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Sample records for lightning long-wave radio

  1. Full-wave reflection of lightning long-wave radio pulses from the ionospheric D region: Comparison with midday observations of broadband lightning signals

    NASA Astrophysics Data System (ADS)

    Jacobson, Abram R.; Shao, Xuan-Min; Holzworth, Robert

    2010-05-01

    We are developing and testing a steep-incidence D region sounding method for inferring profile information, principally regarding electron density. The method uses lightning emissions (in the band 5-500 kHz) as the probe signal. The data are interpreted by comparison against a newly developed single-reflection model of the radio wave's encounter with the lower ionosphere. The ultimate application of the method will be to study transient, localized disturbances of the nocturnal D region, including those instigated by lightning itself. Prior to applying the method to study lightning-induced perturbations of the nighttime D region, we have performed a validation test against more stable and predictable daytime observations, where the profile of electron density is largely determined by direct solar X-ray illumination. This article reports on the validation test. Predictions from our recently developed full-wave ionospheric-reflection model are compared to statistical summaries of daytime lightning radiated waveforms, recorded by the Los Alamos Sferic Array. The comparison is used to retrieve best fit parameters for an exponential profile of electron density in the ionospheric D region. The optimum parameter values are compared to those found elsewhere using a narrowband beacon technique, which used totally different measurements, ranges, and modeling approaches from those of the work reported here.

  2. Fast radio bursts as pulsar lightning

    NASA Astrophysics Data System (ADS)

    Katz, J. I.

    2017-07-01

    There are striking phenomenological similarities between fast radio bursts (FRBs) and lightning in the Earth's and planetary atmospheres. Both have very low duty factors, ≲10-8-10-5 for FRBs and (very roughly) ˜10-4 for the main return strokes in an active thundercloud. Lightning occurs in an electrified insulating atmosphere when a conducting path is created by and permits current flow. FRBs may occur in neutron star magnetospheres whose plasma is believed to be divided by vacuum gaps. Vacuum is a perfect insulator unless electric fields are sufficient for electron-positron pair production by curvature radiation, a high-energy analogue of electrostatic breakdown in an insulating gas. FRB may be 'electrars' powered by the release of stored electrostatic energy, counterparts to soft gamma repeaters powered by the release of stored magnetostatic energy (magnetars). This frees pulsar FRB models from the constraint that their power not exceeds the instantaneous spin-down power. Energetic constraints imply that the sources of more energetic FRBs have shorter spin-down lifetimes, perhaps even less than the 3 yr over which FRB 121102 has been observed to repeat.

  3. 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).

  4. Analysis of ELF Radio Atmospherics Radiated by Rocket-Triggered Lightning

    NASA Astrophysics Data System (ADS)

    Dupree, N. A.; Moore, R. C.; Pilkey, J. T.; Uman, M. A.; Jordan, D. M.; Caicedo, J. A.; Hare, B.; Ngin, T. K.

    2014-12-01

    Experimental observations of ELF radio atmospherics produced by rocket-triggered lightning flashes are used to analyze Earth-ionosphere waveguide excitation and propagation characteristics. Rocket-triggered lightning experiments are performed at the International Center for Lightning Research and Testing (ICLRT) located at Camp Blanding, Florida. Long-distance ELF observations are performed in California, Greenland, and Antarctica. The lightning current waveforms directly measured at the base of the lightning channel (at the ICLRT) along with pertinent Lightning Mapping Array (LMA) data are used together with the Long Wavelength Propagation Capability (LWPC) code to predict the radio atmospheric (sferic) waveform observed at the receiver locations under various ionospheric conditions. We identify fitted exponential electron density profiles that accurately describe the observed propagation delays, phase delays, and signal amplitudes. The ability to infer ionospheric characteristics using distant ELF observations greatly enhances ionospheric remote sensing capabilities, especially in regard to interpreting observations of transient luminous events (TLEs) and other ionospheric effects associated with lightning.

  5. Observations of lightning processes using VHF radio interferometry

    NASA Technical Reports Server (NTRS)

    Rhodes, C. T.; Shao, X. M.; Krehbiel, P. R.; Thomas, R.

    1991-01-01

    A single station, multiple baseline radio interferometer was used to locate the direction of VHF radiation from lightning discharges with microsec time resolution. Radiation source directions and electric field waveforms were analyzed for various types of breakdown events. These include initial breakdown and K type events of in-cloud activity, and the leaders of initial and subsequent strokes to ground and activity during and following return strokes. Radiation during the initial breakdown of a flash and in the early stages of initial leaders to ground is found to be similar. In both instances, the activity consists of localized bursts of radiation that are intense and slow moving. Motion within a given burst is unresolved by the interferometer. Radiation from in-cloud K type events is essentially the same as that from dart leaders; in both cases it is produced at the leading edge of a fast moving streamer that propagates along a well defined, often extensive path. K type events are sometimes terminated by fast field changes that are similar to the return stroke initiated by dart leaders; such K type events are the in-cloud analog of the dart leader return stroke process.

  6. Lightning detection from Space Science and Applications Team review. [optical and radio frequency sensors

    NASA Technical Reports Server (NTRS)

    Few, A. A., Jr.

    1981-01-01

    The various needs for lightning data that exist among potential users of satellite lightning data were identified and systems were defined which utilize the optical and radio frequency radiations from lightning to serve as the satellite based lightning mapper. Three teams worked interactively with NASA to develop a system concept. An assessment of the results may be summarized as follows: (1) a small sensor system can be easily designed to operate on a geostationary satellite that can provide the bulk of the real time user requirements; (2) radio frequency systems in space may be feasible but would be much larger and more costly; RF technology for this problem lags the optical technology by years; and (3) a hybrid approach (optical in space and RF on the ground) would provide the most complete information but is probably unreasonably complex and costly at this time.

  7. Ship-borne Radio and GLD360 Measurements of Intense Oceanic Lightning

    NASA Astrophysics Data System (ADS)

    Zoghzoghy, F. G.; Cohen, M.; Said, R.; Lehtinen, N. G.; Inan, U.

    2013-12-01

    Recent studies with the GLD360 lightning geo-location network have shown that the peak current intensity of cloud-to-ground (CG) lightning is more powerful over the ocean than over land. This remains a poorly understood phenomenon. The Stanford VLF group has recently deployed a Very Low Frequency (1 MHz sampling rate) radio receiver system aboard the NOAA Ronald W. Brown research vessel. The goal of this transatlantic experiment is to improve our understanding of oceanic lightning and to investigate the physical difference between oceanic and land lightning. When positioned reasonably close to deep oceanic thunderstorms, the LF-VLF receiver aboard the Ronald W. Brown detects the impulsive radio emissions from the return stroke, up to 1 MHz, which enables us to estimate the return-stroke waveform shapes generated by the lightning channel. In this presentation, we present our experimental setup and a summary of the data collected during the transatlantic voyages of the NOAA ship. We process lightning-generated waveforms, compare them to LF-VLF data from land lightning over Oklahoma, extract statistical patterns, and compare the data to numerical and analytical models.

  8. Comparison between model predictions and observations of ELF radio atmospherics generated by rocket-triggered lightning

    NASA Astrophysics Data System (ADS)

    Dupree, N. A.; Moore, R. C.

    2011-12-01

    Model predictions of the ELF radio atmospheric generated by rocket-triggered lightning are compared with observations performed at Arrival Heights, Antarctica. The ability to infer source characteristics using observations at great distances may prove to greatly enhance the understanding of lightning processes that are associated with the production of transient luminous events (TLEs) as well as other ionospheric effects associated with lightning. The modeling of the sferic waveform is carried out using a modified version of the Long Wavelength Propagation Capability (LWPC) code developed by the Naval Ocean Systems Center over a period of many years. LWPC is an inherently narrowband propagation code that has been modified to predict the broadband response of the Earth-ionosphere waveguide to an impulsive lightning flash while preserving the ability of LWPC to account for an inhomogeneous waveguide. ELF observations performed at Arrival Heights, Antarctica during rocket-triggered lightning experiments at the International Center for Lightning Research and Testing (ICLRT) located at Camp Blanding, Florida are presented. The lightning current waveforms directly measured at the base of the lightning channel (at the ICLRT) are used together with LWPC to predict the sferic waveform observed at Arrival Heights under various ionospheric conditions. This paper critically compares observations with model predictions.

  9. Modeling Long-Distance ELF Radio Atmospherics Generated by Rocket-Triggered Lightning

    NASA Astrophysics Data System (ADS)

    Moore, R. C.; Kunduri, B.; Anand, S.; Dupree, N.; Mitchell, M.; Agrawal, D.

    2010-12-01

    This paper addresses the generation and propagation of radio atmospherics (sferics) radiated by lightning in order to assess the ability to infer the electrical properties of lightning from great distances. This ability may prove to greatly enhance the understanding of lightning processes that are associated with the production of transient luminous events (TLEs) as well as other ionospheric effects associated with lightning. The modeling of the sferic waveform is carried out using a modified version of the Long Wavelength Propagation Capability (LWPC) code developed by the Naval Ocean Systems Center over a period of many years. LWPC is an inherently narrowband propagation code that has been modified to predict the broadband response of the Earth-ionosphere waveguide to an impulsive lightning flash. Unlike other similar efforts, the modified code presented preserves the ability of LWPC to account for waveguide mode-coupling and to account for changes to the electrical properties of the ground and ionosphere along the propagation path. The effort described is conducted in advance of the deployment of a global extremely low frequency (ELF) magnetic field array, which is presently under construction. The global ELF array is centered on the International Center for Lightning Research and Testing (ICLRT) located at Camp Blanding, Florida. The ICLRT is well-known for conducting rocket-triggered lightning experiments over the last 15-20 years. This paper uses lightning current waveforms directly measured at the base of the lightning channel (observations performed at the ICLRT) as an input to the model to predict the sferic waveform to be observed by the array under various ionospheric conditions. An analysis of the predicted sferic waveforms is presented, and the components of the lightning current waveform that most effectively excite the Earth-ionosphere waveguide are identified.

  10. Power spectra at radio frequency of lightning return stroke waveforms

    NASA Technical Reports Server (NTRS)

    Lanzerotti, L. J.; Thomson, D. J.; Maclennan, C. G.; Rinnert, K.; Krider, E. P.

    1989-01-01

    The power spectra of the wideband (10 Hz to 100 kHz) magnetic field signals in a number of lightning return strokes (primarily first return strokes) measured during a lightning storm which occurred in Lindau, West Germany in August, 1984 have been calculated. The RF magnetic field data were obtained with the engineering unit of the Galileo Jupiter Probe lightning experiment. The spectra of the magnetic field data definitely show fine structure, with two or three distinct peaks appearing in the spectra of many of the waveforms. An enhancement of power at frequencies of about 60-70 kHz is often seen in the spectra of the waveform time segments preceding and following the rise-to-peak amplitude of the return stroke.

  11. NASA Standard Initiator Susceptibility to UHF and S-Band Radio Frequency Power and Lightning Strikes

    NASA Technical Reports Server (NTRS)

    Burnham, Karen; Scully, Robert; Norgard, John

    2013-01-01

    The NASA Standard Initiator (NSI) is an important piece of pyrotechnic equipment used in many space applications. This presentation will outline the results of a series of tests done at UHF and S-Band frequencies to determine NSI susceptibility to Radio Frequency (RF) power. The results show significant susceptibility to pulsed RF power in the S-Band region. Additional testing with lightning pulses injected into the firing line harness, modelling the indirect effects of a lightning strike to a spacecraft, showed no vulnerability

  12. NASA Standard Initiator Susceptibility to UHF and S-Band Radio Frequency Power and Lightning Strikes

    NASA Technical Reports Server (NTRS)

    Burnham, Karen; Scully, Robert C.; Norgard, John D.

    2013-01-01

    The NASA Standard Initiator (NSI) is an important piece of pyrotechnic equipment used in many space applications. This paper outlines the results of a series of tests done at UHF and S-Band frequencies to determine NSI susceptibility to Radio Frequency (RF) power. The results show significant susceptibility to pulsed RF power in the S-Band region. Additional testing with lightning pulses injected into the firing line harness, modelling the indirect effects of a lightning strike to a spacecraft, showed no vulnerability.

  13. Detection and analysis of radio frequency lightning emissions

    NASA Technical Reports Server (NTRS)

    Jalali, F.

    1982-01-01

    The feasibility study of detection of lightning discharges from a geosynchronous satellite requires adequate ground-based information regarding emission characteristics. In this investigation, a measurement system for collection of S-band emission data is set up and calibrated, and the operations procedures for rapid data collection during a storm activity developed. The system collects emission data in two modes; a digitized, high-resolution, short duration record stored in solid-state memory, and a continuous long-duration record on magnetic tape. Representative lightning flash data are shown. Preliminary results indicate appreciable RF emissions at 2 gHz from both the leader and return strokes portions of the cloud-to-ground discharge with strong peaks associated with the return strokes.

  14. Radio frequency observations of lightning discharges by the forte satellite.

    SciTech Connect

    Shao, X.; Jacobson, A. R.; Light, T.

    2002-01-01

    FORTE-observed VHF signatures for different lightning discharges are presented. For in-cloud discharges, a pulse pair is typically recorded and is named a 'transionospheric pulse pair' (TIPP). Many intense TIPPs are coherent and polarized, whereas initial and dart leaders do not show a recognizable degree of polarization. TIPPs are optically weaker than cloud-to-ground (CG) strokes, and stronger VHF TIPPs are optically darker. About 10% of CG strokes, mostly over seawater, produce extremely narrow, powerful VHF pulses at the very beginning of the return strokes. These narrow pulses are found to form an upward beam pattern.

  15. 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)

  16. On the timing between terrestrial gamma ray flashes, radio atmospherics, and optical lightning emission

    NASA Astrophysics Data System (ADS)

    Gjesteland, Thomas; Østgaard, Nikolai; Bitzer, Phillip; Christian, Hugh J.

    2017-07-01

    On 25 October 2012 the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) and the Tropical Rainfall Measuring Mission (TRMM) satellites passed over a thunderstorm on the coast of Sri Lanka. RHESSI observed a terrestrial gamma ray flash (TGF) originating from this thunderstorm. Optical measurements of the causative lightning stroke were made by the lightning imaging sensor (LIS) on board TRMM. The World Wide Lightning Location Network (WWLLN) detected the very low frequency (VLF) radio emissions from the lightning stroke. The geolocation from WWLLN, which we also assume is the TGF source location, was in the convective core of the cloud. By using new information about both RHESSI and LIS timing accuracy, we find that the peak in the TGF light curve occurs 230 μs before the WWLLN time. Analysis of the optical signal from LIS shows that within the uncertainties, we cannot conclude which comes first: the gamma emission or the optical emission. We have also applied the new information about the LIS timing on a previously published event by Østgaard et al. (2012). Also for this event we are not able to conclude which signal comes first. More accurate instruments are needed in order to get the exact timing between the TGF and the optical signal.

  17. Multicolor Photometric Observation of Lightning from Space: Comparison with Radio Measurements

    NASA Technical Reports Server (NTRS)

    Adachi, Toru; Cohen, Morris; Said, Ryan; Blakeslee, Richard J.; Cummer, Steven A.; Li, Jingbo; Lu, Geopeng; Hsu, Rue-Ron; Su, Han-Tzong; Chen, Alfred Bing-Chih; hide

    2011-01-01

    This study evaluates the effectiveness of spectrophotometric measurements from space in revealing properties of lightning flash. The multicolor optical waveform data obtained by FORMOSAT-2/Imager of Sprites and Upper Atmospheric Lightning (ISUAL) were analyzed in relation to National Lightning Detection Network (NLDN), North Alabama Lightning Mapping Array (LMA). As of July 2011, we found six lightning events which were observed by ISUAL and North Alabama LMA. In two of these events, NLDN showed clear positive cloud-to-ground (CG) discharges with peak current of +139.9 kA and +41.6 kA and, around that time, LMA showed continuous intra-cloud (IC) leader activities at 4-6 km altitudes. ISUAL also observed consistent optical waveforms of the IC and CG components and, interestingly, it was found that the blue/red spectral ratio clearly decreased by a factor of 1.5-2.5 at the time of CG discharges. Other four lightning events in which NLDN did not detect any CG discharges were also investigated, but such a feature was not found in any of these cases. These results suggest that the optical color of CG component is more reddish than that of IC component and we explain this as a result of more effective Rayleigh scattering in blue light emissions coming from lower-altitude light source. This finding suggests that spectral measurements could be a new useful technique to characterize ICs and CGs from space. In this talk, we will also present a result from lightning statistical analysis of ISUAL spectrophotometric data and ULF magnetic data.

  18. Coordinated Satellite Observations of the Very Low Frequency Transmission Through the Ionospheric D Layer at Low Latitudes, Using Broadband Radio Emissions From Lightning

    NASA Astrophysics Data System (ADS)

    Jacobson, Abram R.; Holzworth, Robert H.; Pfaff, Robert; Heelis, Roderick

    2018-04-01

    Both ray theory and full-wave models of very low frequency transmission through the ionospheric D layer predict that the transmission is greatly suppressed near the geomagnetic equator. We use data from the low-inclination Communication/Navigation Outage Forecast System satellite to test this semiquantitatively, for broadband very low frequency emissions from lightning. Approximate ground-truthing of the incident wavefields in the Earth-ionosphere waveguide is provided by the World Wide Lightning Location Network. Observations of the wavefields at the satellite are provided by the Vector Electric Field Instrument aboard the satellite. The data set comprises whistler observations with the satellite at magnetic latitudes <26°. Thus, our conclusions, too, must be limited to the near-equatorial region and are not necessarily predictive of midlatitude whistler properties. We find that in most broadband recordings of radio waves at the satellite, very few of the lightning strokes result in a detectable radio pulse at the satellite. However, in a minority of the recordings, there is enhanced transmission of very low frequency lightning emissions through the D layer, at a level exceeding model predictions by at least an order of magnitude. We show that kilometric-scale D-layer irregularities may be implicated in the enhanced transmission. This observation of sporadic enhancements at low magnetic latitude, made with broadband lightning emissions, is consistent with an earlier review of D-layer transmission for transmission from powerful man-made radio beacons.

  19. LOFAR Lightning Imaging: Mapping Lightning With Nanosecond Precision

    NASA Astrophysics Data System (ADS)

    Hare, B. M.; Scholten, O.; Bonardi, A.; Buitink, S.; Corstanje, A.; Ebert, U.; Falcke, H.; Hörandel, J. R.; Leijnse, H.; Mitra, P.; Mulrey, K.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Rutjes, C.; Schellart, P.; Thoudam, S.; Trinh, T. N. G.; ter Veen, S.; Winchen, T.

    2018-03-01

    Lightning mapping technology has proven instrumental in understanding lightning. In this work we present a pipeline that can use lightning observed by the LOw-Frequency ARray (LOFAR) radio telescope to construct a 3-D map of the flash. We show that LOFAR has unparalleled precision, on the order of meters, even for lightning flashes that are over 20 km outside the area enclosed by LOFAR antennas (˜3,200 km2), and can potentially locate over 10,000 sources per lightning flash. We also show that LOFAR is the first lightning mapping system that is sensitive to the spatial structure of the electrical current during individual lightning leader steps.

  20. Faraday Cage Protects Against Lightning

    NASA Technical Reports Server (NTRS)

    Jafferis, W.; Hasbrouck, R. T.; Johnson, J. P.

    1992-01-01

    Faraday cage protects electronic and electronically actuated equipment from lightning. Follows standard lightning-protection principles. Whether lightning strikes cage or cables running to equipment, current canceled or minimized in equipment and discharged into ground. Applicable to protection of scientific instruments, computers, radio transmitters and receivers, and power-switching equipment.

  1. What Initiates Lightning?

    SciTech Connect

    None

    Lightning is an energetic electric discharge, creating a current that flows briefly within a cloud--or between a cloud and the ground--and heating the air to temperatures about five times hotter than the sun’s surface. But there’s a lot about lightning that’s still a mystery. Los Alamos National Laboratory is working to change that. Because lightning produces optical and radio frequency signals similar to those from a nuclear explosion, it’s important to be able to distinguish whether such signals are caused by lightning or a nuclear event. As part of the global security mission at Los Alamos, scientists use lightning tomore » help develop better instruments for nuclear test-ban treaty monitoring and, in the process, have learned a lot about lightning itself.« less

  2. Oceanic Lightning versus Continental Lightning: VLF Peak Current Discrepancies

    NASA Astrophysics Data System (ADS)

    Dupree, N. A., Jr.; Moore, R. C.

    2015-12-01

    Recent analysis of the Vaisala global lightning data set GLD360 suggests that oceanic lightning tends to exhibit larger peak currents than continental lightning (lightning occurring over land). The GLD360 peak current measurement is derived from distant measurements of the electromagnetic fields emanated during the lightning flash. Because the GLD360 peak current measurement is a derived quantity, it is not clear whether the actual peak currents of oceanic lightning tend to be larger, or whether the resulting electromagnetic field strengths tend to be larger. In this paper, we present simulations of VLF signal propagation in the Earth-ionosphere waveguide to demonstrate that the peak field values for oceanic lightning can be significantly stronger than for continental lightning. Modeling simulations are performed using the Long Wave Propagation Capability (LWPC) code to directly evaluate the effect of ground conductivity on VLF signal propagation in the 5-15 kHz band. LWPC is an inherently narrowband propagation code that has been modified to predict the broadband response of the Earth-Ionosphere waveguide to an impulsive lightning flash while preserving the ability of LWPC to account for an inhomogeneous waveguide. Furthermore, we evaluate the effect of return stroke speed on these results.

  3. Remote sensing and modeling of lightning caused long recovery events within the lower ionosphere using VLF/LF radio wave propagation

    NASA Astrophysics Data System (ADS)

    Schmitter, E. D.

    2014-11-01

    On the 4 November 2012 at 3:04:27 UT a strong lightning in the midst of the North Sea affected the propagation conditions of VLF/LF transmitter radio signals from NRK (Iceland, 37.5 kHz) and GBZ (UK, 19.58 kHz) received at 5246° N 8° E (NW Germany). The amplitude and phase dips show a recovery time of 6-12 min pointing to a LOng Recovery Early VLF (LORE) event. Clear assignment of the causative return stroke in space and time was possible with data from the WWLLN (Worldwide Lightning Location Network). Based on a return stroke current model the electric field is calculated and an excess electron density distribution which decays over time in the lower ionosphere is derived. Ionization, attachment and recombination processes are modeled in detail. Entering the electron density distribution in VLF/LF radio wave propagation calculations using the LWPC (Long Wavelength Propagation Capability) code allows to model the VLF/LF amplitude and phase behavior by adjusting the return stroke current moment. The results endorse and quantify the conception of lower ionosphere EMP heating by strong - but not necessarily extremely strong - return strokes of both polarities.

  4. 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.

  5. Planetary lightning

    NASA Astrophysics Data System (ADS)

    Russell, C. T.; Clayton, R. N.; Buseck, P. R.; Hua, X.; Holsapple, K. A.; Esposito, L. W.; Aherns, T. J.; Hecht, J.

    The present state of knowledge concerning lightning on the planets is reviewed. Voyager data have clearly established the presence of lightning discharges at each of the four Jovian planets. In situ data for lightning on Venus are discussed in some detail, including reported quantitative occurrence rates and hypotheses concerning the relationship of Venusian lightning to VLF bursts observed in the Venus atmosphere.

  6. 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.

  7. Measurement of RF lightning emissions

    NASA Technical Reports Server (NTRS)

    Lott, G. K., Jr.; Honnell, M. A.; Shumpert, T. H.

    1981-01-01

    A lightning radio emission observation laboratory is described. The signals observed and recorded include HF, VHF and UHF radio emissions, optical signature, electric field measurements, and thunder. The objectives of the station, the equipment used, and the recording methods are discussed.

  8. Uncooled long-wave infrared hyperspectral imaging

    NASA Technical Reports Server (NTRS)

    Lucey, Paul G. (Inventor)

    2006-01-01

    A long-wave infrared hyperspectral sensor device employs a combination of an interferometer with an uncooled microbolometer array camera to produce hyperspectral images without the use of bulky, power-hungry motorized components, making it suitable for UAV vehicles, small mobile platforms, or in extraterrestrial environments. The sensor device can provide signal-to-noise ratios near 200 for ambient temperature scenes with 33 wavenumber resolution at a frame rate of 50 Hz, with higher results indicated by ongoing component improvements.

  9. An automatic lightning detection and photographic system

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    Conventional 35-mm camera is activated by an electronic signal every time lightning strikes in general vicinity. Electronic circuit detects lightning by means of antenna which picks up atmospheric radio disturbances. Camera is equipped with fish-eye lense, automatic shutter advance, and small 24-hour clock to indicate time when exposures are made.

  10. Lightning Protection

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Lightning Technologies, Inc., Pittsfield, MA, - a spinoff company founded by president J. Anderson Plumer, a former NASA contractor employee who developed his expertise with General Electric Company's High Voltage Laboratory - was a key player in Langley Research Center's Storm Hazards Research Program. Lightning Technologies used its NASA acquired experience to develop protective measures for electronic systems and composite structures on aircraft, both of which are particularly susceptible to lightning damage. The company also provides protection design and verification testing services for complete aircraft systems or individual components. Most aircraft component manufacturers are among Lightning Technologies' clients.

  11. Long Waves and Journalism Ideology in America, 1835-1985.

    ERIC Educational Resources Information Center

    Kaul, Arthur J.; McKerns, Joseph P.

    Framed by the heuristic device of "long waves" of capitalist development, journalism ideology is historically anchored to competitive media economics. (Long waves are 50-year economic cycles comprised of alternating 25-year periods of economic expansion followed by contraction periods.) With each long wave, a new institutional ecology…

  12. 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.

  13. 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

  14. 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.

  15. Analysis and Modeling of Intense Oceanic Lightning

    NASA Astrophysics Data System (ADS)

    Zoghzoghy, F. G.; Cohen, M.; Said, R.; Lehtinen, N. G.; Inan, U.

    2014-12-01

    Recent studies using lightning data from geo-location networks such as GLD360 suggest that lightning strokes are more intense over the ocean than over land, even though they are less common [Said et al. 2013]. We present an investigation of the physical differences between oceanic and land lightning. We have deployed a sensitive Low Frequency (1 MHz sampling rate) radio receiver system aboard the NOAA Ronald W. Brown research vessel and have collected thousands of lightning waveforms close to deep oceanic lightning. We analyze the captured waveforms, describe our modeling efforts, and summarize our findings. We model the ground wave (gw) portion of the lightning sferics using a numerical method built on top of the Stanford Full Wave Method (FWM) [Lehtinen and Inan 2008]. The gwFWM technique accounts for propagation over a curved Earth with finite conductivity, and is used to simulate an arbitrary current profile along the lightning channel. We conduct a sensitivity analysis and study the current profiles for land and for oceanic lightning. We find that the effect of ground conductivity is minimal, and that stronger oceanic radio intensity does not result from shorter current rise-time or from faster return stroke propagation speed.

  16. Electromagnetic Methods of Lightning Detection

    NASA Astrophysics Data System (ADS)

    Rakov, V. A.

    2013-11-01

    Both cloud-to-ground and cloud lightning discharges involve a number of processes that produce electromagnetic field signatures in different regions of the spectrum. Salient characteristics of measured wideband electric and magnetic fields generated by various lightning processes at distances ranging from tens to a few hundreds of kilometers (when at least the initial part of the signal is essentially radiation while being not influenced by ionospheric reflections) are reviewed. An overview of the various lightning locating techniques, including magnetic direction finding, time-of-arrival technique, and interferometry, is given. Lightning location on global scale, when radio-frequency electromagnetic signals are dominated by ionospheric reflections, is also considered. Lightning locating system performance characteristics, including flash and stroke detection efficiencies, percentage of misclassified events, location accuracy, and peak current estimation errors, are discussed. Both cloud and cloud-to-ground flashes are considered. Representative examples of modern lightning locating systems are reviewed. Besides general characterization of each system, the available information on its performance characteristics is given with emphasis on those based on formal ground-truth studies published in the peer-reviewed literature.

  17. Upper limit set for level of lightning activity on Titan

    NASA Technical Reports Server (NTRS)

    Desch, M. D.; Kaiser, M. L.

    1990-01-01

    Because optically thick cloud and haze layers prevent lightning detection at optical wavelength on Titan, a search was conducted for lightning-radiated signals (spherics) at radio wavelengths using the planetary radioastronomy instrument aboard Voyager 1. Given the maximum ionosphere density of about 3000/cu cm, lightning spherics should be detectable above an observing frequency of 500 kHz. Since no evidence for spherics is found, an upper limit to the total energy per flash in Titan lightning of about 10 to the 6th J, or about 1000 times weaker than that of typical terrestrial lightning, is inferred.

  18. Lightning electromagnetics

    NASA Technical Reports Server (NTRS)

    Wahid, Parveen

    1995-01-01

    This project involved the determination of the effective radiated power of lightning sources and the polarization of the radiating source. This requires the computation of the antenna patterns at all the LDAR site receiving antennas. The known radiation patterns and RF signal levels measured at the antennas will be used to determine the effective radiated power of the lightning source. The azimuth and elevation patterns of the antennas in the LDAR system were computed using flight test data that was gathered specifically for this purpose. The results presented in this report deal with the azimuth patterns for all the antennas and the elevation patterns for three of the seven sites.

  19. Lightning on Jupiter - Rate, energetics, and effects

    NASA Technical Reports Server (NTRS)

    Lewis, J. S.

    1980-01-01

    Voyager data on the optical and radio-frequency detection of lightning discharges in the atmosphere of Jupiter suggest a stroke rate significantly lower than on the earth. The efficiency of conversion of atmospheric convective energy flux into lightning is almost certainly less than on the earth, probably near 10 to the -7th rather than the terrestrial value of 10 to the -4th. At this level the rate of production of complex organic molecules by lightning and by thunder shock waves is negligible compared to the rates of known photochemical processes for forming colored inorganic solids.

  20. Lightning on jupiter: rate, energetics, and effects.

    PubMed

    Lewis, J S

    1980-12-19

    Voyager data on the optical and radio-frequency detection of lightning discharges in the atmosphere of Jupiter suggest a stroke rate significantly lower than on the earth. The efficiency of conversion of atmospheric convective energy flux into lightning is almost certainly less than on the earth, probably near 10(-7) rather than the terrestrial value of 10(-4). At this level the rate of production of complex organic molecules by lightning and by thunder shock waves is negligible compared to the rates of known photochemical processes for forming colored inorganic solids.

  1. Prevalent lightning sferics at 600 megahertz near Jupiter's poles

    NASA Astrophysics Data System (ADS)

    Brown, Shannon; Janssen, Michael; Adumitroaie, Virgil; Atreya, Sushil; Bolton, Scott; Gulkis, Samuel; Ingersoll, Andrew; Levin, Steven; Li, Cheng; Li, Liming; Lunine, Jonathan; Misra, Sidharth; Orton, Glenn; Steffes, Paul; Tabataba-Vakili, Fachreddin; Kolmašová, Ivana; Imai, Masafumi; Santolík, Ondřej; Kurth, William; Hospodarsky, George; Gurnett, Donald; Connerney, John

    2018-06-01

    Lightning has been detected on Jupiter by all visiting spacecraft through night-side optical imaging and whistler (lightning-generated radio waves) signatures1-6. Jovian lightning is thought to be generated in the mixed-phase (liquid-ice) region of convective water clouds through a charge-separation process between condensed liquid water and water-ice particles, similar to that of terrestrial (cloud-to-cloud) lightning7-9. Unlike terrestrial lightning, which emits broadly over the radio spectrum up to gigahertz frequencies10,11, lightning on Jupiter has been detected only at kilohertz frequencies, despite a search for signals in the megahertz range12. Strong ionospheric attenuation or a lightning discharge much slower than that on Earth have been suggested as possible explanations for this discrepancy13,14. Here we report observations of Jovian lightning sferics (broadband electromagnetic impulses) at 600 megahertz from the Microwave Radiometer15 onboard the Juno spacecraft. These detections imply that Jovian lightning discharges are not distinct from terrestrial lightning, as previously thought. In the first eight orbits of Juno, we detected 377 lightning sferics from pole to pole. We found lightning to be prevalent in the polar regions, absent near the equator, and most frequent in the northern hemisphere, at latitudes higher than 40 degrees north. Because the distribution of lightning is a proxy for moist convective activity, which is thought to be an important source of outward energy transport from the interior of the planet16,17, increased convection towards the poles could indicate an outward internal heat flux that is preferentially weighted towards the poles9,16,18. The distribution of moist convection is important for understanding the composition, general circulation and energy transport on Jupiter.

  2. Principles of Lightning Physics

    NASA Astrophysics Data System (ADS)

    Mazur, Vladislav

    2016-12-01

    Principles of Lightning Physics presents and discusses the most up-to-date physical concepts that govern many lightning events in nature, including lightning interactions with man-made structures, at a level suitable for researchers, advanced students and well-educated lightning enthusiasts. The author's approach to understanding lightning-to seek out, and show what is common to all lightning flashes-is illustrated by an analysis of each type of lightning and the multitude of lightning-related features. The book examines the work that has gone into the development of new physical concepts, and provides critical evaluations of the existing understanding of the physics of lightning and the lexicon of terms and definitions presently used in lightning research.

  3. 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

  4. The state of technology in electromagnetic (RF) sensors (for lightning detection)

    NASA Technical Reports Server (NTRS)

    Shumpert, T. H.; Honnell, M. A.

    1979-01-01

    A brief overview of the radio-frequency sensors which were applied to the detection, isolation, and/or identification of the transient electromagnetic energy (sferics) radiated from one or more lightning discharges in the atmosphere is presented. Radio frequency (RF) characteristics of lightning discharges, general RF sensor (antenna) characteristics, sensors and systems previously used for sferic detection, electromagnetic pulse sensors are discussed. References containing extensive bibliographies concerning lightning are presented.

  5. 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.

  6. Lightning Safety Tips and Resources

    MedlinePlus

    ... Safety Brochure U.S. Lightning Deaths in 2018 : 5 Youtube: Lightning Safety for the Deaf and Hard of ... for Hard of Hearing: jpg , high res png YouTube: Lightning Safety Tips Lightning Safety When Working Outdoors : ...

  7. 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. PMID:27879700

  8. Lightning Instrumentation at KSC

    NASA Technical Reports Server (NTRS)

    Colon, Jose L.; Eng, D.

    2003-01-01

    This report summarizes lightning phenomena with a brief explanation of lightning generation and lightning activity as related to KSC. An analysis of the instrumentation used at launching Pads 39 A&B for measurements of lightning effects is included with alternatives and recommendations to improve the protection system and upgrade the actual instrumentation system. An architecture for a new data collection system to replace the present one is also included. A novel architecture to obtain lightning current information from several sensors using only one high speed recording channel while monitoring all sensors to replace the actual manual lightning current recorders and a novel device for the protection system are described.

  9. Long-wave radiative forcing due to desert dust

    NASA Astrophysics Data System (ADS)

    Gunn, L. N.; Collins, W.

    2011-12-01

    Radiative forcing due to aerosols has been identified by the IPCC as a major contributor to the total radiative forcing uncertainty budget. Optically thick plumes of dust and pollutants extending out from Africa and Asia can be lifted into the middle troposphere and often are transported over synoptic length scales. These events can decrease the upwelling long-wave fluxes at the top of the atmosphere, especially in the mid-infrared "window". Although the long-wave effects of dust are included in model simulations, they are hard to validate in the absence of satellite-driven global estimates. Using hyper spectral satellite measurements (from NASA's AIRS instrument) it is possible to estimate the effect of dust on the outgoing long-wave radiation directly from the measured spectra, by differencing the simulated clear sky radiance spectra (which are calculated using ECMWF analysis) and the observed dust filled radiance spectra (observations from AIRS). We will summarize this method and show global estimates of the dust radiative effect in the long-wave. These global estimates will be used to validate GCM model output and help us to improve our understanding of dust in the global energy budget.

  10. On the modified intermediate long-wave equation

    NASA Astrophysics Data System (ADS)

    Naumkin, Pavel I.; Sánchez-Suárez, Isahi

    2018-03-01

    We consider the modified intermediate long-wave equation ut-∂xu3+1ϑux+VP∫R12ϑcoth(π(y-x)2ϑ)uyy(t,y)dy=0. We develop the factorization technique to study the large time asymptotics of solutions.

  11. 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.

  12. 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)

  13. 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)

  14. Tennessee Valley Total and Cloud-to-Ground Lightning Climatology Comparison

    NASA Technical Reports Server (NTRS)

    Buechler, Dennis; Blakeslee, R. J.; Hall, J. M.; McCaul, E. W.

    2008-01-01

    The North Alabama Lightning Mapping Array (NALMA) has been in operation since 2001 and consists often VHF receivers deployed across northern Alabama. The NALMA locates sources of impulsive VHF radio signals from total lightning by accurately measuring the time that the signals arrive at the different receiving stations. The sources detected are then clustered into flashes by applying spatially and temporally constraints. This study examines the total lightning climatology of the region derived from NALMA and compares it to the cloud-to-ground (CG) climatology derived from the National Lightning Detection Network (NLDN) The presentation compares the total and CG lightning trends for monthly, daily, and hourly periods.

  15. 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.

  16. Global Lightning Activity

    NASA Technical Reports Server (NTRS)

    Christian, Hugh J.

    2004-01-01

    Our knowledge of the global distribution of lightning has improved dramatically since the advent of spacebased lightning observations. Of major importance was 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 eight-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 (cloud-to-ground and intra-cloud) has been observed over large regions with high detection efficiency 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 lightning activity in severe weather. Accurate flash rate estimates are now available over large 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 space-based observations indicate 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. This talk will summarize our space-based lightning measurements, will discuss how lightning observations can be used to monitor severe weather, and

  17. 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)

  18. Long waves in parallel flow in Hele-Shaw cells

    SciTech Connect

    Zeybek, M.; Yortsos, Y.C.

