case. It is suggested that in comparing the modified spectrum with interfering noise source spectra RF lightning pulses on frequencies up to a few GHz are detectable above the natural noise environment in near space.

  11. Lightning damage to a general aviation aircraft: Description and analysis

    NASA Technical Reports Server (NTRS)

    Hacker, P. T.

    1974-01-01

    The damage sustained by a Beechcraft King Air Model B90 aircraft by a single lightning discharge is presented and analyzed. The incident occurred during landing approach at Jackson, Michigan, on Feb. 19, 1971. In addition to the usual melted-metal damage at the lightning attachment points, there was severe implosion-type damage over a large area on the lower right side of the aircraft and impact- and crushing-type damage on the upper and lower surfaces on the left wingtip near the trailing edge. Analyses indicate that the implosion-type damage was probably caused by lightning-generated shock waves, that the impact-and crushing-type damage was caused by magnetic forces, and that the lightning discharge was a multiple strike with at least 11 strokes separated in time by about 4.5 milliseconds. The evidence indicates that the lightning discharge was rather different from the average in character severity.

  12. Interpretation methodology and analysis of in-flight lightning data

    NASA Technical Reports Server (NTRS)

    Rudolph, T.; Perala, R. A.

    1982-01-01

    A methodology is presented whereby electromagnetic measurements of inflight lightning stroke data can be understood and extended to other aircraft. Recent measurements made on the NASA F106B aircraft indicate that sophisticated numerical techniques and new developments in corona modeling are required to fully understand the data. Thus the problem is nontrivial and successful interpretation can lead to a significant understanding of the lightning/aircraft interaction event. This is of particular importance because of the problem of lightning induced transient upset of new technology low level microcircuitry which is being used in increasing quantities in modern and future avionics. Inflight lightning data is analyzed and lightning environments incident upon the F106B are determined.

  13. Test Report: Direct and Indirect Lightning Effects on Composite Materials

    NASA Technical Reports Server (NTRS)

    Evans, R. W.

    1997-01-01

    Lightning tests were performed on composite materials as a part of an investigation of electromagnetic effects on the materials. Samples were subjected to direct and remote simulated lightning strikes. Samples included various thicknesses of graphite filament reinforced plastic (GFRP), material enhanced by expanded aluminum foil layers, and material with an aluminum honeycomb core. Shielding properties of the material and damage to the sample surfaces and joints were investigated. Adding expanded aluminum foil layers and increasing the thickness of GFRP improves the shielding effectiveness against lightning induced fields and the ability to withstand lightning strikes. A report describing the lightning strike tests performed by the U.S. Army Redstone Technical Test Center, Redstone Arsenal, AL, STERT-TE-E-EM, is included as an appendix.

  14. Regulatory Guidance for Lightning Protection in Nuclear Power Plants

    SciTech Connect

    Kisner, Roger A; Wilgen, John B; Ewing, Paul D; Korsah, Kofi; Antonescu, Christina E

    2006-01-01

    Abstract - Oak Ridge National Laboratory (ORNL) was engaged by the U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research (RES) to develop the technical basis for regulatory guidance to address design and implementation practices for lightning protection systems in nuclear power plants (NPPs). Lightning protection is becoming increasingly important with the advent of digital and low-voltage analog systems in NPPs. These systems have the potential to be more vulnerable than older analog systems to the resulting power surges and electromagnetic interference (EMI) when lightning strikes facilities or power lines. This paper discusses the technical basis for guidance to licensees and applicants covered in Regulatory Guide (RG) 1.204, Guidelines for Lightning Protection of Nuclear Power Plants, issued August 2005. RG 1.204 describes guidance for practices that are acceptable to the NRC staff for protecting nuclear power structures and systems from direct lightning strikes and the resulting secondary effects.

  15. Status of research into lightning effects on aircraft

    NASA Technical Reports Server (NTRS)

    Plumer, J. A.

    1976-01-01

    Developments in aircraft lightning protection since 1938 are reviewed. Potential lightning problems resulting from present trends toward the use of electronic controls and composite structures are discussed, along with presently available lightning test procedures for problem assessment. The validity of some procedures is being questioned because of pessimistic results and design implications. An in-flight measurement program is needed to provide statistics on lightning severity at flight altitudes and to enable more realistic tests, and operators are urged to supply researchers with more details on electronic components damaged by lightning strikes. A need for review of certain aspects of fuel system vulnerability is indicated by several recent accidents, and specific areas for examination are identified. New educational materials and standardization activities are also noted.

  16. Characterizing wind turbine system response to lightning activity

    SciTech Connect

    McNiff, B.; LaWhite, N.; Muljadi, E.

    1998-07-01

    A lightning protection research program was instituted by National Renewable Energy Laboratory to minimize lightning damage to wind turbines and to further the understanding of effective damage mitigation techniques. To that end, a test program is under way to observe lightning activity, protection system response, and damage at a wind power plant in the Department of Energy (DOE) and Electric Power Research Institute (EPRI) Turbine Verification Program. The authors installed Lightning activated surveillance cameras along with a special storm tracking device to observe the activity in the wind plant area. They instrumented the turbines with lightning and ground current detection devices to log direct and indirect strike activity at each unit. They installed a surge monitor on the utility interface to track incoming activity from the transmission lines. Maintenance logs are used to verify damage and determine downtime and repair costs. Actual strikes to turbines were recorded on video and ancillary devices. The test setup and some results are discussed in this paper.

  17. The Lightning Mapper Sensor for GOES-NEXT

    NASA Astrophysics Data System (ADS)

    Manlief, S. K.

    1992-03-01

    This paper presents a design overview of the Lightning Mapper Sensor (LMS). The LMS is an instrument designed to be flown on a GOES-NEXT satellite. Its function is to detect total lightning activity within a 8 x 10 degree FOV with a 90 percent detection efficiency and with a spatial resolution of 10 km (a scale typical of convective storm cells). From the GOES 75-deg W location, the LMS will provide coverage of the continental United States and the northern portion of South America to 10-deg S latitude. It will provide data on the distribution and variability of lightning activity, and increase understanding of the underlying and interrelated phenomena (including atmospheric convection, lightning/precipitation relationships, lightning/trace-gas interactions, and the global electric circuit). The LMS will be a valuable 'nowcasting' tool providing severe storm warning and tracking information to population centers, aircraft, shipping, launch sites and forest-fire fighters.

  18. Smart CMOS image sensor for lightning detection and imaging.

    PubMed

    Rolando, Sébastien; Goiffon, Vincent; Magnan, Pierre; Corbière, Franck; Molina, Romain; Tulet, Michel; Bréart-de-Boisanger, Michel; Saint-Pé, Olivier; Guiry, Saïprasad; Larnaudie, Franck; Leone, Bruno; Perez-Cuevas, Leticia; Zayer, Igor

    2013-03-01

    We present a CMOS image sensor dedicated to lightning detection and imaging. The detector has been designed to evaluate the potentiality of an on-chip lightning detection solution based on a smart sensor. This evaluation is performed in the frame of the predevelopment phase of the lightning detector that will be implemented in the Meteosat Third Generation Imager satellite for the European Space Agency. The lightning detection process is performed by a smart detector combining an in-pixel frame-to-frame difference comparison with an adjustable threshold and on-chip digital processing allowing an efficient localization of a faint lightning pulse on the entire large format array at a frequency of 1 kHz. A CMOS prototype sensor with a 256×256 pixel array and a 60 μm pixel pitch has been fabricated using a 0.35 μm 2P 5M technology and tested to validate the selected detection approach.

  19. The GOES-R Geostationary Lightning Mapper (GLM) and the Global Observing System for Total Lightning

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.; Blakeslee, R. J.; Koshak, W.; Buechler, D.; Carey, L.; Chronis, T.; Mach, D.; Bateman, M.; Peterson, H.; McCaul, E. W., Jr.; Stano, G. T.; Bitzer, P. M.; Rudlosky, S. D.; Cummins, K. L.