    1991-09-09

    The evolution of fluid interfaces in parallel flow in Hele-Shaw cells is studied theoretically and experimentally in the limit of large capillary number. It is shown that such interfaces support wave motion, the amplitude of which for long waves is governed by a set of Korteweg--de Vries and Airy equations. Experiments conducted in a long Hele-Shaw cell validate the theory in the symmetric case.

  19. 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.

  20. 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.

  1. Indirect Lightning Safety Assessment Methodology

    SciTech Connect

    Ong, M M; Perkins, M P; Brown, C G

    2009-04-24

    -cage type facility, when the facility is struck by lightning. In the following examples we will use Dr. Merewether's calculations from a poor quality Faraday cage as the input for the RF coupling analysis. coupling of radio frequency (RF) energy to explosive components is an indirect effect of currents [1]. If HE is adequately separated from the walls of the facility that is struck by disassembled have been turned into Faraday-cage structures to protect against lightning is initiation of the HE. last couple of decades, DOE facilities where HE is manufactured, assembled, stored or lightning. The most sensitive component is typically a detonator, and the safety concern lightning, electrons discharged from the clouds should not reach the HE components. radio receiver, the metal cable of a detonator can extract energy from the EM fields. This to the earth will create electromagnetic (EM) fields in the facility. Like an antenna in a« less

  2. 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)

  3. Lightning Mapping Observations: What we are learning.

    NASA Astrophysics Data System (ADS)

    Krehbiel, P.

    2001-12-01

    The use of radio frequency time-of-arrival techniques for accurately mapping lightning discharges is revolutionizing our ability to study lightning discharge processes and to investigate thunderstorms. Different types of discharges are being observed that we have not been able to study before or knew existed. Included are a variety of inverted and normal polarity intracloud and cloud-to-ground discharges, frequent short-duration discharges at high altitude in storms and in overshooting convective tops, highly energetic impulsive discharge events, and horizontally extensive `spider' lightning discharges in large mesoscale convective systems. High time resolution measurements valuably complement interferometric observations and are starting to exceed the ability of interferometers to provide detailed pictures of flash development. Mapping observations can be used to infer the polarity of the breakdown channels and hence the location and sign of charge regions in the storm. The lightning activity in large, severe storms is found to be essentially continuous and volume-filling, with substantially more lightning inside the storm than between the cloud and ground. Spectacular dendritic structures are observed in many flashes. The lightning observations can be used to infer the electrical structure of a storm and therefore to study the electrification processes. The results are raising fundamental questions about how storms become electrified and how the electrification evolves with time. Supercell storms are commonly observed to electrify in an inverted or anomalous manner, raising questions about how these storms are different from normal storms, and even what is `normal'. The high lightning rates in severe storms raises the distinct possibility that the discharges themselves might be sustaining or enhancing the electrification. Correlated observations with radar, instrumented balloons and aircraft, and ground-based measurements are leading to greatly improved

  4. The Design of Lightning Protection

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Engineering study guides design and monitoring of lightning protection. Design studies for project are collected in 150-page report, containing wealth of information on design of lightning protection systems and on instrumentation for monitoring current waveforms of lightning strokes.

  5. First Lightning Flashes on Saturn

    NASA Image and Video Library

    2010-04-14

    NASA Cassini spacecraft captured the first lightning flashes on Saturn. The storm that generated the lightning lasted from January to October 2009, making it the longest-lasting lightning storm known in the solar system.

  6. Space Shuttle Lightning Protection

    NASA Technical Reports Server (NTRS)

    Suiter, D. L.; Gadbois, R. D.; Blount, R. L.

    1979-01-01

    The technology for lightning protection of even the most advanced spacecraft is available and can be applied through cost-effective hardware designs and design-verification techniques. In this paper, the evolution of the Space Shuttle Lightning Protection Program is discussed, including the general types of protection, testing, and anlayses being performed to assess the lightning-transient-damage susceptibility of solid-state electronics.

  7. Global Lightning Activity

    NASA Technical Reports Server (NTRS)

    Christian, Hugh

    2003-01-01

    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 (46 flashes per second) and has lead to a new realization of the significance of total lightning activity in severe weather. Accurate flash rate estimates are now available for large areas of the earth (+/- 72deg latitude) Ocean-land contrasts as a function of season are clearly revealed, as are orographic effects and seasonal and interannual variability. The data set indicates that air mass thunderstorms, not large storm systems 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 hat this capability could lead to significantly improved severe weather warning times and reduced false warning rates.

  8. Lightning and transportation.

    PubMed

    Cherington, M

    1995-12-01

    It is a little-known fact that lightning casualties often involve travel or transportation. López and colleagues, in their studies on the epidemiology of lightning injuries, have reported that 10% of lightning injuries are categorized under transportation. In the majority of their cases, victims were struck while standing outside or near their vehicles during a thunderstorm. During my review of the neurologic complications of lightning injuries, I was impressed by the number of case reports in which the victim was struck while either in or near a vehicle, airplane or vessel. In this article, I shall put forth information on four aspects of lightning that relate to the danger to people traveling in vehicles, boats, and airplanes. First, I shall deal with lightning safety on ships and boats. People who enjoy recreational sailing, including the "weekend sailor" and those who enjoy fishing from a boat, should be fortified with knowledge about lightning protection. Second, I shall consider the matter of lightning strikes to aircraft. In the third section, I shall discuss the question of lightning safety in automobiles. Fourth, I shall review those cases found in my literature review in which the victim was struck while in or near a vehicle, boat, or airplane.

  9. 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

  10. Lightning and Climate

    NASA Astrophysics Data System (ADS)

    Williams, E.

    2012-12-01

    Lightning is of interest in the domain of climate change for several reasons: (1) thunderstorms are extreme forms of moist convection, and lightning flash rate is a sensitive measure of that extremity, (2) thunderstorms are deep conduits for delivering water substance from the boundary layer to the upper troposphere and stratosphere, and (3) global lightning can be monitored continuously and inexpensively within a natural framework (the Earth-ionosphere waveguide and Schumann resonances). Lightning and temperature, and lightning and upper tropospheric water vapor, are positively correlated on weather-related time scales (diurnal, semiannual, and annual) with a lightning temperature sensitivity of order 10% per oC. Lightning also follows temperature variations on the ENSO time scale, both locally and globally. The response of lightning in some of its extreme forms (exceptional flash rates and the prevalence of sprite-producing mesoscale lightning, for example) to temperature variations will be addressed. Consistently obtained records of lightning activity on longer time scales are scarce as stable detection networks are uncommon. As a consequence, thunder day data have been used to extend the lightning record for climate studies, with evidence for increases over decades in urban areas. Global records of lightning following Schumann resonance intensity and from space-based optical sensors (OTD and LIS) are consistent with the record of ionospheric potential representing the global electrical circuit in showing flat behavior over the few decades. This flatness is not well understood, though the majority of all lightning flashes are found in the tropics, the most closely regulated portion of the atmosphere. Other analysis of frequency variations of Schumann resonances in recent decades shows increased lightning in the northern hemisphere, where the global warming is most pronounced. The quantity more fundamental than temperature for lightning control is cloud buoyancy

  11. [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.

  12. Lightning injury: a review.

    PubMed

    Ritenour, Amber E; Morton, Melinda J; McManus, John G; Barillo, David J; Cancio, Leopoldo C

    2008-08-01

    Lightning is an uncommon but potentially devastating cause of injury in patients presenting to burn centers. These injuries feature unusual symptoms, high mortality, and significant long-term morbidity. This paper will review the epidemiology, physics, clinical presentation, management principles, and prevention of lightning injuries.

  13. Long-wave instabilities of two interlaced helical vortices

    NASA Astrophysics Data System (ADS)

    Quaranta, H. U.; Brynjell-Rahkola, M.; Leweke, T.; Henningson, D. S.

    2016-09-01

    We present a comparison between experimental observations and theoretical predictions concerning long-wave displacement instabilities of the helical vortices in the wake of a two-bladed rotor. Experiments are performed with a small-scale rotor in a water channel, using a set-up that allows the individual triggering of various instability modes at different azimuthal wave numbers, leading to local or global pairing of successive vortex loops. The initial development of the instability and the measured growth rates are in good agreement with the predictions from linear stability theory, based on an approach where the helical vortex system is represented by filaments. At later times, local pairing develops into large-scale distortions of the vortices, whereas for global pairing the non-linear evolution returns the system almost to its initial geometry.

  14. Cultural Artifact Detection in Long Wave Infrared Imagery.

    SciTech Connect

    Anderson, Dylan Zachary; Craven, Julia M.; Ramon, Eric

    2017-01-01

    Detection of cultural artifacts from airborne remotely sensed data is an important task in the context of on-site inspections. Airborne artifact detection can reduce the size of the search area the ground based inspection team must visit, thereby improving the efficiency of the inspection process. This report details two algorithms for detection of cultural artifacts in aerial long wave infrared imagery. The first algorithm creates an explicit model for cultural artifacts, and finds data that fits the model. The second algorithm creates a model of the background and finds data that does not fit the model. Both algorithms are appliedmore » to orthomosaic imagery generated as part of the MSFE13 data collection campaign under the spectral technology evaluation project.« less

  15. 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 spacemore » 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.« less

  16. Infrasound Observations from Lightning

    NASA Astrophysics Data System (ADS)

    Arechiga, R. O.; Johnson, J. B.; Edens, H. E.; Thomas, R. J.; Jones, K. R.

    2008-12-01

    To provide additional insight into the nature of lightning, we have investigated its infrasound manifestations. An array of three stations in a triangular configuration, with three sensors each, was deployed during the Summer of 2008 (July 24 to July 28) in the Magdalena mountains of New Mexico, to monitor infrasound (below 20 Hz) sources due to lightning. Hyperbolic formulations of time of arrival (TOA) measurements and interferometric techniques were used to locate lightning sources occurring over and outside the network. A comparative analysis of simultaneous Lightning Mapping Array (LMA) data and infrasound measurements operating in the same area was made. The 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. The comparison showed strong evidence that lightning does produce infrasound. This work is a continuation of the study of the frequency spectrum of thunder conducted by Holmes et al., who reported measurements of infrasound frequencies. The integration of infrasound measurements with RF source localization by the LMA shows great potential for improved understanding of lightning processes.

  17. Modeling long recovery early events (LOREs) produced by lightning-induced ionization of the nighttime upper mesosphere

    NASA Astrophysics Data System (ADS)

    Kotovsky, D. A.; Moore, R. C.

    2017-07-01

    We present results of a cylindrically symmetric, coupled electrodynamic, and photochemical model which simulates diffuse ionization of the middle atmosphere induced by strong lightning discharges (peak currents >150 kA). Scattering of subionospherically propagating, very low frequency radio waves is then evaluated using the Long-Wave Propagation Capability code. Some modeled sprite halos exhibit continued electron density growth up to timescales of seconds due to O- detachment, though it is not yet clear how this might relate to the slower onset durations (>20 ms) of some early VLF events. Modeled electron density enhancements in sprite halos, capable of strong VLF scattering, can persist for long periods of time (greater than hundreds of seconds) even at lower altitudes where their recovery is initially controlled by fast attachment processes. Consequently, our modeling results indicate that both typical recovery (20 to 240 s) and long recovery (LOREs, >300 s) VLF scattering events can be explained by scattering from conductivity changes associated with sprite halos. In contrast, modeled scattered fields resulting from elve-associated conductivity changes, though exhibiting long recovery times, are too weak to sufficiently explain typical LORE observations. Theoretical scattering from structured ionization events (e.g., sprites columns and gigantic jets) is not considered in this work.

  18. Lightning current detector

    NASA Technical Reports Server (NTRS)

    Livermore, S. F. (Inventor)

    1978-01-01

    An apparatus for measuring the intensity of current produced in an elongated electrical conductive member by a lightning strike for determining the intensity of the lightning strike is presented. The apparatus includes an elongated strip of magnetic material that is carried within an elongated tubular housing. A predetermined electrical signal is recorded along the length of said elongated strip of magnetic material. One end of the magnetic material is positioned closely adjacent to the electrically conductive member so that the magnetic field produced by current flowing through said electrically conductive member disturbs a portion of the recorded electrical signal directly proportional to the intensity of the lightning strike.

  19. Note on lightning temperature

    SciTech Connect

    Alanakyan, Yu. R., E-mail: yralanak@mail.ru

    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.

  20. 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.

  1. Global lightning studies

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.; Wright, Pat; Christian, Hugh; Blakeslee, Richard; Buechler, Dennis; Scharfen, Greg

    1991-01-01

    The global lightning signatures were analyzed from the DMSP Optical Linescan System (OLS) imagery archived at the National Snow and Ice Data Center. Transition to analysis of the digital archive becomes available and compare annual, interannual, and seasonal variations with other global data sets. An initial survey of the quality of the existing film archive was completed and lightning signatures were digitized for the summer months of 1986 to 1987. The relationship is studied between: (1) global and regional lightning activity and rainfall, and (2) storm electrical development and environment. Remote sensing data sets obtained from field programs are used in conjunction with satellite/radar/lightning data to develop and improve precipitation estimation algorithms, and to provide a better understanding of the co-evolving electrical, microphysical, and dynamical structure of storms.

  2. Long waves in parallel flow in Hele-Shaw cells

    SciTech Connect

    Zeybek, M.; Yortsos, Y.C.

    During the past several years the flow of immiscible flow in Hele-Shaw cells and porous media has been investigated extensively. Of particular interest to most studies has been frontal displacement, specifically viscous fingering instabilities and finger growth. The practical ramifications regarding oil recovery, as well as many other industrial processes in porous media, have served as the primary driving force for most of these investigations. By contrast, little attention has been paid to the motion of lateral fluid interface, which are parallel to the main flow direction. Parallel flow is an often encountered, although much overlooked regime. The evolution ofmore » fluid interfaces in parallel flow in Hele-Shaw cells is studied both theoretically and experimentally in the large capillary number limit. It is shown that such interfaces support wave motion, the amplitude of which for long waves is governed by the KdV equation. Experiments are conducted in a long Hele-Shaw cell that validate the theory in the symmetric case. 35 refs., 16 figs.« less

  3. Hydroelastic analysis of ice shelves under long wave excitation

    NASA Astrophysics Data System (ADS)

    Papathanasiou, T. K.; Karperaki, A. E.; Theotokoglou, E. E.; Belibassakis, K. A.

    2015-05-01

    The transient hydroelastic response of an ice shelf under long wave excitation is analysed by means of the finite element method. The simple model, presented in this work, is used for the simulation of the generated kinematic and stress fields in an ice shelf, when the latter interacts with a tsunami wave. The ice shelf, being of large length compared to its thickness, is modelled as an elastic Euler-Bernoulli beam, constrained at the grounding line. The hydrodynamic field is represented by the linearised shallow water equations. The numerical solution is based on the development of a special hydroelastic finite element for the system of governing of equations. Motivated by the 2011 Sulzberger Ice Shelf (SIS) calving event and its correlation with the Honshu Tsunami, the SIS stable configuration is studied. The extreme values of the bending moment distribution in both space and time are examined. Finally, the location of these extrema is investigated for different values of ice shelf thickness and tsunami wave length.

  4. Hydroelastic analysis of ice shelves under long wave excitation

    NASA Astrophysics Data System (ADS)

    Papathanasiou, T. K.; Karperaki, A. E.; Theotokoglou, E. E.; Belibassakis, K. A.

    2015-08-01

    The transient hydroelastic response of an ice shelf under long wave excitation is analysed by means of the finite element method. The simple model, presented in this work, is used for the simulation of the generated kinematic and stress fields in an ice shelf, when the latter interacts with a tsunami wave. The ice shelf, being of large length compared to its thickness, is modelled as an elastic Euler-Bernoulli beam, constrained at the grounding line. The hydrodynamic field is represented by the linearised shallow water equations. The numerical solution is based on the development of a special hydroelastic finite element for the system of governing of equations. Motivated by the 2011 Sulzberger Ice Shelf (SIS) calving event and its correlation with the Honshu Tsunami, the SIS stable configuration is studied. The extreme values of the bending moment distribution in both space and time are examined. Finally, the location of these extrema is investigated for different values of ice shelf thickness and tsunami wave length.

  5. Design of a panoramic long-wave infrared athermal system

    NASA Astrophysics Data System (ADS)

    Yao, Yuan; Geng, Anbing; Bai, Jian; Wang, Haitao; Guo, Jie; Xiong, Tao; Luo, Yujie; Huang, Zhi; Hou, Xiyun

    2016-12-01

    A panoramic long-wave infrared athermal system is introduced in this paper. The proposed system includes a panoramic annular lens (PAL) block providing a stereo field of view of (30 deg - 100 deg) × 360 deg without the need to move its components. Moreover, to ensure the imaging quality at different temperatures, a refractive/diffractive hybrid lens is introduced to achieve optical passive athermalization. The system operates in a spectral band between 8 and 12 μm, with a total length of 175 mm and a focal length of 3.4 mm. To get a bright and clear image, the aperture of the system was set to f/1.15. The introduction of aspherical surface and even-order diffractive surface not only eliminates the differential thermal but also makes the structure simple and lightweight and improves the image quality. The results show that the modulation transfer function below 20 lp/mm of the system is above 0.2 at each temperature ranging from -20°C to +60°C, which is close to the diffraction limit. The system is suitable to be applied in an uncooled infrared focal plane array detector and will serve as a static alert system. It has a number of pixels of 640×480, and the pixel size is 25 μm.

  6. Long-wave infrared profile feature extractor (PFx) sensor

    NASA Astrophysics Data System (ADS)

    Sartain, Ronald B.; Aliberti, Keith; Alexander, Troy; Chiu, David

    2009-05-01

    The Long Wave Infrared (LWIR) Profile Feature Extractor (PFx) sensor has evolved from the initial profiling sensor that was developed by the University of Memphis (Near IR) and the Army Research Laboratory (visible). This paper presents the initial signatures of the LWIR PFx for human with and without backpacks, human with animal (dog), and a number of other animals. The current version of the LWIR PFx sensor is a diverging optical tripwire sensor. The LWIR PFx signatures are compared to the signatures of the Profile Sensor in the visible and Near IR spectral regions. The LWIR PFx signatures were collected with two different un-cooled micro bolometer focal plane array cameras, where the individual pixels were used as stand alone detectors (a non imaging sensor). This approach results in a completely passive, much lower bandwidth, much longer battery life, low weight, small volume sensor that provides sufficient information to classify objects into human Vs non human categories with a 98.5% accuracy.

  7. Ionospheric effects of thunderstorms and lightning

    SciTech Connect

    Lay, Erin H.

    2014-02-03

    Tropospheric thunderstorms have been reported to disturb the lower ionosphere (~65-90 km) by convective atmospheric gravity waves and by electromagnetic field changes produced by lightning discharges. However, due to the low electron density in the lower ionosphere, active probing of its electron distribution is difficult, and the various perturbative effects are poorly understood. Recently, we have demonstrated that by using remotely-detected ?me waveforms of lightning radio signals it is possible to probe the lower ionosphere and its fluctuations in a spatially and temporally-resolved manner. Here we report evidence of gravity wave effects on the lower ionosphere originating from the thunderstorm.more » We also report variations in the nighttime ionosphere atop a small thunderstorm and associate the variations with the storm’s electrical activity. Finally, we present a data analysis technique to map ionospheric acoustic waves near thunderstorms.« less

  8. Lightning Initiation and Propagation

    DTIC Science & Technology

    2009-08-22

    ray (gamma ray ) and multiple-station (>24) cosmic - ray - muon detection network (TERA) pl:esently in place. Upgrade TERA with LaBr3 detectors to...DATES COVERED 4. TITLE AND SUBTITLE Lightning Initistion and Propagation Including the Role of X- Rays , Gamma Rays , and Cosmic Rays 5a... rays , gamma rays , and cosmic rays in the initiation and propagation of lightning and in the phenomenology of thunderclouds. The experimental

  9. Lightning Technology (Supplement)

    DTIC Science & Technology

    1981-01-01

    material presented in this report was taken from a variety of sources; therefore, various units of measure are used. Use of trade names or names of...Clifford, and W. G. Butters 3. IMPLEMENTATION AND EXPERIENCE WITH LIGHTNING HARDENING MEASURES ON THE NAVY/AIR FORCE COMBAT MANEUVERING RANGES...overall lightning event taken from an appropriate base of wideband measurements . In 1979, the Air Force Wright Aeronautical Laboratories began a joint

  10. Lightning Injury: A Review

    DTIC Science & Technology

    2008-01-01

    of lightning strike; thus, burn-care providers should be familiar with the character- istics and treatment of these injuries. This paper will review...specific treatment is required [55]. Thermal injury may occur if the patient is wearing metal objects (e.g. zippers), or if clothing ignites [53...Some authors have used intravenous steroids for the treatment of optic-nerve injury in these patients. Other ophthalmologic sequelae of lightning injury

  11. 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

  12. 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.

  13. 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

  14. Electromagnetic emission from terrestrial lightning in the 0.1-30 MHz frequency range

    NASA Astrophysics Data System (ADS)

    Karashtin, A. N.; Gurevich, A. V.

    Results of measurements carried out at SURA facility of Radiophisical Research Institute and at Tien-Shan Mountain Scientific Station of Lebedev Physical Institute using specially designed installations for short electromagnetic pulse observation in the frequency range from 0.1 to 30 MHz are presented. Specific attention is paid to initial stage of the lightning discharge. It is shown that lightning can be initiated by extensive atmospheric showers caused by high energy cosmic ray particles. Analysis of emission of few thousand lightning discharges showed that • Short wave radio emission of lightning consists of a series of short pulses with duration from less than 100 nanoseconds to several microseconds separated well longer gaps. • Background noise between lightning discharges is not differ from one observed without thunderstorm activity (at given sensitivity). Usually it is the same between lightning pulses at least at the initial stage. • Each lightning discharge radio emission starts with a number of very short (less than 100 nanoseconds at 0.7 level) bi-polar pulses. Gaps between initial pulses vary from several microseconds to few hundreds of microseconds. No radio emission was observed before the first pulse during at least 500 milliseconds. Both positive and negative polarity of the first pulses occur in approximately equal proportion in different lightning discharges while the polarity was the same in any individual lightning. • First pulse amplitude, width and waveform are consistent with predicted by the theory of combined action of runaway breakdown and extensive atmospheric shower caused by cosmic ray particle of 1016 eV energy. Lightning discharges at other planets can be initiated by cosmic ray particles as well. This work was partly supported by ISTC grant # 2236p. The work of one of the authors (A. N. Karashtin) was also partly supported by INTAS grant # 03-51-5727.

  15. Development of a long wave infrared detector for SGLI instrument

    NASA Astrophysics Data System (ADS)

    Dariel, Aurélien; Chorier, P.; Reeb, N.; Terrier, B.; Vuillermet, M.; Tribolet, P.

    2007-10-01

    The Japanese Aerospace Exploration Agency (JAXA) will be conducting the Global Change Observation Mission (GCOM) for monitoring of global environmental change. SGLI (Second Generation Global Imager) is an optical sensor on board GCOM-C (Climate), that includes a Long Wave IR Detector (LWIRD) sensitive up to about 13 μm. SGLI will provide high accuracy measurements of the atmosphere (aerosol, cloud ...), the cryosphere (glaciers, snow, sea ice ...), the biomass and the Earth temperature (sea and land). Sofradir is a major supplier of Space industry based on the use of a Space qualified MCT technology for detectors from 0.8 to 15 μm. This mature and reproducible technology has been used for 15 years to produce thousands of LWIR detectors with cut-off wavelengths between 9 and 12 μm. NEC Toshiba Space, prime contractor for the Second Generation Global Imager (SGLI), has selected SOFRADIR for its heritage in space projects and Mercury Cadmium Telluride (MCT) detectors to develop the LWIR detector. This detector includes two detection circuits for detection at 10.8 μm and 12.0 μm, hybridized on a single CMOS readout circuit. Each detection circuit is made of 20x2 square pixels of 140 μm. In order to optimize the overall performance, each pixel is made of 5x5 square sub-pixels of 28 μm and the readout circuit enables sub-pixel deselection. The MCT material and the photovoltaic technology are adapted to maximize response for the requested bandwidths: cut-off wavelengths of the 2 detection circuits are 12.6 and 13.4 μm at 55K. This detector is packaged into a sealed housing for full integration into a Dewar at 55K. This paper describes the main technical requirements, the design features of this detector, including trade-offs regarding performance optimization, and presents preliminary electro-optical results.

  16. 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.

  17. User's Guide - WRF Lightning Assimilation

    EPA Pesticide Factsheets

    This document describes how to run WRF with the lightning assimilation technique described in Heath et al. (2016). The assimilation method uses gridded lightning data to trigger and suppress sub-grid deep convection in Kain-Fritsch.

  18. An uncertain future for lightning

    NASA Astrophysics Data System (ADS)

    Murray, Lee T.

    2018-03-01

    The most commonly used method for representing lightning in global atmospheric models generally predicts lightning increases in a warmer world. A new scheme finds the opposite result, directly challenging the predictive skill of an old stalwart.

  19. Development and Application of a Low Frequency Near-Field Interferometric-TOA 3D Lightning Mapping Array

    NASA Astrophysics Data System (ADS)

    Lyu, F.; Cummer, S. A.; Weinert, J. L.; McTague, L. E.; Solanki, R.; Barrett, J.

    2014-12-01

    Lightning processes radiated extremely wideband electromagnetic signals. Lightning images mapped by VHF interferometry and VHF time of arrival lightning mapping arrays enable us to understand the lightning in-cloud detail development during the extent of flash that can not always be captured by cameras because of the shield of cloud. Lightning processes radiate electromagnetically over an extremely wide bandwidth, offering the possibility of multispectral lightning radio imaging. Low frequency signals are often used for lightning detection, but usually only for ground point location or thunderstorm tracking. Some recent results have demonstrated lightning LF 3D mapping of discrete lightning pulses, but imaging of continuous LF emissions have not been shown. In this work, we report a GPS-synchronized LF near field interferometric-TOA 3D lightning mapping array applied to image the development of lightning flashes on second time scale. Cross-correlation, as used in broadband interferometry, is applied in our system to find windowed arrival time differences with sub-microsecond time resolution. However, because the sources are in the near field of the array, time of arrival processing is used to find the source locations with a typical precision of 100 meters. We show that this system images the complete lightning flash structure with thousands of LF sources for extensive flashes. Importantly, this system is able to map both continuous emissions like dart leaders, and bursty or discrete emissions. Lightning stepped leader and dart leader propagation speeds are estimated to 0.56-2.5x105 m/s and 0.8-2.0x106 m/s respectively, which are consistent with previous reports. In many aspects our LF images are remarkably similar to VHF lightning mapping array images, despite the 1000 times difference in frequency, which may suggest some special links between the LF and VHF emission during lightning processes.

  20. Trigeminal Neuralgia Following Lightning Injury.

    PubMed

    López Chiriboga, Alfonso S; Cheshire, William P

    2017-01-01

    Lightning and other electrical incidents are responsible for more than 300 injuries and 100 deaths per year in the United States alone. Lightning strikes can cause a wide spectrum of neurologic manifestations affecting any part of the neuraxis through direct strikes, side flashes, touch voltage, connecting leaders, or acoustic shock waves. This article describes the first case of trigeminal neuralgia induced by lightning injury to the trigeminal nerve, thereby adding a new syndrome to the list of possible lightning-mediated neurologic injuries.

  1. 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.

  2. Lightning Mapping and Leader Propagation Reconstruction using LOFAR-LIM

    NASA Astrophysics Data System (ADS)

    Hare, B.; Ebert, U.; Rutjes, C.; Scholten, O.; Trinh, G. T. N.

    2017-12-01

    LOFAR (LOw Frequency ARray) is a radio telescope that consists of a large number of dual-polarized antennas spread over the northern Netherlands and beyond. The LOFAR for Lightning Imaging project (LOFAR-LIM) has successfully used LOFAR to map out lightning in the Netherlands. Since LOFAR covers a large frequency range (10-90 MHz), has antennas spread over a large area, and saves the raw trace data from the antennas, LOFAR-LIM can combine all the strongest aspects of both lightning mapping arrays and lightning interferometers. These aspects include a nanosecond resolution between pulses, nanosecond timing accuracy, and an ability to map lightning in all 3 spatial dimensions and time. LOFAR should be able to map out overhead lightning with a spatial accuracy on the order of meters. The large amount of complex data provide by LOFAR has presented new data processing challenges, such as handling the time offsets between stations with large baselines and locating as many sources as possible. New algorithms to handle these challenges have been developed and will be discussed. Since the antennas are dual-polarized, all three components of the electric field can be extracted and the structure of the R.F. pulses can be investigated at a large number of distances and angles relative to the lightning source, potentially allowing for modeling of lightning current distributions relevant to the 10 to 90 MHz frequency range. R.F. pulses due to leader propagation will be presented, which show a complex sub-structure, indicating intricate physics that could potentially be reconstructed.

  3. Mathematical Inversion of Lightning Data: Techniques and Applications

    NASA Technical Reports Server (NTRS)

    Koshak, William

    2003-01-01

    A survey of some interesting mathematical inversion studies dealing with radio, optical, and electrostatic measurements of lightning are presented. A discussion of why NASA is interested in lightning, what specific physical properties of lightning are retrieved, and what mathematical techniques are used to perform the retrievals are discussed. In particular, a relatively new multi-station VHF time-of-arrival (TOA) antenna network is now on-line in Northern Alabama and will be discussed. The network, called the Lightning Mapping Array (LMA), employs GPS timing and detects VHF radiation from discrete segments (effectively point emitters) that comprise the channel of lightning strokes within cloud and ground flashes. The LMA supports on-going ground-validation activities of the low Earth orbiting Lightning Imaging Sensor (LIS) satellite developed at NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama. The LMA also provides detailed studies of the distribution and evolution of thunderstorms and lightning in the Tennessee Valley, and offers interesting comparisons with other meteorological/geophysical datasets. In order to take full advantage of these benefits, it is essential that the LMA channel mapping accuracy (in both space and time) be fully characterized and optimized. A new channel mapping retrieval algorithm is introduced for this purpose. To characterize the spatial distribution of retrieval errors, the algorithm has been applied to analyze literally tens of millions of computer-simulated lightning VHF point sources that have been placed at various ranges, azimuths, and altitudes relative to the LMA network. Statistical results are conveniently summarized in high-resolution, color-coded, error maps.

  4. Lightning fires in southwestern forests

    Treesearch

    Jack S. Barrows

    1978-01-01

    Lightning is the leading cause of fires in southwestern forests. On all protected private, state and federal lands in Arizona and New Mexico, nearly 80 percent of the forest, brush and range fires are ignited by lightning. The Southwestern region leads all other regions of the United States both in total number of lightning fires and in the area burned by these fires...

  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. Lightning Physics: A Three Year Program

    DTIC Science & Technology

    1983-01-01

    because these aircraft are controlled poeal’ r r o(z’, I- RIC) with low-voltage digital electronics and are in part construct- 4w J(,3 cR "*t • at ed of... millise - limits pretrigger and delayed-trigger mode,. and a variety of sample conds, and hundreds of microseconds, respectively, the time of simple...processes, but we feel it prudent to discontinue use of the Proctor, D. E., A radio study of lightning, Ph.D. thesis , Univ. of designations in order

  7. Snapshot Imaging Spectrometry in the Visible and Long Wave Infrared

    NASA Astrophysics Data System (ADS)

    Maione, Bryan David

    perform single target detection on raw instrument data, thereby eliminating the need for an explicit spectral calibration step. As an extension of the results in chapter 2, neural networks are once again demonstrated to be an improvement when compared to linear operator based detection. In chapter 4 a non-interferometric design is developed for the long wave infrared (wavelengths spanning 8-12 microns). The imaging spectrometer developed in this chapter is a multi-aperture filtered microbolometer. Since the detector is uncooled, the presented design is ultra-compact and low power. Additionally, cost effective polymer absorption filters are used in lieu of interference filters. Since, each measurement of the system is spectrally multiplexed, an SNR advantage is realized. A theoretical model for the filtered design is developed, and the performance of the sensor for detecting liquid contaminants is investigated. Similar to past chapters, neural networks are used and achieve false detection rates of less than 1%. Lastly, this dissertation is concluded with a discussion on future work and potential impact of these devices.

  8. Lightning activity on Jupiter

    NASA Technical Reports Server (NTRS)

    Borucki, W. J.; Bar-Nun, A.; Scarf, F. L.; Look, A. F.; Hunt, G. E.

    1982-01-01

    Photographic observations of the nightside of Jupiter by the Voyager 1 spacecraft show the presence of extensive lightning activity. Detection of whistlers by the plasma wave analyzer confirms the optical observations and implies that many flashes were not recorded by the Voyager camera because the intensity of the flashes was below the threshold sensitivity of the camera. Measurements of the optical energy radiated per flash indicate that the observed flashes had energies similar to that for terrestrial superbolts. The best estimate of the lightning energy dissipation rate of 0.0004 W/sq m was derived from a consideration of the optical and radiofrequency measurements. The ratio of the energy dissipated by lightning compared to the convective energy flux is estimated to be between 0.000027 and 0.00005. The terrestrial value is 0.0001.

  9. Ionospheric signatures of Lightning

    NASA Astrophysics Data System (ADS)

    Hsu, M.; Liu, J.

    2003-12-01

    The geostationary metrology satellite (GMS) monitors motions of thunderstorm cloud, while the lightning detection network (LDN) in Taiwan and the very high Frequency (VHF) radar in Chung-Li (25.0›XN, 121.2›XE) observed occurrences of lightning during May and July, 1997. Measurements from the digisonde portable sounder (DPS) at National Central University shows that lightning results in occurrence of the sporadic E-layer (Es), as well as increase and decrease of plasma density at the F2-peak and E-peak in the ionosphere, respectively. A network of ground-based GPS receivers is further used to monitor the spatial distribution of the ionospheric TEC. To explain the plasma density variations, a model is proposed.

  10. Lightning on Venus

    NASA Technical Reports Server (NTRS)

    Scarf, F. L.

    1985-01-01

    On the night side of Venus, the plasma wave instrument on the Pioneer-Venus Orbiter frequently detects strong and impulsive low-frequency noise bursts when the local magnetic field is strong and steady and when the field is oriented to point down to the ionosphere. The signals have characteristics of lightning whistlers, and an attempt was made to identify the sources by tracing rays along the B-field from the Orbiter down toward the surface. An extensive data set strongly indicates a clustering of lightning sources near the Beta and Phoebe Regios, with additional significant clustering near the Atla Regio at the eastern edge of Aphrodite Terra. These results suggest that there are localized lightning sources at or near the planetary surface.

  11. Air traffic controller lightning strike.

    PubMed Central

    Spieth, M. E.; Kimura, R. L.; Schryer, T. D.

    1994-01-01

    Andersen Air Force Base in Guam boasts the tallest control tower in the Air Force. In 1986, an air traffic controller was struck by lightning as the bolt proceeded through the tower. Although he received only a backache, the lightning left a hole with surrounding scorch marks on his fatigue shirt and his undershirt. The lightning strike also ignited a portion of the field lighting panel, which caused the runway lights to go out immediately. Lack of a lightning rod is the most likely reason the controller was struck. Proper precautions against lightning strikes can prevent such occupational safety hazards. PMID:7966436

  12. Impact of lightning strikes on hospital functions.

    PubMed

    Mortelmans, Luc J M; Van Springel, Gert L J; Van Boxstael, Sam; Herrijgers, Jan; Hoflacks, Stefaan

    2009-01-01

    Two regional hospitals were struck by lightning during a one-month period. The first hospital, which had 236 beds, suffered a direct strike to the building. This resulted in a direct spread of the power peak and temporary failure of the standard power supply. The principle problems, after restoring standard power supply, were with the fire alarm system and peripheral network connections in the digital radiology systems. No direct impact on the hardware could be found. Restarting the servers resolved all problems. The second hospital, which had 436 beds, had a lightning strike on the premises and mainly experienced problems due to induction. All affected installations had a cable connection from outside in one way or another. The power supplies never were endangered. The main problem was the failure of different communication systems (telephone, radio, intercom, fire alarm system). Also, the electronic entrance control went out. During the days after the lightening strike, multiple software problems became apparent, as well as failures of the network connections controlling the technical support systems. There are very few ways to prepare for induction problems. The use of fiber-optic networks can limit damage. To the knowledge of the authors, these are the first cases of lightning striking hospitals in medical literature.

  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. Effects of Lightning in the Upper Atmosphere

    NASA Astrophysics Data System (ADS)

    Sentman, Davis D.; Pasko, Victor P.; Morrill, Jeff S.

    2010-02-01

    AGU Chapman Conference on Effects of Thunderstorms and Lightning in the Upper Atmosphere; University Park, Pennsylvania, 10-14 May 2009; The serendipitous observation in 1989 of electrical discharge in the high atmosphere induced by thundercloud lightning launched a new field of geophysical investigation. From this single unexpected observation sprang a vigorous and fertile new research field that simultaneously encompasses geophysical disciplines that are normally pursued independently, such as meteorology and lightning, plasma and gas discharge physics, atmospheric chemistry, ionospheric physics, and energetic particle physics. Transient electrical discharge in the upper atmosphere spans the full range of altitudes between the tropopause and the ionosphere and takes a variety of forms that carry the whimsical names red sprites, blue jets, gigantic jets, elves (emissions of light and very low frequency perturbations from electromagnetic pulse sources), and sprite halos, collectively known as transient luminous events (TLEs). To date, TLEs have been observed from ground and airborne or spaceborne platforms above thunderstorm systems worldwide, and radio observations made concomitantly with optical observations have shown that they are produced by the transient far fields of thundercloud lightning. TLEs appear to be large-scale (tens of kilometers in dimension), upper atmospheric versions of conventional gas discharge akin to weakly ionized, collision-dominated systems found in laboratory discharge devices (millimeter-centimeter dimensions), with characteristic energies of a few electron volts. The dominant physical processes have been identified as described by the familiar kinetic theory of the photochemistry of the upper atmosphere, but with electric field-driven electron impact ionization playing the role of photolysis or energetic precipitating particle-induced ionization.