    2014-01-01

    for the existing GOES system currently operating over the Western Hemisphere. New and improved instrument technology will support expanded detection of environmental phenomena, resulting in more timely and accurate forecasts and warnings. Advancements over current GOES include a new capability for total lightning detection (cloud and cloud-to-ground flashes) from the Geostationary Lightning Mapper (GLM), and improved temporal, spatial, and spectral resolution for the next generation Advanced Baseline Imager (ABI). The GLM will map total lightning continuously day and night with near-uniform spatial resolution of 8 km with a product latency of less than 20 sec over the Americas and adjacent oceanic regions. This will aid in forecasting severe storms and tornado activity, and convective weather impacts on aviation safety and efficiency among a number of potential applications. The GLM will help address the National Weather Service requirement for total lightning observations globally to support warning decision-making and forecast services. Science and application development along with pre-operational product demonstrations and evaluations at NWS national centers, forecast offices, and NOAA testbeds will prepare the forecasters to use GLM as soon as possible after the planned launch and check-out of GOES-R in 2016. New applications will use GLM alone, in combination with the ABI, or integrated (fused) with other available tools (weather radar and ground strike networks, nowcasting systems, mesoscale analysis, and numerical weather prediction models) in the hands of the forecaster responsible for issuing more timely and accurate forecasts and warnings.

  20. 1994 Triggered Lightning Test Program: Measured responses of a reinforced concrete building under direct lightning attachments

    SciTech Connect

    Schnetzer, G.H.; Chael, J.; Davis, R.; Fisher, R.J.; Magnotti, P.J.

    1995-08-01

    A rocket-triggered lightning test was carried out during the summer of 1994 on a specially designed steel reinforced concrete test building located at Ft. McClellan, Alabama. Currents, voltages, and magnetic fields were measured at 24 instrumented locations during 42 return strokes triggered to designated points on the structure and its lightning protection systems. As was found during an earlier similar lightning test of an earth covered munitions storage building, the buried power service conduits carried a much larger fraction of incident stroke current away from the building than did the intended grounding elements of the lightning protection system. Electrical breakdown and subsequent arcing occurred repeatedly to create dominant current paths to earth that were not accounted for in pretest linear modeling. Potential hazard level transient voltages, surprisingly more resistive than inductive in nature, were recorded throughout the structure. Also surprisingly, strikes to a single grounded protection mast system resulted in internal environments that were generally comparable to those occurring during strikes to roof-mounted air terminals. A description of the test structure, experimental procedures, and a full set of the resultant data are presented in this two-volume report.

  1. Correlating Ground-Based Lightning Measurements with Ash Cloud Satellite Data from the 2010 Eruption of Eyjafjallajökull Volcano, Iceland

    NASA Astrophysics Data System (ADS)

    McMahon, N. D.; Thomas, R. J.; Pavolonis, M. J.; Sieglaff, J.; Aster, R. C.

    2012-12-01

    Airborne volcanic ash is a major aviation hazard. For example, the 2010 eruption of Eyjafjallajökull volcano in Iceland resulted in the largest air-traffic shutdown since World War II. More than 100,000 flights were grounded, stranding passengers in Europe and across the globe, and producing a multi-billion dollar economic impact. Because of the high impact on aviation, sophisticated tools are needed to provide real-time alerts, tracking, and forecasting of volcanic clouds. In an attempt address the 5-minute volcanic cloud warning criteria established by the international aviation community, an automated volcanic cloud alert system for the Geostationary Operational Environmental Satellite - R Series (GOES-R) built upon the automated ash cloud alert system for the Advanced Very High Resolution Radiometer (AVHRR) is in development. The new system will be capable of identifying ash and SO2 clouds with greater accuracy. One component of GOES-R will be a lightning mapper. To study the temporal, spatial, and physical relationships between ash clouds and lightning, and the utility of lightning detection in a real-time alert system, we analyze data collected by the Lightning Mapping Array, a ground-based lightning detection network, in conjunction with satellite data gathered by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument aboard Meteosat-9 during in the 2010 eruption of Eyjafjallajökull volcano. We correlate lightning characteristics, intensity, and distribution with plume location, height, mass loading, and effective particle radius. Lightning mapping in volcanic ash clouds potentially will allow for better characterization of the ash cloud and aid in forecasting the distribution of ash and its effects on aviation.

  2. Evaluation of the damages caused by lightning current flowing through bearings

    NASA Technical Reports Server (NTRS)

    Celi, O.; Pigini, A.; Garbagnati, E.

    1991-01-01

    A laboratory for lightning current tests was set up allowing the generation of the lightning currents foreseen by the Standards. Lightning tests are carried out on different objects, aircraft materials and components, evaluating the direct and indirect effects of lightning. Recently a research was carried out to evaluate the effects of the lightning current flow through bearings with special reference to wind power generator applications. For this purpose, lightning currents of different amplitude were applied to bearings in different test conditions and the damages caused by the lightning current flow were analyzed. The influence of the load acting on the bearing, the presence of lubricant and the bearing rotation were studied.

  3. National Athletic Trainers' Association Position Statement: Lightning Safety for Athletics and Recreation

    PubMed Central

    Walsh, Katie M.; Cooper, Mary Ann; Holle, Ron; Rakov, Vladimir A.; Roeder, William P.; Ryan, Michael

    2013-01-01

    Objective: To present recommendations for the education, prevention, and management of lightning injuries for those involved in athletics or recreation. Background: Lightning is the most common severe-storm activity encountered annually in the United States. The majority of lightning injuries can be prevented through an aggressive educational campaign, vacating outdoor activities before the lightning threat, and an understanding of the attributes of a safe place from the hazard. Recommendations: This position statement is focused on supplying information specific to lightning safety and prevention and treatment of lightning injury and providing lightning-safety recommendations for the certified athletic trainer and those who are involved in athletics and recreation. PMID:23672391

  4. Evidence for lightning-associated enhancement of the ionospheric sporadic E layer dependent on lightning stroke energy

    NASA Astrophysics Data System (ADS)

    Yu, Bingkun; Xue, Xianghui; Lu, Gaopeng; Ma, Ming; Dou, Xiankang; Qie, Xiushu; Ning, Baiqi; Hu, Lianhuan; Wu, Jianfei; Chi, Yutian

    2015-10-01

    In this study we analyze the lightning data obtained by the World-Wide Lightning Location Network (WWLLN) and hourly ionospheric data observed by ionosondes located at Sanya and Beijing, to examine the changes in ionospheric electron density in response to the underlying thunderstorms and to investigate the possible connection between lightning discharges and the enhancement of the ionospheric sporadic E(Es) layer. We identify a statistically significant enhancement and a decrease in altitude of the Es layer at Sanya station, in agreement with the results found at Chilton, UK. However, the lightning-associated modification of the Es layer investigated using the same approach is not evident at Beijing station. Furthermore, we compare the responses to weak and strong lightning strokes using WWLLN-determined energies at Sanya in 2012. The lightning-associated enhancement of the Es layer is predominantly attributed to powerful strokes with high stroke energy. A statistically significant intensification of the Es layer with higher-energy strokes at Sanya, along with the statistical dependence of lightning-associated enhancement of the Es layer on stroke energy, leads us to conclude that the magnitude of the enhancement is likely associated with lightning stroke energy.

  5. Maximum cloud-to-ground lightning flash densities observed by lightning location systems in the tropical region: A review

    NASA Astrophysics Data System (ADS)

    Pinto, O.; Pinto, I. R. C. A.; Naccarato, K. P.

    2007-05-01

    A comprehensive review of maximum cloud-to-ground (CG) lightning flash densities observed in the tropical region by different Lightning Location Systems (LLS) is presented. From the observed values, absolute maximum values for a spatial resolution of 1 km × 1 km are estimated, using an empirical curve relating flash density and resolution and correcting the data for differences in the detection efficiency and in the intracloud (IC) contamination of the different LLS. Maximum CG lightning flash densities are compared with total lightning observations by satellite in the same regions, for a spatial resolution of approximately 55 km × 55 km, to infer IC to CG ratios (IC/CG). It was found that absolute maximum CG lightning flash densities in the tropical region vary from 19 to 65 flashes km - 2 year - 1 and IC/CG ratios from 3.9 to 12.6. Absolute maximum CG lightning flash densities and the IC/CG ratios in the tropical region are then compared with similar values in the temperate region. Only the regions corresponding to the highest maximum CG lightning flash densities observed by LLS for each continent in the temperate region are considered. The comparison suggests that higher absolute maximum CG lightning flash densities occur in the tropical region and similar IC/CG ratios occur in both regions, with the exception of Colombia and Venezuela, where this ratio seems to be higher than in any other regions.

  6. Infrasound from lightning: characteristics and impact on an infrasound station

    NASA Astrophysics Data System (ADS)

    Farges, Thomas; Blanc, Elisabeth

    2010-05-01

    More than two third of the infrasound stations of the International Monitoring System (IMS) of the CTBTO are now certified and measure routinely signals due particularly to natural activity (swell, volcano, severe weather including lightning, …). It is well established that more than 2,000 thunderstorms are continuously active all around the world and that about 45 lightning flashes are produced per second over the globe. During the Eurosprite 2005 campaign, we took the opportunity to measure, in France during summer, infrasound from lightning and from sprites (which are transient luminous events occurring over thunderstorm). We examine the possibility to measure infrasound from lightning when thunderstorms are close or far from the infrasound station. Main results concern detection range of infrasound from lightning, amplitude vs. distance law, and characteristics of frequency spectrum. We show clearly that infrasound from lightning can be detected when the thunderstorm is within about 75 km from the station. In good noise conditions, infrasound from lightning can be detected when thunderstorms are located more than 200 km from the station. No signal is recorded from lightning flashes occurring between 75 and 200 km away from the station, defining then a silence zone. When the thunderstorm is close to the station, the infrasound signal could reach several Pascal. The signal is then on average 30 dB over the noise level at 1 Hz. Infrasound propagate upward where the highest frequencies are dissipated and can produce a significant heating of the upper mesosphere. Some of these results have been confirmed by case studies with data from the IMS Ivory Coast station. The coverage of the IMS stations is very good to study the thunderstorm activity and its disparity which is a good proxy of the global warming. Progress in data processing for infrasound data in the last ten years and the appearance of global lightning detection network as the World Wide Lightning

  7. Infrasound from lightning: characteristics and impact on an infrasound station

    NASA Astrophysics Data System (ADS)

    Farges, T.; Blanc, E.

    2009-12-01

    More than two third of the infrasound stations of the International Monitoring System (IMS) of the CTBTO are now certified and measure routinely signals due particularly to natural activity (swell, volcano, severe weather including lightning, …). It is well established that more than 2,000 thunderstorms are continuously active all around the world and that about 45 lightning flashes are produced per second over the globe. During the Eurosprite 2005 campaign, we took the opportunity to measure, in France during summer, infrasound from lightning and from sprites (which are transient luminous events occurring over thunderstorm). We examine the possibility to measure infrasound from lightning when thunderstorms are close or far from the infrasound station. Main results concern detection range of infrasound from lightning, amplitude vs. distance law, and characteristics of frequency spectrum. We show clearly that infrasound from lightning can be detected when the thunderstorm is within about 75 km from the station. In good noise conditions, infrasound from lightning can be detected when thunderstorms are located more than 200 km from the station. No signal is recorded from lightning flashes occurring between 75 and 200 km away from the station, defining then a silence zone. When the thunderstorm is close to the station, the infrasound signal could reach several Pascal. The signal is then on average 30 dB over the noise level at 1 Hz. Infrasound propagate upward where the highest frequencies are dissipated and can produce a significant heating of the upper mesosphere. Some of these results have been confirmed by case studies with data from the IMS Ivory Coast station. The coverage of the IMS stations is very good to study the thunderstorm activity and its disparity which is a good proxy of the global warming. Progress in data processing for infrasound data in the last ten years and the appearance of global lightning detection network as the World Wide Lightning

  8. Spatio-temporal activity of lightnings over Greece

    NASA Astrophysics Data System (ADS)

    Nastos, P. T.; Matsangouras, I. T.; Chronis, T. G.

    2012-04-01

    Extreme precipitation events are always associated with convective weather conditions driving to intense lightning activity: Cloud to Ground (CG), Ground to Cloud (GC) and Cloud to Cloud (CC). Thus, the study of lightnings, which typically occur during thunderstorms, gives evidence of the spatio-temporal variability of intense precipitation. Lightning is a natural phenomenon in the atmosphere, being a major cause of storm related with deaths and main trigger of forest fires during dry season. Lightning affects the many electrochemical systems of the body causing nerve damage, memory loss, personality change, and emotional problems. Besides, among the various nitrogen oxides sources, the contribution from lightning likely represents the largest uncertainty. An operational lightning detection network (LDN) has been established since 2007 by HNMS, consisting of eight time-of-arrival sensors (TOA), spatially distributed across Greek territory. In this study, the spatial and temporal variability of recorded lightnings (CG, GC and CC) are analyzed over Greece, during the period from January 14, 2008 to December 31, 2009, for the first time. The data for retrieving the location and time-of-occurrence of lightning were acquired from Hellenic National Meteorological Service (HNMS). In addition to the analysis of spatio-temporal activity over Greece, the HNMS-LDN characteristics are also presented. The results of the performed analysis reveal the specific geographical sub-regions associated with lightnings incidence. Lightning activity occurs mainly during the autumn season, followed by summer and spring. Higher frequencies of flashes appear over Ionian and Aegean Sea than over land during winter period against continental mountainous regions during summer period.

  9. An 'Anomalous' Triggered Lightning Flash in Florida

    NASA Astrophysics Data System (ADS)

    Gamerota, W. R.; Uman, M. A.; Hill, J. D.; Pilkey, J. T.; Ngin, T.; Jordan, D. M.; Mata, C.; Mata, A.

    2012-12-01

    Classical (grounded wire) rocket-and-wire triggered lightning flashes whose leaders do not traverse the path of the wire remnants are sometimes referred to as 'anomalous'. We present high-speed video images captured at 10 kilo-frames per second (kfps), with supporting data, to characterize an 'anomalous' rocket-triggered lightning flash that occurred on 15 May 2012 at the International Center for Lightning Research and Testing (ICLRT) in north-central Florida. The event begins as a classical rocket-triggered lightning flash with an upward positive leader (UPL) initiating from the tip of the wire at a height of about 280 m above ground level. The top 259 m of the trailing wire explodes 2.7 s after the rocket exits the launch tube, while the bottom 17 m of the wire does not explode (does not become luminous). Approximately 1.4 ms after wire explosion, a stepped leader initiates a few meters above the top of the wire remnants and propagates downward, attaching to the top of a grounded utility pole 2.1 ms after initiation and 117 m southwest of the launching facility. Beginning 600 μs prior to this sustained stepped leader development, attempted stepped leaders (luminous steps emanating from the UPL channel above the wire remnants) are observed in three locations: 20 m and 5 m above the top of the wire remnants and at the top of the wire remnants. Correlated electric field derivative (dE/dt), channel-base current, and high-speed video captured at 300 kfps reveal an electrical discharge of peak current 365 A initiating from about 17 m above the launching facility, apparently the top of the unexploded triggering wire, when the stepped leader is no more than 60 m above ground level. There are significant differences between the 'anomalous' triggered lightning flash described here and those observed in New Mexico and in France in the late 1970s and early 1980s: First, the time duration between explosion of our wire and the sustained stepped leader development a few meters