  15. Breakpoint-forced and bound long waves in the nearshore: A model comparison

    USGS Publications Warehouse

    List, Jeffrey H.; ,

    1993-01-01

    A finite-difference model is used to compare long wave amplitudes arising from two-group forced generation mechanisms in the nearshore: long waves generated at a time-varying breakpoint and the shallow-water extension of the bound long wave. Plane beach results demonstrate that the strong frequency selection in the outgoing wave predicted by the breakpoint-forcing mechanism may not be observable in field data due to this wave's relatively small size and its predicted phase relation with the bound wave. Over a bar/trough nearshore, it is shown that a strong frequency selection in shoreline amplitudes is not a unique result of the time-varying breakpoint model, but a general result of the interaction between topography and any broad-banded forcing of nearshore long waves.

  16. 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 maymore » be discarding events that have the same nature as known perytons.« less

  17. A case study of lightning, whistlers, and associated ionospheric effects during a substorm particle injection event

    NASA Technical Reports Server (NTRS)

    Rodriguez, J. V.; Inan, U. S.; Li, Y. Q.; Holzworth, R. H.; Smith, A. J.; Orville, R. E.; Rosenberg, T. J.

    1992-01-01

    The relationships among cloud-to-ground (CG) lightning, sferics, whistlers, VLF amplitude perturbations, and other ionospheric phenomena occurring during substorm events were investigated using data from simultaneous ground-based observations of narrow-band and broad-band VLF radio waves and of CG lightning made during the 1987 Wave-Induced Particle Precipitation campaign conducted from Wallops Island (Virginia). Results suggest that the data collected on ionospheric phenomena during this event may represent new evidence of direct coupling of lightning energy to the lower ionosphere, either in conjunction with or in the absence of gyroresonant interactions between whistler mode waves and electrons in the magnetosphere.

  18. 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.

  19. Bead lightning formation

    SciTech Connect

    Ludwig, G.O.; Saba, M.M.F.; Division of Space Geophysics, National Space Research Institute, 12227-010, Sao Jose dos Campos, SP

    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 anomalousmore » 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.« less

  20. Lightning protection for aircraft

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    Reference book summarizes current knowledge concerning potential lightning effects on aircraft and means available to designers and operators to protect against effects. Book is available because of increasing use of nonmetallic materials in aircraft structural components and use of electronic equipment for control of critical flight operations and navigation.

  1. 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)

  2. On the interactions between energetic electrons and lightning whistler waves observed at high L-shells on Van Allen Probes

    NASA Astrophysics Data System (ADS)

    Zheng, H.; Holzworth, R. H., II; Brundell, J. B.; Hospodarsky, G. B.; Jacobson, A. R.; Fennell, J. F.; Li, J.

    2017-12-01

    Lightning produces strong broadband radio waves, called "sferics", which propagate in the Earth-ionosphere waveguide and are detected thousands of kilometers away from their source. Global real-time detection of lightning strokes including their time, location and energy, is conducted with the World Wide Lightning Location Network (WWLLN). In the ionosphere, these sferics couple into very low frequency (VLF) whistler waves which propagate obliquely to the Earth's magnetic field. A good match has previously been shown between WWLLN sferics and Van Allen Probes lightning whistler waves. It is well known that lightning whistler waves can modify the distribution of energetic electrons in the Van Allen belts by pitch angle scattering into the loss cone, especially at low L-Shells (referred to as LEP - Lightning-induced Electron Precipitation). It is an open question whether lightning whistler waves play an important role at high L-shells. The possible interactions between energetic electrons and lightning whistler waves at high L-shells are considered to be weak in the past. However, lightning is copious, and weak pitch angle scattering into the drift or bounce loss cone would have a significant influence on the radiation belt populations. In this work, we will analyze the continuous burst mode EMFISIS data from September 2012 to 2016, to find out lightning whistler waves above L = 3. Based on that, MAGEIS data are used to study the related possible wave-particle interactions. In this talk, both case study and statistical analysis results will be presented.

  3. 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

  4. Lightning charge moment changes estimated by high speed photometric observations from ISS

    NASA Astrophysics Data System (ADS)

    Hobara, Y.; Kono, S.; Suzuki, K.; Sato, M.; Takahashi, Y.; Adachi, T.; Ushio, T.; Suzuki, M.

    2017-12-01

    Optical observations by the CCD camera using the orbiting satellite is generally used to derive the spatio-temporal global distributions of the CGs and ICs. However electrical properties of the lightning such as peak current and lightning charge are difficult to obtain from the space. In particular, CGs with considerably large lightning charge moment changes (CMC) and peak currents are crucial parameters to generate red sprites and elves, respectively, and so it must be useful to obtain these parameters from space. In this paper, we obtained the lightning optical signatures by using high speed photometric observations from the International Space Station GLIMS (Global Lightning and Sprit MeasurementS JEM-EF) mission. These optical signatures were compared quantitatively with radio signatures recognized as truth values derived from ELF electromagnetic wave observations on the ground to verify the accuracy of the optically derived values. High correlation (R > 0.9) was obtained between lightning optical irradiance and current moment, and quantitative relational expression between these two parameters was derived. Rather high correlation (R > 0.7) was also obtained between the integrated irradiance and the lightning CMC. Our results indicate the possibility to derive lightning electrical properties (current moment and CMC) from optical measurement from space. Moreover, we hope that these results will also contribute to forthcoming French microsatellite mission TARANIS.

  5. ELF Sferics Produced by Rocket-Triggered Lightning and Observed at Great Distances

    NASA Astrophysics Data System (ADS)

    Dupree, N. A.; Moore, R. C.; Fraser-Smith, A. C.

    2013-12-01

    Experimental observations of ELF radio atmospherics produced by rocket-triggered lightning flashes are used to analyze Earth-ionosphere waveguide excitation and propagation characteristics as a function of return stroke. Rocket-triggered lightning experiments are performed at the International Center for Lightning Research and Testing (ICLRT) located at Camp Blanding, Florida. Long-distance ELF observations are performed in California, Greenland, and Antarctica, although this work focuses on observations performed in Greenland. The lightning current waveforms directly measured at the base of the lightning channel (at the ICLRT) are used together with the Long Wavelength Propagation Capability (LWPC) code to predict the sferic waveform observed at the receiver locations under various ionospheric conditions. LWPC was developed by the Naval Ocean Systems Center over a period of many years. It is an inherently narrowband propagation code that has been modified to predict the broadband response of the Earth-ionosphere waveguide to an impulsive lightning flash while preserving the ability of LWPC to account for an inhomogeneous waveguide. This paper critically compares observations with model predictions, and in particular analyzes Earth-ionosphere waveguide excitation as a function of return stroke. The ability to infer source characteristics using observations at great distances may prove to greatly enhance the understanding of lightning processes that are associated with the production of transient luminous events (TLEs) as well as other ionospheric effects associated with lightning.

  6. Lightning fire research in the Rocky Mountains

    Treesearch

    J. S. Barrows

    1954-01-01

    Lightning is the major cause of fires in Rocky Mountain forests. The lightning fire problem is the prime target of a broad research program now known as Project Skyfire. KEYWORDS: lightning, fire research

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

    SciTech Connect

    Istomin, Ya. N., E-mail: istomin@lpi.ru; Sob'yanin, D. N., E-mail: sobyanin@lpi.ru

    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 ofmore » 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).« less

  8. Lightning Activity Analyses with Respect to the SPCZ Location and to Surface Air Humidity Around Tahiti

    NASA Astrophysics Data System (ADS)

    Ortega, P.; Guignes, T.

    2006-12-01

    The South Pacific Convergence Zone (SPCZ) is located from the West Pacific warm pool and trends Southeast towards French Polynesia. The Island Climate Update monthly publishes the mean location deduced from the outgoing long-wave radiation anomalies or higher rainfall. On the other hand, the Wide World Lightning Location Network monthly provides data from which the lightning activity distribution in the 0°-30° South latitude and 150°-240° West longitude area can be drawn. Scanning this rectangle from West to East the location of the maximum lightning activity can be located versus the longitude. Fitting the location of these maximum with a polynomial function leads to a curve comparable with the monthly mean position of the SPCZ, showing that this band of cloudiness is the main source of lightning in this whole area. Besides, relations between surface atmospheric parameters, the number of thunder days and the number of flashes recorded around Tahiti have been analyzed using, the absolute humidity and the lightning activity recorded during the last nine years with the help of CIGRE Lightning Flash Counters. Since it is known that the cloud base is closely related to the boundary layer relative humidity, the aim of the analysis was to sort out a correlation between this parameter and the lightning activity. No correlation has been clearly put in evidence with the number of thunder days but the monthly mean values of the amount of flashes recorded exhibit similar oscillation with air humidity over a 9 year long period including the several phases of the ENSO.

  9. 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.

  10. Lightning protection of distribution lines

    SciTech Connect

    McDermott, T.E.; Short, T.A.; Anderson, J.G.

    1994-01-01

    This paper reports a study of distribution line lightning performance, using computer simulations of lightning overvoltages. The results of previous investigations are extended with a detailed model of induced voltages from nearby strokes, coupled into a realistic power system model. The paper also considers the energy duty of distribution-class surge arresters exposed to direct strokes. The principal result is that widely separated pole-top arresters can effectively protect a distribution line from induced-voltage flashovers. This means that nearby lightning strokes need not be a significant lightning performance problem for most distribution lines.

  11. 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.

  12. RF radiation from lightning

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1978-01-01

    Radiation from lightning in the RF band from 3-300 MHz were monitored. Radiation in this frequency range is of interest as a potential vehicle for monitoring severe storms and for studying the lightning itself. Simultaneous measurements were made of RF radiation and fast and slow field changes. Continuous analogue recordings with a system having 300 kHz of bandwidth were made together with digital records of selected events (principally return strokes) at greater temporal resolution. The data reveal patterns in the RF radiation for the entire flash which are characteristic of flash type and independent of the frequency of observation. Individual events within the flash also have characteristic RF patterns. Strong radiation occurs during the first return strokes, but delayed about 20 micron sec with respect to the begining of the return stroke; whereas, RF radiation from subsequent return strokes tends to be associated with cloud processes preceding the flash with comparatively little radiation occurring during the return stroke itself.

  13. Lightning Scaling Laws Revisited

    NASA Technical Reports Server (NTRS)

    Boccippio, D. J.; Arnold, James E. (Technical Monitor)

    2000-01-01

    Scaling laws relating storm electrical generator power (and hence lightning flash rate) to charge transport velocity and storm geometry were originally posed by Vonnegut (1963). These laws were later simplified to yield simple parameterizations for lightning based upon cloud top height, with separate parameterizations derived over land and ocean. It is demonstrated that the most recent ocean parameterization: (1) yields predictions of storm updraft velocity which appear inconsistent with observation, and (2) is formally inconsistent with the theory from which it purports to derive. Revised formulations consistent with Vonnegut's original framework are presented. These demonstrate that Vonnegut's theory is, to first order, consistent with observation. The implications of assuming that flash rate is set by the electrical generator power, rather than the electrical generator current, are examined. The two approaches yield significantly different predictions about the dependence of charge transfer per flash on storm dimensions, which should be empirically testable. The two approaches also differ significantly in their explanation of regional variability in lightning observations.

  14. Radio Galaxies.

    ERIC Educational Resources Information Center

    Downes, Ann

    1986-01-01

    Provides background information on radio galaxies. Topic areas addressed include: what produces the radio emission; radio telescopes; locating radio galaxies; how distances to radio galaxies are found; physics of radio galaxies; computer simulations of radio galaxies; and the evolution of radio galaxies with cosmic time. (JN)

  15. Statistical Patterns in Natural Lightning

    NASA Astrophysics Data System (ADS)

    Zoghzoghy, F. G.; Cohen, M.; Said, R.; Inan, U. S.

    2011-12-01

    Every day millions of lightning flashes occur around the globe but the understanding of this natural phenomenon is still lacking. Fundamentally, lightning is nature's way of destroying charge separation in clouds and restoring electric neutrality. Thus, statistical patterns of lightning activity indicate the scope of these electric discharges and offer a surrogate measure of timescales for charge buildup in thunderclouds. We present a statistical method to investigate spatio-temporal correlations among lightning flashes using National Lightning Detection Network (NLDN) stroke data. By monitoring the distribution of lightning activity, we can observe the charging and discharging processes in a given thunderstorm. In particular, within a given storm, the flashes do not occur as a memoryless random process. We introduce the No Flash Zone (NFZ) which results from the suppressed probability of two consecutive neighboring flashes. This effect lasts for tens of seconds and can extend up to 15 km around the location of the initial flash, decaying with time. This suppression effect may be a function of variables such as storm location, storm phase, and stroke peak current. We develop a clustering algorithm, Storm-Locator, which groups strokes into flashes, storm cells, and thunderstorms, and enables us to study lightning and the NFZ in different geographical regions, and for different storms. The recursive algorithm also helps monitor the interaction among spatially displaced storm cells, and can provide more insight into the spatial and temporal impacts of lightning discharges.

  16. Artist's Concept of Jupiter Lightning

    NASA Image and Video Library

    2018-06-06

    This artist's concept of lightning distribution in Jupiter's northern hemisphere incorporates a JunoCam image with artistic embellishments. Data from NASA's Juno mission indicates that most of the lightning activity on Jupiter is near its poles. https://photojournal.jpl.nasa.gov/catalog/PIA22474

  17. First results of the Colombia Lightning Mapping Array

    NASA Astrophysics Data System (ADS)

    López, Jesus; Montanyà, Joan; van der Velde, Oscar; Romero, David; Fabró, Ferran; Taborda, John; Aranguren, Daniel; Torres, Horacio

    2016-04-01

    In April 2015 the 3D Lightning Mapping Array (COLMA) network was installed on Santa Marta area (north of Colombia). The COLMA maps VHF radio emissions of lightning leaders in three dimensions by the time-of-arrival technique (Rison et al., 1999). This array has six sensors with base lines between 5 km to 20 km. The COLMA is the first VHF 3D network operating in the tropics and it has been installed in the frame of ASIM (Atmosphere-Space Interactions Monitor) ESA's mission in order to investigate the electrical characteristics of tropical thunderstorms favorable for the production of Terrestrial Gamma ray Flashes (TGF). In this paper we present COLMA data of several storms. We discuss lightning activity, lightning leader altitudes and thunderstorm charge structures compared to data form our ELMA (Ebro Lightning Mapping Array) at the north-east coast of Spain. The data confirm what we expected, lightning leaders can propagate at higher altitudes compared to mid latitude thunderstorms because the higher vertical development of tropical thunderstorms. A simple inspection of a ten minute period of the 16th of November of 2015 storm shows a tripolar electric charge structure. In that case, the midlevel negative charge region was located between 7 to 9 km. The structure presented a lower positive charge below the midlevel negative and centred at 6.5 km and an upper positive charge region extending from 9 km to slightly more than 15 km. This vertical extension of the upper positive charge where negative leaders evolve is significantly larger compared to the storms at the ELMA area in Spain. COLMA has shown frequent activity of negative leaders reaching altitudes of more than 15 km.

  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. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

  20. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

  1. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  2. 14 CFR 25.581 - Lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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

  3. Dark- and bright-rogue-wave solutions for media with long-wave-short-wave resonance.

    PubMed

    Chen, Shihua; Grelu, Philippe; Soto-Crespo, J M

    2014-01-01

    Exact explicit rogue-wave solutions of intricate structures are presented for the long-wave-short-wave resonance equation. These vector parametric solutions feature coupled dark- and bright-field counterparts of the Peregrine soliton. Numerical simulations show the robustness of dark and bright rogue waves in spite of the onset of modulational instability. Dark fields originate from the complex interplay between anomalous dispersion and the nonlinearity driven by the coupled long wave. This unusual mechanism, not available in scalar nonlinear wave equation models, can provide a route to the experimental realization of dark rogue waves in, for instance, negative index media or with capillary-gravity waves.

  4. Electrification processes and lightning generation in volcanic plumes—observations from recent eruptions

    NASA Astrophysics Data System (ADS)

    Van Eaton, A. R.; Smith, C. M.; Schneider, D. J.

    2017-12-01

    Lightning in volcanic plumes provides a promising way to monitor ash-producing eruptions and investigate their dynamics. Among the many methods of lightning detection are global networks of sensors that detect electromagnetic radiation in the very low frequency band (3-30 kHz), including the World Wide Lightning Location Network. These radio waves propagate thousands of kilometers at the speed of light, providing an opportunity for rapid detection of explosive volcanism anywhere in the world. Lightning is particularly valuable as a near real-time indicator of ash-rich plumes that are hazardous to aviation. Yet many fundamental questions remain. Under what conditions does electrical activity in volcanic plumes become powerful, detectable lightning? And conversely, can we use lightning to illuminate eruption processes and hazards? This study highlights recent observations from the eruptions of Redoubt (Alaska, 2009), Kelud (Indonesia, 2014), Calbuco (Chile, 2015), and Bogoslof (Alaska, 2017) to examine volcanic lighting from a range of eruption styles (Surtseyan to Plinian) and mass eruption rates from 10^5 to 10^8 kg/s. It is clear that lightning stroke-rates do not scale in a simple way with mass eruption rate or plume height across different eruptions. However, relative changes in electrical activity through individual eruptions relate to changes in eruptive intensity, ice content, and volcanic plume processes (fall vs. flow).

  5. Search for possible relationship between volcanic ash particles and thunderstorm lightning activity

    NASA Astrophysics Data System (ADS)

    Várai, A.; Vincze, M.; Lichtenberger, J.; Jánosi, I. M.

    2011-12-01

    Explosive volcanic eruptions that eject columns of ash from the crater often generate lightning discharges strong enough to be remotely located by very low frequency radio waves. A fraction of volcanic ash particles can stay and disperse long enough to have an effect on weather phenomena days later such as thunderstorms and lightnings. In this work we report on lightning activity analysis over Europe following two recent series of volcanic eruptions in order to identify possible correlations between ash release and subsequent thunderstorm flash frequency. Our attempts gave negative results which can be related to the fact that we have limited information on local atmospheric variables of high enough resolution, however lightning frequency is apparently determined by very local circumstances.

  6. Correlation of satellite lightning observations with ground-based lightning experiments in Florida, Texas and Oklahoma

    NASA Technical Reports Server (NTRS)

    Edgar, B. C.; Turman, B. N.

    1982-01-01

    Satellite observations of lightning were correlated with ground-based measurements of lightning from data bases obtained at three separate sites. The percentage of ground-based observations of lightning that would be seen by an orbiting satellite was determined.

  7. Aircraft Lightning Protection Handbook

    DTIC Science & Technology

    1989-09-01

    tape or metal braid . The shield. The effect of leakage through the connector can transfer characteristics can seldom be determined by thus be...62 REFERENCES 66 CHAPTER 4 LIGHTNING EFFECTS ON AIRCRAFT 69 4.1 Introduction 69 4.2 Direct Effects on Metal Structures 70 4.2.1 Pitting and Melt...Certification plans 112 5.8 Test Plans 113 REFERENCES 113 Chapter 6 DIRECT EFFECTS PROTECTION 115 6.1 Introduction 115 6.2 Direct Effects on Metal Structures

  8. Lightning NOx Estimates from Space-Based Lightning Imagers

    NASA Technical Reports Server (NTRS)

    Koshak, William J.

    2017-01-01

    The intense heating of air by a lightning channel, and subsequent rapid cooling, leads to the production of lightning nitrogen oxides (NOx = NO + NO2) as discussed in Chameides [1979]. In turn, the lightning nitrogen oxides (or "LNOx" for brevity) indirectly influences the Earth's climate because the LNOx molecules are important in controlling the concentration of ozone (O3) and hydroxyl radicals (OH) in the atmosphere. Climate is most sensitive to O3 in the upper troposphere, and LNOx is the most important source of NOx in the upper troposphere at tropical and subtropical latitudes; hence, lightning is a useful parameter to monitor for climate assessments. The National Climate Assessment (NCA) program was created in response to the Congressionally-mandated Global Change Research Act (GCRA) of 1990. Thirteen US government organizations participate in the NCA program which examines the effects of global change on the natural environment, human health and welfare, energy production and use, land and water resources, human social systems, transportation, agriculture, and biological diversity. The NCA focuses on natural and human-induced trends in global change, and projects major trends 25 to 100 years out. In support of the NCA, the NASA Marshall Space Flight Center (MSFC) continues to assess lightning-climate inter-relationships. This activity applies a variety of NASA assets to monitor in detail the changes in both the characteristics of ground- and space- based lightning observations as they pertain to changes in climate. In particular, changes in lightning characteristics over the conterminous US (CONUS) continue to be examined by this author using data from the Tropical Rainfall Measuring Mission Lightning Imaging Sensor. In this study, preliminary estimates of LNOx trends derived from TRMM/LIS lightning optical energy observations in the 17 yr period 1998-2014 are provided. This represents an important first step in testing the ability to make remote retrievals

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    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 1028. 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).

  10. 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

  11. Development of Algorithms and Error Analyses for the Short Baseline Lightning Detection and Ranging System

    NASA Technical Reports Server (NTRS)

    Starr, Stanley O.

    1998-01-01

    NASA, at the John F. Kennedy Space Center (KSC), developed and operates a unique high-precision lightning location system to provide lightning-related weather warnings. These warnings are used to stop lightning- sensitive operations such as space vehicle launches and ground operations where equipment and personnel are at risk. The data is provided to the Range Weather Operations (45th Weather Squadron, U.S. Air Force) where it is used with other meteorological data to issue weather advisories and warnings for Cape Canaveral Air Station and KSC operations. This system, called Lightning Detection and Ranging (LDAR), provides users with a graphical display in three dimensions of 66 megahertz radio frequency events generated by lightning processes. The locations of these events provide a sound basis for the prediction of lightning hazards. This document provides the basis for the design approach and data analysis for a system of radio frequency receivers to provide azimuth and elevation data for lightning pulses detected simultaneously by the LDAR system. The intent is for this direction-finding system to correct and augment the data provided by LDAR and, thereby, increase the rate of valid data and to correct or discard any invalid data. This document develops the necessary equations and algorithms, identifies sources of systematic errors and means to correct them, and analyzes the algorithms for random error. This data analysis approach is not found in the existing literature and was developed to facilitate the operation of this Short Baseline LDAR (SBLDAR). These algorithms may also be useful for other direction-finding systems using radio pulses or ultrasonic pulse data.

  12. Finite Element Modeling and Long Wave Infrared Imaging for Detection and Identification of Buried Objects

    DTIC Science & Technology

    surface temperature profile of a sandbox containing buried objects using a long-wave infrared camera. Images were recorded for several days under ambient...time of day . Best detection of buried objects corresponded to shallow depths for observed intervals where maxima/minima ambient temperatures coincided

  13. Sensitivity and Specificity of Long Wave Infrared Imaging for Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Coben, Robert; Myers, Thomas E.

    2009-01-01

    Objective: This study was the first to investigate the efficacy of long wave infrared (LWIR) imaging as a diagnostic tool for ADHD. Method: with ADHD and a high level of specificity (94%) in discriminating those with ADHD from those with other diagnoses. The overall classification rate was 73.16%. This was indicative of a high level of…

  14. Variability In Long-Wave Runup as a Function of Nearshore Bathymetric Features

    SciTech Connect

    Dunkin, Lauren McNeill

    Beaches and barrier islands are vulnerable to extreme storm events, such as hurricanes, that can cause severe erosion and overwash to the system. Having dunes and a wide beach in front of coastal infrastructure can provide protection during a storm, but the influence that nearshore bathymetric features have in protecting the beach and barrier island system is not completely understood. The spatial variation in nearshore features, such as sand bars and beach cusps, can alter nearshore hydrodynamics, including wave setup and runup. The influence of bathymetric features on long-wave runup can be used in evaluating the vulnerability of coastal regionsmore » to erosion and dune overtopping, evaluating the changing morphology, and implementing plans to protect infrastructure. In this thesis, long-wave runup variation due to changing bathymetric features as determined with the numerical model XBeach is quantified (eXtreme Beach behavior model). Wave heights are analyzed to determine the energy through the surfzone. XBeach assumes that coastal erosion at the land-sea interface is dominated by bound long-wave processes. Several hydrodynamic conditions are used to force the numerical model. The XBeach simulation results suggest that bathymetric irregularity induces significant changes in the extreme long-wave runup at the beach and the energy indicator through the surfzone.« less

  15. Lightning protection of wind turbines

    NASA Technical Reports Server (NTRS)

    Dodd, C. W.

    1982-01-01

    Possible damages to wind turbine components due to lightning strikes are discussed and means to prevent the damage are presented. A low resistance path to the ground is noted to be essential for any turbine system, including metal paths on nonmetal blades to conduct the strike. Surge arrestors are necessary to protect against overvoltages both from utility lines in normal operation and against lightning damage to control equipment and contactors in the generator. MOS structures are susceptible to static discharge injury, as are other semiconductor devices, and must be protected by the presence of static protection circuitry. It is recommended that the electronics be analyzed for the circuit transient response to a lightning waveform, to induced and dc current injection, that input/output leads be shielded, everything be grounded, and lightning-resistant components be chosen early in the design phase.

  16. Lightning protection of wind turbines

    NASA Astrophysics Data System (ADS)

    Dodd, C. W.

    1982-05-01

    Possible damages to wind turbine components due to lightning strikes are discussed and means to prevent the damage are presented. A low resistance path to the ground is noted to be essential for any turbine system, including metal paths on nonmetal blades to conduct the strike. Surge arrestors are necessary to protect against overvoltages both from utility lines in normal operation and against lightning damage to control equipment and contactors in the generator. MOS structures are susceptible to static discharge injury, as are other semiconductor devices, and must be protected by the presence of static protection circuitry. It is recommended that the electronics be analyzed for the circuit transient response to a lightning waveform, to induced and dc current injection, that input/output leads be shielded, everything be grounded, and lightning-resistant components be chosen early in the design phase.

  17. Camp Blanding Lightning Mapping Array

    NASA Technical Reports Server (NTRS)

    Blakeslee,Richard; Christian, Hugh; Bailey, Jeffrey; Hall, John; Uman, Martin; Jordan, Doug; Krehbiel, Paul; Rison, William; Edens, Harald

    2011-01-01

    A seven station, short base-line Lightning Mapping Array was installed at the Camp Blanding International Center for Lightning Research and Testing (ICLRT) during April 2011. This network will support science investigations of Terrestrial Gamma-Ray Flashes (TGFs) and lightning initiation using rocket triggered lightning at the ICLRT. The network operations and data processing will be carried out through a close collaboration between several organizations, including the NASA Marshall Space Flight Center, University of Alabama in Huntsville, University of Florida, and New Mexico Tech. The deployment was sponsored by the Defense Advanced Research Projects Agency (DARPA). The network does not have real-time data dissemination. Description, status and plans will be discussed.

  18. Lightning strike protection of composites

    NASA Astrophysics Data System (ADS)

    Gagné, Martin; Therriault, Daniel

    2014-01-01

    Aircraft structures are being redesigned to use fiber-reinforced composites mainly due to their high specific stiffness and strength. One of the main drawbacks from changing from electrically conductive metals to insulating or semi-conducting composites is the higher vulnerability of the aircraft to lightning strike damage. The current protection approach consists of bonding a metal mesh to the surface of the composite structure, but this weight increase negatively impact the fuel efficiency. This review paper presents an overview of the lightning strike problematic, the regulations, the lightning damage to composite, the current protection solutions and other material or technology alternatives. Advanced materials such as polymer-based nanocomposites and carbon nanotube buckypapers are promising candidates for lightweight lightning strike protection technology.

  19. 2016 T Division Lightning Talks

    SciTech Connect

    Ramsey, Marilyn Leann; Adams, Luke Clyde; Ferre, Gregoire Robing

    These are the slides for all of the 2016 T Division lightning talks. There are 350 pages worth of slides from different presentations, all of which cover different topics within the theoretical division at Los Alamos National Laboratory (LANL).

  20. 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.

  1. 2017 T Division Lightning Talks

    SciTech Connect

    Ramsey, Marilyn Leann; Abeywardhana, Jayalath AMM; Adams, Colin Mackenzie

    All members of the T Division Community, students, staff members, group leaders, division management, and other interested individuals are invited to come and support the following student(s) as they present their Lightning Talks.

  2. Characterization of infrasound from lightning

    NASA Astrophysics Data System (ADS)

    Assink, J. D.; Evers, L. G.; Holleman, I.; Paulssen, H.

    2008-08-01

    During thunderstorm activity in the Netherlands, electromagnetic and infrasonic signals are emitted due to the process of lightning and thunder. It is shown that correlating infrasound detections with results from a electromagnetic lightning detection network is successful up to distances of 50 km from the infrasound array. Infrasound recordings clearly show blastwave characteristics which can be related to cloud-ground discharges, with a dominant frequency between 1-5 Hz. Amplitude measurements of CG discharges can partly be explained by the beam pattern of a line source with a dominant frequency of 3.9 Hz, up to a distance of 20 km. The ability to measure lightning activity with infrasound arrays has both positive and negative implications for CTBT verification purposes. As a scientific application, lightning studies can benefit from the worldwide infrasound verification system.

  3. Neurologic complications of lightning injuries.

    PubMed Central

    Cherington, M; Yarnell, P R; London, S F

    1995-01-01

    Over the past ten years, we have cared for 13 patients who suffered serious neurologic complications after being struck by lightning. The spectrum of neurologic lesions includes the entire neuraxis from the cerebral hemispheres to the peripheral nerves. We describe these various neurologic disorders with regard to the site of the lesion, severity of the deficit, and the outcome. Damage to the nervous system can be a serious problem for patients struck by lightning. Fatalities are associated with hypoxic encephalopathy in patients who suffered cardiac arrests. Patients with spinal cord lesions are likely to have permanent sequelae and paralysis. New technology for detecting lightning with wideband magnetic direction finders is useful in establishing lightning-flash densities in each state. Florida and the Gulf Coast states have the highest densities. Colorado and the Rocky Mountain states have the next highest. Images PMID:7785254

  4. Acoustic localization of triggered lightning

    NASA Astrophysics Data System (ADS)

    Arechiga, Rene O.; Johnson, Jeffrey B.; Edens, Harald E.; Thomas, Ronald J.; Rison, William

    2011-05-01

    We use acoustic (3.3-500 Hz) arrays to locate local (<20 km) thunder produced by triggered lightning in the Magdalena Mountains of central New Mexico. The locations of the thunder sources are determined by the array back azimuth and the elapsed time since discharge of the lightning flash. We compare the acoustic source locations with those obtained by the Lightning Mapping Array (LMA) from Langmuir Laboratory, which is capable of accurately locating the lightning channels. To estimate the location accuracy of the acoustic array we performed Monte Carlo simulations and measured the distance (nearest neighbors) between acoustic and LMA sources. For close sources (<5 km) the mean nearest-neighbors distance was 185 m compared to 100 m predicted by the Monte Carlo analysis. For far distances (>6 km) the error increases to 800 m for the nearest neighbors and 650 m for the Monte Carlo analysis. This work shows that thunder sources can be accurately located using acoustic signals.

  5. Ground Optical Lightning Detector (GOLD)

    NASA Technical Reports Server (NTRS)

    Jackson, John, Jr.; Simmons, David

    1990-01-01

    A photometer developed to characterize lightning from the ground is discussed. The detector and the electronic signal processing and data storage systems are presented along with field data measured by the system. The discussion will include improvements that will be incorporated to enhance the measurement of lightning and the data storage capability to record for many days without human involvement. Finally, the calibration of the GOLD system is presented.

  6. Fatal lightning strikes in Malaysia.

    PubMed

    Murty, O P; Kian, Chong Kah; Ari Husin, Mohammed Husrul; Nanta Kumar, Ranjeev Kumar; Mohammed Yusuf, Wan Yuhana W

    2009-09-01

    Lightning strike is a natural phenomenon with potentially devastating effects and represents one of the important causes of deaths from environmental phenomena. Almost every organ system may be affected as lightning current passes through the human body taking the shortest pathways between the contact points. A 10 years retrospective study (1996-2005) was conducted at University Hospital Kuala Lumpur (20 cases) also including cases during last 3 years from Hospital Tengku Ampuan Rahimah, Klang (7 cases) from the autopsy reports at Forensic Pathology Units of these 2 hospitals. Both these hospitals are attached to University of Malaya. There were 27 fatal cases of lightning strike with male preponderance(92.59%) and male to female ratio of 12.5:1. Majority of victims of lightning strike were from the age group between 30 and 39 years old. Most of the victims were foreign workers. Indonesians workers contributed to 59.26% of overall cases. Majority of them were construction workers who attributed i.e.11 of 27 cases (40.74%). Most of the victims were brought in dead (37.04%). In majority of the cases the lightning incidence occurred in the evenings, with the frequency of 15 of 27 cases (62.5%). The month of December represented with the highest number of cases (5 cases of 23 cases); 2004 had the highest incidence of lightning strike which was 5 (19.23%). Lightning strike incidence occurred when victims had taken shelter (25.9%) under trees or shades. Lightning strike in open areas occurred in 10 of 27 cases (37.0%). Head and neck were the most commonly affected sites with the incidence of 77.78% and 74% respectively in all the victims. Only 29.63% of the cases presented with ear bleeding.

  7. Lightning injuries during snowy conditions

    PubMed Central

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

    1998-01-01

    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. 




 PMID:9865407

  8. Lightning over Equatorial Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These two images were taken 9 seconds apart as the STS-97 Space Shuttle flew over equatorial Africa east of Lake Volta on December 11, 2000. The top of the large thunderstorm, roughly 20 km across, is illuminated by a full moon and frequent bursts of lightning. Because the Space Shuttle travels at about 7 km/sec, the astronaut perspectives on this storm system becomes more oblique over the 9-second interval between photographs. The images were taken with a Nikon 35 mm camera equipped with a 400 mm lens and high-speed (800 ISO) color negative film. Images are STS097-351-9 and STS097-351-12, provided and archived by the Earth Science and Image Analysis Laboratory, Johnson Space Center. Additional images taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth at http://eol.jsc.nasa.gov/

  9. Lightning discharge protection rod

    NASA Technical Reports Server (NTRS)

    Bryan, Charles F., Jr. (Inventor)

    1987-01-01

    A system for protecting an in-air vehicle from damage due to a lighning strike is disclosed. It is an extremely simple device consisting of a sacrificial graphite composite rod, approximately the diameter of a pencil with a length of about five inches. The sacrificial rod is constructed with the graphite fibers running axially within the rod in a manner that best provides a path of conduction axially from the trailing edge of an aircraft to the trailing end of the rod. The sacrificial rod is inserted into an attachment hole machined into trailing edges of aircraft flight surfaces, such as a vertical fin cap and attached with adhesive in a manner not prohibiting the conduction path between the rod and the aircraft. The trailing end of the rod may be tapered for aerodynamic and esthetic requirements. This rod is sacrificial but has the capability to sustain several lightning strikes and still provide protection.

  10. Industrial accidents triggered by lightning.

    PubMed

    Renni, Elisabetta; Krausmann, Elisabeth; Cozzani, Valerio

    2010-12-15

    Natural disasters can cause major accidents in chemical facilities where they can lead to the release of hazardous materials which in turn can result in fires, explosions or toxic dispersion. Lightning strikes are the most frequent cause of major accidents triggered by natural events. In order to contribute towards the development of a quantitative approach for assessing lightning risk at industrial facilities, lightning-triggered accident case histories were retrieved from the major industrial accident databases and analysed to extract information on types of vulnerable equipment, failure dynamics and damage states, as well as on the final consequences of the event. The most vulnerable category of equipment is storage tanks. Lightning damage is incurred by immediate ignition, electrical and electronic systems failure or structural damage with subsequent release. Toxic releases and tank fires tend to be the most common scenarios associated with lightning strikes. Oil, diesel and gasoline are the substances most frequently released during lightning-triggered Natech accidents. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. From Radio to X-rays--Some 'Real' Electrical Applications.

    ERIC Educational Resources Information Center

    Freeman, J. C.

    1986-01-01

    Describes practical applications related to X-rays, ultra-violet radiation, light radiation, short-wave infra-red radiation, medium-wave infra-red radiation, long-wave infra-red radiation, microwave radiation, and radio frequency radiation. Suggests that these applications be used during instruction on electricity. (JN)

  12. The North Alabama Lightning Warning Product

    NASA Technical Reports Server (NTRS)

    Buechler, Dennis E.; Blakeslee, R. J.; Stano, G. T.

    2009-01-01

    The North Alabama Lightning Mapping Array NALMA has been collecting total lightning data on storms in the Tennessee Valley region since 2001. Forecasters from nearby National Weather Service (NWS) offices have been ingesting this data for display with other AWIPS products. The current lightning product used by the offices is the lightning source density plot. The new product provides a probabalistic, short-term, graphical forecast of the probability of lightning activity occurring at 5 min intervals over the next 30 minutes . One of the uses of the current lightning source density product by the Huntsville National Weather Service Office is to identify areas of potential for cloud-to-ground flashes based on where LMA total lightning is occurring. This product quantifies that observation. The Lightning Warning Product is derived from total lightning observations from the Washington, D.C. (DCLMA) and North Alabama Lightning Mapping Arrays and cloud-to-ground lightning flashes detected by the National Lightning Detection Network (NLDN). Probability predictions are provided for both intracloud and cloud-to-ground flashes. The gridded product can be displayed on AWIPS workstations in a manner similar to that of the lightning source density product.