  10. Spherical microwave confinement and ball lightning

    NASA Astrophysics Data System (ADS)

    Robinson, William Richard

    This dissertation presents the results of research done on unconventional energy technologies from 1995 to 2009. The present civilization depends on an infrastructure that was constructed and is maintained almost entirely using concentrated fuels and ores, both of which will run out. Diffuse renewable energy sources rely on this same infrastructure, and hence face the same limitations. I first examined sonoluminescence directed toward fusion, but demonstrated theoretically that this is impossible. I next studied Low Energy Nuclear Reactions and developed methods for improving results, although these have not been implemented. In 2000, I began Spherical Microwave Confinement (SMC), which confines and heats plasma with microwaves in a spherical chamber. The reactor was designed and built to provide the data needed to investigate the possibility of achieving fusion conditions with microwave confinement. A second objective was to attempt to create ball lightning (BL). The reactor featured 20 magnetrons, which were driven by a capacitor bank and operated in a 0.2 s pulse mode at 2.45 GHz. These provided 20 kW to an icosahedral array of 20 antennas. Video of plasmas led to a redesign of the antennas to provide better coupling of the microwaves to the plasma. A second improvement was a grid at the base of the antennas, which provided corona electrons and an electric field to aid quick formation of plasmas. Although fusion conditions were never achieved and ball lightning not observed, experience gained from operating this basic, affordable system has been incorporated in a more sophisticated reactor design intended for future research. This would use magnets that were originally planned. The cusp geometry of the magnetic fields is suitable for electron cyclotron resonance in the same type of closed surface that in existing reactors has generated high-temperature plasmas. Should ball lightning be created, it could be a practical power source with nearly ideal

  11. First Cloud-to-Ground Lightning Timing Study

    NASA Technical Reports Server (NTRS)

    Huddleston, Lisa L.

    2013-01-01

    NASA's LSP, GSDO and other programs use the probability of cloud-to-ground (CG) lightning occurrence issued by the 45th Weather Squadron (45 WS) in their daily and weekly lightning probability forecasts. These organizations use this information when planning potentially hazardous outdoor activities, such as working with fuels, or rolling a vehicle to a launch pad, or whenever personnel will work outside and would be at-risk from lightning. These organizations would benefit greatly if the 45 WS could provide more accurate timing of the first CG lightning strike of the day. The Applied Meteorology Unit (AMU) has made significant improvements in forecasting the probability of lightning for the day, but forecasting the time of the first CG lightning with confidence has remained a challenge. To address this issue, the 45 WS requested the AMU to determine if flow regimes, wind speed categories, or a combination of the two could be used to forecast the timing of the first strike of the day in the Kennedy Space Center (KSC)/Cape Canaveral Air Force Station (CCAFS) lightning warning circles. The data was stratified by various sea breeze flow regimes and speed categories in the surface to 5,000-ft layer. The surface to 5,000-ft layer was selected since that is the layer the 45 WS uses to predict the behavior of sea breeze fronts, which are the dominant influence on the occurrence of first lightning in Florida during the warm season. Due to small data sample sizes after stratification, the AMU could not determine a statistical relationship between flow regimes or speed categories and the time of the first CG strike.. As expected, although the amount and timing of lightning activity varies by time of day based on the flow regimes and speed categories, there are extended tails of low lightning activity making it difficult to specify times when the threat of the first lightning flash can be avoided. However, the AMU developed a graphical user interface with input from the 45 WS

  12. Are Perytons Signatures of Ball Lightning?

    NASA Astrophysics Data System (ADS)

    Dodin, I. Y.; Fisch, N. J.

    2014-10-01

    The enigmatic downchirped signals, called "perytons," that are detected by radio telescopes in the GHz frequency range may be produced by an atmospheric phenomenon known as ball lightning (BL). If BLs act as nonstationary radio frequency cavities, their characteristic emission frequencies and evolution timescales are consistent with peryton observations, and so are general patterns in which BLs are known to occur. Based on this evidence, testable predictions are made that can confirm or rule out a causal connection between perytons and BLs. In either case, how perytons are searched for in observational data may warrant reconsideration because existing procedures may be discarding events that have the same nature as known perytons.

  13. Lightning activity and severe storm structure

    NASA Technical Reports Server (NTRS)

    Taylor, W. L.; Brandes, E. A.; Rust, W. D.; Macgorman, D. R.

    1984-01-01

    Space-time mapping of VHF sources from four severe storms on June 19, 1980 reveals that lightning processes for cloud-to-ground (CG) and large intracloud (IC) flashes are confined to an altitude below about 10 km and closely associated with the central regions of high reflectivity. Another class of IC flashes produces a splattering of sources within the storms' main electrically active volumes and also within the large divergent wind canopy aloft. There is no apparent temporal association between the small high altitude IC flashes that occur almost continuously and the large IC and CG flashes that occur sporadically in the lower portions of storms.

  14. Determining Polarities Of Distant Lightning Strokes

    NASA Technical Reports Server (NTRS)

    Blakeslee, Richard J.; Brook, Marx

    1990-01-01

    Method for determining polarities of lightning strokes more than 400 km away. Two features of signal from each stroke correlated. New method based on fact each stroke observed thus far for which polarity determined unambiguously, initial polarity of tail same as polarity of initial deflection before initial-deflection signal altered by propagation effects. Receiving station equipped with electric-field-change antenna coupled to charge amplifier having time constant of order of 1 to 10 seconds. Output of amplifier fed to signal-processing circuitry, which determines initial polarity of tail.

  15. [Lightnings--danger while practising sport].

    PubMed

    Lewartowski, Mateusz

    2015-01-01

    Certain kinds of sporting disciplines are connected with a high risk of the lightning strike. Although most injuries are non-fatal, the transient or permanent damages of the nervous and ciruculatory systems or other internal organs are common. The concomitant psychological trauma may also be crucial. Various cases could be avoided by following simple safety rules. Wide educational programmes how to act during the stormy weather and elaboration of "stormy guidelines" should concern both sportsmen and people responsible for events safety. PMID:26827562

  16. Experimental simulation of early Martian volcanic lightning.

    PubMed

    Segura, A; Navarro-Gonzalez, R

    2001-01-01

    A mixture of possible Martian volcanic gases were reproduced and irradiated by a high-energy infrared laser to reproduce the effects of lightning on the production of prebiotic molecules. The analysis of products were performed by a gas chromatograph interfaced in parallel with a FTIR-detector and a quadrupole mass spectrometer equipped with an electron impact and chemical ionization modes. The main products identified were hydrocarbons and an uncharacterized yellow film deposit. Preliminary results indicate the presence of hydrogen cyanide among the resultant compounds. PMID:11605634

  17. Are perytons signatures of ball lightning?

    SciTech Connect

    Dodin, I. Y.; Fisch, N. J.

    2014-10-20

    The enigmatic downchirped signals, called 'perytons', that are detected by radio telescopes in the GHz frequency range may be produced by an atmospheric phenomenon known as ball lightning (BL). If BLs act as nonstationary radio frequency cavities, their characteristic emission frequencies and evolution timescales are consistent with peryton observations, and so are general patterns in which BLs are known to occur. Based on this evidence, testable predictions are made that can confirm or rule out a causal connection between perytons and BLs. In either case, how perytons are searched for in observational data may warrant reconsideration because existing procedures may be discarding events that have the same nature as known perytons.

  18. Lightning detection network averts damage and speeds restoration

    SciTech Connect

    Bernstein, R.; Samm, R.; Cummins, K.; Pyle, R.; Tuel, J.