  13. Radio Frequency Signals in Jupiter's Atmosphere

    PubMed

    Lanzerotti; Rinnert; Dehmel; Gliem; Krider; Uman; Bach

    1996-05-10

    During the Galileo probe's descent through Jupiter's atmosphere, under the ionosphere, the lightning and radio emission detector measured radio frequency signals at levels significantly above the probe's electromagnetic noise. The signal strengths at 3 and 15 kilohertz were relatively large at the beginning of the descent, decreased with depth to a pressure level of about 5 bars, and then increased slowly until the end of the mission. The 15-kilohertz signals show arrival direction anisotropies. Measurements of radio frequency wave forms show that the probe passed through an atmospheric region that did not support lightning within at least 100 kilometers and more likely a few thousand kilometers of the descent trajectory. The apparent opacity of the jovian atmosphere increases sharply at pressures greater than about 4 bars.

  14. Large-Amplitude Long-Wave Instability of a Supersonic Shear Layer

    NASA Technical Reports Server (NTRS)

    Messiter, A. F.

    1995-01-01

    For sufficiently high Mach numbers, small disturbances on a supersonic vortex sheet are known to grow in amplitude because of slow nonlinear wave steepening. Under the same external conditions, linear theory predicts slow growth of long-wave disturbances to a thin supersonic shear layer. An asymptotic formulation is given here which adds nonzero shear-layer thickness to the weakly nonlinear formulation for a vortex sheet. Spatial evolution is considered, for a spatially periodic disturbance having amplitude of the same order, in Reynolds number, as the shear-layer thickness. A quasi-equilibrium inviscid nonlinear critical layer is found, with effects of diffusion and slow growth appearing through nonsecularity condition. Other limiting cases are also considered, in an attempt to determine a relationship between the vortex-sheet limit and the long-wave limit for a thin shear layer; there appear to be three special limits, corresponding to disturbances of different amplitudes at different locations along the shear layer.

  15. Two Long-Wave Infrared Spectral Polarimeters for Use in Understanding Polarization Phenomenology

    DTIC Science & Technology

    2002-05-01

    3550 Aberdeen SE Kirtland Air Force Base, New Mexico 87117 Abstract. Spectrally varying long-wave infrared ( LWIR ) polarization measurements can be used...to identify materials and to discriminate samples from a cluttered background. Two LWIR instruments have been built and fielded by the Air Force...Research Laboratory: a multispectral LWIR imaging polarimeter (LIP) and a full-Stokes Fourier transform in- frared (FTIR) spectral polarimeter (FSP

  16. Long-Wave Type-II Superlattice Detectors with Unipolar Electron and Hole Barriers

    DTIC Science & Technology

    2012-12-01

    technologies are readily deployed for the visible, short- wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared ( LWIR ) spectral bands.1 These... LWIR band, sensor technologies include Hg1−xCdxTe (MCT), microbolometers, and Type-II superlattices (SLS).3 In addition to the aforementioned materials...well infrared photodetector (QWIP) was born,6 and has since become well-positioned as a mainstream technology for LWIR sen- sors. In recognition of the

  17. Long waves in the eastern equatorial pacific ocean: a view from a geostationary satellite.

    PubMed

    Legeckis, R

    1977-09-16

    During 1975, westward-moving long waves with a period of about 25 days and a wavelength of 1000 kilometers were observed at a sea surface temperature front in the equatorial Pacific on infrared images obtained by a geostationary environmental satellite system. The absence of these waves during 1976, and the above-average equatorial sea surface temperatures during 1976, may be related to a decrease in the southeasterly trade winds during that year.

  18. Technical considerations for designing low-cost, long-wave infrared objectives

    NASA Astrophysics Data System (ADS)

    Desroches, Gerard; Dalzell, Kristy; Robitaille, Blaise

    2014-06-01

    With the growth of uncooled infrared imaging in the consumer market, the balance between cost implications and performance criteria in the objective lens must be examined carefully. The increased availability of consumer-grade, long-wave infrared cameras is related to a decrease in military usage but it is also due to the decreasing costs of the cameras themselves. This has also driven up demand for low-cost, long-wave objectives that can resolve smaller pixels while maintaining high performance. Smaller pixels are traditionally associated with high cost objectives because of higher resolution requirements but, with careful consideration of all the requirements and proper selection of materials, costs can be moderated. This paper examines the cost/performance trade-off implications associated with optical and mechanical requirements of long-wave infrared objectives. Optical performance, f-number, field of view, distortion, focus range and thermal range all affect the cost of the objective. Because raw lens material cost is often the most expensive item in the construction, selection of the material as well as the shape of the lens while maintaining acceptable performance and cost targets were explored. As a result of these considerations, a low-cost, lightweight, well-performing objective was successfully designed, manufactured and tested.

  19. Initiation of Long-Wave Instability of Vortex Pairs at Cruise Altitudes

    NASA Technical Reports Server (NTRS)

    Rossow, Vernon J.

    2011-01-01

    Previous studies have usually attributed the initiation of the long-wave instability of a vortex pair to turbulence in the atmosphere or in the wake of the aircraft. The purpose here is to show by use of observations and photographs of condensation trails shed by aircraft at cruise altitudes that another initiating mechanism is not only possible but is usually the mechanism that initiates the long-wave instability at cruise altitudes. The alternate initiating mechanism comes about when engine thrust is robust enough to form an array of circumferential vortices around each jet-engine-exhaust stream. In those cases, initiation begins when the vortex sheet shed by the wing has rolled up into a vortex pair and descended to the vicinity of the inside bottom of the combined shear-layer vortex arrays. It is the in-and-out (up and down) velocity field between sequential circumferential vortices near the bottom of the array that then impresses disturbance waves on the lift-generated vortex pair that initiate the long-wave instability. A time adjustment to the Crow and Bate estimate for vortex linking is then derived for cases when thrust-based linking occurs.

  20. Long-wave plasma radiofrequency ablation for treatment of xanthelasma palpebrarum.

    PubMed

    Baroni, Adone

    2018-03-01

    Xanthelasma palpebrarum is the most common type of xanthoma affecting the eyelids. It is characterized by asymptomatic soft yellowish macules, papules, or plaques over the upper and lower eyelids. Many treatments are available for management of xanthelasma palpebrarum, the most commonly used include surgical excision, ablative CO 2 or erbium lasers, nonablative Q-switched Nd:YAG laser, trichloroacetic acid peeling, and radiofrequency ablation. This study aims to evaluate the effectiveness of RF ablation in the treatment of xanthelasma palpebrarum, with D.A.S. Medical portable device (Technolux, Italia), a radiofrequency tool working with long-wave plasma energy and without anesthesia. Twenty patients, 15 female and 5 male, affected by xanthelasma palpebrarum, were enrolled for long-wave plasma radiofrequency ablation treatment. The treatment consisted of 3/4 sessions that were carried out at intervals of 30 days. Treatments were well tolerated by all patients with no adverse effects and optimal aesthetic results. The procedure is very fast and can be performed without anesthesia because of the low and tolerable pain stimulation. Long-wave plasma radiofrequency ablation is an effective option for treatment of xanthelasma palpebrarum and adds an additional tool to the increasing list of medical devices for aesthetic treatments. © 2018 Wiley Periodicals, Inc.

  1. Measuring Method for Lightning Channel Temperature.

    PubMed

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

    2016-09-26

    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.

  2. 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

  3. ScienceCast 88: Dark Lightning

    NASA Image and Video Library

    2013-01-07

    Researchers studying thunderstorms have made a surprising discovery: The lightning we see with our eyes has a dark competitor that discharges storm clouds and flings antimatter into space. Scientists are scrambling to understand "dark lightning."

  4. Measuring Method for Lightning Channel Temperature

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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.

  5. 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.

  6. Multivariate Statistical Inference of Lightning Occurrence, and Using Lightning Observations

    NASA Technical Reports Server (NTRS)

    Boccippio, Dennis

    2004-01-01

    Two classes of multivariate statistical inference using TRMM Lightning Imaging Sensor, Precipitation Radar, and Microwave Imager observation are studied, using nonlinear classification neural networks as inferential tools. The very large and globally representative data sample provided by TRMM allows both training and validation (without overfitting) of neural networks with many degrees of freedom. In the first study, the flashing / or flashing condition of storm complexes is diagnosed using radar, passive microwave and/or environmental observations as neural network inputs. The diagnostic skill of these simple lightning/no-lightning classifiers can be quite high, over land (above 80% Probability of Detection; below 20% False Alarm Rate). In the second, passive microwave and lightning observations are used to diagnose radar reflectivity vertical structure. A priori diagnosis of hydrometeor vertical structure is highly important for improved rainfall retrieval from either orbital radars (e.g., the future Global Precipitation Mission "mothership") or radiometers (e.g., operational SSM/I and future Global Precipitation Mission passive microwave constellation platforms), we explore the incremental benefit to such diagnosis provided by lightning observations.

  7. Thunderstorm observations by air-shower radio antenna arrays

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga, J. C.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Ender, M.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Nehls, S.; Oehlschläger, J.; Palmieri, N.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.

    2011-10-01

    Relativistic, charged particles present in extensive air showers (EAS) lead to a coherent emission of radio pulses which are measured to identify the shower initiating high-energy cosmic rays. Especially during thunderstorms, there are additional strong electric fields in the atmosphere, which can lead to further multiplication and acceleration of the charged particles and thus have influence on the form and strength of the radio emission. For a reliable energy reconstruction of the primary cosmic ray by means of the measured radio signal it is very important to understand how electric fields affect the radio emission. In addition, lightning strikes are a prominent source of broadband radio emissions that are visible over very long distances. This, on the one hand, causes difficulties in the detection of the much lower signal of the air shower. On the other hand the recorded signals can be used to study features of the lightning development. The detection of cosmic rays via the radio emission and the influence of strong electric fields on this detection technique is investigated with the LOPES experiment in Karlsruhe, Germany. The important question if a lightning is initiated by the high electron density given at the maximum of a high-energy cosmic-ray air shower is also investigated, but could not be answered by LOPES. But, these investigations exhibit the capabilities of EAS radio antenna arrays for lightning studies. We report about the studies of LOPES measured radio signals of air showers taken during thunderstorms and give a short outlook to new measurements dedicated to search for correlations of lightning and cosmic rays.

  8. Triangulations of sprites relative to parent lighting near the Oklahoma Lightning Mapping Array

    NASA Astrophysics Data System (ADS)

    Lu, G.; Cummer, S. A.; Li, J.; Lyons, W. A.; Stanley, M. A.; Krehbiel, P. R.; Rison, W.; Thomas, R. J.; Weiss, S. A.; Beasley, W. H.; Bruning, E. C.; MacGorman, D. R.; Palivec, K.; Samaras, T. M.

    2012-12-01

    Temporal and spatial development of sprite-producing lightning flashes is examined with coordinated observations over an asymmetric mesoscale convective system on June 29, 2011 near the Oklahoma Lightning Mapping Array (OK-LMA). About 30 sprites were mutually observed from Bennett, Colorado and Hawley, Texas, allowing us to triangulate sprite formation in comparison with spatial/temporal development of the parent lightning. Complementary measurements of broadband (<1 Hz to ~300 kHz) radio frequency lightning signals are available from several magnetic sensors across the United States. Our analyses indicate that although sprite locations can be significantly offset horizontally (up to 70 km) from the parent ground stroke, they are usually laterally within 30 km of the in-cloud lightning activity during the 100 ms time interval prior to the sprite production. This is true for short-delayed sprites produced within 20 ms after a causative stroke, and long-delayed sprites appearing up to more than 200 ms after the stroke. Multiple sprites appearing as dancing/jumping events can be produced during one single flash either in a single lightning channel, through series of current surges superposed on a long and intense continuing current, or in multiple lightning channels through distinct ground strokes of the flash. The burst of continuous very-low-frequency/low-frequency lightning sferics commonly observed in association with sprites is linked to the horizontal progression of multiple negative leaders through positive charged regions of the cloud, which are typically centered at altitudes ~1-2 km (or more) above the freezing level.

  9. A lightning multiple casualty incident in Sequoia and Kings Canyon National Parks.

    PubMed

    Spano, Susanne J; Campagne, Danielle; Stroh, Geoff; Shalit, Marc

    2015-03-01

    Multiple casualty incidents (MCIs) are uncommon in remote wilderness settings. This is a case report of a lightning strike on a Boy Scout troop hiking through Sequoia and Kings Canyon National Parks (SEKI), in which the lightning storm hindered rescue efforts. The purpose of this study was to review the response to a lightning-caused MCI in a wilderness setting, address lightning injury as it relates to field management, and discuss evacuation options in inclement weather incidents occurring in remote locations. An analysis of SEKI search and rescue data and a review of current literature were performed. A lightning strike at 10,600 feet elevation in the Sierra Nevada Mountains affected a party of 5 adults and 7 Boy Scouts (age range 12 to 17 years old). Resources mobilized for the rescue included 5 helicopters, 2 ambulances, 2 hospitals, and 15 field and 14 logistical support personnel. The incident was managed from strike to scene clearance in 4 hours and 20 minutes. There were 2 fatalities, 1 on scene and 1 in the hospital. Storm conditions complicated on-scene communication and evacuation efforts. Exposure to ongoing lightning and a remote wilderness location affected both victims and rescuers in a lightning MCI. Helicopters, the main vehicles of wilderness rescue in SEKI, can be limited by weather, daylight, and terrain. Redundancies in communication systems are vital for episodes of radio failure. Reverse triage should be implemented in lightning injury MCIs. Education of both wilderness travelers and rescuers regarding these issues should be pursued. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  10. LOFAR for lightning-interferometery and mapping

    NASA Astrophysics Data System (ADS)

    Scholten, Olaf; Buitink, Stijn; trinh, Gia; Bonardi, Antonio; Corstanje, Arthur; Ebert, Ute; Falcke, Heino; Hoerandel, Joerg; Mitra, Pragati; Mulrey, Katherine; Nelles, Anna; Rachen, Joerg; Rossetto, Laura; Rutjes, Casper; Schellart, Pim; Thoudam, Satayendra; ter Veen, Sander; Winchen, Tobias; Hare, Brian

    2017-04-01

    We show that a new observation mode at the Low Frequency Array (LOFAR) for Lightning-Interferometery and Mapping (LIM) allows for lightning observations with a resolution that is at least an order of magnitude better than presently operating Lightning Napping Arrays LMAs. Furthermore the polarization of the signal can be used to reconstruct the direction of the discharge. LOFAR, consisting of many thousands of antennas, is a digital radio telescope, primarily build for astronomy observations. The Low Band Antennas (LBA) we use for this work are sensitive to the frequency range of 10 - 90 MHz and consist of two inverted V-shaped dipoles. The antennas are grouped in stations consisting of 48 LBA spread over an area with a diameter of about 30 m for which the relative timing is known accurately. The LOFAR core of approximately 2 km diameter contains 24 such stations located near Exloo in the north of The Netherlands. Remote stations for LIM may lie at a distance of 100 km from the core. Signals are sampled at 200 MS/s (sampling time of 5 ns). All antennas are equipped with ring buffers, that store the raw voltage traces for up to 5 s. When a trigger is received, for example with a lightning flash, the ring buffers are frozen and their contents are copied over the network to a central storage location. We will show an initial analysis of data taken on June 19, 2013, for a thunderstorm at a distance of some 50 km from the telescope. The source location and emission time for each event (lightning step) is found by fitting the arrival times of the pulses for each separate antenna adjusting the station offsets, keeping them the same for all events. The fit reproduces the measurements with an accuracy of about 1 time sample. Interestingly much fine structure is seen in the time-traces and examples will be shown for some events. The time traces for antennas in different stations are very similar and thus not due to noise. We also see a clear polarization-dependent structure

  11. Relating lightning data to fire occurrence data

    Treesearch

    Frank H. Koch

    2009-01-01

    Lightning disturbance can affect forest health at various scales. Lightning strikes may kill or weaken individual trees. Lightning-damaged trees may in turn function as epicenters of pest outbreaks in forest stands, as is the case with the southern pine beetle and other bark beetles (Rykiel and others 1988).

  12. 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 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Lightning Protection § 25.581 Lightning protection. (a...

  13. 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.

  14. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... path connecting an air terminal to an earth electrode system. (iii) Earth electrode system. An earth... to the initiation of explosives by lightning. (1) Elements of a lighting protection system. Unless an... facilities shall have a lightning protection system to ensure explosives are not initiated by lightning. A...

  15. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... path connecting an air terminal to an earth electrode system. (iii) Earth electrode system. An earth... to the initiation of explosives by lightning. (1) Elements of a lighting protection system. Unless an... facilities shall have a lightning protection system to ensure explosives are not initiated by lightning. A...

  16. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... path connecting an air terminal to an earth electrode system. (iii) Earth electrode system. An earth... to the initiation of explosives by lightning. (1) Elements of a lighting protection system. Unless an... facilities shall have a lightning protection system to ensure explosives are not initiated by lightning. A...

  17. 14 CFR 420.71 - Lightning protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... path connecting an air terminal to an earth electrode system. (iii) Earth electrode system. An earth... to the initiation of explosives by lightning. (1) Elements of a lighting protection system. Unless an... facilities shall have a lightning protection system to ensure explosives are not initiated by lightning. A...

  18. Lightning and plasma wave observations from the galileo flyby of venus.

    PubMed

    Gurnett, D A; Kurth, W S; Roux, A; Gendrin, R; Kennel, C F; Bolton, S J

    1991-09-27

    During the Galileo flyby of Venus the plasma wave instrument was used to search for impulsive radio signals from lightning and to investigate locally generated plasma waves. A total of nine events were detected in the frequency range from 100 kilohertz to 5.6 megahertz. Although the signals are weak, lightning is the only known source of these signals. Near the bow shock two types of locally generated plasma waves were observed, low-frequency electromagnetic waves from about 5 to 50 hertz and electron plasma oscillation at about 45 kilohertz. The plasma oscillations have considerable fine structure, possibly because of the formation of soliton-like wave packets.

  19. Lightning and plasma wave observations from the Galileo flyby of Venus

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.; Kurth, W. S.; Roux, A.; Gendrin, R.; Kennel, C. F.; Bolton, S. J.

    1991-01-01

    Durig the Galileo flyby of Venus the plasma wave instrument was used to search for impulsive radio signals from lightning and to investigate locally generated plasma waves. A total of nine events were detected in the frequency range from 100 kilohertz to 5.6 megahertz. Although the signals are weak, lightning is the only known source of these signals. Near the bow shock two types of locally generated plasma waves were observed, low-frequency electromagnetic waves from about 5 to 50 hertz and electron plasma oscillation at about 45 kilohertz. The plasma oscillations have considerable fine structure, possibly because of the formation of soliton-like wave packets.

  20. 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.

  1. Lightning protection of distribution systems

    NASA Astrophysics Data System (ADS)

    Darveniza, M.; Uman, M. A.

    1982-09-01

    Research work on the lightning protection of distribution systems is described. The rationale behind the planning of the first major phase of the work - the field experiments conducted in the Tampa Bay area during August 1978 and July to September 1979 is explained. The aims of the field work were to characterize lightning in the Tampa Bay area, and to identify the lightning parameters associated with the occurrence of line outages and equipment damage on the distribution systems of the participating utilities. The equipment developed for these studies is fully described. The field work provided: general data on lightning - e.g., electric and magnetic fields of cloud and ground flashes; data from automated monitoring of lightning activity; stroke current waveshapes and peak currents measured at distribution arresters; and line outage and equipment damage on 13 kV networks in the Tampa Bay area. Computer aided analyses were required to collate and to process the accumulated data. The computer programs developed for this work are described.

  2. 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.

  3. 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.

  4. 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

  5. Lightning-channel conditioning

    NASA Astrophysics Data System (ADS)

    Sonnenfeld, R.; da Silva, C. L.; Eack, K.; Edens, H. E.; Harley, J.; McHarg, M.; Contreras Vidal, L.

    2017-12-01

    The concept of "conditioning" has several distinct applications in understanding lightning. It is commonly associated to the greater speed of dart-leaders vs. stepped leaders and the retrace of a cloud-to-ground channel by later return strokes. We will showadditional examples of conditioning: (A) High-speed videos of triggered flashes show "dark" periods of up to 50 ms between rebrightenings of an existing channel. (B) Interferometer (INTF) images of intra-cloud (IC) flashes demonstrate that electric-field "K-changes" correspond to rapid propagation of RF impulses along a previously formed channel separated by up to 20 ms with little RF emission on that channel. (C) Further, INTF images (like the one below) frequently show that the initial IC channel is more branched and "fuzzier'' than its later incarnations. Also, we contrast high-speed video, INTF observations, and spectroscopic measurements with possible physical mechanisms that can explain how channel conditioning guides and facilitates dart leader propagation. These mechanisms include: (1) a plasmochemical effect where electrons are stored in negative ions and released during the dart leader propagation via field-induced detachment; (2) small-amplitude residual currents that can maintain electrical conductivity; and (3) slow heat conduction cooling of plasma owing to channel expansion dynamics.

  6. New Physical Mechanism for Lightning

    NASA Astrophysics Data System (ADS)

    Artekha, Sergey N.; Belyan, Andrey V.

    2018-02-01

    The article is devoted to electromagnetic phenomena in the atmosphere. The set of experimental data on the thunderstorm activity is analyzed. It helps to identify a possible physical mechanism of lightning flashes. This mechanism can involve the formation of metallic bonds in thunderclouds. The analysis of the problem is performed at a microphysical level within the framework of quantum mechanics. The mechanism of appearance of metallic conductivity includes the resonant tunneling of electrons along resonance-percolation trajectories. Such bonds allow the charges from the vast cloud charged subsystems concentrate quickly in lightning channel. The formation of metal bonds in the thunderstorm cloudiness is described as the second-order phase transition. A successive mechanism for the process of formation and development of the lightning channel is suggested. This mechanism is associated with the change in the orientation of crystals in growing electric field. Possible consequences of the quantum-mechanical mechanism under discussion are compared with the results of observations.

  7. Electro-Optic Lightning Detector

    NASA Technical Reports Server (NTRS)

    Koshak, Willliam; Solakiewicz, Richard

    1998-01-01

    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 then related to small changes in the transmission of laser light through the optical cell. Several hundred lightning electric field change excursions were recorded during 4 thunderstorms that occurred in the summer of 1998 at the NASA Marshall Space Flight Center (MSFC) in Northern Alabama.

  8. 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.

  9. 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.

  10. 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.

  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. Radiation from lightning return strokes over a finitely conducting earth

    NASA Technical Reports Server (NTRS)

    Le Vine, D. M.; Gesell, L.; Kao, Michael

    1986-01-01

    The effects of the conductivity of the earth on radiation from lightning return strokes are examined theoretically using a piecewise linear transmission line model for the return stroke. First, calculations are made of the electric field radiated during the return stroke, and then this electric field is used to compute the response of conventional AM radio receivers and electric field change systems during the return stroke. The calculations apply to the entire transient waveform (they are not restricted to the initial portions of the return stroke) and yield fast field changes and RF radiation in agreement with measurements made during real lightning. This research was motivated by measurements indicating that a time delay exists between the time of arrival of the fast electric field change and the RF radiation from first return strokes. The time delay is on the order of 20 microsec for frequencies in the HF-UHF range for lightning in Florida. The time delay is obtained theoretically in this paper. It occurs when both the effects of attenuation due to conductivity of the earth, and the finite velocity of propagation of the current pulse up the return stroke channel, are taken into account in the model.

  13. Cardiac Effects of Lightning Strikes

    PubMed Central

    Khan, Sarosh; Ahmad, Mahmood; Fayed, Hossam; Bogle, Richard

    2017-01-01

    Lightning strikes are a common and leading cause of morbidity and mortality. Multiple organ systems can be involved, though the effects of the electrical current on the cardiovascular system are one of the main modes leading to cardiorespiratory arrest in these patients. Cardiac effects of lightning strikes can be transient or persistent, and include benign or life-threatening arrhythmias, inappropriate therapies from cardiac implantable electronic devices, cardiac ischaemia, myocardial contusion, pericardial disease, aortic injury, as well as cardiomyopathy with associated ventricular failure. Prolonged resuscitation can lead to favourable outcomes especially in young and previously healthy victims. PMID:29018518

  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. Physical modeling of long-wave run-up mitigation using submerged breakwaters

    NASA Astrophysics Data System (ADS)

    Lee, Yu-Ting; Wu, Yun-Ta; Hwung, Hwung-Hweng; Yang, Ray-Yeng

    2016-04-01

    Natural hazard due to tsunami inundation inland has been viewed as a crucial issue for coastal engineering community. The 2004 India Ocean tsunami and the 2011 Tohoku earthquake tsunami were caused by mega scale earthquakes that brought tremendous catastrophe in the disaster regions. It is thus of great importance to develop innovative approach to achieve the reduction and mitigation of tsunami hazards. In this study, new experiments have been carried out in a laboratory-scale to investigate the physical process of long-wave through submerged breakwaters built upon a mild slope. Solitary-wave is employed to represent the characteristic of long-wave with infinite wavelength and wave period. Our goal is twofold. First of all, through changing the positions of single breakwater and multiple breakwaters upon a mild slope, the optimal locations of breakwaters can be pointed out by means of maximum run-up reduction. Secondly, through using a state-of-the-art measuring technique Bubble Image Velocimetry, which features non-intrusive and image-based measurement, the wave kinematics in the highly aerated region due to solitary-wave shoaling, breaking and uprush can be quantitated. Therefore, the mitigation of long-wave due to the construction of submerged breakwaters built upon a mild slope can be evaluated not only for imaging run-up and run-down characteristics but also for measuring turbulent velocity fields due to breaking wave. Although we understand the most devastating tsunami hazards cannot be fully mitigated with impossibility, this study is to provide quantitated information on what kind of artificial coastal structure that can withstand which level of wave loads.

  16. Lightning impact on micro-second long ionospheric variability

    NASA Astrophysics Data System (ADS)

    Koh, Kuang Liang; Liu, Zhongjian; Fullekrug, Martin

    2017-04-01

    Lightning discharges cause electron heating and enhanced ionisation in the D region ionosphere which disturb the transmission of VLF communications [Inan et al., 2010]. A disturbance of such nature was measured in a VLF transmission with a sampling rate of 1 MHz, enabling much faster ionospheric variability to be observed when compared to previous studies which typically report results with a time resolution >5-20ms. The disturbance resembles "Long Recovery Early VLF" (LORE) events [Haldoupis et al. 2013, Cotts & Inan 2007]. LOREs exhibit observable ionospheric effects that last longer (>200s) than other lightning related disturbances. It was proposed that the mechanism behind the long-lasting effects of LOREs is different to shorter events [Gordillo-Vázquez et al. 2016]. The ionospheric variability inferred from the transmitted signal is seen to change dramatically after the lightning onset, suggesting that there are fast processes in the ionosphere affected or produced which have not been considered in previous research. The ionospheric variability inferred from the main two frequencies of the transmission is different. A possible explanation is a difference in the propagation paths of the two main frequencies of the transmission [Füllekrug et al., 2015]. References Inan, U.S., Cummer, S.A., Marshall, R.A., 2010. A survey of ELF and VLF research on lightning-ionosphere interactions and causative discharges. J. Geophys. Res. 115, A00E36. doi:10.1029/2009JA014775 Cotts, B.R.T., Inan, U.S., 2007. VLF observation of long ionospheric recovery events. Geophys. Res. Lett. 34, L14809. doi:10.1029/2007GL030094 Haldoupis, C., Cohen, M., Arnone, E., Cotts, B., Dietrich, S., 2013. The VLF fingerprint of elves: Step-like and long-recovery early VLF perturbations caused by powerful ±CG lightning EM pulses. J. Geophys. Res. Space Physics 118, 5392-5402. doi:10.1002/jgra.50489 Gordillo-Vázquez, F.J., Luque, A., Haldoupis, C., 2016. Upper D region chemical kinetic modeling of

  17. Hollow Core Fiber Optics for Mid-Wave and Long-Wave Infrared Spectroscopy

    SciTech Connect

    Kriesel, J.M.; Gat, N.; Bernacki, Bruce E.

    The development and testing of hollow core glass waveguides (i.e., fiber optics) for use in Long-Wave Infrared (LWIR) spectroscopy systems is described. LWIR fiber optics are a key enabling technology needed to improve the utility and effectiveness of trace chemical detection systems based in the 8 to 12 micron region. This paper focuses on recent developments in hollow waveguide technology geared specifically for LWIR spectroscopy, including a reduction in both the length dependent loss and the bending loss while maintaining relatively high beam quality. Results will be presented from tests conducted with a Quantum Cascade Laser.

  18. Advances in low-cost long-wave infrared polymer windows

    NASA Astrophysics Data System (ADS)

    Weimer, Wayne A.; Klocek, Paul

    1999-07-01

    Recent improvements in engineered polymeric material compositions and advances in processing methodologies developed and patented at Raytheon Systems Company have produced long wave IR windows at exceptionally low costs. These UV stabilized, high strength windows incorporating subwavelength structured antireflection surfaces are enabling IR imaging systems to penetrate commercial markets and will reduce the cost of systems delivered to the military. The optical and mechanical properties of these windows will be discussed in detail with reference to the short and long-term impact on military IR imaging systems.

  19. Nonlinear rovibrational polarization response of water vapor to ultrashort long-wave infrared pulses

    NASA Astrophysics Data System (ADS)

    Schuh, K.; Rosenow, P.; Kolesik, M.; Wright, E. M.; Koch, S. W.; Moloney, J. V.

    2017-10-01

    We study the rovibrational polarization response of water vapor using a fully correlated optical Bloch equation approach employing data from the HITRAN database. For a 10 -μ m long-wave infrared pulse the resulting linear response is negative, with a negative nonlinear response at intermediate intensities and a positive value at higher intensities. For a model atmosphere comprised of the electronic response of argon combined with the rovibrational response of water vapor this leads to a weakened positive nonlinear response at intermediate intensities. Propagation simulations using a simplified noncorrelated approach show the resultant reduction in the peak filament intensity sustained during filamentation due to the presence of the water vapor.

  20. INAS hole-immobilized doping superlattice long-wave-infrared detector

    NASA Technical Reports Server (NTRS)

    Maserjian, Joseph (Inventor)

    1992-01-01

    An approach to long-wave-infrared (LWIR) technology is discussed. The approach is based on molecular beam epitaxy (MBE) growth of hole immobilized doping superlattices in narrow band gap 3-5 semiconductors, specifically, InAs and InSb. Such superlattices are incorporated into detector structures suitable for focal plane arrays. An LWIR detector that has high detectivity performance to wavelengths of about 16 microns at operating temperatures of 65K, where long-duration space refrigeration is plausible, is presented.

  1. The North Alabama Lightning Mapping Array (LMA): A Network Overview

    NASA Technical Reports Server (NTRS)

    Blakeslee, R. J.; Bailey, J.; Buechler, D.; Goodman, S. J.; McCaul, E. W., Jr.; Hall, J.

    2005-01-01

    The North Alabama Lightning Mapping Array (LMA) is s a 3-D VHF regional lightning detection system that provides on-orbit algorithm validation and instrument performance assessments for the NASA Lightning Imaging Sensor, as well as information on storm kinematics and updraft evolution that offers the potential to improve severe storm warning lead time by up t o 50% and decrease te false alarm r a t e ( for non-tornado producing storms). In support of this latter function, the LMA serves as a principal component of a severe weather test bed to infuse new science and technology into the short-term forecasting of severe and hazardous weather, principally within nearby National Weather Service forecast offices. The LMA, which became operational i n November 2001, consists of VHF receivers deployed across northern Alabama and a base station located at the National Space Science and Technology Center (NSSTC), which is on t h e campus of the University of Alabama in Huntsville. The LMA system locates the sources of impulsive VHF radio signals s from lightning by accurately measuring the time that the signals aririve at the different receiving stations. Each station's records the magnitude and time of the peak lightning radiation signal in successive 80 ms intervals within a local unused television channel (channel 5, 76-82 MHz in our case ) . Typically hundreds of sources per flash can be reconstructed, which i n t u r n produces accurate 3-dimensional lightning image maps (nominally <50 m error within 150 la. range). The data are transmitted back t o a base station using 2.4 GHz wireless Ethernet data links and directional parabolic grid antennas. There are four repeaters in the network topology and the links have an effective data throughput rate ranging from 600 kbits s -1 t o 1.5 %its s -1. This presentation provides an overview of t h e North Alabama network, the data processing (both real-time and post processing) and network statistics.

  2. 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.

  3. The relationship of lightning activity and short-duation rainfall events during warm seasons over the Beijing metropolitan region

    NASA Astrophysics Data System (ADS)

    Wu, F.; Cui, X.; Zhang, D. L.; Lin, Q.

    2017-12-01

    The relationship between lightning activity and rainfall associated with 2925 short-duration rainfall (SDR) events over the Beijing metropolitan region (BMR) is examined during the warm seasons of 2006-2007, using the cloud-to-ground (CG) and intracloud (IC) lightning data from Surveillance et Alerte Foudre par Interférometrie Radioélectrique (SAFIR)-3000 and 5-min rainfall data from automatic weather stations (AWSs). To facilitate the analysis of the rainfall-lightning correlations, the SDR events are categorized into six different intensity grades according to their hourly rainfall rates (HRRs), and an optimal radius of 10 km from individual AWSs for counting their associated lightning flashes is used. Results show that the lightning-rainfall correlations vary significantly with different intensity grades. Weak correlations (R 0.4) are found in the weak SDR events, and 40-50% of the events are no-flash ones. And moderate correlation (R 0.6) are found in the moderate SDR events, and > 10-20% of the events are no-flash ones. In contrast, high correlations (R 0.7) are obtained in the SDHR events, and < 10% of the events are no-flash ones. The results indicate that lightning activity is observed more frequently and correlated more robust with the rainfall in the SDHR events. Significant time lagged correlations between lightning and rainfall are also found. About 80% of the SDR events could reach their highest correlation coefficients when the associated lightning flashes shift at time lags of < 25 min before and after rainfall begins. The percentages of SDR events with CG or total lightning activity preceding, lagging or coinciding with rainfall shows that (i) in about 55% of the SDR events lightning flashes preceded rainfall; (ii) the SDR events with lightning flashes lagging behind rainfall accounted for about 30%; and (iii) the SDR events without any time shifts accounted for the remaining 15%. Better lightning-rainfall correlations can be attained when time

  4. 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.

  5. 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

  6. The Interferometric View of Lightning

    NASA Astrophysics Data System (ADS)

    Stock, M.; Lapierre, J. L.

    2017-12-01

    Recent advances in off the shelf high-speed digitizers has enabled vast improvements in broadband, digital VHF interferometers. These simple instruments consist of 3 or more VHF antennas distributed in an array which are then digitized at a speed above the Nyquist frequency of the antenna bandwidth (usually 200+ MHz). Broadband interferometers are capable of creating very detailed maps of lightning, with time resolution better than 1us, and angular resolution only limited by their baseline lengths. This is combined with high sensitivity, and the ability to locate both continuously emitting and impulsive radiation sources. They are not without their limitations though. Because the baselines are relatively short, the maps are only 2-dimensional (direction to the source), unless many antennas are used only a single VHF radiation source can be located at any instant, and because the antennas are almost always arranged in a planar array they are better suited for observing lightning at high elevation angles. Even though imperfect, VHF interferometers provide one of the most detailed views of the behavior of lightning flashes inside a cloud. This presentation will present the overall picture of in-cloud lightning as seen by VHF interferometers. Most flashes can be split into 3 general phases of activity. Phase 1 is the initiation phase, covering all activity until the negative leader completes its vertical extension, and includes both lightning initiation and initial breakdown pulses. Phase 2 is the active phase and includes all activity during the horizontal extension of the negative leader. During Phase 2, any K-processes which occur tend to be short in duration and extent. Phase 3 is the final phase, and includes all activity after the negative leader stops propagating. During Phase 3, the conductivity of the lightning channels starts to decline, and extensive K-processes are seen which traverse the entire channel structure, this is also the period in which regular

  7. The Colorado Lightning Mapping Array

    NASA Astrophysics Data System (ADS)

    Rison, W.; Krehbiel, P. R.; Thomas, R. J.; Rodeheffer, D.; Fuchs, B.

    2012-12-01

    A fifteen station Lightning Mapping Array (LMA) was installed in northern Colorado in the spring of 2012. While the driving force for the array was to produce 3-dimensional lightning data to support the Deep Convective Clouds and Chemistry (DC3) Experiment (Barth, this conference), data from the array are being used for several other projects. These include: electrification studies in conjunction with the CSU CHILL radar (Lang et al, this conference); observations of the parent lightning discharges of sprites (Lyons et al, this conference); trying to detect upward discharges triggered by wind turbines, characterizing conditions in which aircraft flying through clouds produce discharges which can be detected by the LMA, and other opportunities, such as observations of lightning in pyrocumulus clouds produced by the High Park Fire west of Fort Collins, CO. All the COLMA stations are solar-powered, and use broadband cellular modems for data communications. This makes the stations completely self-contained and autonomous, allowing a station to be installed anywhere a cellular signal is available. Because most of the stations were installed well away from anthropogenic noise sources, the COLMA is very sensitive. This is evidenced by the numerous plane tracks detected in its the vicinity. The diameter, D, of the COLMA is about 100 km, significantly larger than other LMAs. Because the error in the radial distance r is proportional to (r/D)2, and the error in the altitude z is proportional to (z/D)2, the larger array diameter greatly expands the usable range of the COLMA. The COLMA is able to detect and characterize lighting flashes to a distance of about 350 km from the array center. In addition to a web-based display (lightning.nmt.edu/colma), geo-referenced images are produced and updated at one-minute intervals. These geo-referenced images can be used to overlay the real-time lightning data on Google Earth and other mapping software. These displays were used by the DC3

  8. Lightning Location Using Acoustic Signals

    NASA Astrophysics Data System (ADS)

    Badillo, E.; Arechiga, R. O.; Thomas, R. J.