    1996-04-01

    This article describes new tools to track thunderstorms for advance warning, enabling utilities to reduce damage and shorten repair time. Based on an extensive survey of US power utilities, lightning is the single largest cause of outages on distribution and transmission systems in lightning prone areas. But now with the aid of a network of electromagnetic sensors, computer systems, and satellite communications, the National Lightning Detection Network{trademark} (NLDN) helps utilities prepare for storms. Utilities in the path of intense lightning storms can prepare for storms, alert repair crews, and arrange for help from neighboring utilities. Real-time lightning data has been shown to reduce maintenance costs by shortening the thunder-storm-watch period and to improve reliability by allowing prepositioning of repair crews. Also, using line failure history, designers can analyze the lightning and line historical data and prioritize line upgrades to protect them from future storms by employing additional protection. Documented evidence available from the NLDN system helps utilities prove the time and location of lightning strikes, quickly resolving insurance claims. This network is a product of two EPRI research projects (RP3669 and RP2741).

  19. From an electron avalanche to the lightning discharge

    NASA Astrophysics Data System (ADS)

    Zalikhanov, B. Zh.

    2016-01-01

    The goal of this work is to describe qualitatively the physics of processes which begin with an electron avalanche and finish in a lightning discharge. A streamer model is considered that is based on studies of the recently discovered processes occurring in the prestreamer region. The investigation and analysis of these processes enabled making the conclusion that they are, in essence, the attendant processes, which ensure the electron avalanche-to-streamer transition, and may be interpreted as a manifestation of properties of a double charge layer exposed to the external electric field. The pressing problems of physical processes which form a lightning discharge are considered from the standpoint of new ideas about the mechanism of the streamer formation and growth. Causes of the emergence of coherent super-high-frequency radiation of a leader and the neutron production in a lightning discharge are revealed that have not been explained so far in the theory of gas discharge. Based also on new ideas about the lightning discharge, a simple ball-lightning model, providing answers to almost allquestions formulated from numerous observations on the behavior of ball lightning, is offered, and the need of a new design of lightning protection instead of the traditional rod is discussed.

  20. Exploring a Physically Based Tool for Lightning Cessation: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Schultz, Elsie V.; Petersen, Walter A.; Carey, Lawrence D.; Buechler, Dennis E.; Gatlin, Patrick N.

    2010-01-01

    The University of Alabama in Huntsville (UAHuntsville) and NASA s Marshall Space Flight Center are collaborating with the 45th Weather Squadron (45WS) at Cape Canaveral Air Force Station (CCAFS) to enable improved nowcasting of lightning cessation. The project centers on use of dual-polarimetric radar capabilities, and in particular, the new C-band dual-polarimetric weather radar acquired by the 45WS. Special emphasis is placed on the development of a physically based operational algorithm to predict lightning cessation. While previous studies have developed statistically based lightning cessation algorithms, we believe that dual-polarimetric radar variables offer the possibility to improve existing algorithms through the inclusion of physically meaningful trends reflecting interactions between in-cloud electric fields and microphysics. Specifically, decades of polarimetric radar research using propagation differential phase has demonstrated the presence of distinct phase and ice crystal alignment signatures in the presence of strong electric fields associated with lightning. One question yet to be addressed is: To what extent can these ice-crystal alignment signatures be used to nowcast the cessation of lightning activity in a given storm? Accordingly, data from the UAHuntsville Advanced Radar for Meteorological and Operational Research (ARMOR) along with the North Alabama Lightning Mapping Array are used in this study to investigate the radar signatures present before and after lightning cessation. A summary of preliminary results will be presented.

  1. Effect of Lightning Impulse Discharge on PVC Thin Film

    NASA Astrophysics Data System (ADS)

    Takamura, Norimitsu; Matsumoto, Takao; Nerome, Hazuki; Mishima, Kenji; Izawa, Yasuji; Hanai, Masahiro; Nishijima, Kiyoto

    2015-09-01

    Lightning damage to blades of wind turbine generators has been increasing in parallel with the recent increase in the installation of the generators. According to a paper, it is said that a large current produced by a lightning penetrates into the blades, the air temperature and pressure inside the blades increase, which causes destruction of the blades. In order to solve this problem, preventing lightning penetration into the blades and passing lightning only on the surface of the blades are required. Therefore, we undertook a basic research for finding out the mechanism of lightning penetration into the blades. In this study, as our original research for clarifying the above mechanism, we investigated the effect of lightning impulse discharge on some polyvinyl chloride thin films. A high voltage electrode and a ground electrode were set with 1.0 m separation. Each film was set at the midpoint of the electrodes and approximately 750 kV of only one positive lightning impulse voltage was applied to the electrodes. After discharge, the hole-, deformed- and tarnished- diameters of the films, formed by discharge, were measured using a microscope. The results suggest that the thickness and/or the volume resistivity of the films are deeply tied to destruction of the films by discharge.

  2. Summary of Global lightning and sprite measurements (GLIMS) mission

    NASA Astrophysics Data System (ADS)

    Ushio, T.; Kikuchi, H.; Sato, M.; Morimoto, T.; Suzuki, M.; Yamazaki, A.; Hobara, Y.; Kikuchi, M.; Adachi, T.; Takahashi, Y.

    2015-12-01

    The Global lightning and sprite measurements (GLIMS) mission aims to study the generation mechanism of lightning-associated transient luminous events (TLEs) and the relationship between lightning and TLEs. Four types of sensors attached to the International Space Station are used to observe a lightning and TLEs. All four types of sensors work synchronously. Two complementary-metal-oxide semiconductor cameras at two different wavelengths (lightning and sprite imager: LSI) are used to capture a position of optical emission from lightning and TLEs. Six photometers at six different wavelengths (PHs) record an optical emission intensity at high temporal resolution. Each photometer works to detect an altitude of optical mission through the use of the optical spectrum that are absorbed by atmospheric gases. A very low frequency (VLF) receiver is used for recording Whistler mode waves from lightning. Very high frequency interferometer (VITF) with two VHF sensors estimates the radiation source direction using phase interference technique. In JEM-GLIMS mission, it is notable that it is possible to conduct a simultaneous observation of optical and radio instruments. The mission has been conducted since November 2012. In this paper, we will show the findings of experimental work conducted during the past 3 years (2013-2015).

  3. A Comparison between Lightning Activity and Passive Microwave Measurements

    NASA Technical Reports Server (NTRS)

    Kevin, Driscoll T.; Hugh, Christian J.; Goodman, Steven J.

    1999-01-01

    A recent examination of data from the Lightning Imaging Sensor (LIS) and the TRMM Microwave Imager (TMI) suggests that storm with the highest frequency of lightning also possess the most pronounced microwave scattering signatures at 37 and 85 GHz. This study demonstrates a clear dependence between lightning and the passive microwave measurements, and accentuates how direct the relationship really is between cloud ice and lightning activity. In addition, the relationship between the quantity of ice content and the frequency of lightning (not just the presence of lightning) , is consistent throughout the seasons in a variety of regimes. Scatter plots will be presented which show the storm-averaged brightness temperatures as a function of the lightning density of the storms (L/Area) . In the 85 GHz and 37 GHz scatter plots, the brightness temperature is presented in the form Tb = k1 x log10(L/Area) + k2, where the slope of the regression, k1, is 58 for the 85 GHz relationship and 30.7 for the 37 GHz relationship. The regression for both these fits showed a correlation of 0.76 (r2 = 0.58), which is quite promising considering the simple procedure used to make the comparisons, which have not yet even been corrected for the view angle differences between the instruments, or the polarization corrections in the microwave imager.