    2013-05-01

    In the summer of 2011 and 2012 a network of acoustic arrays was deployed in the Magdalena mountains of central New Mexico to locate lightning flashes. A Times-Correlation (TC) ray-tracing-based-technique was developed in order to obtain the location of lightning flashes near the network. The TC technique, locates acoustic sources from lightning. It was developed to complement the lightning location of RF sources detected by the Lightning Mapping Array (LMA) developed at Langmuir Laboratory, in New Mexico Tech. The network consisted of four arrays with four microphones each. The microphones on each array were placed in a triangular configuration with one of the microphones in the center of the array. The distance between the central microphone and the rest of them was about 30 m. The distance between centers of the arrays ranged from 500 m to 1500 m. The TC technique uses times of arrival (TOA) of acoustic waves to trace back the location of thunder sources. In order to obtain the times of arrival, the signals were filtered in a frequency band of 2 to 20 hertz and cross-correlated. Once the times of arrival were obtained, the Levenberg-Marquardt algorithm was applied to locate the spatial coordinates (x,y, and z) of thunder sources. Two techniques were used and contrasted to compute the accuracy of the TC method: Nearest-Neighbors (NN), between acoustic and LMA located sources, and standard deviation from the curvature matrix of the system as a measure of dispersion of the results. For the best case scenario, a triggered lightning event, the TC method applied with four microphones, located sources with a median error of 152 m and 142.9 m using nearest-neighbors and standard deviation respectively.; Results of the TC method in the lightning event recorded at 18:47:35 UTC, August 6, 2012. Black dots represent the results computed. Light color dots represent the LMA data for the same event. The results were obtained with the MGTM station (four channels). This figure

  9. Long-wave theory for a new convective instability with exponential growth normal to the wall.

    PubMed

    Healey, J J

    2005-05-15

    A linear stability theory is presented for the boundary-layer flow produced by an infinite disc rotating at constant angular velocity in otherwise undisturbed fluid. The theory is developed in the limit of long waves and when the effects of viscosity on the waves can be neglected. This is the parameter regime recently identified by the author in a numerical stability investigation where a curious new type of instability was found in which disturbances propagate and grow exponentially in the direction normal to the disc, (i.e. the growth takes place in a region of zero mean shear). The theory describes the mechanisms controlling the instability, the role and location of critical points, and presents a saddle-point analysis describing the large-time evolution of a wave packet in frames of reference moving normal to the disc. The theory also shows that the previously obtained numerical solutions for numerically large wavelengths do indeed lie in the asymptotic long-wave regime, and so the behaviour and mechanisms described here may apply to a number of cross-flow instability problems.

  10. Numerical Study of Nonlinear Structures of Locally Excited Marangoni Convection in the Long-Wave Approximation

    NASA Astrophysics Data System (ADS)

    Wertgeim, Igor I.

    2018-02-01

    We investigate stationary and non-stationary solutions of nonlinear equations of the long-wave approximation for the Marangoni convection caused by a localized source of heat or a surface active impurity (surfactant) in a thin horizontal layer of a viscous incompressible fluid with a free surface. The distribution of heat or concentration flux is determined by the uniform vertical gradient of temperature or impurity concentration, distorted by the imposition of a slightly inhomogeneous heating or of surfactant, localized in the horizontal plane. The lower boundary of the layer is considered thermally insulated or impermeable, whereas the upper boundary is free and deformable. The equations obtained in the long-wave approximation are formulated in terms of the amplitudes of the temperature distribution or impurity concentration, deformation of the surface, and vorticity. For a simplification of the problem, a sequence of nonlinear equations is obtained, which in the simplest form leads to a nonlinear Schrödinger equation with a localized potential. The basic state of the system, its dependence on the parameters and stability are investigated. For stationary solutions localized in the region of the surface tension inhomogeneity, domains of parameters corresponding to different spatial patterns are delineated.

  11. Wave Tank Studies of Strong Modulation of Wind Ripples Due To Long Waves

    NASA Astrophysics Data System (ADS)

    Ermakov, S.; Sergievskaya, I.; Shchegolkov, Yu.

    Modulation of wind capillary-gravity ripples due to long waves has been studied in wave tank experiment at low wind speeds using Ka-band radar. The experiments were carried out both for clean water and the water surface covered with surfactant films. It is obtained that the modulation of radar signals is quite strong and can increase with surfactant concentration and fetch. It is shown that the hydrodynamic Modulation Transfer Function (MTF) calculated for free wind ripples and taking into account the kinematic (straining) effect, variations of the wind stress and variations of surfactant concentration strongly underestimates experimental MTF-values. The effect of strong modulation is assumed to be connected with nonlinear harmonics of longer dm-cm- scale waves - bound waves ("parasitic ripples"). The intensity of bound waves depends strongly on the amplitude of decimetre-scale waves, therefore even weak modulation of the dm-scale waves due to long waves results to strong ("cascade") modulation of bound waves. Modulation of the system of "free/bound waves" is estimated using results of wave tank studies of bound waves generation and is shown to be in quali- tative agreement with experiment. This work was supported by MOD, UK via DERA Winfrith (Project ISTC 1774P) and by RFBR (Project 02-05-65102).

  12. Detection of gas plumes in cluttered environments using long-wave infrared hyperspectral sensors

    NASA Astrophysics Data System (ADS)

    Broadwater, Joshua B.; Spisz, Thomas S.; Carr, Alison K.

    2008-04-01

    Long-wave infrared hyperspectral sensors provide the ability to detect gas plumes at stand-off distances. A number of detection algorithms have been developed for such applications, but in situations where the gas is released in a complex background and is at air temperature, these detectors can generate a considerable amount of false alarms. To make matters more difficult, the gas tends to have non-uniform concentrations throughout the plume making it spatially similar to the false alarms. Simple post-processing using median filters can remove a number of the false alarms, but at the cost of removing a significant amount of the gas plume as well. We approach the problem using an adaptive subpixel detector and morphological processing techniques. The adaptive subpixel detection algorithm is able to detect the gas plume against the complex background. We then use morphological processing techniques to isolate the gas plume while simultaneously rejecting nearly all false alarms. Results will be demonstrated on a set of ground-based long-wave infrared hyperspectral image sequences.

  13. The relationship of lightning activity and short-duration rainfall events during warm seasons over the Beijing metropolitan region

    NASA Astrophysics Data System (ADS)

    Wu, Fan; Cui, Xiaopeng; Zhang, Da-Lin; Qiao, Lin

    2017-10-01

    The relationship between lightning activity and rainfall associated with 2925 short-duration rainfall (SDR) events over the Beijing metropolitan region (BMR) is examined during the warm seasons of 2006-2007, using the cloud-to-ground (CG) and intracloud (IC) lightning data from Surveillance et Alerte Foudre par Interférometrie Radioélectrique (SAFIR)-3000 and 5-min rainfall data from automatic weather stations (AWSs). An optimal radius of 10 km around selected AWSs is used to determine the lightning-rainfall relationship. The lightning-rainfall correlations vary significantly, depending upon the intensity of SDR events. That is, correlation coefficient (R 0.7) for the short-duration heavy rainfall (SDHR, i.e., ≥ 20 mm h- 1) events is found higher than that (R 0.4) for the weak SDR (i.e., 5-10 mm h- 1) events, and lower percentage of the SDHR events (< 10%) than the weak SDR events (40-50%) are observed with few flashes. Significant time-lagged correlations between lightning and rainfall are also found. About 80% of the SDR events could reach their highest correlation coefficients when the associated lightning flashes shift at time lags of < 25 min before and after rainfall begins. Those events with lightning preceding rainfall account for 50-60% of the total SDR events. Better lightning-rainfall correlations can be attained when time lags are incorporated, with the use of total (CG and IC) lightning data. These results appear to have important implications for improving the nowcast of SDHR events.

  14. 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

  15. On the Relationship between Observed NLDN Lightning ...

    EPA Pesticide Factsheets

    Lightning-produced nitrogen oxides (NOX=NO+NO2) in the middle and upper troposphere play an essential role in the production of ozone (O3) and influence the oxidizing capacity of the troposphere. Despite much effort in both observing and modeling lightning NOX during the past decade, considerable uncertainties still exist with the quantification of lightning NOX production and distribution in the troposphere. It is even more challenging for regional chemistry and transport models to accurately parameterize lightning NOX production and distribution in time and space. The Community Multiscale Air Quality Model (CMAQ) parameterizes the lightning NO emissions using local scaling factors adjusted by the convective precipitation rate that is predicted by the upstream meteorological model; the adjustment is based on the observed lightning strikes from the National Lightning Detection Network (NLDN). For this parameterization to be valid, the existence of an a priori reasonable relationship between the observed lightning strikes and the modeled convective precipitation rates is needed. In this study, we will present an analysis leveraged on the observed NLDN lightning strikes and CMAQ model simulations over the continental United States for a time period spanning over a decade. Based on the analysis, new parameterization scheme for lightning NOX will be proposed and the results will be evaluated. The proposed scheme will be beneficial to modeling exercises where the obs

  16. 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.

  17. 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.

  18. Data Retrieval Algorithms for Validating the Optical Transient Detector and the Lightning Imaging Sensor

    NASA Technical Reports Server (NTRS)

    Koshak, W. J.; Blakeslee, R. J.; Bailey, J. C.

    2000-01-01

    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 these measurements. The accuracy of the retrieval method is tested using computer-simulated datasets, and the relative influence of bearing and arrival time data an the outcome of the final solution is formally demonstrated. The algorithm is sufficiently accurate to validate NASA:s Optical Transient Detector and Lightning Imaging Sensor. A quadratic planar solution that is useful when only three arrival time measurements are available is also introduced. The algebra of the quadratic root results are examined in detail to clarify what portions of the analysis region lead to fundamental ambiguities in sc)iirce 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. For arbitrary noncollinear network geometries and in the absence of measurement errors, it is shown that the two quadratic roots are equivalent (no source location ambiguity) on the outer sensor baselines. The accuracy of the quadratic planar method is tested with computer-generated datasets, and the results are generally better than those obtained from the three-station linear planar method when bearing errors are about 2 deg.

  19. Discovery of rapid whistlers close to Jupiter implying lightning rates similar to those on Earth

    NASA Astrophysics Data System (ADS)

    Kolmašová, Ivana; Imai, Masafumi; Santolík, Ondřej; Kurth, William S.; Hospodarsky, George B.; Gurnett, Donald A.; Connerney, John E. P.; Bolton, Scott J.

    2018-06-01

    Electrical currents in atmospheric lightning strokes generate impulsive radio waves in a broad range of frequencies, called atmospherics. These waves can be modified by their passage through the plasma environment of a planet into the form of dispersed whistlers1. In the Io plasma torus around Jupiter, Voyager 1 detected whistlers as several-seconds-long slowly falling tones at audible frequencies2. These measurements were the first evidence of lightning at Jupiter. Subsequently, Jovian lightning was observed by optical cameras on board several spacecraft in the form of localized flashes of light3-7. Here, we show measurements by the Waves instrument8 on board the Juno spacecraft9-11 that indicate observations of Jovian rapid whistlers: a form of dispersed atmospherics at extremely short timescales of several milliseconds to several tens of milliseconds. On the basis of these measurements, we report over 1,600 lightning detections, the largest set obtained to date. The data were acquired during close approaches to Jupiter between August 2016 and September 2017, at radial distances below 5 Jovian radii. We detected up to four lightning strokes per second, similar to rates in thunderstorms on Earth12 and six times the peak rates from the Voyager 1 observations13.

  20. A Comparison of Lightning Flashes as Observed by the Lightning Imaging Sensor and the North Alabama Lightning Mapping Array

    NASA Technical Reports Server (NTRS)

    Bateman, M. G.; Mach, D. M.; McCaul, M. G.; Bailey, J. C.; Christian, H. J.

    2008-01-01

    The Lightning Imaging Sensor (LIS) aboard the TRMM satellite has been collecting optical lightning data since November 1997. A Lightning Mapping Array (LMA) that senses VHF impulses from lightning was installed in North Alabama in the Fall of 2001. A dataset has been compiled to compare data from both instruments for all times when the LIS was passing over the domain of our LMA. We have algorithms for both instruments to group pixels or point sources into lightning flashes. This study presents the comparison statistics of the flash data output (flash duration, size, and amplitude) from both algorithms. We will present the results of this comparison study and show "point-level" data to explain the differences. AS we head closer to realizing a Global Lightning Mapper (GLM) on GOES-R, better understanding and ground truth of each of these instruments and their respective flash algorithms is needed.

  1. Electromagnetic Effects Harmonization Working Group (EEHWG) - Lightning Task Group : report on aircraft lightning strike data

    DOT National Transportation Integrated Search

    2002-07-01

    In 1995, in response to the lightning community's desire to revise the zoning criteria on aircraft, the Electromagnetic Effects Harmonization Working Group (EEHWG) decided that lightning attachments to aircraft causing damage should be studied and co...

  2. 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

  3. Lightning attachment process to common buildings

    NASA Astrophysics Data System (ADS)

    Saba, M. M. F.; Paiva, A. R.; Schumann, C.; Ferro, M. A. S.; Naccarato, K. P.; Silva, J. C. O.; Siqueira, F. V. C.; Custódio, D. M.

    2017-05-01

    The physical mechanism of lightning attachment to grounded structures is one of the most important issues in lightning physics research, and it is the basis for the design of the lightning protection systems. Most of what is known about the attachment process comes from leader propagation models that are mostly based on laboratory observations of long electrical discharges or from observations of lightning attachment to tall structures. In this paper we use high-speed videos to analyze the attachment process of downward lightning flashes to an ordinary residential building. For the first time, we present characteristics of the attachment process to common structures that are present in almost every city (in this case, two buildings under 60 m in São Paulo City, Brazil). Parameters like striking distance and connecting leaders speed, largely used in lightning attachment models and in lightning protection standards, are revealed in this work.Plain Language SummarySince the time of Benjamin Franklin, no one has ever recorded high-speed video images of a <span class="hlt">lightning</span> connection to a common building. It is very difficult to do it. Cameras need to be very close to the structure chosen to be observed, and long observation time is required to register one <span class="hlt">lightning</span> strike to that particular structure. Models and theories used to determine the zone of protection of a <span class="hlt">lightning</span> rod have been developed, but they all suffer from the lack of field data. The submitted manuscript provides results from high-speed video observations of <span class="hlt">lightning</span> attachment to low buildings that are commonly found in almost every populated area around the world. The proximity of the camera and the high frame rate allowed us to see interesting details that will improve the understanding of the attachment process and, consequently, the models and theories used by <span class="hlt">lightning</span> protection standards. This paper also presents spectacular images and videos of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790010865','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790010865"><span>High current <span class="hlt">lightning</span> test of space shuttle external tank <span class="hlt">lightning</span> protection system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mumme, E.; Anderson, A.; Schulte, E. H.</p> <p>1977-01-01</p> <p>During lift-off, the shuttle launch vehicle (external tank, solid rocket booster and orbiter) may be subjected to a <span class="hlt">lightning</span> strike. Tests of a proposed <span class="hlt">lightning</span> protection method for the external tank and development materials which were subjected to simulated <span class="hlt">lightning</span> strikes are described. Results show that certain of the high resistant paint strips performed remarkably well in diverting the 50 kA <span class="hlt">lightning</span> strikes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.6697B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.6697B"><span>On the Nature of Cloud <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Betz, H. D.; Schmidt, K.; Oettinger, W. P.; Montag, B.; Wuerl, A.</p> <p>2009-04-01</p> <p>Studies of <span class="hlt">lightning</span> discharges generally deal with electrical activities that occur both inside thunderclouds (IC) and may involve a ground connection (CG). Even though CG has been studied more extensively than IC, it is known that the two types of discharges are accompanied by emission of qualitatively similar radiation. Less well recognized is the observation that relatively strong strokes are produced not only in connection with CG, but also by discharge processes that do not connect to ground. These IC strokes tend to exhibit somewhat smaller field amplitudes than CG strokes, but they produce thunder and the field records often resemble the ones known from CG. In fact, the number of these IC-strokes is large enough to allow efficient monitoring of cloud activity with the same technique as one applies for CG detection (VLF/LF). Very frequently, IC-strokes are produced during the initial breakdown phase, whereby initiation is probably caused by electron runaway processes that extend over hundreds of meters. Further prominent discharge phases can be effectively observed, most important are stepped leaders with copious emission of VHF <span class="hlt">radio</span> signals. Experimental data for the various cloud processes are discussed and evaluated with respect to theoretical and practical significance. Open questions on the production mechanisms are elucidated, and the relative occurrence of IC versus CG strokes is illustrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160000240','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160000240"><span>An Integrated 0-1 Hour First-Flash <span class="hlt">Lightning</span> Nowcasting, <span class="hlt">Lightning</span> Amount and <span class="hlt">Lightning</span> Jump Warning Capability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey; Chronis, Themis</p> <p>2015-01-01</p> <p>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 <span class="hlt">lightning</span> initiation (LI) and later period <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> using <span class="hlt">Lightning</span> Mapping Array (LMA) and pseudo-Geostationary <span class="hlt">Lightning</span> Mapper (GLM) data to assess per-storm <span class="hlt">lightning</span> trends (e.g., as tied to <span class="hlt">lightning</span> jumps) and outline threat regions. Evaluate the ability to produce LI nowcasts through a "<span class="hlt">lightning</span> threat" product, and obtain feedback from National Weather Service forecasters on its value as a decision support tool.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.nws.noaa.gov/om/marine/wxradio.htm','SCIGOVWS'); return false;" href="http://www.nws.noaa.gov/om/marine/wxradio.htm"><span>NATIONAL WEATHER SERVICE MARINE PRODUCTS VIA NOAA WEATHER <span class="hlt">RADIO</span></span></a></p> <p><a target="_blank" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>! Boating Safety Beach Hazards Rip Currents Hypothermia Hurricanes Thunderstorms <span class="hlt">Lightning</span> <em>Coastal</em> Flooding <span class="hlt">Radio</span> network provides voice broadcasts of local and <em>coastal</em> marine forecasts on a continuous cycle. The forecasts are produced by local National Weather Service Forecast Offices. <em>Coastal</em> stations also broadcast</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27328835','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27328835"><span>Relativistic-microwave theory of ball <span class="hlt">lightning</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, H-C</p> <p>2016-06-22</p> <p>Ball <span class="hlt">lightning</span>, a fireball sometimes observed during <span class="hlt">lightnings</span>, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>, such as the occurrence site, relation to the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...628263W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...628263W"><span>Relativistic-microwave theory of ball <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, H.-C.</p> <p>2016-06-01</p> <p>Ball <span class="hlt">lightning</span>, a fireball sometimes observed during <span class="hlt">lightnings</span>, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>, such as the occurrence site, relation to the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4916449','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4916449"><span>Relativistic-microwave theory of ball <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, H.-C.</p> <p>2016-01-01</p> <p>Ball <span class="hlt">lightning</span>, a fireball sometimes observed during <span class="hlt">lightnings</span>, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>, such as the occurrence site, relation to the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics. PMID:27328835</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA614923','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA614923"><span>Utilizing Four Dimensional <span class="hlt">Lightning</span> and Dual-Polarization Radar to Develop <span class="hlt">Lightning</span> Initiation Forecast Guidance</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-03-26</p> <p>Electrification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.3 <span class="hlt">Lightning</span> Discharge ...charge is caused by falling graupel that is positively charged (Wallace and Hobbs 2006). 2.3 <span class="hlt">Lightning</span> Discharge <span class="hlt">Lightning</span> occurs when the electric...emission of positive corona from the surface of precipitation particles, causing the electric field to become locally enhanced and supporting the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMAE33A2529K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMAE33A2529K"><span>Comparison Study of <span class="hlt">Lightning</span> observations from VHF interferometer and Geostationary <span class="hlt">Lightning</span> Mapper</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kudo, A.; Stock, M.; Ushio, T.</p> <p>2017-12-01</p> <p>We compared the optical observation from Geostationary <span class="hlt">Lightning</span> Mapper (GLM) which is mounted on the geostationary meteorological satellite GOES-16 launched last year, and the <span class="hlt">radio</span> observations from the ground-based VHF broad band interferometer. GLM detects 777.4 nm wavelength infrared optical signals from thunderstorm cells which are illuminated by the heated path during <span class="hlt">lightning</span> discharge, and was developed mainly for the purpose of increasing the lead time for warning of severe weather and clarifying the discharge mechanism. Its detection has 2 ms frame rate, and 8 km square of space resolution at nadir. The VHF broad band interferometer is able to capture the electromagnetic waves from 20 MHz to 75 MHz and estimate the direction of arrival of the radiation sources using the interferometry technique. This system also has capability of observing the fast discharge process which cannot be captured by other systems, so it is expected to able to make detailed comparison. The recording duration of the system is 1 second. We installed the VHF broad band interferometer which consists of three VHF antenna and one fast antenna at Huntsville, Alabama from April 22nd to May 15th and in this total observation period, 720 triggers of data were observed by the interferometer. For comparison, we adopted the data from April 27th , April 30th. Most April 27th data has GLM "event" detection which is coincident time period. In time-elevation plot comparison, we found GLM detection timing was well coincide with interferometer during K-changes or return strokes and few detection during breakdown process. On the other hand, no GLM detection near the site for all data in April 30th and we are triyng to figure out the reason. We would like to thank University of Alabama Huntsville, New Mexico Institute of Mining and Technology, and RAIRAN Pte. Ltd for the help during the campaign.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27116922','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27116922"><span><span class="hlt">Lightning</span> Strike in Pregnancy With Fetal Injury.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Galster, Kellen; Hodnick, Ryan; Berkeley, Ross P</p> <p>2016-06-01</p> <p>Injuries from <span class="hlt">lightning</span> strikes are an infrequent occurrence, and are only rarely noted to involve pregnant victims. Only 13 cases of <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>-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 <span class="hlt">lightning</span> strikes along with common injury patterns of which emergency providers should be aware. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18814638','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18814638"><span>Beyond the basics: <span class="hlt">lightning</span>-strike injuries.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mistovich, Joseph J; Krost, William S; Limmer, Daniel D</p> <p>2008-03-01</p> <p>It is estimated that a <span class="hlt">lightning</span> flash occurs approximately 8 million times per day throughout the world. Most strikes are benign and cause little damage to property and physical structures; however, when <span class="hlt">lightning</span> strikes a person or group of people, it is a significant medical and potentially traumatic event that could lead to immediate death or permanent disability. By understanding some basic physics of <span class="hlt">lightning</span> and pathophysiology of injuries associated with <span class="hlt">lightning</span> strikes, EMS providers will be better prepared to identify assessment findings, anticipate complications and provide effective emergency care.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SGeo...34..755P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SGeo...34..755P"><span><span class="hlt">Lightning</span> Applications in Weather and Climate Research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Price, Colin G.</p> <p>2013-11-01</p> <p>Thunderstorms, and <span class="hlt">lightning</span> in particular, are a major natural hazard to the public, aviation, power companies, and wildfire managers. <span class="hlt">Lightning</span> causes great damage and death every year but also tells us about the inner working of storms. Since <span class="hlt">lightning</span> can be monitored from great distances from the storms themselves, <span class="hlt">lightning</span> may allow us to provide early warnings for severe weather phenomena such as hail storms, flash floods, tornadoes, and even hurricanes. <span class="hlt">Lightning</span> itself may impact the climate of the Earth by producing nitrogen oxides (NOx), a precursor of tropospheric ozone, which is a powerful greenhouse gas. Thunderstorms themselves influence the climate system by the redistribution of heat, moisture, and momentum in the atmosphere. What about future changes in <span class="hlt">lightning</span> and thunderstorm activity? Many studies show that higher surface temperatures produce more <span class="hlt">lightning</span>, but future changes will depend on what happens to the vertical temperature profile in the troposphere, as well as changes in water balance, and even aerosol loading of the atmosphere. Finally, <span class="hlt">lightning</span> itself may provide a useful tool for tracking climate change in the future, due to the nonlinear link between <span class="hlt">lightning</span>, temperature, upper tropospheric water vapor, and cloud cover.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMAE42A..01C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMAE42A..01C"><span>Fifty Years of <span class="hlt">Lightning</span> Observations from Space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Christian, H. J., Jr.</p> <p>2017-12-01</p> <p>Some of the earliest satellites, starting with OSO (1965), ARIEL (1967), and RAE (1968), detected <span class="hlt">lightning</span> using either optical and RF sensors, although that was not their intent. One of the earliest instruments designed to detect <span class="hlt">lightning</span> was the PBE (1977). The use of space to study <span class="hlt">lightning</span> activity has exploded since these early days. The advent of focal-plane imaging arrays made it possible to develop high performance optical <span class="hlt">lightning</span> sensors. Prior to the use of charged-coupled devices (CCD), most space-based <span class="hlt">lightning</span> sensors used only a few photo-diodes, which limited the location accuracy and detection efficiency (DE) of the instruments. With CCDs, one can limit the field of view of each detector (pixel), and thus improve the signal to noise ratio over single-detectors that summed the light reflected from many clouds with the <span class="hlt">lightning</span> produced by a single cloud. This pixelization enabled daytime DE to increase from a few percent to close to 90%. The OTD (1995), and the LIS (1997), were the first <span class="hlt">lightning</span> sensors to utilize focal-plane arrays. Together they detected global <span class="hlt">lightning</span> activity for more than twenty years, providing the first detailed information on the distribution of global <span class="hlt">lightning</span> and its variability. The FORTE satellite was launched shortly after LIS, and became the first dedicated satellite to simultaneously measure RF and optical <span class="hlt">lightning</span> emissions. It too used a CCD focal plane to detect and locate <span class="hlt">lightning</span>. In November 2016, the GLM became the first <span class="hlt">lightning</span> instrument in geostationary orbit. Shortly thereafter, China placed its GLI in orbit. <span class="hlt">Lightning</span> sensors in geostationary orbit significantly increase the value of space-based observations. For the first time, <span class="hlt">lightning</span> activity can be monitored continuously, over large areas of the Earth with high, uniform DE and location accuracy. In addition to observing standard <span class="hlt">lightning</span>, a number of sensors have been placed in orbit to detect transient luminous events and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730018655','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730018655"><span>A three-station <span class="hlt">lightning</span> detection system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ruhnke, L. H.</p> <p>1972-01-01</p> <p>A three-station network is described which senses magnetic and electric fields of <span class="hlt">lightning</span>. Directional and distance information derived from the data are used to redundantly determine <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> by the ratio of magnetic-to-electric field as observed at 400 Hz. It was found that VLF direction finders can determine <span class="hlt">lightning</span> positions with only one-half the accuracy of the method that uses the ratio of magnetic-to-electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940018765','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940018765"><span><span class="hlt">Lightning</span> studies using LDAR and LLP data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Forbes, Gregory S.</p> <p>1993-01-01</p> <p>This study intercompared <span class="hlt">lightning</span> data from LDAR and LLP systems in order to learn more about the spatial relationships between thunderstorm electrical discharges aloft and <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> by weather forecasters who issue <span class="hlt">lightning</span> advisories. The <span class="hlt">Lightning</span> Detection and Ranging (LDAR) System provides data on electrical discharges from thunderstorms that includes cloud-ground flashes as well as <span class="hlt">lightning</span> aloft (within cloud, cloud-to-cloud, and sometimes emanating from cloud to clear air outside or above cloud). The <span class="hlt">Lightning</span> Location and Protection (LLP) system detects primarily ground strikes from <span class="hlt">lightning</span>. 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 <span class="hlt">lightning</span> ground strikes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000004589','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000004589"><span><span class="hlt">Lightning</span> Protection Guidelines for Aerospace Vehicles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goodloe, C. C.</p> <p>1999-01-01</p> <p>This technical memorandum provides <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>. Generic descriptions of the <span class="hlt">lightning</span> environment and vehicle protection technical processes are presented. More specific aerospace vehicle requirements for <span class="hlt">lightning</span> protection design, performance, and interface characteristics are available upon request to the MSFC Electromagnetics and Aerospace Environments Branch, mail code EL23.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22104330','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22104330"><span>Secondary missile injury from <span class="hlt">lightning</span> strike.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blumenthal, Ryan</p> <p>2012-03-01</p> <p>A 48-year-old-woman was struck dead by <span class="hlt">lightning</span> on October 24, 2010, in Pretoria, South Africa. The cause of death was due to direct <span class="hlt">lightning</span> strike. Examination showed secondary missile injury on her legs. This secondary missile (shrapnel) injury was caused by the <span class="hlt">lightning</span> striking the concrete pavement next to her. Small pieces of concrete were located embedded within the shrapnel wounds. This case report represents the first documented case of secondary missile formation (shrapnel injury) due to <span class="hlt">lightning</span> strike in the literature.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870003628&hterms=thunder+lightning&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthunder%2Blightning','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870003628&hterms=thunder+lightning&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthunder%2Blightning"><span>Optical characteristics of <span class="hlt">lightning</span> and thunderstorm currents</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krider, E. P.; Blakeslee, R. J.</p> <p>1985-01-01</p> <p>Researchers determined that <span class="hlt">lightning</span> can be used to determine the diurnal variations of thunderstorms, i.e., storms that produce audible thunder, and that these variations are also in good agreement with diurnal variations in rainfall and convective activity. Measurements of the Maxwell current density, J sub m, under active thunderstorms show that this physical quantity is quasi-steady between <span class="hlt">lightning</span> discharges and that <span class="hlt">lightning</span> does not produce large changes in J sub m. Maps of J sub m show contours of iso-current density that are consistent with the locations of radar echos and the locations of where <span class="hlt">lightning</span> has altered the cloud charge distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRC..123.2066R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRC..123.2066R"><span><span class="hlt">Long</span> <span class="hlt">Wave</span> Runup in Asymmetric Bays and in Fjords With Two Separate Heads</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raz, Amir; Nicolsky, Dmitry; Rybkin, Alexei; Pelinovsky, Efim</p> <p>2018-03-01</p> <p>Modeling of tsunamis in glacial fjords prompts us to evaluate applicability of the cross-sectionally averaged nonlinear shallow water equations to model propagation and runup of <span class="hlt">long</span> <span class="hlt">waves</span> in asymmetrical bays and also in fjords with two heads. We utilize the Tuck-Hwang transformation, initially introduced for the plane beaches and currently generalized for bays with arbitrary cross section, to transform the nonlinear governing equations into a linear equation. The solution of the linearized equation describing the runup at the shore line is computed by taking into account the incident wave at the toe of the last sloping segment. We verify our predictions against direct numerical simulation of the 2-D shallow water equations and show that our solution is valid both for bays with an asymmetric L-shaped cross section, and for fjords with two heads—bays with a W-shaped cross section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhD...51v5105Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhD...51v5105Z"><span>High intersubband absorption in <span class="hlt">long-wave</span> quantum well infrared photodetector based on waveguide resonance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, Yuanliao; Chen, Pingping; Ding, Jiayi; Yang, Heming; Nie, Xiaofei; Zhou, Xiaohao; Chen, Xiaoshuang; Lu, Wei</p> <p>2018-06-01</p> <p>A hybrid structure consisting of periodic gold stripes and an overlaying gold film has been proposed as the optical coupler of a <span class="hlt">long-wave</span> quantum well infrared photodetector. Absorption spectra and field distributions of the structure at back-side normal incidence are calculated by the finite difference time-domain method. The results indicate that the intersubband absorption can be greatly enhanced based on the waveguide resonance as well as the surface plasmon polariton (SPP) mode. With the optimized structural parameters of the periodic gold stripes, the maximal intersubband absorption can exceed 80%, which is much higher than the SPP-enhanced intersubband absorption (<50%) and about 6 times the one of the standard device. The relationship between the structural parameters and the waveguide resonant wavelength is derived. Other advantages of the efficient optical coupling based on waveguide resonance are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25314555','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25314555"><span>Coexisting rogue waves within the (2+1)-component <span class="hlt">long-wave</span>-short-wave resonance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Shihua; Soto-Crespo, Jose M; Grelu, Philippe</p> <p>2014-09-01</p> <p>The coexistence of two different types of fundamental rogue waves is unveiled, based on the coupled equations describing the (2+1)-component <span class="hlt">long-wave</span>-short-wave resonance. For a wide range of asymptotic background fields, each family of three rogue wave components can be triggered by using a slight deterministic alteration to the otherwise identical background field. The ability to trigger markedly different rogue wave profiles from similar initial conditions is confirmed by numerical simulations. This remarkable feature, which is absent in the scalar nonlinear Schrödinger equation, is attributed to the specific three-wave interaction process and may be universal for a variety of multicomponent wave dynamics spanning from oceanography to nonlinear optics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25810953','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25810953"><span>Exact solutions of unsteady Korteweg-de Vries and time regularized <span class="hlt">long</span> <span class="hlt">wave</span> equations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Islam, S M Rayhanul; Khan, Kamruzzaman; Akbar, M Ali</p> <p>2015-01-01</p> <p>In this paper, we implement the exp(-Φ(ξ))-expansion method to construct the exact traveling wave solutions for nonlinear evolution equations (NLEEs). Here we consider two model equations, namely the Korteweg-de Vries (KdV) equation and the time regularized <span class="hlt">long</span> <span class="hlt">wave</span> (TRLW) equation. These equations play significant role in nonlinear sciences. We obtained four types of explicit function solutions, namely hyperbolic, trigonometric, exponential and rational function solutions of the variables in the considered equations. It has shown that the applied method is quite efficient and is practically well suited for the aforementioned problems and so for the other NLEEs those arise in mathematical physics and engineering fields. PACS numbers: 02.30.Jr, 02.70.Wz, 05.45.Yv, 94.05.Fq.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992JMP....33.3783D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992JMP....33.3783D"><span>Generalized intermediate <span class="hlt">long-wave</span> hierarchy in zero-curvature representation with noncommutative spectral parameter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Degasperis, A.; Lebedev, D.; Olshanetsky, M.; Pakuliak, S.; Perelomov, A.; Santini, P. M.</p> <p>1992-11-01</p> <p>The simplest generalization of the intermediate <span class="hlt">long-wave</span> hierarchy (ILW) is considered to show how to extend the Zakharov-Shabat dressing method to nonlocal, i.e., integro-partial differential, equations. The purpose is to give a procedure of constructing the zero-curvature representation of this class of equations. This result obtains by combining the Drinfeld-Sokolov formalism together with the introduction of an operator-valued spectral parameter, namely, a spectral parameter that does not commute with the space variable x. This extension provides a connection between the ILWk hierarchy and the Saveliev-Vershik continuum graded Lie algebras. In the case of ILW2 the Fairlie-Zachos sinh-algebra was found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9840E..1NM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9840E..1NM"><span>Flag-based detection of weak gas signatures in <span class="hlt">long-wave</span> infrared hyperspectral image sequences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marrinan, Timothy; Beveridge, J. Ross; Draper, Bruce; Kirby, Michael; Peterson, Chris</p> <p>2016-05-01</p> <p>We present a flag manifold based method for detecting chemical plumes in <span class="hlt">long-wave</span> infrared hyperspectral movies. The method encodes temporal and spatial information related to a hyperspectral pixel into a flag, or nested sequence of linear subspaces. The technique used to create the flags pushes information about the background clutter, ambient conditions, and potential chemical agents into the leading elements of the flags. Exploiting this temporal information allows for a detection algorithm that is sensitive to the presence of weak signals. This method is compared to existing techniques qualitatively on real data and quantitatively on synthetic data to show that the flag-based algorithm consistently performs better on data when the SINRdB is low, and beats the ACE and MF algorithms in probability of detection for low probabilities of false alarm even when the SINRdB is high.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3188012','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3188012"><span><span class="hlt">Lightning</span> Strike in Golf Practice</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Elena-Sorando, E.; Galeano-Ricaño, N.; Agulló-Domingo, A.; Cimorra-Moreno, G.; Gil-Castillo, C.</p> <p>2006-01-01</p> <p>Summary The case is presented of a golfer who was struck by <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170007231','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170007231"><span><span class="hlt">Lightning</span> Protection and Detection System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mielnik, John J. (Inventor); Woodard, Marie (Inventor); Smith, Laura J. (Inventor); Wang, Chuantong (Inventor); Koppen, Sandra V. (Inventor); Dudley, Kenneth L. (Inventor); Szatkowski, George N. (Inventor); Nguyen, Truong X. (Inventor); Ely, Jay J. (Inventor)</p> <p>2017-01-01</p> <p>A <span class="hlt">lightning</span> protection and detection system includes a non-conductive substrate material of an apparatus; a sensor formed of a conductive material and deposited on the non-conductive substrate material of the apparatus. The sensor includes a conductive trace formed in a continuous spiral winding starting at a first end at a center region of the sensor and ending at a second end at an outer corner region of the sensor, the first and second ends being open and unconnected. An electrical measurement system is in communication with the sensor and receives a resonant response from the sensor, to perform detection, in real-time, of <span class="hlt">lightning</span> strike occurrences and damage therefrom to the sensor and the non-conductive substrate material.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45.2097L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45.2097L"><span>Very High Frequency <span class="hlt">Radio</span> Emissions Associated With the Production of Terrestrial Gamma-Ray Flashes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lyu, Fanchao; Cummer, Steven A.; Krehbiel, Paul R.; Rison, William; Briggs, Michael S.; Cramer, Eric; Roberts, Oliver; Stanbro, Matthew</p> <p>2018-02-01</p> <p>Recent studies of the close association between terrestrial gamma-ray flashes (TGFs) production and simultaneous <span class="hlt">lightning</span> processes have shown that many TGFs are produced during the initial leader of intracloud flashes and that some low-frequency (LF) <span class="hlt">radio</span> emissions may directly come from TGF itself. Measurements of any simultaneous very high frequency (VHF) <span class="hlt">radio</span> emissions would give important insight into any <span class="hlt">lightning</span> leader dynamics that are associated with TGF generation, and thus, such measurements are needed. Here we report on coordinated observations of TGFs detected simultaneously by Fermi Gamma-ray Burst Monitor, two VHF <span class="hlt">lightning</span> mapping arrays, and Duke ground-based LF <span class="hlt">radio</span> sensors to investigate more on the close association between TGFs and LF and VHF <span class="hlt">radio</span> emissions. Three TGFs are analyzed here and confirm previous findings on the close association between TGF generation and <span class="hlt">lightning</span> processes and, for the first time, provide time-aligned measurements of the VHF <span class="hlt">radio</span> signature within a few tens of microseconds of TGF generation. Strong VHF emissions were observed essentially simultaneously with two TGFs and within a few tens of microseconds of a third TGF. Equally importantly, the VHF measurement details indicate that the TGF-associated emissions are nonimpulsive and extended in time. We conclude that the TGF-producing process is at least sometimes closely associated with strong VHF emissions, and thus, there may be a link between the generation of TGFs and active <span class="hlt">lightning</span> streamer dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023414','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023414"><span>How to create ball <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Golka, Robert K., Jr.</p> <p>1991-01-01</p> <p>Procedures are given on how to produce ball <span class="hlt">lightning</span>. 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.6357P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.6357P"><span>3D modeling of <span class="hlt">lightning</span>-induced electromagnetic pulses on Venus, Jupiter and Saturn</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pérez-Invernón, Francisco J.; Luque, Alejandro; Gordillo-Vázquez, Francisco J.</p> <p>2017-04-01</p> <p>Atmospheric electricity is a common phenomenon in some planets of The Solar System. We know that atmospheric discharges exist on Earth and gaseous planets; however, some characteristics of <span class="hlt">lightning</span> on Saturn and Jupiter as well as their relevance on the effects of <span class="hlt">lightning</span> in the atmospheres of these planets are still unknown. In the case of Venus, there exist some <span class="hlt">radio</span> evidences of <span class="hlt">lightning</span>, but the lack of optical observations suggests exploring indirect methods of detection, such as searching for <span class="hlt">lightning</span>-induced transient optical emissions from the upper atmosphere. The Akatsuki probe, currently orbiting Venus, is equipped with a camera whose temporal resolution is high enough to detect optical emissions from <span class="hlt">lightning</span> discharges and to measure nightglow enhancements. In this work, we extend previous models [1,2] to investigate the chemical impact and transient optical emissions produced by possible <span class="hlt">lightning</span>-emitted electromagnetic pulses (EMP) in Venus, Saturn and Jupiter. Using a 3D FDTD ("Finite Differences Time Domain") model we solve the Maxwell equations coupled with the Langevin equation for electrons [3] and with a kinetic scheme, different for each planetary atmosphere. This method is useful to investigate the temporal and spatial impact of <span class="hlt">lightning</span>-induced electromagnetic fields in the atmosphere of each planet for different <span class="hlt">lightning</span> characteristics (e.g. energy released, orientation). This 3D FDTD model allows us to include the saturnian and jovian background magnetic field inclination and magnitude at different latitudes, and to determine the effects of different <span class="hlt">lightning</span> channel inclinations. Results provide useful information to interpret <span class="hlt">lightning</span> observations on giant gaseous planets and in the search for indirect optical signals from atmospheric discharge on Venus such as fast nightglow transient enhancements related to <span class="hlt">lightning</span> as seen on Earth. Furthermore, we underline the observation of electrical discharges characteristics as a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5965181','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5965181"><span><span class="hlt">Lightning</span> Burns and Electrical Trauma in a Couple Simultaneously Struck by <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Eyerly-Webb, Stephanie A.; Solomon, Rachele; Lee, Seong K.; Sanchez, Rafael; Carrillo, Eddy H.; Davare, Dafney L.; Kiffin, Chauniqua; Rosenthal, Andrew</p> <p>2017-01-01</p> <p>More people are struck and killed by <span class="hlt">lightning</span> each year in Florida than any other state in the United States. This report discusses a couple that was simultaneously struck by <span class="hlt">lightning</span> while walking arm-in-arm. Both patients presented with characteristic <span class="hlt">lightning</span> burns and were admitted for hemodynamic monitoring, serum labs, and observation and were subsequently discharged home. Despite the superficial appearance of <span class="hlt">lightning</span> burns, serious internal electrical injuries are common. Therefore, <span class="hlt">lightning</span> strike victims should be admitted and evaluated for cardiac arrhythmias, renal injury, and neurological sequelae.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V11E..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V11E..06S"><span>Monitoring the development of volcanic eruptions through volcanic <span class="hlt">lightning</span> - Using a <span class="hlt">lightning</span> mapping array, seismic and infrasound array, and visual plume analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, C. M.; Thompson, G.; McNutt, S. R.; Behnke, S. A.; Edens, H. E.; Van Eaton, A. R.; Gaudin, D.; Thomas, R. J.</p> <p>2017-12-01</p> <p>The period of 28 May - 7 June 2015 at Sakurajima Volcano, Japan witnessed a multitude of Vulcanian eruptive events, which resulted in plumes reaching 500-3000m above the vent. These plumes varied from white, gas-rich plumes to dark grey and black ash-rich plumes, and were recorded on lowlight and infrared cameras. A nine-station <span class="hlt">lightning</span> mapping array (LMA) was deployed to locate sources of VHF (67-73 MHz) radiation produced by <span class="hlt">lightning</span> flashes and other types of electrical activity such as `continuous RF (<span class="hlt">radio</span> frequency)'. Two Nanometrics Trillium broadband seismometers and six BSU infrasound sensors were deployed. Over this ten day period we recorded 1556 events that consisted of both seismic and infrasound signals, indicating explosive activity. There are an additional 1222 events that were recorded as only seismic or infrasound signals, which may be a result of precursory seismic signals or noise contamination. Plume discharge types included both distinct <span class="hlt">lightning</span> flashes and `continuous RF'. The LMA ran continuously for the duration of the experiment. On 30 May 2015 at least seven <span class="hlt">lightning</span> flashes were also detected by the Vaisala Global <span class="hlt">Lightning</span> Detection 360 network, which detects VLF (3-30 kHz) radiation. However the University of Washington's World Wide <span class="hlt">Lightning</span> Location Network, which also detects VLF radiation, detected no volcanic <span class="hlt">lightning</span> flashes in this time period. This indicates that the electrical activity in Sakurajima's plume occurs near the lower limits of the VLF detection threshold. We investigate relationships between the plume dynamics, the geophysical signal and the corresponding electrical activity through: plume velocity and height; event waveform cross-correlation; volcano acoustic-seismic ratios; overall geophysical energy; RSAM records; and VHF sources detected by the LMA. By investigating these relationships we hope to determine the seismic/infrasound energy threshold required to generate measurable electrical activity</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023313','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023313"><span>Launch pad <span class="hlt">lightning</span> protection effectiveness</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stahmann, James R.</p> <p>1991-01-01</p> <p>Using the striking distance theory that <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRD..117.3113C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRD..117.3113C"><span>Preliminary <span class="hlt">lightning</span> observations over Greece</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chronis, Themis G.</p> <p>2012-02-01</p> <p>The first Precision <span class="hlt">Lightning</span> Network, monitoring the Cloud-to-Ground (CG) <span class="hlt">lightning</span> stroke activity over Greece and surrounding waters is operated and maintained by the Hellenic National Meteorological Service. This paper studies the regional (land/water interface), seasonal and diurnal variability of the CG strokes as a function of density, polarity and peak current. Additional investigation uniquely links the CG stroke current to sea surface salinity and cloud electrical capacitance. In brief, this study's major findings area as follows: (1) The seasonal maps of thunder days agree well with the regional climatic convective characteristics of the study area, (2) the CG diurnal variability is consistent with the global <span class="hlt">lightning</span> activity observations over land and ocean, (3) the maxima of monthly averaged CG counts are located over land and water during typical summer and fall months respectively for both polarities, (4) CG peak currents show a distinct seasonality with larger currents during relatively colder months and smaller currents during summer months, and (5) strong linear trends between -CGs and sea surface salinity; (6) this trend is absent for +CGs data analysis of the employed database relate to the thunderstorm's RC constant and agrees with previous numerical modeling studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRD..123.2347S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRD..123.2347S"><span>Characteristics of <span class="hlt">Lightning</span> Within Electrified Snowfall Events Using <span class="hlt">Lightning</span> Mapping Arrays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schultz, Christopher J.; Lang, Timothy J.; Bruning, Eric C.; Calhoun, Kristin M.; Harkema, Sebastian; Curtis, Nathan</p> <p>2018-02-01</p> <p>This study examined 34 <span class="hlt">lightning</span> flashes within four separate thundersnow events derived from <span class="hlt">lightning</span> mapping arrays (LMAs) in northern Alabama, central Oklahoma, and Washington DC. The goals were to characterize the in-cloud component of each <span class="hlt">lightning</span> flash, as well as the correspondence between the LMA observations and <span class="hlt">lightning</span> data taken from national <span class="hlt">lightning</span> networks like the National <span class="hlt">Lightning</span> Detection Network (NLDN). Individual flashes were examined in detail to highlight several observations within the data set. The study results demonstrated that the structures of these flashes were primarily normal polarity. The mean area encompassed by this set of flashes is 375 km2, with a maximum flash extent of 2,300 km2, a minimum of 3 km2, and a median of 128 km2. An average of 2.29 NLDN flashes were recorded per LMA-derived <span class="hlt">lightning</span> flash. A maximum of 11 NLDN flashes were recorded in association with a single LMA-derived flash on 10 January 2011. Additionally, seven of the 34 flashes in the study contain zero NLDN-identified flashes. Eleven of the 34 flashes initiated from tall human-made objects (e.g., communication towers). In at least six <span class="hlt">lightning</span> flashes, the NLDN detected a return stroke from the cloud back to the tower and not the initial upward leader. This study also discusses <span class="hlt">lightning</span>'s interaction with the human-built environment and provides an example of <span class="hlt">lightning</span> within heavy snowfall observed by Geostationary Operational Environmental Satellite-16's Geostationary <span class="hlt">Lightning</span> Mapper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29910996','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29910996"><span>Characteristics of <span class="hlt">Lightning</span> within Electrified Snowfall Events using <span class="hlt">Lightning</span> Mapping Arrays.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schultz, Christopher J; Lang, Timothy J; Bruning, Eric C; Calhoun, Kristin M; Harkema, Sebastian; Curtis, Nathan</p> <p>2018-02-27</p> <p>This study examined 34 <span class="hlt">lightning</span> flashes within four separate thundersnow events derived from <span class="hlt">lightning</span> mapping arrays (LMAs) in northern Alabama, central Oklahoma, and Washington DC. The goals were to characterize the in-cloud component of each <span class="hlt">lightning</span> flash, as well as the correspondence between the LMA observations and <span class="hlt">lightning</span> data taken from national <span class="hlt">lightning</span> networks like the National <span class="hlt">Lightning</span> Detection Network (NLDN). Individual flashes were examined in detail to highlight several observations within the dataset. The study results demonstrated that the structures of these flashes were primarily normal polarity. The mean area encompassed by this set of flashes is 375 km 2 , with a maximum flash extent of 2300 km 2 , a minimum of 3 km 2 , and a median of 128 km 2 . An average of 2.29 NLDN flashes were recorded per LMA-derived <span class="hlt">lightning</span> flash. A maximum of 11 NLDN flashes were recorded in association with a single LMA-derived flash on 10 January 2011. Additionally, seven of the 34 flashes in the study contain zero NLDN identified flashes. Eleven of the 34 flashes initiated from tall human-made objects (e.g., communication towers). In at least six <span class="hlt">lightning</span> flashes, the NLDN detected a return stroke from the cloud back to the tower and not the initial upward leader. This study also discusses <span class="hlt">lightning</span>'s interaction with the human built environment and provides an example of <span class="hlt">lightning</span> within heavy snowfall observed by GOES-16's Geostationary <span class="hlt">Lightning</span> Mapper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMAE12A..02F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMAE12A..02F"><span>Infrasound from <span class="hlt">lightning</span> measured in Ivory Coast</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farges, T.; Matoza, R. S.</p> <p>2011-12-01</p> <p>It is well established that more than 2,000 thunderstorms occur continuously around the world and that about 45 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> flashes, ...). Some of the IMS stations are located where worldwide <span class="hlt">lightning</span> detection networks (e.g. WWLLN) have a weak detection capability but <span class="hlt">lightning</span> activity is high (e.g. Africa, South America). These infrasound stations are well localised to study <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> studies possible. For example, Farges and Blanc (2010) show clearly that it is possible to measure <span class="hlt">lightning</span> infrasound from thunderstorms within a range of distances from the infrasound station. Infrasound from <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> flashes can be detected with this technique, giving better results locally than worldwide <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> activity and its temporal variation. First statistical results will be presented in this paper based on 3 years of data (2005-2008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21909737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21909737"><span>[<span class="hlt">Lightning</span> strikes and <span class="hlt">lightning</span> injuries in prehospital emergency medicine. Relevance, results, and practical implications].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hinkelbein, J; Spelten, O; Wetsch, W A</p> <p>2013-01-01</p> <p>Up to 32.2% of patients in a burn center suffer from electrical injuries. Of these patients, 2-4% present with <span class="hlt">lightning</span> injuries. In Germany, approximately 50 people per year are injured by a <span class="hlt">lightning</span> strike and 3-7 fatally. Typically, people involved in outdoor activities are endangered and affected. A <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> injuries, internal injuries are of special importance. Mortality ranges between 10 and 30% after a <span class="hlt">lightning</span> strike. Emergency medical treatment is similar to common electrical injuries. Patients with <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990084078&hterms=metal+detector&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmetal%2Bdetector','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990084078&hterms=metal+detector&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmetal%2Bdetector"><span>Electro-Optic <span class="hlt">Lightning</span> Detector</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, William J.; Solakiewica, R. J.</p> <p>1998-01-01</p> <p>Electric field measurements are fundamental to the study of thunderstorm electrification, thundercloud charge structure, and the determination of the locations and magnitudes of charges deposited by <span class="hlt">lightning</span>. Continuous field observations can also be used to warn of impending electrical hazards. For example, the USAF Eastern Range (ER) and NASA Kennedy Space Center (KSC) in Florida currently operate a ground-based network of electric field mill sensors to warn against <span class="hlt">lightning</span> hazards to space vehicle operations/launches. The sensors provide continuous recordings of the ambient field. Others investigators have employed flat-plate electric field antennas to detect changes In the ambient field due to <span class="hlt">lightning</span>. In each approach, electronic circuitry is used to directly detect and amplify the effects of the ambient field on an exposed metal conductor (antenna plate); in the case of continuous field recordings, the antenna plate is alternately shielded and unshielded by a grounded conductor. In this work effort, an alternate optical method for detecting <span class="hlt">lightning</span>-caused electric field changes is Introduced. The primary component in the detector is an anisotropic electro-optic crystal of potassium di-hydrogen phosphate (chemically written as KH2PO4 (KDP)). When a voltage Is placed across the electro-optic crystal, the refractive Indices of the crystal change. This change alters the polarization state of a laser light beam that is passed down the crystal optic axis. With suitable application of vertical and horizontal polarizers, a light transmission measurement is related to the applied crystal voltage (which in turn Is related to the <span class="hlt">lightning</span> caused electric field change). During the past two years, all critical optical components were procured, assembled, and aligned. An optical housing, calibration set-up, and data acquisition system was integrated for breadboard testing. The sensor was deployed at NASA Marshall Space Flight Center (MSFC) in the summer of 1998 to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030005433','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030005433"><span>Firefighters' <span class="hlt">Radios</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1976-01-01</p> <p>Public Technology Inc. asked for NASA assistance to devise the original firefighter's <span class="hlt">radio</span>. Good short-range <span class="hlt">radio</span> communications are essential during a fire to coordinate hose lines, rescue victims, and otherwise increase efficiency. Useful firefighting tool is lower cost, more rugged short range two-way <span class="hlt">radio</span>. Inductorless electronic circuit replaced inductances and coils in <span class="hlt">radio</span> circuits with combination of transistors and other low-cost components. Substitution promises reduced circuit size and cost. Enhanced electrical performance made <span class="hlt">radio</span> more durable and improved maintainability by incorporating modular construction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/28599','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/28599"><span>Verification of the WFAS <span class="hlt">Lightning</span> Efficiency Map</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Paul Sopko; Don Latham; Isaac Grenfell</p> <p>2007-01-01</p> <p>A <span class="hlt">Lightning</span> Ignition Efficiency map was added to the suite of daily maps offered by the Wildland Fire Assessment System (WFAS) in 1999. This map computes a <span class="hlt">lightning</span> probability of ignition (POI) based on the estimated fuel type, fuel depth, and 100-hour fuel moisture interpolated from the Remote Automated Weather Station (RAWS) network. An attempt to verify the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=lightning&pg=5&id=EJ351674','ERIC'); return false;" href="https://eric.ed.gov/?q=lightning&pg=5&id=EJ351674"><span>Protecting Your Park When <span class="hlt">Lightning</span> Strikes.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Frydenlund, Marvin M.</p> <p>1987-01-01</p> <p>A formula for assessing specific risk of <span class="hlt">lightning</span> strikes is provided. Recent legal cases are used to illustrate potential liability. Six actions park managers can take to minimize danger from <span class="hlt">lightning</span> are presented, and commonsense rules which should be publicly posted are listed. (MT)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983RvGSP..21..892W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983RvGSP..21..892W"><span>Planetary <span class="hlt">lightning</span> - Earth, Jupiter, and Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, M. A.; Krider, E. P.; Hunten, D. M.</p> <p>1983-05-01</p> <p>The principal characteristics of <span class="hlt">lightning</span> on earth are reviewed, and the evidence for <span class="hlt">lightning</span> on Venus and Jupiter is examined. The mechanisms believed to be important to the electrification of terrestrial clouds are reviewed, with attention given to the applicability of some of these mechanisms to the atmospheres of Venus and Jupiter. The consequences of the existence of <span class="hlt">lightning</span> on Venus and Jupiter for their atmospheres and for theories of cloud electrification on earth are also considered. Since spacecraft observations do not conclusively show that <span class="hlt">lightning</span> does occur on Venus, it is suggested that alternative explanations for the experimental results be explored. Since Jupiter has no true surface, the Jovian <span class="hlt">lightning</span> flashes are cloud dischargaes. Observations suggest that Jovian <span class="hlt">lightning</span> emits, on average, 10 to the 10 J of optical energy per flash, whereas on earth <span class="hlt">lightning</span> radiates only about 10 to the 6th J per flash. Estimates of the average planetary <span class="hlt">lightning</span> rate on Jupiter range from 0.003 per sq km per yr to 40 per sq km per yr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770026308','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770026308"><span>Space shuttle program: <span class="hlt">Lightning</span> protection criteria document</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1975-01-01</p> <p>The <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> are imposed. Specifications, criteria, and guidelines included provide a practical and logical approach to protection problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=sky&pg=6&id=EJ1128438','ERIC'); return false;" href="https://eric.ed.gov/?q=sky&pg=6&id=EJ1128438"><span>When <span class="hlt">Lightning</span> Strikes a Second Time</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Allen, Kent</p> <p>2017-01-01</p> <p>The chances of <span class="hlt">lightning</span> striking twice are infinitesimal, at best. What are the odds, in middle age, of being struck with a jarring bolt of figurative <span class="hlt">lightning</span>, then a few months later being an eyewitness as the same sizzle in the sky jolts a group of students--those decision-makers of tomorrow? The author describes two experiences that proved…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol1/pdf/CFR-2011-title14-vol1-sec35-38.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol1/pdf/CFR-2011-title14-vol1-sec35-38.pdf"><span>14 CFR 35.38 - <span class="hlt">Lightning</span> strike.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... STANDARDS: PROPELLERS Tests and Inspections § 35.38 <span class="hlt">Lightning</span> strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a <span class="hlt">lightning</span> strike without causing a major or hazardous propeller effect. The limit to which the propeller has...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec35-38.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec35-38.pdf"><span>14 CFR 35.38 - <span class="hlt">Lightning</span> strike.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... STANDARDS: PROPELLERS Tests and Inspections § 35.38 <span class="hlt">Lightning</span> strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a <span class="hlt">lightning</span> strike without causing a major or hazardous propeller effect. The limit to which the propeller has...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title14-vol1/pdf/CFR-2013-title14-vol1-sec35-38.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title14-vol1/pdf/CFR-2013-title14-vol1-sec35-38.pdf"><span>14 CFR 35.38 - <span class="hlt">Lightning</span> strike.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-01-01</p> <p>... STANDARDS: PROPELLERS Tests and Inspections § 35.38 <span class="hlt">Lightning</span> strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a <span class="hlt">lightning</span> strike without causing a major or hazardous propeller effect. The limit to which the propeller has...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title14-vol1/pdf/CFR-2012-title14-vol1-sec35-38.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title14-vol1/pdf/CFR-2012-title14-vol1-sec35-38.pdf"><span>14 CFR 35.38 - <span class="hlt">Lightning</span> strike.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-01-01</p> <p>... STANDARDS: PROPELLERS Tests and Inspections § 35.38 <span class="hlt">Lightning</span> strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a <span class="hlt">lightning</span> strike without causing a major or hazardous propeller effect. The limit to which the propeller has...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title14-vol1/pdf/CFR-2014-title14-vol1-sec35-38.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title14-vol1/pdf/CFR-2014-title14-vol1-sec35-38.pdf"><span>14 CFR 35.38 - <span class="hlt">Lightning</span> strike.