  4. Structural Analysis of Lightning Protection System for New Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Cope, Anne; Moore, Steve; Pruss, Richard

    2008-01-01

    This project includes the design and specification of a lightning protection system for Launch Complex 39 B (LC39B) at Kennedy Space Center, FL in support of the Constellation Program. The purpose of the lightning protection system is to protect the Crew Launch Vehicle (CLV) or Cargo Launch Vehicle (CaLV) and associated launch equipment from direct lightning strikes during launch processing and other activities prior to flight. The design includes a three-tower, overhead catenary wire system to protect the vehicle and equipment on LC39B as described in the study that preceded this design effort: KSC-DX-8234 "Study: Construct Lightning Protection System LC3 9B". The study was a collaborative effort between Reynolds, Smith, and Hills (RS&H) and ASRC Aerospace (ASRC), where ASRC was responsible for the theoretical design and risk analysis of the lightning protection system and RS&H was responsible for the development of the civil and structural components; the mechanical systems; the electrical and grounding systems; and the siting of the lightning protection system. The study determined that a triangular network of overhead catenary cables and down conductors supported by three triangular free-standing towers approximately 594 ft tall (each equipped with a man lift, ladder, electrical systems, and communications systems) would provide a level of lightning protection for the Constellation Program CLV and CaLV on Launch Pad 39B that exceeds the design requirements.

  5. Simulating lightning into the RAMS model: implementation and preliminary results

    NASA Astrophysics Data System (ADS)

    Federico, S.; Avolio, E.; Petracca, M.; Panegrossi, G.; Sanò, P.; Casella, D.; Dietrich, S.

    2014-05-01

    This paper shows the results of a tailored version of a previously published methodology, designed to simulate lightning activity, implemented into the Regional Atmospheric Modeling System (RAMS). The method gives the flash density at the resolution of the RAMS grid-scale allowing for a detailed analysis of the evolution of simulated lightning activity. The system is applied in detail to two case studies occurred over the Lazio Region, in Central Italy. Simulations are compared with the lightning activity detected by the LINET network. The cases refer to two thunderstorms of different intensity. Results show that the model predicts reasonably well both cases and that the lightning activity is well reproduced especially for the most intense case. However, there are errors in timing and positioning of the convection, whose magnitude depends on the case study, which mirrors in timing and positioning errors of the lightning distribution. To assess objectively the performance of the methodology, standard scores are presented for four additional case studies. Scores show the ability of the methodology to simulate the daily lightning activity for different spatial scales and for two different minimum thresholds of flash number density. The performance decreases at finer spatial scales and for higher thresholds. The comparison of simulated and observed lighting activity is an immediate and powerful tool to assess the model ability to reproduce the intensity and the evolution of the convection. This shows the importance of the use of computationally efficient lightning schemes, such as the one described in this paper, in forecast models.

  6. Understanding Return Stroke Data with Time Domain Fractal Lightning Modeling

    NASA Astrophysics Data System (ADS)

    Liang, C.; Carlson, B. E.; Lehtinen, N. G.; Inan, U. S.

    2012-12-01

    Time domain fractal lightning (TDFL) modeling is an evolving technique for the study of lightning in the context of comprehensive existing experimental data. It incorporates the complex geometry of the lightning channel, keeps track of the time evolution of charge and current distribution along the lightning channel, and with both combined, simulates realistic electromagnetic radiation signals from lightning flashes. Recent development enhances the technique by bringing in various elements from the plasma physics aspect of lightning physics. For example, simple models are included to take account of effects due to corona sheath, channel heating and cooling, channel conductivity dependence on temperature etc. With future development, an even more sophisticated treatment of these elements is expected. With these features at hand, we present studies of return stroke related experimental data using TDFL. A wide variety of experimental data exists for the return stroke, including ground-base-current measurements, electric and magnetic field record, channel luminosity and estimations of various channel properties. We study these various aspects of lightning data under the single framework provided by TDFL. Emphasis is on exploring and explaining connections between the different types of data, e.g. dependence of the return stroke speed and electric field on channel properties, relation between ground-base-current peak current and charge transfer. Various other aspects such as effect of tortuous channel geometry, branches, and corona sheath are also explored.

  7. Lightning flash density in relation to aerosol over Nanjing (China)

    NASA Astrophysics Data System (ADS)

    Tan, Y. B.; Peng, L.; Shi, Z.; Chen, H. R.

    2016-06-01

    Time series data of lightning flash density, aerosol optical depth (AOD), surface temperature, convective available potential energy (CAPE) and thunderstorm days for 10 years (2002-2011), cloud-to-ground lightning (CG), and AOD of 5 years for summer season, i.e., June, July, and August over Nanjing, China, have been analyzed, to investigate the impact of aerosols on lightning. The results indicate that the radiative effect of aerosol may be one of the main reason for the decrease of the lightning flash density in a long period, while the aerosol microphysical effect may be a major role in the increase of the percent of + CG flashes (P+ CG). The dependence of surface temperature, CAPE, and thunderstorm days on AOD (R = - 0.748, - 0.741, - 0.744), and the negative correlation (R = - 0.634) between lightning flash density and AOD may lend support for the radiative effect of aerosol on lightning. In addition, elevated aerosols may change the charge distribution in thundercloud, hence enhancing the positive cloud-to-ground lightning (+ CG) activity, as P+ CG is positively correlated with AOD.

  8. Beijing Lightning Network (BLNET): Configuration, Function and Preliminary Results

    NASA Astrophysics Data System (ADS)

    Qie, X.; Wang, D.; Wang, Y.; Liu, M.; Tian, Y.; Lu, G.

    2015-12-01

    A regional multi-frequency-band lightning detection network in Beijing (BLNET) has been developed for both research and operational purposes. The network is employed in the experiment of Dynamic-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards (Storm973), supported by Ministry of Science and Technology as National Key Basic Research Program of China or 973 Program. The network consisted of 16 stations in 2015 covering most part of The "Jing-Jin-Ji" (Beijing-Tianjin-Hebei) metropolis zone, one of the most developed areas in China. Four different sensors, including slow antenna, fast antenna, magnetic antenna, and VHF antenna, are integrated in each station to detect lightning radiation signals in different frequency band. The Chan algorithm and Levenberg-Marquardt method are adopted jointly in the lightning location algorithm. In addition to locate the lightning radiation pulses in two-dimension or three-dimension in different band, the charge source neutralized by the lightning discharge can be retrieved either. The theoretical horizontal error over the network is less than 200 m and the vertical error is less than 500 m over the network. The comparison of total lightning location results with corresponding radar echoes for thunderstorm cases indicates the good performance of BLNET in the severe convection surveillance. The actual two-dimensional location error in VLF/LF band, compared with a ground truth that acquired with a GPS-synchronized high-speed video camera, is about 250 m.

  9. Extensive air showers, lightning, and thunderstorm ground enhancements

    NASA Astrophysics Data System (ADS)

    Chilingarian, A.; Hovsepyan, G.; Kozliner, L.

    2016-09-01

    For lightning research, we monitor particle fluxes from thunderclouds, the so-called thunderstorm ground enhancements (TGEs) initiated by runaway electrons, and extensive air showers (EASs) originating from high-energy protons or fully stripped nuclei that enter the Earth's atmosphere. We also monitor the near-surface electric field and atmospheric discharges using a network of electric field mills. The Aragats "electron accelerator" produced several TGEs and lightning events in the spring of 2015. Using 1-s time series, we investigated the relationship between lightning and particle fluxes. Lightning flashes often terminated the particle flux; in particular, during some TGEs, lightning events would terminate the particle flux thrice after successive recovery. It was postulated that a lightning terminates a particle flux mostly in the beginning of a TGE or in its decay phase; however, we observed two events (19 October 2013 and 20 April 2015) when the huge particle flux was terminated just at the peak of its development. We discuss the possibility of a huge EAS facilitating lightning leader to find its path to the ground.

  10. On remote measurements of lightning return stroke peak currents

    NASA Astrophysics Data System (ADS)

    Mallick, S.; Rakov, V. A.; Tsalikis, D.; Nag, A.; Biagi, C.; Hill, D.; Jordan, D. M.; Uman, M. A.; Cramer, J. A.