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-01-01</p> <p>... STANDARDS: PROPELLERS Tests and Inspections § 35.38 <span class="hlt">Lightning</span> strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a <span class="hlt">lightning</span> strike without causing a major or hazardous propeller effect. The limit to which the propeller has...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040170489&hterms=Atlantic+Forest&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DAtlantic%2BForest','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040170489&hterms=Atlantic+Forest&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DAtlantic%2BForest"><span>The GOES-R <span class="hlt">Lightning</span> Mapper Sensor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buechler, Dennis; Christian, Hugh; Goodman, Steve</p> <p>2004-01-01</p> <p>The <span class="hlt">Lightning</span> Mapper Sensor on GOES-R builds on previous measurements of <span class="hlt">lightning</span> from low earth orbit by the OTD (Optical Transient Detector) and LIS (<span class="hlt">Lightning</span> Imaging Sensor) sensors. Unlike observations from low earth orbit, the GOES-R platform will allow continuous monitoring of <span class="hlt">lightning</span> activity over the Continental United States and southern Canada, Central and South America, and portions of the Atlantic and Pacific Oceans. The LMS will detect total (cloud-to-ground and intracloud) <span class="hlt">lightning</span> at storm scale resolution (approx. 8 km) using a highly sensitive Charge Coupled Device (CCD) detector array. Discrimination between <span class="hlt">lightning</span> optical transients and a bright sunlit background scene is accomplished by employing spectral, spatial, and temporal filtering along with a background subtraction technique. The result is 24 hour detection capability of total <span class="hlt">lightning</span>. These total <span class="hlt">lightning</span> observations can be made available to users within about 20 seconds. Research indicates a number of ways that total <span class="hlt">lightning</span> observations from LMS could benefit operational activities, including 1) potential increases in lead times and reduced false alarms for severe thunderstorm and tornado Warnings, 2) improved routing of &rail around thunderstorms, 3) support for spacecraft launches and landings, 4) improved ability to monitor tropical cyclone intensity, 5) ability to monitor thunderstorm intensification/weakening during radar outages or where radar coverage is poor, 6) better identification of deep convection for the initialization of numerical prediction models, 7) improved forest fire forecasts, 8) identification of convective initiation, 9) identification of heavy convective snowfall, and 10) enhanced temporal resolution of storm evolution (1 minute) than is available from radar observations. Total <span class="hlt">lightning</span> data has been used in an operational environment since July 2003 at the Huntsville, Alabama National Weather Service office. Total <span class="hlt">lightning</span> measurements are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23478564','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23478564"><span><span class="hlt">Lightning</span> injuries in sports and recreation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thomson, Eric M; Howard, Thomas M</p> <p>2013-01-01</p> <p>The powers of <span class="hlt">lightning</span> have been worshiped and feared by all known human cultures. While the chance of being struck by <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>-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 <span class="hlt">lightning</span>-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 <span class="hlt">lightning</span> safety. Challenges remain in educating the general population involved in recreational outdoor activities that do not fall under the guidelines of organized sports.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850009173','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850009173"><span>Mathematical physics approaches to <span class="hlt">lightning</span> discharge problems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kyrala, A.</p> <p>1985-01-01</p> <p>Mathematical physics arguments useful for <span class="hlt">lightning</span> discharge and generation problems are pursued. A soliton Ansatz for the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> dischage are considered. The stability of the pre-<span class="hlt">lightning</span> charge distributions and the use of Boltzmann relaxational equations to determine them are discussed along with a covered impedance path provided by the aircraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMAE22A..02T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMAE22A..02T"><span><span class="hlt">Lightning</span> Enhancement Over Major Shipping Lanes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thornton, J. A.; Holzworth, R. H., II; Virts, K.; Mitchell, T. P.</p> <p>2017-12-01</p> <p>Using twelve years of high resolution global <span class="hlt">lightning</span> stroke data from the World Wide <span class="hlt">Lightning</span> Location Network (WWLLN), we show that <span class="hlt">lightning</span> density is enhanced by up to a factor of two directly over shipping lanes in the northeastern Indian Ocean and the South China Sea as compared to adjacent areas with similar climatological characteristics. The <span class="hlt">lightning</span> enhancement is most prominent during the convectively active season, November-April for the Indian Ocean and April - December in the South China Sea, and has been detectable from at least 2005 to the present. We hypothesize that emissions of aerosol particles and precursors by maritime vessel traffic leads to a microphysical enhancement of convection and storm electrification in the region of the shipping lanes. These persistent localized anthropogenic perturbations to otherwise clean regions are a unique opportunity to more thoroughly understand the sensitivity of maritime deep convection and <span class="hlt">lightning</span> to aerosol particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/39379','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/39379"><span>Progress towards a <span class="hlt">lightning</span> ignition model for the Northern Rockies</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Paul Sopko; Don Latham</p> <p>2010-01-01</p> <p>We are in the process of constructing a <span class="hlt">lightning</span> ignition model specific to the Northern Rockies using fire occurrence, <span class="hlt">lightning</span> strike, ecoregion, and historical weather, NFDRS (National Fire Danger Rating System), <span class="hlt">lightning</span> efficiency and <span class="hlt">lightning</span> "possibility" data. Daily grids for each of these categories were reconstructed for the 2003 fire season (...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD0603089','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD0603089"><span>RELATIONS BETWEEN <span class="hlt">LIGHTNING</span> DISCHARGES AND DIFFERENT TYPES OF MUSICAL ATMOSPHERICS,</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p></p> <p>Recording cathode-ray oscillographs were used for the analysis of the <span class="hlt">lightning</span> discharges whose relations to musical atmospherics were investigated...of the <span class="hlt">lightning</span> discharges investigated. Through comparative harmonic analyses it was shown that <span class="hlt">lightning</span> discharges producing musical atmospherics...followed by multiple whistlers. An investigation was made of correlations between <span class="hlt">lightning</span> discharges and musical atmospherics of unusual and irregular</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030061356&hterms=bateman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbateman','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030061356&hterms=bateman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbateman"><span>A Total <span class="hlt">Lightning</span> Climatology for the Tennessee Valley Region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McCaul, E. W.; Goodman, S. J.; Buechler, D. E.; Blakeslee, R.; Christian, H.; Boccippio, D.; Koshak, W.; Bailey, J.; Hallm, J.; Bateman, M.</p> <p>2003-01-01</p> <p>Total flash counts derived from the North Alabama <span class="hlt">Lightning</span> Mapping Array are being processed for 2002 to form a climatology of total <span class="hlt">lightning</span> for the Tennessee Valley region. The data from this active and interesting period will be compared to data fiom the National <span class="hlt">Lightning</span> Detection Network, space-based <span class="hlt">lightning</span> sensors, and weather radars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMAE33A0266A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMAE33A0266A"><span>Acoustic Manifestations of Natural versus Triggered <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arechiga, R. O.; Johnson, J. B.; Edens, H. E.; Rison, W.; Thomas, R. J.; Eack, K.; Eastvedt, E. M.; Aulich, G. D.; Trueblood, J.</p> <p>2010-12-01</p> <p>Positive leaders are rarely detected by VHF <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> and to assess which types of thunder signals have electromagnetic activity detected by the <span class="hlt">lightning</span> mapping array (LMA). Towards this end we are investigating the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>. Even though there was some mismatch, generally LMA and acoustic techniques saw the same phenomena. To increase the database of acoustic data from <span class="hlt">lightning</span>, 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 <span class="hlt">lightning</span>. 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 <span class="hlt">lightning</span> data from July 20 to September 18 of 2009, and from August 3 to September 1 of 2010. So far, <span class="hlt">lightning</span> activity around the Kiva was higher during the summer of 2009. We will present acoustic data from several interesting <span class="hlt">lightning</span> flashes including a comparison between a natural and a triggered one.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008654','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008654"><span>The <span class="hlt">Lightning</span> Nitrogen Oxides Model (LNOM): Status and Recent Applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, William; Khan, Maudood; Peterson, Harold</p> <p>2011-01-01</p> <p>Improvements to the NASA Marshall Space Flight Center <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> NOx (= NO + NO2) estimates are provided. The LNOM analyzes <span class="hlt">Lightning</span> Mapping Array (LMA) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of <span class="hlt">lightning</span> NOx. The latest LNOM estimates of (a) <span class="hlt">lightning</span> channel length distributions, (b) <span class="hlt">lightning</span> 1-m segment altitude distributions, and (c) the vertical profile of NOx are presented. The impact of including LNOM-estimates of <span class="hlt">lightning</span> NOx on CMAQ output is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100021055','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100021055"><span>Estimates of the <span class="hlt">Lightning</span> NOx Profile in the Vicinity of the North Alabama <span class="hlt">Lightning</span> Mapping Array</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, William J.; Peterson, Harold S.; McCaul, Eugene W.; Blazar, Arastoo</p> <p>2010-01-01</p> <p>The NASA Marshall Space Flight Center <span class="hlt">Lightning</span> Nitrogen Oxides Model (LNOM) is applied to August 2006 North Alabama <span class="hlt">Lightning</span> Mapping Array (NALMA) data to estimate the (unmixed and otherwise environmentally unmodified) vertical source profile of <span class="hlt">lightning</span> nitrogen oxides, NOx = NO + NO2. Data from the National <span class="hlt">Lightning</span> Detection Network (Trademark) (NLDN) is also employed. This is part of a larger effort aimed at building a more realistic <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> variables including: the frequency and geographical distribution of <span class="hlt">lightning</span> in the vicinity of the NALMA network, <span class="hlt">lightning</span> type (ground or cloud flash), <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> NOx source profiles are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900004089','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900004089"><span>Cable coupling <span class="hlt">lightning</span> transient qualification</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cook, M.</p> <p>1989-01-01</p> <p>Simulated <span class="hlt">lightning</span> strike testing of instrumentation cabling on the redesigned solid rocket motor was performed. Testing consisted of subjecting the <span class="hlt">lightning</span> evaluation test article to simulated <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.6010...70T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.6010...70T"><span><span class="hlt">Long</span> <span class="hlt">wave</span> infrared cavity-enhanced sensors using quantum cascade lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taubman, Matthew S.; Scott, David C.; Myers, Tanya L.; Cannon, Bret D.</p> <p>2005-11-01</p> <p>Quantum cascade lasers (QCLs) are becoming well known as convenient and stable semiconductor laser sources operating in the mid- to <span class="hlt">long-wave</span> infrared, and are able to be fabricated to operate virtually anywhere in the 3.5 to 25 micron region. This makes them an ideal choice for infrared chemical sensing, a topic of great interest at present, spanning at least three critical areas: national security, environmental monitoring and protection, and the early diagnosis of disease through breath analysis. There are many different laser-based spectroscopic chemical sensor architectures in use today, from simple direct detection through to more complex and highly sensitive systems. Many current sensor needs can be met by combining QCLs and appropriate sensor architectures, those needs ranging from UAV-mounted surveillance systems, through to larger ultra-sensitive systems for airport security. In this paper we provide an overview of various laser-based spectroscopic sensing techniques, pointing out advantages and disadvantages of each. As part of this process, we include our own results and observations for techniques under development at PNNL. We also present the latest performance of our ultra-quiet QCL control electronics now being commercialized, and explore how using optimized supporting electronics enables increased sensor performance and decreased sensor footprint for given applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6240E..0FB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6240E..0FB"><span>Evaluation and display of polarimetric image data using <span class="hlt">long-wave</span> cooled microgrid focal plane arrays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bowers, David L.; Boger, James K.; Wellems, L. David; Black, Wiley T.; Ortega, Steve E.; Ratliff, Bradley M.; Fetrow, Matthew P.; Hubbs, John E.; Tyo, J. Scott</p> <p>2006-05-01</p> <p>Recent developments for <span class="hlt">Long</span> <span class="hlt">Wave</span> InfraRed (LWIR) imaging polarimeters include incorporating a microgrid polarizer array onto the focal plane array (FPA). Inherent advantages over typical polarimeters include packaging and instantaneous acquisition of thermal and polarimetric information. This allows for real time video of thermal and polarimetric products. The microgrid approach has inherent polarization measurement error due to the spatial sampling of a non-uniform scene, residual pixel to pixel variations in the gain corrected responsivity and in the noise equivalent input (NEI), and variations in the pixel to pixel micro-polarizer performance. The Degree of Linear Polarization (DoLP) is highly sensitive to these parameters and is consequently used as a metric to explore instrument sensitivities. Image processing and fusion techniques are used to take advantage of the inherent thermal and polarimetric sensing capability of this FPA, providing additional scene information in real time. Optimal operating conditions are employed to improve FPA uniformity and sensitivity. Data from two DRS Infrared Technologies, L.P. (DRS) microgrid polarizer HgCdTe FPAs are presented. One FPA resides in a liquid nitrogen (LN2) pour filled dewar with a 80°K nominal operating temperature. The other FPA resides in a cryogenic (cryo) dewar with a 60° K nominal operating temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.tmp..132S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.tmp..132S"><span><span class="hlt">Long-wave</span> equivalent viscoelastic solids for porous rocks saturated by two-phase fluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santos, J. E.; Savioli, G. B.</p> <p>2018-04-01</p> <p>Seismic waves traveling across fluid-saturated poroelastic materials with mesoscopic-scale heterogeneities induce fluid flow and Biot's slow waves generating energy loss and velocity dispersion. Using Biot's equations of motion to model these type of heterogeneities would require extremely fine meshes. We propose a numerical upscaling procedure to determine the complex and frequency dependent P-wave and shear moduli of an effective viscoelastic medium <span class="hlt">long-wave</span> equivalent to a poroelastic solid saturated by a two-phase fluid. The two-phase fluid is defined in terms of capillary pressure and relative permeability flow functions. The P-wave and shear effective moduli are determined using harmonic compressibility and shear experiments applied on representative samples of the bulk material. Each experiment is associated with a boundary value problem that is solved using the finite element method. Since a poroelastic solid saturated by a two-phase fluid supports the existence of two slow waves, this upscaling procedure allows to analyze their effect on the mesoscopic-loss mechanism in hydrocarbon reservoir formations. Numerical results show that a two-phase Biot medium model predicts higher attenuation than classic Biot models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.214..302S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.214..302S"><span><span class="hlt">Long-wave</span> equivalent viscoelastic solids for porous rocks saturated by two-phase fluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santos, J. E.; Savioli, G. B.</p> <p>2018-07-01</p> <p>Seismic waves travelling across fluid-saturated poroelastic materials with mesoscopic-scale heterogeneities induce fluid flow and Biot's slow waves generating energy loss and velocity dispersion. Using Biot's equations of motion to model these type of heterogeneities would require extremely fine meshes. We propose a numerical upscaling procedure to determine the complex and frequency-dependent Pwave and shear moduli of an effective viscoelastic medium <span class="hlt">long-wave</span> equivalent to a poroelastic solid saturated by a two-phase fluid. The two-phase fluid is defined in terms of capillary pressure and relative permeability flow functions. The Pwave and shear effective moduli are determined using harmonic compressibility and shear experiments applied on representative samples of the bulk material. Each experiment is associated with a boundary value problem that is solved using the finite element method. Since a poroelastic solid saturated by a two-phase fluid supports the existence of two slow waves, this upscaling procedure allows to analyse their effect on the mesoscopic loss mechanism in hydrocarbon reservoir formations. Numerical results show that a two-phase Biot medium model predicts higher attenuation than classic Biot models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6431007-review-ionospheric-model-long-wave-prediction-capability-final-report','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6431007-review-ionospheric-model-long-wave-prediction-capability-final-report"><span>Review of the ionospheric model for the <span class="hlt">long</span> <span class="hlt">wave</span> prediction capability. Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ferguson, J.A.</p> <p>1992-11-01</p> <p>The Naval Command, Control and Ocean Surveillance Center's <span class="hlt">Long</span> <span class="hlt">Wave</span> Prediction Capability (LWPC) has a built-in ionospheric model. The latter was defined after a review of the literature comparing measurements with calculations. Subsequent to this original specification of the ionospheric model in the LWPC, a new collection of data were obtained and analyzed. The new data were collected aboard a merchant ship named the Callaghan during a series of trans-Atlantic trips over a period of a year. This report presents a detailed analysis of the ionospheric model currently in use by the LWPC and the new model suggested by themore » shipboard measurements. We conclude that, although the fits to measurements are almost the same between the two models examined, the current LWPC model should be used because it is better than the new model for nighttime conditions at long ranges. This conclusion supports the primary use of the LWPC model for coverage assessment that requires a valid model at the limits of a transmitter's reception.... Communications, Very low frequency and low frequency, High voltage, Antennas, Measurement.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992ncco.rept.....F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ncco.rept.....F"><span>A review of the ionospheric model for the <span class="hlt">long</span> <span class="hlt">wave</span> prediction capability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferguson, J. A.</p> <p>1992-11-01</p> <p>The Naval Command, Control, and Ocean Surveillance Center's <span class="hlt">Long</span> <span class="hlt">Wave</span> Prediction Capability (LWPC) has a built-in ionospheric model. The latter was defined after a review of the literature comparing measurements with calculations. Subsequent to this original specification of the ionospheric model in the LWPC, a new collection of data were obtained and analyzed. The new data were collected aboard a merchant ship named the Callaghan during a series of trans-Atlantic trips over a period of a year. This report presents a detailed analysis of the ionospheric model currently in use by the LWPC and the new model suggested by the shipboard measurements. We conclude that, although the fits to measurements are almost the same between the two models examined, the current LWPC model should be used because it is better than the new model for nighttime conditions at long ranges. This conclusion supports the primary use of the LWPC model for coverage assessment that requires a valid model at the limits of a transmitter's reception.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1899f0006Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1899f0006Z"><span>Mathematical investigation of tsunami-like <span class="hlt">long</span> <span class="hlt">waves</span> interaction with submerge dike of different thickness</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhiltsov, Konstantin; Kostyushin, Kirill; Kagenov, Anuar; Tyryshkin, Ilya</p> <p>2017-11-01</p> <p>This paper presents a mathematical investigation of the interaction of a long tsunami-type wave with a submerge dike. The calculations were performed by using the freeware package OpenFOAM. Unsteady two-dimensional Navier-Stokes equations were used for mathematical modeling of incompressible two-phase medium. The Volume of Fluid (VOF) method is used to capture the free surface of a liquid. The effects caused by <span class="hlt">long</span> <span class="hlt">wave</span> of defined amplitude motion through a submerged dike of varying thickness were discussed in detail. Numerical results show that after wave passing through the barrier, multiple vortex structures were formed behind. Intensity of vortex depended on the size of the barrier. The effectiveness of the submerge barrier was estimated by evaluating the wave reflection and transmission coefficients using the energy integral method. Then, the curves of the dependences of the reflection and transmission coefficients were obtained for the interaction of waves with the dike. Finally, it was confirmed that the energy of the wave could be reduced by more than 50% when it passed through the barrier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CNSNS..57...80A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CNSNS..57...80A"><span>Modelling of <span class="hlt">long-wave</span> chaotic radar system for anti-stealth applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Al-Suhail, Ghaida A.; Tahir, Fadhil Rahma; Abd, Mariam Hussien; Pham, Viet-Thanh; Fortuna, Luigi</p> <p>2018-04-01</p> <p>Although the Very Low-Frequency (VLF) waveforms have limited practical applications in acoustics (sonar) and secure military communications with radars and submarines; to this end; this paper presents a new and simple analytical model of VLF monostatic direct chaotic radar system. The model hypothetically depends on the two identical coupled time-delayed feedback chaotic systems which can generate and recover a <span class="hlt">long-wave</span> chaotic signal. To resist the influence of positive Lyapunov exponents of the time-delay chaotic systems, the complete replacement of Pecaro and Carroll (PC) synchronization is employed. It can faithfully recover the chaotic signal from the back-scattered (echo) signal from the target over a noisy channel. The system performance is characterized in terms of the time series of synchronization in addition to the peak of the cross-correlation. Simulation results are conducted for substantial sensitivities of the chaotic signal to the system parameters and initial conditions. As a result, it is found that an effective and robust chaotic radar (CRADAR) model can be obtained when the signal-to-noise ratio (SNR) highly degrades to 0 dB, but with clear peak in correlation performance for detecting the target. Then, the model can be considered as a state of the art towards counter stealth technology and might be developed for other acoustic secure applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24032844','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24032844"><span><span class="hlt">Long-wave</span> model for strongly anisotropic growth of a crystal step.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Khenner, Mikhail</p> <p>2013-08-01</p> <p>A continuum model for the dynamics of a single step with the strongly anisotropic line energy is formulated and analyzed. The step grows by attachment of adatoms from the lower terrace, onto which atoms adsorb from a vapor phase or from a molecular beam, and the desorption is nonnegligible (the "one-sided" model). Via a multiscale expansion, we derived a <span class="hlt">long-wave</span>, strongly nonlinear, and strongly anisotropic evolution PDE for the step profile. Written in terms of the step slope, the PDE can be represented in a form similar to a convective Cahn-Hilliard equation. We performed the linear stability analysis and computed the nonlinear dynamics. Linear stability depends on whether the stiffness is minimum or maximum in the direction of the step growth. It also depends nontrivially on the combination of the anisotropy strength parameter and the atomic flux from the terrace to the step. Computations show formation and coarsening of a hill-and-valley structure superimposed onto a long-wavelength profile, which independently coarsens. Coarsening laws for the hill-and-valley structure are computed for two principal orientations of a maximum step stiffness, the increasing anisotropy strength, and the varying atomic flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7383E..2AY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7383E..2AY"><span>System design and simulation of a <span class="hlt">long-wave</span> infrared hyperspectral imaging spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Li-yin; Xu, Wei-ming; He, Zhi-ping; Lin, Ying; Shu, Rong; Wang, Jian-yu</p> <p>2009-07-01</p> <p>A ground-based <span class="hlt">long-wave</span> hyperspectral imaging spectrometer (LWHIS) is designed and simulated. The spectrometer is based on a focal plane array detector with a spectral response that covers the range 7700 to 9300 nm. Optical system of this instrument is all-reflective and provides up to 30 continuous spectral channels with 54 nm of dispersion per pixel. The entrance aperture is 20 mm and feeds an F/2 telescope front end. The telescope has a 11-deg field of view with 256 spatially resolved elements (detector pixel size is 30 μm). To get high enough signal noise rate (SNR), no concern about the electronic part, first, the cool stop of the detector is used as soon as possible, and second, background thermal radiance of the opto-mechanical system seen by the focal plane must be suppressed. Thus, the entire instrument is set in a vacuum chamber and the opto-mechanical subsystem is cooled by liquid nitrogen. The background thermal radiance verse different cases is discussed. Based on the radiation simulation and analysis, if the opto-mechanical subsystem of the spectrometer within the vacuum chamber is cooled blew 100 Kelvin, significant performance gains can be realized. The design and simulation provides an example for illustrating the design principles specific and radiation simulation to this type of system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptEn..56h1804P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptEn..56h1804P"><span>Performance limitations of temperature-emissivity separation techniques in <span class="hlt">long-wave</span> infrared hyperspectral imaging applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pieper, Michael; Manolakis, Dimitris; Truslow, Eric; Cooley, Thomas; Brueggeman, Michael; Jacobson, John; Weisner, Andrew</p> <p>2017-08-01</p> <p>Accurate estimation or retrieval of surface emissivity from <span class="hlt">long-wave</span> infrared or thermal infrared (TIR) hyperspectral imaging data acquired by airborne or spaceborne sensors is necessary for many scientific and defense applications. This process consists of two interwoven steps: atmospheric compensation and temperature-emissivity separation (TES). The most widely used TES algorithms for hyperspectral imaging data assume that the emissivity spectra for solids are smooth compared to the atmospheric transmission function. We develop a model to explain and evaluate the performance of TES algorithms using a smoothing approach. Based on this model, we identify three sources of error: the smoothing error of the emissivity spectrum, the emissivity error from using the incorrect temperature, and the errors caused by sensor noise. For each TES smoothing technique, we analyze the bias and variability of the temperature errors, which translate to emissivity errors. The performance model explains how the errors interact to generate temperature errors. Since we assume exact knowledge of the atmosphere, the presented results provide an upper bound on the performance of TES algorithms based on the smoothness assumption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23231901','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23231901"><span><span class="hlt">Long-wave</span>, infrared laser-induced breakdown (LIBS) spectroscopy emissions from energetic materials.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Clayton S-C; Brown, Ei E; Hommerich, Uwe; Jin, Feng; Trivedi, Sudhir B; Samuels, Alan C; Snyder, A Peter</p> <p>2012-12-01</p> <p>Laser-induced breakdown spectroscopy (LIBS) has shown great promise for applications in chemical, biological, and explosives sensing and has significant potential for real-time standoff detection and analysis. In this study, LIBS emissions were obtained in the mid-infrared (MIR) and <span class="hlt">long-wave</span> infrared (LWIR) spectral regions for potential applications in explosive material sensing. The IR spectroscopy region revealed vibrational and rotational signatures of functional groups in molecules and fragments thereof. The silicon-based detector for conventional ultraviolet-visible LIBS operations was replaced with a mercury-cadmium-telluride detector for MIR-LWIR spectral detection. The IR spectral signature region between 4 and 12 μm was mined for the appearance of MIR and LWIR-LIBS emissions directly indicative of oxygenated breakdown products as well as dissociated, and/or recombined sample molecular fragments. Distinct LWIR-LIBS emission signatures from dissociated-recombination sample molecular fragments between 4 and 12 μm are observed for the first time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1239382-minority-carrier-lifetimes-very-long-wave-infrared-inas-gainsb-superlattices','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1239382-minority-carrier-lifetimes-very-long-wave-infrared-inas-gainsb-superlattices"><span>Minority carrier lifetimes in very <span class="hlt">long-wave</span> infrared InAs/GaInSb superlattices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Olson, Benjamin Varberg; Haugan, Heather J.; Brown, Gail J.; ...</p> <p>2016-01-01</p> <p>Here, significantly improved carrier lifetimes in very-<span class="hlt">long</span> <span class="hlt">wave</span> infrared InAs/GaInSb superlattice(SL) absorbers are demonstrated by using time-resolved microwave reflectance (TMR) measurements. A nominal 47.0 Å InAs/21.5 Å Ga 0.75In 0.25Sb SLstructure that produces an approximately 25 μm response at 10 K has a minority carrier lifetime of 140 ± 20 ns at 18 K, which is markedly long for SL absorber with such a narrow bandgap. This improvement is attributed to the strain-engineered ternary design. Such SL employs a shorter period with reduced gallium in order to achieve good optical absorption and epitaxial advantages, which ultimately leads to the improvementsmore » in the minority carrier lifetime by reducing Shockley–Read–Hall (SRH) defects. By analyzing the temperature-dependence of TMR decay data, the recombination mechanisms and trap states that currently limit the performance of this SL absorber have been identified. The results show a general decrease in the long-decay lifetime component, which is dominated by the SRH recombination at temperature below ~30 K, and by Auger recombination at temperatures above ~45 K.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..12010890Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..12010890Z"><span>Shipborne LF-VLF oceanic <span class="hlt">lightning</span> observations and modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zoghzoghy, F. G.; Cohen, M. B.; Said, R. K.; Lehtinen, N. G.; Inan, U. S.</p> <p>2015-10-01</p> <p>Approximately 90% of natural <span class="hlt">lightning</span> occurs over land, but recent observations, using Global <span class="hlt">Lightning</span> Detection (GLD360) geolocation peak current estimates and satellite optical data, suggested that cloud-to-ground flashes are on average stronger over the ocean. We present initial statistics from a novel experiment using a Low Frequency (LF) magnetic field receiver system installed aboard the National Oceanic Atmospheric Agency (NOAA) Ronald W. Brown research vessel that allowed the detection of impulsive <span class="hlt">radio</span> emissions from deep-oceanic discharges at short distances. Thousands of LF waveforms were recorded, facilitating the comparison of oceanic waveforms to their land counterparts. A computationally efficient electromagnetic radiation model that accounts for propagation over lossy and curved ground is constructed and compared with previously published models. We include the effects of Earth curvature on LF ground wave propagation and quantify the effects of channel-base current risetime, channel-base current falltime, and return stroke speed on the radiated LF waveforms observed at a given distance. We compare simulation results to data and conclude that previously reported larger GLD360 peak current estimates over the ocean are unlikely to fully result from differences in channel-base current risetime, falltime, or return stroke speed between ocean and land flashes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012GeoRL..3919807E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012GeoRL..3919807E"><span>VHF <span class="hlt">lightning</span> mapping observations of a triggered <span class="hlt">lightning</span> flash</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Edens, H. E.; Eack, K. B.; Eastvedt, E. M.; Trueblood, J. J.; Winn, W. P.; Krehbiel, P. R.; Aulich, G. D.; Hunyady, S. J.; Murray, W. C.; Rison, W.; Behnke, S. A.; Thomas, R. J.</p> <p>2012-10-01</p> <p>On 3 August 2010 an extensive <span class="hlt">lightning</span> flash was triggered over Langmuir Laboratory in New Mexico. The upward positive leader propagated into the storm's midlevel negative charge region, extending over a horizontal area of 13 × 13 km and 7.5 km altitude. The storm had a normal-polarity tripolar charge structure with upper positive charge over midlevel negative charge. <span class="hlt">Lightning</span> Mapping Array (LMA) observations were used to estimate positive leader velocities along various branches, which were in the range of 1-3 × 104 m s-1, slower than in other studies. The upward positive leader initiated at 3.4 km altitude, but was mapped only above 4.0 km altitude after the onset of retrograde negative breakdown, indicating a change in leader propagation and VHF emissions. The observations suggest that both positive and negative breakdown produce VHF emissions that can be located by time-of-arrival systems, and that not all VHF emissions occurring along positive leader channels are associated with retrograde negative breakdown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMAE24A..05F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMAE24A..05F"><span>Monitoring <span class="hlt">lightning</span> from space with TARANIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farges, T.; Blanc, E.; Pinçon, J.</p> <p>2010-12-01</p> <p>Some recent space experiments, e.g. OTD, LIS, show the large interest of <span class="hlt">lightning</span> monitoring from space and the efficiency of optical measurement. Future instrumentations are now defined for the next generation of geostationary meteorology satellites. Calibration of these instruments requires ground truth events provided by <span class="hlt">lightning</span> location networks, as NLDN in US, and EUCLID or LINET in Europe, using electromagnetic observations at a regional scale. One of the most challenging objectives is the continuous monitoring of the <span class="hlt">lightning</span> activity over the tropical zone (Africa, America, and Indonesia). However, one difficulty is the lack of <span class="hlt">lightning</span> location networks at regional scale in these areas to validate the data quality. TARANIS (Tool for the Analysis of Radiations from <span class="hlt">lightNings</span> and Sprites) is a CNES micro satellite project. It is dedicated to the study of impulsive transfers of energy, between the Earth atmosphere and the space environment, from nadir observations of Transient Luminous Events (TLEs), Terrestrial Gamma ray Flashes (TGFs) and other possible associated emissions. Its orbit will be sun-synchronous at 10:30 local time; its altitude will be 700 km. Its lifetime will be nominally 2 years. Its payload is composed of several electromagnetic instruments in different wavelengths: X and gamma-ray detectors, optical cameras and photometers, electromagnetic wave sensors from DC to 30 MHz completed by high energy electron detectors. The optical instrument includes 2 cameras and 4 photometers. All sensors are equipped with filters for sprite and <span class="hlt">lightning</span> differentiation. The filters of cameras are designed for sprite and <span class="hlt">lightning</span> observations at 762 nm and 777 nm respectively. However, differently from OTD or LIS instruments, the filter bandwidth and the exposure time (respectively 10 nm and 91 ms) prevent <span class="hlt">lightning</span> optical observations during daytime. The camera field of view is a square of 500 km at ground level with a spatial sampling frequency of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA21A2504A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA21A2504A"><span>Sferic propagation perturbations caused by energetic particle events as seen in global <span class="hlt">lightning</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, T.; Holzworth, R. H., II; Brundell, J. B.</p> <p>2017-12-01</p> <p>Energetic particle precipitation associated with solar events have been known to cause changes in the Earth-ionosphere waveguide. Previous studies of solar proton events (SPEs) have shown that high-energy protons can ionize lower-altitude layers of the ionosphere, leading to changes in Schumann resonance parameters (Schlegel and Fullekrug, 1999) and absorption of <span class="hlt">radio</span> waves over the polar cap (Kundu and Haddock, 1960). We use the World-Wide <span class="hlt">Lightning</span> Location Network (WWLLN) to study propagation of VLF waves during SPEs. WWLLN detects <span class="hlt">lightning</span>-generated sferics in the VLF band using 80 stations distributed around the world. By comparing received power at individual stations from specific <span class="hlt">lightning</span> source regions during SPEs, we can infer changes in the lower ionosphere conductivity profile caused by high-energy proton precipitation. In particular, we find that some WWLLN stations see different distributions of sferic power and range during SPEs. We also use the power/propagation analysis to improve WWLLN's <span class="hlt">lightning</span> detection accuracy, by developing a better model for ionosphere parameters and speed of light in the waveguide than we have previously used.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002884','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002884"><span>An Integrated 0-1 Hour First-Flash <span class="hlt">Lightning</span> Nowcasting, <span class="hlt">Lightning</span> Amount and <span class="hlt">Lightning</span> Jump Warning Capability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey</p> <p>2015-01-01</p> <p><span class="hlt">Lightning</span> one of the most dangerous weather-related phenomena, especially as many jobs and activities occur outdoors, presenting risk from a <span class="hlt">lightning</span> strike. Cloud-to-ground (CG) <span class="hlt">lightning</span> represents a considerable safety threat to people at airfields, marinas, and outdoor facilities-from airfield personnel, to people attending outdoor stadium events, on beaches and golf courses, to mariners, as well as emergency personnel. Holle et al. (2005) show that 90% of <span class="hlt">lightning</span> deaths occurred outdoors, while 10% occurred indoors despite the perception of safety when inside buildings. Curran et al. (2000) found that nearly half of fatalities due to weather were related to convective weather in the 1992-1994 timeframe, with <span class="hlt">lightning</span> causing a large component of the fatalities, in addition to tornadoes and flash flooding. Related to the aviation industry, CG <span class="hlt">lightning</span> represents a considerable hazard to baggage-handlers, aircraft refuelers, food caterers, and emergency personnel, who all become exposed to the risk of being struck within short time periods while convective storm clouds develop. Airport safety protocols require that ramp operations be modified or discontinued when <span class="hlt">lightning</span> is in the vicinity (typically 16 km), which becomes very costly and disruptive to flight operations. Therefore, much focus has been paid to nowcasting the first-time initiation and extent of <span class="hlt">lightning</span>, both of CG and of any <span class="hlt">lightning</span> (e.g, in-cloud, cloud-to-cloud). For this project three <span class="hlt">lightning</span> nowcasting methodologies will be combined: (1) a GOESbased 0-1 hour <span class="hlt">lightning</span> initiation (LI) product (Harris et al. 2010; Iskenderian et al. 2012), (2) a High Resolution Rapid Refresh (HRRR) <span class="hlt">lightning</span> probability and forecasted <span class="hlt">lightning</span> flash density product, such that a quantitative amount of <span class="hlt">lightning</span> (QL) can be assigned to a location of expected LI, and (3) an algorithm that relates Pseudo-GLM data (Stano et al. 2012, 2014) to the so-called "<span class="hlt">lightning</span> jump" (LJ) methodology (Shultz et al</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.1285F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.1285F"><span>Infrasound from <span class="hlt">lightning</span> measured in Ivory Coast</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farges, T.; Millet, C.; Matoza, R. S.</p> <p>2012-04-01</p> <p>It is well established that more than 2,000 thunderstorms occur continuously around the world and that about 45 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> flashes, …). Some of the IMS stations are located where worldwide <span class="hlt">lightning</span> detection networks (e.g. WWLLN) have a weak detection capability but <span class="hlt">lightning</span> activity is high (e.g. Africa, South America). These infrasound stations are well localised to study <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> studies possible. For example, Farges and Blanc (2010) show clearly that it is possible to measure <span class="hlt">lightning</span> infrasound from thunderstorms within a range of distances from the infrasound station. Infrasound from <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> flashes can be detected with this technique, giving better results locally than worldwide <span class="hlt">lightning</span> detection networks. An IMS infrasound station has been installed in Ivory Coast for 9 years. The <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> activity and its temporal variation. First statistical results will be presented in this paper based on 4 years of data (2005-2009). For short <span class="hlt">lightning</span> distances (less than 20 km), up to 60 % of <span class="hlt">lightning</span> detected by WWLLN has been one-to-one correlated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21143289-approach-lightning-overvoltage-protection-medium-voltage-lines-severe-lightning-areas','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21143289-approach-lightning-overvoltage-protection-medium-voltage-lines-severe-lightning-areas"><span>An Approach to the <span class="hlt">Lightning</span> Overvoltage Protection of Medium Voltage Lines in Severe <span class="hlt">Lightning</span> Areas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Omidiora, M. A.; Lehtonen, M.</p> <p>2008-05-08</p> <p>This paper deals with the effect of shield wires on <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> protection in Finnish distribution networks where <span class="hlt">lightning</span> is most severe. The true index of <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> strokes and simulated with the Alternative Transients Program/Electromagnetic Transients program (ATP/EMTP). Themore » response of the distribution line to <span class="hlt">lightning</span> 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.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=336118&keyword=air&subject=air%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=09/03/2012&dateendpublishedpresented=09/03/2017&sortby=pubdateyear','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=336118&keyword=air&subject=air%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=09/03/2012&dateendpublishedpresented=09/03/2017&sortby=pubdateyear"><span>A simple <span class="hlt">lightning</span> assimilation technique for improving ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Convective rainfall is often a large source of error in retrospective modeling applications. In particular, positive rainfall biases commonly exist during summer months due to overactive convective parameterizations. In this study, <span class="hlt">lightning</span> assimilation was applied in the Kain-Fritsch (KF) convective scheme to improve retrospective simulations using the Weather Research and Forecasting (WRF) model. The assimilation method has a straightforward approach: force KF deep convection where <span class="hlt">lightning</span> is observed and, optionally, suppress deep convection where <span class="hlt">lightning</span> is absent. WRF simulations were made with and without <span class="hlt">lightning</span> assimilation over the continental United States for July 2012, July 2013, and January 2013. The simulations were evaluated against NCEP stage-IV precipitation data and MADIS near-surface meteorological observations. In general, the use of <span class="hlt">lightning</span> assimilation considerably improves the simulation of summertime rainfall. For example, the July 2012 monthly averaged bias of 6 h accumulated rainfall is reduced from 0.54 to 0.07 mm and the spatial correlation is increased from 0.21 to 0.43 when <span class="hlt">lightning</span> assimilation is used. Statistical measures of near-surface meteorological variables also are improved. Consistent improvements also are seen for the July 2013 case. These results suggest that this <span class="hlt">lightning</span> assimilation technique has the potential to substantially improve simulation of warm-season rainfall in retrospective WRF applications. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=325491&keyword=air&subject=air%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=02/27/2012&dateendpublishedpresented=02/27/2017&sortby=pubdateyear','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=325491&keyword=air&subject=air%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=02/27/2012&dateendpublishedpresented=02/27/2017&sortby=pubdateyear"><span>A Simple <span class="hlt">Lightning</span> Assimilation Technique For Improving ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Convective rainfall is often a large source of error in retrospective modeling applications. In particular, positive rainfall biases commonly exist during summer months due to overactive convective parameterizations. In this study, <span class="hlt">lightning</span> assimilation was applied in the Kain-Fritsch (KF) convective scheme to improve retrospective simulations using the Weather Research and Forecasting (WRF) model. The assimilation method has a straightforward approach: Force KF deep convection where <span class="hlt">lightning</span> is observed and, optionally, suppress deep convection where <span class="hlt">lightning</span> is absent. WRF simulations were made with and without <span class="hlt">lightning</span> assimilation over the continental United States for July 2012, July 2013, and January 2013. The simulations were evaluated against NCEP stage-IV precipitation data and MADIS near-surface meteorological observations. In general, the use of <span class="hlt">lightning</span> assimilation considerably improves the simulation of summertime rainfall. For example, the July 2012 monthly-averaged bias of 6-h accumulated rainfall is reduced from 0.54 mm to 0.07 mm and the spatial correlation is increased from 0.21 to 0.43 when <span class="hlt">lightning</span> assimilation is used. Statistical measures of near-surface meteorological variables also are improved. Consistent improvements also are seen for the July 2013 case. These results suggest that this <span class="hlt">lightning</span> assimilation technique has the potential to substantially improve simulation of warm-season rainfall in retrospective WRF appli</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/362646-grounding-lightning-protection-volume','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/362646-grounding-lightning-protection-volume"><span>Grounding and <span class="hlt">lightning</span> protection. Volume 5</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Robinson, M.D.</p> <p>1987-12-31</p> <p>Grounding systems protect personnel and equipment by isolating faulted systems and dissipating transient currents. <span class="hlt">Lightning</span> protection systems minimize the possible consequences of a direct strike by <span class="hlt">lightning</span>. This volume focuses on design requirements of the grounding system and on present-day concepts used in the design of <span class="hlt">lightning</span> protection systems. Various types of grounding designs are presented, and their advantages and disadvantages discussed. Safety, of course, is the primary concern of any grounding system. Methods are shown for grounding the non-current-carrying parts of electrical equipment to reduce shock hazards to personnel. <span class="hlt">Lightning</span> protection systems are installed on tall structures (such asmore » chimneys and cooling towers) to minimize the possibility of structural damage caused by direct <span class="hlt">lightning</span> strokes. These strokes may carry currents of 200,000 A or more. The volume examines the formation and characteristics of <span class="hlt">lightning</span> strokes and the way stroke characteristics influence the design of <span class="hlt">lightning</span> protection systems. Because a large portion of the grounding system is buried in soil or concrete, it is not readily accessible for inspection or repair after its installation. The volume details the careful selection and sizing of materials needed to ensure a long, maintenance-free life for the system. Industry standards and procedures for testing the adequacy of the grounding system are also discussed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1320247','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1320247"><span>A Model <span class="hlt">Lightning</span> Safety Policy for Athletics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bennett, Brian L.</p> <p>1997-01-01</p> <p>Objective: The purpose of this paper is to present a model policy on <span class="hlt">lightning</span> safety for athletic trainers. Background: Among college athletic programs in the United States there is a serious lack of written policy on <span class="hlt">lightning</span> safety. Available evidence shows that most National Collegiate Athletic Association (NCAA) Division I institutions, even though they are located in high <span class="hlt">lightning</span> activity areas of the country, do not have formal, written <span class="hlt">lightning</span> safety policies. Clinical Advantages/ Recommendations: The policy presented herein, which is at the forefront of such policies, is the <span class="hlt">lightning</span> safety policy written as part of a policies and procedures manual for the division of sports medicine at a public NCAA Division I university. This is a policy based on practicality that utilizes the “flash-to- bang” method for determining the distance of <span class="hlt">lightning</span> activity from the observer. The policy begins with the importance of prevention, including the daily monitoring of weather reports. The policy defines a “safe shelter” and specifies the chain of command for determining who removes a team or individuals from an athletic site in the event of dangerous <span class="hlt">lightning</span> activity. PMID:16558459</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990008509','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990008509"><span>Optical Detection of <span class="hlt">Lightning</span> from Space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boccippio, Dennis J.; Christian, Hugh J.</p> <p>1998-01-01</p> <p>Optical sensors have been developed to detect <span class="hlt">lightning</span> from space during both day and night. These sensors have been fielded in two existing satellite missions and may be included on a third mission in 2002. Satellite-hosted, optically-based <span class="hlt">lightning</span> detection offers three unique capabilities: (1) the ability to reliably detect <span class="hlt">lightning</span> over large, often remote, spatial regions, (2) the ability to sample all (IC and CG) <span class="hlt">lightning</span>, and (3) the ability to detect <span class="hlt">lightning</span> with uniform (i.e., not range-dependent) sensitivity or detection efficiency. These represent significant departures from conventional RF-based detection techniques, which typically have strong range dependencies (biases) or range limitations in their detection capabilities. The atmospheric electricity team of the NASA Marshall Space Flight Center's Global Hydrology and Climate Center has implemented a three-step satellite <span class="hlt">lightning</span> research program which includes three phases: proof-of-concept/climatology, science algorithm development, and operational application. The first instrument in the program, the Optical Transient Detector (OTD), is deployed on a low-earth orbit (LEO) satellite with near-polar inclination, yielding global coverage. The sensor has a 1300 x 1300 sq km field of view (FOV), moderate detection efficiency, moderate localization accuracy, and little data bias. The OTD is a proof-of-concept instrument and its mission is primarily a global <span class="hlt">lightning</span> climatology. The limited spatial accuracy of this instrument makes it suboptimal for use in case studies, although significant science knowledge has been gained from the instrument as deployed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100026543','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100026543"><span>Recent Advancements in <span class="hlt">Lightning</span> Jump Algorithm Work</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schultz, Christopher J.; Petersen, Walter A.; Carey, Lawrence D.</p> <p>2010-01-01</p> <p>In the past year, the primary objectives were to show the usefulness of total <span class="hlt">lightning</span> as compared to traditional cloud-to-ground (CG) networks, test the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> jump algorithm configuration holds the most promise in terms of prospective operational <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> jump algorithms, accurate thunderstorm cell tracking work must be undertaken to track <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> jump algorithm, because of the suppressed vertical depth impact on overall flash counts (i.e., a relative dearth in <span class="hlt">lightning</span>). 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).