    2014-01-01

    Return-stroke peak current is one of the most important measures of lightning intensity needed in different areas of atmospheric electricity research. It can be estimated from the corresponding electric or magnetic radiation field peak. Electric fields of 89 strokes in lightning flashes triggered using the rocket-and-wire technique at Camp Blanding (CB), Florida, were recorded at the Lightning Observatory in Gainesville, about 45 km from the lightning channel. Lightning return-stroke peak currents were estimated from the measured electric field peaks using the empirical formula of Rakov et al. (1992) and the field-to-current conversion equation based on the transmission line model (Uman and McLain, 1969). These estimates, along with peak currents reported by the U.S. National Lightning Detection Network (NLDN), were compared with the ground-truth data, currents directly measured at the lightning channel base. The empirical formula, based on data for 28 triggered-lightning strokes acquired at the Kennedy Space Center (KSC), tends to overestimate peak currents, whereas the NLDN-reported peak currents are on average underestimates. The field-to-current conversion equation based on the transmission line model gives the best match with directly measured peak currents for return-stroke speeds between c/2 and 2c/3 (1.5 and 2 × 108 m/s, respectively). Possible reasons for the discrepancy in the peak current estimates from the empirical formula and the ground-truth data include an error in the field calibration factor, difference in the typical return-stroke speeds at CB and at the KSC (considered here to be the most likely reason), and limited sample sizes, particularly for the KSC data. A new empirical formula, I = - 0.66-0.028rE, based on data for 89 strokes in lightning flashes triggered at CB, is derived.

  11. Estimating Lightning NOx Emissions for Regional Air Quality Modeling

    NASA Astrophysics Data System (ADS)

    Holloway, T.; Scotty, E.; Harkey, M.

    2014-12-01

    Lightning emissions have long been recognized as an important source of nitrogen oxides (NOx) on a global scale, and an essential emission component for global atmospheric chemistry models. However, only in recent years have regional air quality models incorporated lightning NOx emissions into simulations. The growth in regional modeling of lightning emissions has been driven in part by comparisons with satellite-derived estimates of column NO2, especially from the Ozone Monitoring Instrument (OMI) aboard the Aura satellite. We present and evaluate a lightning inventory for the EPA Community Multiscale Air Quality (CMAQ) model. Our approach follows Koo et al. [2010] in the approach to spatially and temporally allocating a given total value based on cloud-top height and convective precipitation. However, we consider alternate total NOx emission values (which translate into alternate lightning emission factors) based on a review of the literature and performance evaluation against OMI NO2 for July 2007 conditions over the U.S. and parts of Canada and Mexico. The vertical distribution of lightning emissions follow a bimodal distribution from Allen et al. [2012] calculated over 27 vertical model layers. Total lightning NO emissions for July 2007 show the highest above-land emissions in Florida, southeastern Texas and southern Louisiana. Although agreement with OMI NO2 across the domain varied significantly depending on lightning NOx assumptions, agreement among the simulations at ground-based NO2 monitors from the EPA Air Quality System database showed no meaningful sensitivity to lightning NOx. Emissions are compared with prior studies, which find similar distribution patterns, but a wide range of calculated magnitudes.

  12. Lightning and radar observations of hurricane Rita landfall

    SciTech Connect

    Henderson, Bradley G; Suszcynsky, David M; Hamlin, Timothy E; Jeffery, C A; Wiens, Kyle C; Orville, R E

    2009-01-01

    Los Alamos National Laboratory (LANL) owns and operates an array of Very-Low Frequency (VLF) sensors that measure the Radio-Frequency (RF) waveforms emitted by Cloud-to-Ground (CG) and InCloud (IC) lightning. This array, the Los Alamos Sferic Array (LASA), has approximately 15 sensors concentrated in the Great Plains and Florida, which detect electric field changes in a bandwidth from 200 Hz to 500 kHz (Smith et al., 2002). Recently, LANL has begun development of a new dual-band RF sensor array that includes the Very-High Frequency (VHF) band as well as the VLF. Whereas VLF lightning emissions can be used to deduce physical parameters such as lightning type and peak current, VHF emissions can be used to perform precise 3d mapping of individual radiation sources, which can number in the thousands for a typical CG flash. These new dual-band sensors will be used to monitor lightning activity in hurricanes in an effort to better predict intensification cycles. Although the new LANL dual-band array is not yet operational, we have begun initial work utilizing both VLF and VHF lightning data to monitor hurricane evolution. In this paper, we present the temporal evolution of Rita's landfall using VLF and VHF lightning data, and also WSR-88D radar. At landfall, Rita's northern eyewall experienced strong updrafts and significant lightning activity that appear to mark a transition between oceanic hurricane dynamics and continental thunderstorm dynamics. In section 2, we give a brief overview of Hurricane Rita, including its development as a hurricane and its lightning history. In the following section, we present WSR-88D data of Rita's landfall, including reflectivity images and temporal variation. In section 4, we present both VHF and VLF lightning data, overplotted on radar reflectivity images. Finally, we discuss our observations, including a comparison to previous studies and a brief conclusion.

  13. Volcanic Lightning: New Global Observations and Constraints on Source Mechanisms

    NASA Astrophysics Data System (ADS)

    McNutt, S. R.; Venzke, E.; Williams, E.

    2012-12-01

    New data on volcanic lightning from the Smithsonian Volcano Reference File are added to an existing database and greatly expand the number of cases available for study. Lightning has now been documented at 154 volcanoes in association with 394 eruptions, a significant increase from the earlier numbers of 89 volcanoes and 240 eruptions. Lightning and electrification at volcanoes are important because they represent a hazard in their own right, they are a component of the global electrical circuit, and because they contribute to ash particle aggregation and modification within ash plumes. The role of water substance (water in all forms) in particular has not been well studied. The Volcanic Explosivity Index (VEI) was determined for 177 eruptions. Eight percent of VEI=3-5 eruptions have reported lightning, and 10 percent of VEI=6, but less than 2 percent of those with VEI=1-2, suggesting consistent reporting for larger eruptions but either less lightning or under-reporting for small eruptions. Ash plume heights (142 observations) show a bimodal distribution with peaks at 7-12 km and 1-4 km. The former are similar to heights of typical thunderstorms and suggest involvement of water substance, whereas the latter suggest other factors contributing to electrical behavior near the vent. The distributions of the latitudes of volcanoes with lightning and eruptions with lightning roughly mimic the distribution of all volcanoes; flat with latitude. Meteorological lightning, on the other hand, is common in the tropics and decreases markedly with increasing latitude as the ability of the atmosphere to hold water decreases poleward. This finding supports the idea that if lightning in large eruptions depends on water substance, then the origin of the water is primarily magma and not entrainment from the surrounding atmosphere.

  14. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely-piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. Data obtained through sensors mounted to the aircraft will allow researchers in ACES to gauge elements such as lightning activity and the electrical environment in and around storms. By learning more about individual storms, scientists hope to better understand the global water and energy cycle, as well as climate variability. Contained in one portion of the aircraft is a three-axis magnetic search coil, which measures the AC magnetic field; a three-axis electric field change sensor; an accelerometer; and a three-axis magnetometer, which measures the DC magnetic field. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  15. Optical Emissions Associated with Stepping Lightning Leaders in Cloud-to-Ground Lightning Flashes

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Celestin, Sebastien; Pasko, Victor

    2015-04-01

    Intense and brief bursts of X-ray emissions have been detected from the ground during natural cloud-to-ground (CG) [Moore et al., GRL, 28, 2141-2144, 2001] and rocket-triggered lightning flashes [Dwyer et al., Science, 299, 694-697, 2003]. The measurements at the International Center for Lightning Research and Testing (ICLRT) have further revealed that discrete and intense bursts of X-rays were closely correlated with the formation of leader steps during CGs [Dwyer et al., GRL, 32, L01803, 2005]. The mechanism of relativistic runaway electron avalanches (RREAs) in large-scale thunderstorm electric fields has been ruled out for this energetic phenomenon as it is not capable of explaining the observed energy spectra [Dwyer, GRL, 31, L12102, 2004]. On the other hand, Celestin and Pasko [JGR, 116, A03315, 2011] have shown theoretically how the large flux of thermal runaway electrons generated by streamers during the negative corona flash stage of stepping lightning leaders could instead be responsible for these X-ray bursts during negative CGs, and for terrestrial gamma-ray flashes (TGFs) [Fishman et al., Science, 264, 1313-1316, 1994] during intra-cloud lightning flashes (IC). In addition to intense X-ray emissions, Stolzenburg et al. [JGR, 118, 2918-2937, 2013] have suggested that the impulsive breakdown associated with initial leaders during the initial breakdown (IB) stages of CGs and ICs can generate considerable amount of visible light. The purpose of the present work is to quantify the optical emissions resulting from the excitation of air molecules produced during the acceleration process of thermal runaway electrons in the highly inhomogeneous electric field produced around lightning leader tip region in negative CGs. For this purpose, a full energy range Monte Carlo model combined with an optical emission model is employed to simulate, from first principles, the dynamics of electrons in the energy range from sub-eV to GeV and the subsequent generation of

  16. NO{sub x} from lightning 1. Global distribution based on lightning physics

    SciTech Connect

    Price, C. |; Penner, J. |; Prather, M.

    1997-03-01

    This paper begins a study on the role of lightning in maintaining the global distribution of nitrogen oxides (NO{sub x}) in the troposphere. It presents the first global and seasonal distributions of lightning-produced NO{sub x} (LNO{sub x}) based on the observed distribution of electrical storms and the physical properties of lightning strokes. We derive a global rate for cloud-to-ground (CG) flashes of 20{endash}30 flashes/s with a mean energy per flash of 6.7{times}10{sup 9}J. Intracloud (IC) flashes are more frequent, 50{endash}70 flashes/s but have 10{percent} of the energy of CG strokes and, consequently, produce significantly less NO{sub x}. It appears to us that the majority of previous studies have mistakenly assumed that all lightning flashes produce the same amount of NO{sub x}, thus overestimating the NO{sub x} production by a factor of 3. On the other hand, we feel these same studies have underestimated the energy released in CG flashes, resulting in two negating assumptions. For CG energies we adopt a production rate of 10{times}10{sup 16} molecules NO/J based on the current literature. Using a method to simulate global lightning frequencies from satellite-observed cloud data, we have calculated the LNO{sub x} on various spatial (regional, zonal, meridional, and global) and temporal scales (daily, monthly, seasonal, and interannual). Regionally, the production of LNO{sub x} is concentrated over tropical continental regions, predominantly in the summer hemisphere. The annual mean production rate is calculated to be 12.2 Tg N/yr, and we believe it extremely unlikely that this number is less than 5 or more than 20 Tg N/yr. Although most of LNO{sub x} is produced in the lowest 5 km by CG lightning, convective mixing in the thunderstorms is likely to deposit large amounts of NO{sub x} in the upper troposphere where it is important in ozone production. (Abstract Truncated)

  17. Laser decontamination of the radioactive lightning rods

    NASA Astrophysics Data System (ADS)

    Potiens, A. J.; Dellamano, J. C.; Vicente, R.; Raele, M. P.; Wetter, N. U.; Landulfo, E.

    2014-02-01

    Between 1970 and 1980 Brazil experienced a significant market for radioactive lightning rods (RLR). The device consists of an air terminal with one or more sources of americium-241 attached to it. The sources were used to ionize the air around them and to increase the attraction of atmospheric discharges. Because of their ineffectiveness, the nuclear regulatory authority in Brazil suspended the license for manufacturing, commerce and installation of RLR in 1989, and determined that the replaced RLR were to be collected to a centralized radioactive waste management facility for treatment. The first step for RLR treatment is to remove the radioactive sources. Though they can be easily removed, some contaminations are found all over the remaining metal scrap that must decontaminated for release, otherwise it must be treated as radioactive waste. Decontamination using various chemicals has proven to be inefficient and generates large amounts of secondary wastes. This work shows the preliminary results of the decontamination of 241Am-contaminated metal scrap generated in the treatment of radioactive lightning rods applying laser ablation. A Nd:YAG nanoseconds laser was used with 300 mJ energy leaving only a small amount of secondary waste to be treated.

  18. Another look at aircraft-triggered lightning

    NASA Technical Reports Server (NTRS)

    Clifford, D. W.

    1980-01-01

    There is positive evidence that a rapidly moving aircraft charged to high potentials by triboelectric processes can trigger lightning discharges by passage through freezing precipitation. The freezing zone in a nonstormy rain cloud is shown to be an electrically volatile region because of the potent charge exchange mechanisms which are active in agitated mixtures of supercooled water droplet and ice. Several intensifying effects are suggested which can be produced by the passage of an aircraft through this precipitation, resulting in a highly-ionized wake which acts like a trailing conductor. If weak charge centers are present in the cloud, the ionized wake acts to short out the gradient field resulting in very high potentials at the aircraft. The high potentials explain the electrical activity at the aircraft described by pilots, including intense corona, sparks and radio interference terminating in a loud discharge. Lightning strikes to naval aircraft towing gunnery targets at the end of long steel cables are described, showing that the same triggering mechanism may be involved in those cases. Recommendations are made to include triggering experiments in government flight programs now in progress.

  19. Tortuosity of lightning return stroke channels

    NASA Technical Reports Server (NTRS)

    Levine, D. M.; Gilson, B.

    1984-01-01

    Data obtained from photographs of lightning are presented on the tortuosity of return stroke channels. The data were obtained by making piecewise linear fits to the channels, and recording the cartesian coordinates of the ends of each linear segment. The mean change between ends of the segments was nearly zero in the horizontal direction and was about eight meters in the vertical direction. Histograms of these changes are presented. These data were used to create model lightning channels and to predict the electric fields radiated during return strokes. This was done using a computer generated random walk in which linear segments were placed end-to-end to form a piecewise linear representation of the channel. The computer selected random numbers for the ends of the segments assuming a normal distribution with the measured statistics. Once the channels were simulated, the electric fields radiated during a return stroke were predicted using a transmission line model on each segment. It was found that realistic channels are obtained with this procedure, but only if the model includes two scales of tortuosity: fine scale irregularities corresponding to the local channel tortuosity which are superimposed on large scale horizontal drifts. The two scales of tortuosity are also necessary to obtain agreement between the electric fields computed mathematically from the simulated channels and the electric fields radiated from real return strokes. Without large scale drifts, the computed electric fields do not have the undulations characteristics of the data.

  20. Two experimental investigations of ball lightning

    NASA Astrophysics Data System (ADS)

    Alexeff, Igor; Parameswaran, Sriram; Grace, Michael

    2004-11-01

    We have carried out two experiments that appear to produce ball lightning in the laboratory. The first set of observations were made at the Holifield high voltage accelerator at the Oak Ridge National Laboratory (1). In these experiments at very high voltage, closed current loops were photographed in high voltage sparkovers. These may be current loops sustained by the enclosed magnetic field. In the second set of experiments, a pulsed electric arc in a zero - gravity environment produced orange balls in atmospheric - pressure air that persisted for over 1/2 second after power turn - off (2). These balls were photographed with a high - speed 16 mm movie camera. Photos and movies of these experiments will be presented. 1. "Observation of Closed Loops in High-Voltage Discharges: A Possible Precursor of Magnetic Flux Trapping", Igor Alexeff and Mark Rader, IEEE Transactions on Plasma Science, Vol. 20, No. 6, December 1992, pp.669 - 671: ``Possible Precursors of Ball Lightning--Observation of Closed Loops in High- Voltage Discharges,'' Igor Alexeff and Mark Rader, Fusion Technology, Vol. 27, May 1995, pp 271 - 273 2. I. Alexeff et. al., Invited paper at The International Conference on Plasma Science, Preceedings of the Conference, Baltimore, Md., June 2004.