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AtmRe.197..255L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AtmRe.197..255L"><span>Spatio-temporal dimension of <span class="hlt">lightning</span> flashes based on three-dimensional <span class="hlt">Lightning</span> Mapping Array</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>López, Jesús A.; Pineda, Nicolau; Montanyà, Joan; Velde, Oscar van der; Fabró, Ferran; Romero, David</p> <p>2017-11-01</p> <p>3D mapping system like the LMA - <span class="hlt">Lightning</span> Mapping Array - are a leap forward in <span class="hlt">lightning</span> observation. LMA measurements has lead to an improvement on the analysis of the fine structure of <span class="hlt">lightning</span>, allowing to characterize the duration and maximum extension of the cloud fraction of a <span class="hlt">lightning</span> flash. During several years of operation, the first LMA deployed in Europe has been providing a large amount of data which now allows a statistical approach to compute the full duration and horizontal extension of the in-cloud phase of a <span class="hlt">lightning</span> flash. The "Ebro <span class="hlt">Lightning</span> Mapping Array" (ELMA) is used in the present study. Summer and winter lighting were analyzed for seasonal periods (Dec-Feb and Jun-Aug). A simple method based on an ellipse fitting technique (EFT) has been used to characterize the spatio-temporal dimensions from a set of about 29,000 <span class="hlt">lightning</span> flashes including both summer and winter events. Results show an average <span class="hlt">lightning</span> flash duration of 440 ms (450 ms in winter) and a horizontal maximum length of 15.0 km (18.4 km in winter). The uncertainties for summer <span class="hlt">lightning</span> lengths were about ± 1.2 km and ± 0.7 km for the mean and median values respectively. In case of winter <span class="hlt">lightning</span>, the level of uncertainty reaches up to 1 km and 0.7 km of mean and median value. The results of the successful correlation of CG discharges with the EFT method, represent 6.9% and 35.5% of the total LMA flashes detected in summer and winter respectively. Additionally, the median value of <span class="hlt">lightning</span> lengths calculated through this correlative method was approximately 17 km for both seasons. On the other hand, the highest median ratios of <span class="hlt">lightning</span> length to CG discharges in both summer and winter were reported for positive CG discharges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070013848&hterms=Ronald+Reagan&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRonald%2BReagan','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070013848&hterms=Ronald+Reagan&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRonald%2BReagan"><span>The Washington DC Metro Area <span class="hlt">Lightning</span> Mapping Array</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krehbiel, Paul; Rison, William; Edens, Harald; OConnor, Nicholas; Aulich, Graydon; Thomas, Ronald; Kieft, Sandra; Goodman, Steven; Blakeslee, Richard; Hall, John; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20070013848'); toggleEditAbsImage('author_20070013848_show'); toggleEditAbsImage('author_20070013848_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20070013848_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20070013848_hide"></p> <p>2006-01-01</p> <p>During the spring and summer of 2006, a network of eight <span class="hlt">lightning</span> mapping stations has been set up in the greater DC metropolitan area to monitor the total <span class="hlt">lightning</span> activity in storms over Virginia, Maryland and the Washington DC area. The network is a joint project between New Mexico Tech, NASA, and NOAA/National Weather Service, with real-time data being provided to the NWS for use in their forecast and warning operations. The network utilizes newly available portable stations developed with support from the National Science Foundation. Cooperating institutions involved in hosting mapping stations are Howard University, Montgomery County Community College in Rockville MD, NOAA/NWS's Test and Evaluation Site in Sterling, VA, College of Southern Maryland near La Plata MD, the Applied Physics Laboratory of Johns Hopkins University, Northern Virginia Community College in Annandale, VA, the University of Maryland at Baltimore County, and George Mason University (Prince William Campus) in Manassas, VA. The network is experimental in that its stations a) operate in the upper rather than the lower VHF (TV channel 10, 192-198 MHz) to reduce the <span class="hlt">radio</span> frequency background noise associated with urban environments, and b) are linked to the central processing site via the internet rather than by dedicated wireless communication links. The central processing is done in Huntsville, AL, and updated observations are sent to the National Weather Service every 2 min. The observational data will also be available on a public website. The higher operating frequency results in a decrease in signal strength estimated to be about 15-20 dB, relative to the LMA networks being operated in northern Alabama and central Oklahoma (which operate on TV channels 5 and 3, respectively). This is offset somewhat by decreased background noise levels at many stations. The receiver threshold levels range from about -95 dBm up to -80 dBm and the peak <span class="hlt">lightning</span> signals typically extend 15-20 dB above</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070038289&hterms=Geostationary&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGeostationary','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070038289&hterms=Geostationary&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGeostationary"><span>Geostationary <span class="hlt">Lightning</span> Mapper for GOES-R</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goodman, Steven; Blakeslee, Richard; Koshak, William</p> <p>2007-01-01</p> <p>The Geostationary <span class="hlt">Lightning</span> Mapper (GLM) is a single channel, near-IR optical detector, used to detect, locate and measure total <span class="hlt">lightning</span> activity over the full-disk as part of a 3-axis stabilized, geostationary weather satellite system. The next generation NOAA Geostationary Operational Environmental Satellite (GOES-R) series with a planned launch in 2014 will carry a GLM that will provide continuous day and night observations of <span class="hlt">lightning</span> from the west coast of Africa (GOES-E) to New Zealand (GOES-W) when the constellation is fully operational. The mission objectives for the GLM are to 1) provide continuous, full-disk <span class="hlt">lightning</span> measurements for storm warning and Nowcasting, 2) provide early warning of tornadic activity, and 3) accumulate a long-term database to track decadal changes of <span class="hlt">lightning</span>. The GLM owes its heritage to the NASA <span class="hlt">Lightning</span> Imaging Sensor (1997-Present) and the Optical Transient Detector (1995-2000), which were developed for the Earth Observing System and have produced a combined 11 year data record of global <span class="hlt">lightning</span> activity. Instrument formulation studies begun in January 2006 will be completed in March 2007, with implementation expected to begin in September 2007. Proxy total <span class="hlt">lightning</span> data from the NASA <span class="hlt">Lightning</span> Imaging Sensor on the Tropical Rainfall Measuring Mission (TRMM) satellite, airborne science missions (e.g., African Monsoon Multi-disciplinary Analysis, AMMA), and regional test beds (e.g, <span class="hlt">Lightning</span> Mapping Arrays) are being used to develop the pre-launch algorithms and applications, and also improve our knowledge of thunderstorm initiation and evolution. Real time <span class="hlt">lightning</span> mapping data now being provided to selected forecast offices will lead to improved understanding of the application of these data in the severe storm warning process and accelerate the development of the pre-launch algorithms and Nowcasting applications. Proxy data combined with MODIS and Meteosat Second Generation SEVERI observations will also lead to new</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100020940&hterms=lightning+protection+system+buildings&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlightning%2Bprotection%2Bsystem%2Bbuildings','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100020940&hterms=lightning+protection+system+buildings&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlightning%2Bprotection%2Bsystem%2Bbuildings"><span>Estimates of the <span class="hlt">Lightning</span> NOx Profile in the Vicinity of the North Alabama <span class="hlt">Lightning</span> Mapping Array</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, William J.; Peterson, Harold</p> <p>2010-01-01</p> <p>The NASA Marshall Space Flight Center <span class="hlt">Lightning</span> Nitrogen Oxides Model (LNOM) is applied to August 2006 North Alabama <span class="hlt">Lightning</span> Mapping Array (LMA) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of <span class="hlt">lightning</span> nitrogen oxides, NOx = NO + NO 2 . This is part of a larger effort aimed at building a more realistic <span class="hlt">lightning</span> NOx emissions inventory for use by the U.S. Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) modeling system. Data from the National <span class="hlt">Lightning</span> Detection Network TM (NLDN) is also employed. Overall, special attention is given to several important <span class="hlt">lightning</span> variables including: the frequency and geographical distribution of <span class="hlt">lightning</span> in the vicinity of the LMA network, <span class="hlt">lightning</span> type (ground or cloud flash), <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT........94L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT........94L"><span>Investigating <span class="hlt">lightning</span>-to-ionosphere energy coupling based on VLF <span class="hlt">lightning</span> propagation characterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lay, Erin Hoffmann</p> <p></p> <p>In this dissertation, the capabilities of the World-Wide <span class="hlt">Lightning</span> Location Network (WWLLN) are analyzed in order to study the interactions of <span class="hlt">lightning</span> energy with the lower ionosphere. WWLLN is the first global ground-based <span class="hlt">lightning</span> location network and the first <span class="hlt">lightning</span> detection network that continuously monitors <span class="hlt">lightning</span> around the world in real time. For this reason, a better characterization of the WWLLN could allow many global atmospheric science problems to be addressed, including further investigation into the global electric circuit and global mapping of regions of the lower ionosphere likely to be impacted by strong <span class="hlt">lightning</span> and transient luminous events. This dissertation characterizes the World-Wide Location Network (WWLLN) in terms of detection efficiency, location and timing accuracy, and <span class="hlt">lightning</span> type. This investigation finds excellent timing and location accuracy for WWLLN. It provides the first experimentally-determined estimate of relative global detection efficiency that is used to normalize <span class="hlt">lightning</span> counts based on location. These normalized global <span class="hlt">lightning</span> data from the WWLLN are used to map intense storm regions around the world with high time and spatial resolution as well as to provide information on energetic emissions known as elves and terrestrial gamma-ray flashes (TGFs). This dissertation also improves WWLLN by developing a procedure to provide the first estimate of relative <span class="hlt">lightning</span> stroke radiated energy in the 1-24 kHz frequency range by a global <span class="hlt">lightning</span> detection network. These characterizations and improvements to WWLLN are motivated by the desire to use WWLLN data to address the problem of <span class="hlt">lightning</span>-to-ionosphere energy coupling. Therefore, WWLLN stroke rates are used as input to a model, developed by Professor Mengu Cho at the Kyushu Institute of Technology in Japan, that describes the non-linear effect of <span class="hlt">lightning</span> electromagnetic pulses (EMP) on the ionosphere by accumulating electron density changes resulting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20180001961','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20180001961"><span>ENSO Related Inter-Annual <span class="hlt">Lightning</span> Variability from the Full TRMM LIS <span class="hlt">Lightning</span> Climatology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clark, Austin; Cecil, Daniel</p> <p>2018-01-01</p> <p>The El Nino/Southern Oscillation (ENSO) contributes to inter-annual variability of <span class="hlt">lightning</span> production more than any other atmospheric oscillation. This study further investigated how ENSO phase affects <span class="hlt">lightning</span> production in the tropics and subtropics using the Tropical Rainfall Measuring Mission (TRMM) <span class="hlt">Lightning</span> Imaging Sensor (LIS). <span class="hlt">Lightning</span> data were averaged into mean annual warm, cold, and neutral 'years' for analysis of the different phases and compared to model reanalysis data. An examination of the regional sensitivities and preliminary analysis of three locations was conducted using model reanalysis data to determine the leading convective mechanisms in these areas and how they might respond to the ENSO phases</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMAE12A..06B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMAE12A..06B"><span>Trends in <span class="hlt">Lightning</span> Electrical Energy Derived from the <span class="hlt">Lightning</span> Imaging Sensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bitzer, P. M.; Koshak, W. J.</p> <p>2016-12-01</p> <p>We present results detailing an emerging application of space-based measurement of <span class="hlt">lightning</span>: the electrical energy. This is a little-used attribute of <span class="hlt">lightning</span> data which can have applications for severe weather, <span class="hlt">lightning</span> physics, and wildfires. In particular, we use data from the Tropical Rainfall Measuring Mission <span class="hlt">Lightning</span> Imaging Sensor (TRMM/LIS) to find the temporal and spatial variations in the detected spectral energy density. This is used to estimate the total <span class="hlt">lightning</span> electrical energy, following established methodologies. Results showing the trend in time of the electrical energy, as well as the distribution around the globe, will be highlighted. While flashes have been typically used in most studies, the basic scientifically-relevant measured unit by LIS is the optical group data product. This generally corresponds to a return stroke or IC pulse. We explore how the electrical energy varies per LIS group, providing an extension and comparison with previous investigations. The result is an initial climatology of this new and important application of space-based optical measurements of <span class="hlt">lightning</span>, which can provide a baseline for future applications using the Geostationary <span class="hlt">Lightning</span> Mapper (GLM), the European <span class="hlt">Lightning</span> Imager (LI), and the International Space Station <span class="hlt">Lightning</span> Imaging Sensor (ISS/LIS) instruments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990009077','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990009077"><span><span class="hlt">Lightning</span> Characteristics and <span class="hlt">Lightning</span> Strike Peak Current Probabilities as Related to Aerospace Vehicle Operations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, Dale L.; Vaughan, William W.</p> <p>1998-01-01</p> <p>A summary is presented of basic <span class="hlt">lightning</span> characteristics/criteria for current and future NASA aerospace vehicles. The paper estimates the probability of occurrence of a 200 kA peak <span class="hlt">lightning</span> return current, should <span class="hlt">lightning</span> strike an aerospace vehicle in various operational phases, i.e., roll-out, on-pad, launch, reenter/land, and return-to-launch site. A literature search was conducted for previous work concerning occurrence and measurement of peak lighting currents, modeling, and estimating probabilities of launch vehicles/objects being struck by <span class="hlt">lightning</span>. This paper presents these results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140007319','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140007319"><span><span class="hlt">Lightning</span> Tracking Tool for Assessment of Total Cloud <span class="hlt">Lightning</span> within AWIPS II</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burks, Jason E.; Stano, Geoffrey T.; Sperow, Ken</p> <p>2014-01-01</p> <p>Total <span class="hlt">lightning</span> (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 <span class="hlt">lightning</span> has been related to the strength of a storm's updraft. Therefore a rapid increase in total <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>. A tool has been developed at NASA's Short-term Prediction Research and Transition (SPoRT) Center to assist in quickly analyzing the total <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>. This tool also takes advantage of the new architecture available within the AWIPS II environment. SPoRT's <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> jump algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvF...3c4001W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvF...3c4001W"><span><span class="hlt">Long-wave</span>-instability-induced pattern formation in an evaporating sessile or pendent liquid layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Tao; Duan, Fei</p> <p>2018-03-01</p> <p>We investigate the nonlinear dynamics and stability of an evaporating liquid layer subject to vapor recoil, capillarity, thermocapillarity, ambient cooling, viscosity, and negative or positive gravity combined with buoyancy effects in the lubrication approximation. Using linear theory, we identify the mechanisms of finite-time rupture, independent of thermocapillarity and direction of gravity, and predict the effective growth rate of an interfacial perturbation which reveals competition among the mechanisms. A stability diagram is predicted for the onset of <span class="hlt">long-wave</span> (LW) evaporative convection. In the two-dimensional simulation, we observe well-defined capillary ridges on both sides of the valley under positive gravity and main and secondary droplets under negative gravity, while a ridge can be trapped in a large-scale drained region in both cases. Neglecting the other non-Boussinesq effects, buoyancy does not have a significant influence on interfacial evolution and rupture time but makes contributions to the evaporation-driven convection and heat transfer. The average Nusselt number is found to increase with a stronger buoyancy effect. The flow field and interface profile jointly manifest the LW Marangoni-Rayleigh-Bénard convection under positive gravity and the LW Marangoni convection under negative gravity. In the three-dimensional simulation of moderate evaporation with a random perturbation, the rupture patterns are characterized by irregular ridge networks with distinct height scales for positive and negative gravity. A variety of interfacial and internal dynamics are displayed, depending on evaporation conditions, gravity, Marangoni effect, and ambient cooling. Reasonable agreement is found between the present results and the reported experiments and simulations. The concept of dissipative compacton also sheds light on the properties of interfacial fractalization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980017072','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980017072"><span>LDAR, A Three-Dimensional <span class="hlt">Lightning</span> Warning System: Its Development and Use by the Government, and Transition to Public Availability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Starr, Stan; Sharp, David; Merceret, Francis; Madura, John; Murphy, Martin</p> <p>1998-01-01</p> <p>NASA, at the John F. Kennedy Space Center (KSC), developed and operates a unique high precision <span class="hlt">lightning</span> location system to provide <span class="hlt">lightning</span> related weather warnings. These warnings are used to stop <span class="hlt">lightning</span>-sensitive operations such as space vehicle launches and ground operations where equipment and personnel are at risk. The data is provided to the Range Weather Operations [45th Weather Squadron, U. S. Air Force (USAF)] where it is used with other meteorological data to issue weather advisories and warnings for Cape Canaveral Air Station (CCAS) and KSC operations. This system, called <span class="hlt">Lightning</span> Detection and Ranging (LDAR), provides users with a graphical display in three dimensions of 66 MHz <span class="hlt">radio</span> frequency events generated by <span class="hlt">lightning</span> processes. The locations of these events provide a sound basis for the prediction of <span class="hlt">lightning</span> hazards. NASA and Global Atmospherics, Inc. are developing a new system that will replace the unique LDAR components with commercially available and maintainable components having improved capabilities. These components will be phased in to ensure full continuity and access to this important warning technology. These LDAR systems are expected to eventually be available for installation and use by the public at specialized facilities, such as airports, and for general weather warnings via the National Weather Service (NWS) or television broadcast. The NWS in Melbourne has had access to real-time LDAR data since 1993 on an experimental basis. This use of LDAR has shown promise for the improvement of aviation forecasts and severe weather warnings. More so, it has opened the door to investigate the feasibility of issuing <span class="hlt">lightning</span>-related public advisories. The success of its early use suggests that this technology may improve safety and potentially save lives, therefore constituting a significant benefit to the public. This paper describes the LDR system, the plans and progress of these upgrades, and the potential benefits of its use.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810004700','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810004700"><span><span class="hlt">Radio</span> astronomy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Taylor, R. M.; Manchester, R. N.</p> <p>1980-01-01</p> <p>The activities of the Deep Space Network in support of <span class="hlt">radio</span> and radar astronomy operations during July and August 1980 are reported. A brief update on the OSS-sponsored planetary <span class="hlt">radio</span> astronomy experiment is provided. Also included are two updates, one each from Spain and Australia on current host country activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED385885.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED385885.pdf"><span>College <span class="hlt">Radio</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sauls, Samuel J.</p> <p></p> <p>As with commercial stations, the underlying premise of the college <span class="hlt">radio</span> station is to serve the community, whether it be the campus community or the community at large, but in unique ways often geared to underserved niches of the population. Much of college <span class="hlt">radio</span>'s charm lies in its unpredictable nature and constant mutations. The stations give…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990045716','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990045716"><span>ALDF Data Retrieval Algorithms for Validating the Optical Transient Detector (OTD) and the <span class="hlt">Lightning</span> Imaging Sensor (LIS)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, W. J.; Blakeslee, R. J.; Bailey, J. C.</p> <p>1997-01-01</p> <p>A linear algebraic solution is provided for the problem of retrieving the location and time of occurrence of <span class="hlt">lightning</span> ground strikes from in Advanced <span class="hlt">Lightning</span> Direction Finder (ALDF) network. The ALDF network measures field strength, magnetic bearing, and arrival time of <span class="hlt">lightning</span> <span class="hlt">radio</span> emissions and solutions for the plane (i.e.. no Earth curvature) are provided that implement all of these measurements. The accuracy of the retrieval method is tested using computer-simulated data sets and the relative influence of bearing and arrival time data on the outcome of the final solution is formally demonstrated. The algorithm is sufficiently accurate to validate NASA's Optical Transient Detector (OTD) and <span class="hlt">Lightning</span> Imaging System (LIS). 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 <span class="hlt">lightning</span> source lies near an outer sensor baseline of the ALDF network. For arbitrary noncollinear network geometries and in the absence of measurement errors, it is shown that the two quadratic roots are equivalent (no source location ambiguity) on the outer sensor baselines. The accuracy of the quadratic planar method is tested with computer-generated data sets and the results are generally better than those obtained from the three station linear planar method when bearing errors are about 2 degrees.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.5513O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.5513O"><span>Towards understanding the nature of any relationship between Solar Activity and Cosmic Rays with thunderstorm activity and <span class="hlt">lightning</span> discharge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Regan, J.; Muller, J.-P.; Matthews, S.</p> <p>2012-04-01</p> <p>The runaway breakdown hypothesis of <span class="hlt">lightning</span> discharge has predicted relationships between cosmic rays' interactions with the atmosphere and thunderstorm production and <span class="hlt">lightning</span> activity. Precipitating energetic particles lead to the injection of MeV-energy electrons into electrified thunderclouds [1,2], resulting in runaway breakdown occurring, and assisting in the process of charge separation [2]. Previous <span class="hlt">lightning</span> studies show that correlations to solar activity are weak but significant, with better correlations to solar activity and cosmic rays when carried out over smaller geographical areas [3,4,5,6] and over longer timescales [6]. In this work, correlations are explored between variations of SEPs and <span class="hlt">lightning</span> activity levels at various spatio-temporal scales. Temporal scales span from short-term (days) scales surrounding large Earth-directed coronal mass ejection (CME) events to long-term (years) scales. Similarly, spatial scales span from 1-degree x 1-degree latitudinal-longitudinal grid scales to an entirely global study, for varying timescales. Additionally, investigation of correlation sign and statistical significance by 1-degree latitudinal bands is also employed, allowing a comparative study of <span class="hlt">lightning</span> activity relative to regions of greatest - and contrasting regions of relative absence of - energetic particle precipitation. These regions are determined from electron and proton flux maps, derived from measurements from the Medium Energy Proton and Electron Detector (MEPED) onboard the Polar Orbiting Environmental Satellite (POES) system. <span class="hlt">Lightning</span> data is obtained from the World Wide <span class="hlt">Lightning</span> Location Network (WWLLN) for the period 2005 to 2011. The correlations of <span class="hlt">lightning</span> strike rates are carried out with respect to Relative Sunspot Number (R), 10.7cm Solar <span class="hlt">radio</span> flux (F10.7), Galactic Cosmic Ray (GCR) neutron monitor flux, the Ap geomagnetic activity index, and Disturbance Storm Time (DST) index. Correlations show dramatic variations in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23761114','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23761114"><span>Central hyperadrenergic state after <span class="hlt">lightning</span> strike.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>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</p> <p>2013-08-01</p> <p>To describe and review autonomic complications of <span class="hlt">lightning</span> strike. Case report and laboratory data including autonomic function tests in a subject who was struck by <span class="hlt">lightning</span>. A 24-year-old man was struck by <span class="hlt">lightning</span>. Following that, he developed dysautonomia, with persistent inappropriate sinus tachycardia and autonomic storms, as well as posttraumatic stress disorder (PTSD) and functional neurologic problems. The combination of persistent sinus tachycardia and episodic exacerbations associated with hypertension, diaphoresis, and agitation was 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 <span class="hlt">lightning</span> strike on the central nervous system or a secondary response is open to speculation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GI......3..135C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GI......3..135C"><span>Protection against <span class="hlt">lightning</span> at a geomagnetic observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Čop, R.; Milev, G.; Deželjin, D.; Kosmač, J.</p> <p>2014-08-01</p> <p>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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> in a thunderstorm cloud and the application of already-proven methods of protection against a stroke of <span class="hlt">lightning</span> and against its secondary effects. To reach this goal the following groups of experts have to cooperate: experts in the field of protection against <span class="hlt">lightning</span>, constructors and manufacturers of equipment and observatory managers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840040382&hterms=barret&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbarret','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840040382&hterms=barret&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbarret"><span>Correlated observations of three triggered <span class="hlt">lightning</span> flashes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Idone, V. P.; Orville, R. E.; Hubert, P.; Barret, L.; Eybert-Berard, A.</p> <p>1984-01-01</p> <p>Three triggered <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> data do not concur with the weak positive correlation between dart leader propagation speed and interstroke interval. Therefore, application of triggered <span class="hlt">lightning</span> results to natural <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002GeoRL..29.2142P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002GeoRL..29.2142P"><span><span class="hlt">Lightning</span> activity during the 1999 Superior derecho</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Price, Colin G.; Murphy, Brian P.</p> <p>2002-12-01</p> <p>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) <span class="hlt">lightning</span> 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) <span class="hlt">lightning</span> measured by the Canadian <span class="hlt">Lightning</span> Detection Network (CLDN) was greater than 70% for more than three hours, with peak values reaching 97% positive CG <span class="hlt">lightning</span>. Such high ratios of +CG are rare, and may be useful indicators of severe weather.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.A71B0092P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.A71B0092P"><span><span class="hlt">Lightning</span> Activity During the 1999 Superior Derecho</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Price, C. G.; Murphy, B. P.</p> <p>2002-12-01</p> <p>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) <span class="hlt">lightning</span> 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) <span class="hlt">lightning</span> measured by the Canadian <span class="hlt">Lightning</span> Detection Network (CLDN) was greater than 70% for more than three hours, with peak values reaching 97% positive CG <span class="hlt">lightning</span>. Such high ratios of +CG are rare, and may be useful indicators of severe weather.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3737249','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3737249"><span>Central Hyperadrenergic State After <span class="hlt">Lightning</span> Strike</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>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.</p> <p>2013-01-01</p> <p>Objective To describe and review autonomic complications of <span class="hlt">lightning</span> strike. Methods Case report and laboratory data including autonomic function tests in a subject who was struck by <span class="hlt">lightning</span>. Results A 24-year-old man was struck by <span class="hlt">lightning</span>. 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 <span class="hlt">lightning</span> strike on the CNS or a secondary response is open to speculation. PMID:23761114</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890038205&hterms=rust&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Drust','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890038205&hterms=rust&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Drust"><span>A solid state <span class="hlt">lightning</span> propagation speed sensor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mach, Douglas M.; Rust, W. David</p> <p>1989-01-01</p> <p>A device to measure the propagation speeds of cloud-to-ground <span class="hlt">lightning</span> has been developed. The <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> is different than that for natural <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/7156499-lightning-prevention-systems-paper-mills','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/7156499-lightning-prevention-systems-paper-mills"><span><span class="hlt">Lightning</span> prevention systems for paper mills</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Carpenter, R.B. Jr.</p> <p>1989-05-01</p> <p>Paper mills are increasingly relying on sensitive electronic equipment to control their operations. However, the sensitivity of these devices has made mills vulnerable to the effects of <span class="hlt">lightning</span> strokes. An interruption in the power supply or the destruction of delicate microcircuits can have devastating effects on mill productivity. The authors discuss how <span class="hlt">lightning</span> strokes can be prevented by a Dissipation Array system (DAS). During the past 17 years, the concept has been applied to a host of applications in regions with a high incidence of <span class="hlt">lightning</span> activity. With nearly 700 systems now installed, more than 4000 system-years of history havemore » been accumulated. Areas as large as 1 km{sup 2} and towers as high as 2000 ft have been protected and completely isolated from <span class="hlt">lightning</span> strokes. There have been very few failures, and in every case, the cause of the failure was determined and corrected.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140007322','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140007322"><span>Correlation of DIAL Ozone Observations with <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peterson, Harold; Kuang, Shi; Koshak, William; Newchurch, Michael</p> <p>2014-01-01</p> <p>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 <span class="hlt">lightning</span> 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 <span class="hlt">Lightning</span> Detection Network (NLDN) are used to examine the presence/absence of <span class="hlt">lightning</span> along the trajectory. This type of analysis suggests that <span class="hlt">lightning</span>-produced NOx may be responsible for some of the ozone maxima over Huntsville.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140006433','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140006433"><span>Correlation of DIAL Ozone Observations with <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peterson, Harold; Kuang, Shi; Koshak, William; Newchurch, Michael</p> <p>2013-01-01</p> <p>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 <span class="hlt">lightning</span> 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 <span class="hlt">Lightning</span> Detection Network (NLDN) are used to examine the presence/absence of <span class="hlt">lightning</span> along the trajectory. This type of analysis suggests that <span class="hlt">lightning</span>-produced NOx may be responsible for some of the ozone maxima over Huntsville.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840034431&hterms=ATLA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DATLA','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840034431&hterms=ATLA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DATLA"><span><span class="hlt">Lightning</span> measurements from the Pioneer Venus Orbiter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scarf, F. L.; Russell, C. T.</p> <p>1983-01-01</p> <p>The plasma wave instrument on the Pioneer Venus Orbiter frequently detects strong and impulsive low-frequency signals when the spacecraft traverses the nightside ionosphere near periapsis. These particular noise bursts appear only when the local magnetic field is strong and steady and when the field is oriented to point down to the ionosphere thus; the signals have all characteristics of <span class="hlt">lightning</span> whistlers. We have tried to identify <span class="hlt">lightning</span> sources between the cloud layers and the planet itself by tracing rays along the B-field from the Orbiter down toward the surface. An extensive data set, consisting of measurements through Orbit 1185, strongly indicates a clustering of <span class="hlt">lightning</span> sources near the Beta and Phoebe Regios, with an additional significant cluster near the Atla Regio at the eastern edge of Aphrodite Terra. These results suggest that there are localized <span class="hlt">lightning</span> sources at or near the planetary surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NatAs.tmp...69B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NatAs.tmp...69B"><span>Jovian <span class="hlt">lightning</span> whistles a new tune</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bortnik, Jacob</p> <p>2018-06-01</p> <p>The Juno spacecraft has detected unprecedented numbers of `whistlers' and `sferics' in its orbits around Jupiter, both indications of high <span class="hlt">lightning</span> flash rates in the atmosphere of the gas giant planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=The+AND+lightning&pg=6&id=EJ415490','ERIC'); return false;" href="https://eric.ed.gov/?q=The+AND+lightning&pg=6&id=EJ415490"><span>A Simple <span class="hlt">Lightning</span> Flash Polarity Discriminating Counter.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Devan, K. R. S.; Jayaratne, E. R.</p> <p>1990-01-01</p> <p>Described are the apparatus and procedures needed for a demonstration of a determination of the polarity of charges carried by individual ground flashes of <span class="hlt">lightning</span>. Discussed are materials, apparatus construction, and experimental results. (CW)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000FlDyR..26..289O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000FlDyR..26..289O"><span>Generation of <span class="hlt">long</span> <span class="hlt">waves</span> in a fluid flowing over a localized topography at a periodically varying velocity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ohsugi, Yasuo; Funakoshi, Mitsuaki</p> <p>2000-05-01</p> <p>The generation of <span class="hlt">long</span> <span class="hlt">waves</span> in a fluid flowing over a localized topography is examined numerically using the forced KdV equation under the assumption that the velocity U of the fluid far from the topography is close to the phase speed of a linear <span class="hlt">long</span> <span class="hlt">wave</span> and varies periodically with period T. For T within a few regions, we observe the 1: n entrainment of the wave motion near the topography to period T, in which n upstream-advancing waves are generated in period T. These regions extend and shift to larger T as the average value or amplitude of the variation of U increases. Furthermore, when the entrainment occurs, the spatial region where time-periodic evolution is almost attained extends toward both upstream and downstream directions with increasing time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1107581','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1107581"><span>Systems having optical absorption layer for mid and <span class="hlt">long</span> <span class="hlt">wave</span> infrared and methods for making the same</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kuzmenko, Paul J</p> <p>2013-10-01</p> <p>An optical system according to one embodiment includes a substrate; and an optical absorption layer coupled to the substrate, wherein the optical absorption layer comprises a layer of diamond-like carbon, wherein the optical absorption layer absorbs at least 50% of mid wave infrared light (3-5 .mu.m wavelength) and at least 50% of <span class="hlt">long</span> <span class="hlt">wave</span> infrared light (8-13 .mu.m wavelength). A method for applying an optical absorption layer to an optical system according to another embodiment includes depositing a layer of diamond-like carbon of an optical absorption layer above a substrate using plasma enhanced chemical vapor deposition, wherein the optical absorption layer absorbs at least 50% of mid wave infrared light (3-5 .mu.m wavelength) and at least 50% of <span class="hlt">long</span> <span class="hlt">wave</span> infrared light (8-13 .mu.m wavelength). Additional systems and methods are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMAE31B0430S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMAE31B0430S"><span>Scientific <span class="hlt">Lightning</span> Detection Network for Kazakhstan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Streltsov, A. V.; Lozbin, A.; Inchin, A.; Shpadi, Y.; Inchin, P.; Shpadi, M.; Ayazbayev, G.; Bykayev, R.; Mailibayeva, L.</p> <p>2015-12-01</p> <p>In the frame of grant financing of the scientific research in 2015-2017 the project "To Develop Electromagnetic System for <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> location (Time-of-arrival and Direction Finding (TOA+DF)) and provide a <span class="hlt">lightning</span> activity research in North Tien-Shan region with respect to seismicity and other natural and manmade activities. Also, it is planned to use <span class="hlt">lightning</span> data for Global Electric Circuit (GEC) investigation. Currently, there are <span class="hlt">lightning</span> detection networks in many countries. In Kazakhstan we have only separate units in airports. So, we don't have full <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EOSTr..95s.360W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EOSTr..95s.360W"><span><span class="hlt">Lightning</span> channel current persists between strokes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wendel, JoAnna</p> <p>2014-09-01</p> <p>The usual cloud-to-ground <span class="hlt">lightning</span> occurs when a large negative charge contained in a "stepped leader" travels down toward the Earth's surface. It then meets a positive charge that comes up tens of meters from the ground, resulting in a powerful neutralizing explosion that begins the first return stroke of the <span class="hlt">lightning</span> flash. The entire flash lasts only a few hundred milliseconds, but during that time, multiple subsequent stroke-return stroke sequences usually occur.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/981833','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/981833"><span><span class="hlt">Lightning</span> protection system for a wind turbine</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Costin, Daniel P [Chelsea, VT; Petter, Jeffrey K [Williston, VT</p> <p>2008-05-27</p> <p>In a wind turbine (104, 500, 704) having a plurality of blades (132, 404, 516, 744) and a blade rotor hub (120, 712), a <span class="hlt">lightning</span> protection system (100, 504, 700) for conducting <span class="hlt">lightning</span> 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).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6356663-shielding-theory-upward-lightning','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6356663-shielding-theory-upward-lightning"><span>A shielding theory for upward <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shindo, Takatoshi; Aihara, Yoshinori</p> <p>1993-01-01</p> <p>A new shielding theory is proposed based on the assumption that the occurrence of <span class="hlt">lightning</span> strokes on the Japan Sea coast in winter is due to the inception of upward leaders from tall structures. Ratios of the numbers of <span class="hlt">lightning</span> strokes to high structures observed there in winter show reasonable agreement with values calculated by this theory. Shielding characteristics of a high structure in various conditions are predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790009256&hterms=Electricity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DElectricity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790009256&hterms=Electricity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DElectricity"><span>Summary report of the <span class="hlt">Lightning</span> and Static Electricity Committee</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Plumer, J. A.</p> <p>1979-01-01</p> <p><span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> 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) <span class="hlt">lightning</span> strike incident data from General Aviation; (6) <span class="hlt">lightning</span> detection systems; (7) obtain pilot reports of <span class="hlt">lightning</span> strikes; and (8) better training in <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/952468','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/952468"><span><span class="hlt">Lightning</span> Arrestor Connectors Production Readiness</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marten, Steve; Linder, Kim; Emmons, Jim</p> <p>2008-10-20</p> <p>The <span class="hlt">Lightning</span> 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 themore » LAC granule fabrication process. This report summarizes the accomplishments achieved in improving the LAC Production Readiness.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ChPhB..18.3090X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ChPhB..18.3090X"><span>GEOPHYSICS, ASTRONOMY AND ASTROPHYSICS: Numerical method of studying nonlinear interactions between <span class="hlt">long</span> <span class="hlt">waves</span> and multiple short waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Tao; Kuang, Hai-Lan; William, Perrie; Zou, Guang-Hui; Nan, Cheng-Feng; He, Chao; Shen, Tao; Chen, Wei</p> <p>2009-07-01</p> <p>Although the nonlinear interactions between a single short gravity wave and a <span class="hlt">long</span> <span class="hlt">wave</span> can be solved analytically, the solution is less tractable in more general cases involving multiple short waves. In this work we present a numerical method of studying nonlinear interactions between a <span class="hlt">long</span> <span class="hlt">wave</span> and multiple short harmonic waves in infinitely deep water. Specifically, this method is applied to the calculation of the temporal and spatial evolutions of the surface elevations in which a given <span class="hlt">long</span> <span class="hlt">wave</span> interacts with several short harmonic waves. Another important application of our method is to quantitatively analyse the nonlinear interactions between an arbitrary short wave train and another short wave train. From simulation results, we obtain that the mechanism for the nonlinear interactions between one short wave train and another short wave train (expressed as wave train 2) leads to the energy focusing of the other short wave train (expressed as wave train 3). This mechanism occurs on wave components with a narrow frequency bandwidth, whose frequencies are near that of wave train 3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4587745','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4587745"><span>Low-Dose, <span class="hlt">Long-Wave</span> UV Light Does Not Affect Gene Expression of Human Mesenchymal Stem Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wong, Darice Y.; Ranganath, Thanmayi; Kasko, Andrea M.</p> <p>2015-01-01</p> <p>Light is a non-invasive tool that is widely used in a range of biomedical applications. Techniques such as photopolymerization, photodegradation, and photouncaging can be used to alter the chemical and physical properties of biomaterials in the presence of live cells. <span class="hlt">Long-wave</span> UV light (315 nm–400 nm) is an easily accessible and commonly used energy source for triggering biomaterial changes. Although exposure to low doses of <span class="hlt">long-wave</span> UV light is generally accepted as biocompatible, most studies employing this wavelength only establish cell viability, ignoring other possible (non-toxic) effects. Since light exposure of wavelengths longer than 315 nm may potentially induce changes in cell behavior, we examined changes in gene expression of human mesenchymal stem cells exposed to light under both 2D and 3D culture conditions, including two different hydrogel fabrication techniques, decoupling UV exposure and radical generation. While exposure to <span class="hlt">long-wave</span> UV light did not induce significant changes in gene expression regardless of culture conditions, significant changes were observed due to scaffold fabrication chemistry and between cells plated in 2D versus encapsulated in 3D scaffolds. In order to facilitate others in searching for more specific changes between the many conditions, the full data set is available on Gene Expression Omnibus for querying. PMID:26418040</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29138444','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29138444"><span>The Elusive Evidence of Volcanic <span class="hlt">Lightning</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Genareau, K; Gharghabi, P; Gafford, J; Mazzola, M</p> <p>2017-11-14</p> <p><span class="hlt">Lightning</span> strikes are known to morphologically alter and chemically reduce geologic formations and deposits, forming fulgurites. A similar process occurs as the result of volcanic <span class="hlt">lightning</span> discharge, when airborne volcanic ash is transformed into <span class="hlt">lightning</span>-induced volcanic spherules (LIVS). Here, we adapt the calculations used in previous studies of <span class="hlt">lightning</span>-induced damage to infrastructure materials to determine the effects on pseudo-ash samples of simplified composition. Using laboratory high-current impulse experiments, this research shows that within the <span class="hlt">lightning</span> discharge channel there is an ideal melting zone that represents roughly 10% or less of the total channel radius at which temperatures are sufficient to melt the ash, regardless of peak current. The melted ash is simultaneously expelled from the channel by the heated, expanding air, permitting particles to cool during atmospheric transport before coming to rest in ash fall deposits. The limited size of this ideal melting zone explains the low number of LIVS typically observed in volcanic ash despite the frequent occurrence of <span class="hlt">lightning</span> during explosive eruptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27466230','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27466230"><span>A Fossilized Energy Distribution of <span class="hlt">Lightning</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pasek, Matthew A; Hurst, Marc</p> <p>2016-07-28</p> <p>When <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground <span class="hlt">lightning</span>. 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating <span class="hlt">lightning</span> energy and damage potential of strikes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4964350','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4964350"><span>A Fossilized Energy Distribution of <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pasek, Matthew A.; Hurst, Marc</p> <p>2016-01-01</p> <p>When <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground <span class="hlt">lightning</span>. 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating <span class="hlt">lightning</span> energy and damage potential of strikes. PMID:27466230</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28465545','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28465545"><span>On the initiation of <span class="hlt">lightning</span> in thunderclouds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chilingarian, Ashot; Chilingaryan, Suren; Karapetyan, Tigran; Kozliner, Lev; Khanikyants, Yeghia; Hovsepyan, Gagik; Pokhsraryan, David; Soghomonyan, Suren</p> <p>2017-05-02</p> <p>The relationship of <span class="hlt">lightning</span> and elementary particle fluxes in the thunderclouds is not fully understood to date. Using the particle beams (the so-called Thunderstorm Ground Enhancements - TGEs) as a probe we investigate the characteristics of the interrelated atmospheric processes. The well-known effect of the TGE dynamics is the abrupt termination of the particle flux by the <span class="hlt">lightning</span> flash. With new precise electronics, we can see that particle flux decline occurred simultaneously with the rearranging of the charge centers in the cloud. The analysis of the TGE energy spectra before and after the <span class="hlt">lightning</span> demonstrates that the high-energy part of the TGE energy spectra disappeared just after <span class="hlt">lightning</span>. The decline of particle flux coincides on millisecond time scale with first atmospheric discharges and we can conclude that Relativistic Runaway Electron Avalanches (RREA) in the thundercloud assist initiation of the negative cloud to ground <span class="hlt">lightning</span>. Thus, RREA can provide enough ionization to play a significant role in the unleashing of the <span class="hlt">lightning</span> flash.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023316','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023316"><span><span class="hlt">Lightning</span> protection for shuttle propulsion elements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goodloe, Carolyn C.; Giudici, Robert J.</p> <p>1991-01-01</p> <p>The results of <span class="hlt">lightning</span> protection analyses and tests are weighed against the present set of waivers to the NASA <span class="hlt">lightning</span> protection specification. The significant analyses and tests are contrasted with the release of a new and more realistic <span class="hlt">lightning</span> protection specification, in September 1990, that resulted in an inordinate number of waivers. A variety of <span class="hlt">lightning</span> protection analyses and tests of the Shuttle propulsion elements, the Solid Rocket Booster, the External Tank, and the Space Shuttle Main Engine, were conducted. These tests range from the sensitivity of solid propellant during shipping to penetration of cryogenic tanks during flight. The Shuttle propulsion elements have the capability to survive certain levels of <span class="hlt">lightning</span> strikes at certain times during transportation, launch site operations, and flight. Changes are being evaluated that may improve the odds of withstanding a major <span class="hlt">lightning</span> strike. The Solid Rocket Booster is the most likely propulsion element to survive if systems tunnel bond straps are improved. Wiring improvements were already incorporated and major protection tests were conducted. The External Tank remains vulnerable to burn-through penetration of its skin. Proposed design improvements include the use of a composite nose cone and conductive or laminated thermal protection system coatings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170001583','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170001583"><span>Rationales for the <span class="hlt">Lightning</span> Launch Commit Criteria</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Willett, John C. (Editor); Merceret, Francis J. (Editor); Krider, E. Philip; O'Brien, T. Paul; Dye, James E.; Walterscheid, Richard L.; Stolzenburg, Maribeth; Cummins, Kenneth; Christian, Hugh J.; Madura, John T.</p> <p>2016-01-01</p> <p>Since natural and triggered <span class="hlt">lightning</span> are demonstrated hazards to launch vehicles, payloads, and spacecraft, NASA and the Department of Defense (DoD) follow the <span class="hlt">Lightning</span> Launch Commit Criteria (LLCC) for launches from Federal Ranges. The LLCC were developed to prevent future instances of a rocket intercepting natural <span class="hlt">lightning</span> or triggering a <span class="hlt">lightning</span> flash during launch from a Federal Range. NASA and DoD utilize the <span class="hlt">Lightning</span> Advisory Panel (LAP) to establish and develop robust rationale from which the criteria originate. The rationale document also contains appendices that provide additional scientific background, including detailed descriptions of the theory and observations behind the rationales. The LLCC in whole or part are used across the globe due to the rigor of the documented criteria and associated rationale. The Federal Aviation Administration (FAA) adopted the LLCC in 2006 for commercial space transportation and the criteria were codified in the FAA's Code of Federal Regulations (CFR) for Safety of an Expendable Launch Vehicle (Appendix G to 14 CFR Part 417, (G417)) and renamed <span class="hlt">Lightning</span> Flight Commit Criteria in G417.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810029852&hterms=Grounded+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGrounded%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810029852&hterms=Grounded+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGrounded%2Btheory"><span><span class="hlt">Lightning</span> protection design external tank /Space Shuttle/</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, A.; Mumme, E.</p> <p>1979-01-01</p> <p>The possibility of <span class="hlt">lightning</span> striking the Space Shuttle during liftoff is considered and the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> strike to an area of the spacecraft which can sustain the strike. The ET <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> protection system design is shown to be comprised of the following: (1) a <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900005214','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900005214"><span>JPS heater and sensor <span class="hlt">lightning</span> qualification</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cook, M.</p> <p>1989-01-01</p> <p>Simulated <span class="hlt">lightning</span> strike testing of the Redesigned Solid Rocket Motor (RSRM) field joint protection system heater assembly was performed at Thiokol Corp., Wendover <span class="hlt">Lightning</span> Facility. Testing consisted of subjecting the <span class="hlt">lightning</span> evaluation test article to simulated <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> discharges only, no heater operating power was applied during the test. The results showed that, for a worst-case <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT.......132P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT.......132P"><span>Four-Wave Mixing of Gigawatt Power, <span class="hlt">Long-Wave</span> Infrared Radiation in Gases and Semiconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pigeon, Jeremy James</p> <p></p> <p>The nonlinear optics of gigawatt power, 10 microm, 3 and 200 ps long pulses propagating in gases and semiconductors has been studied experimentally and numerically. In this work, the development of a high-repetition rate, picosecond, CO2 laser system has enabled experiments using peak intensities in the range of 1-10 GW/cm2, approximately one thousand times greater than previous nonlinear optics experiments in the <span class="hlt">long-wave</span> infrared (LWIR) spectral region. The first measurements of the nonlinear refractive index of the atomic and molecular gases Kr, Xe, N2, O2 and the air at a wavelength near 10 microm were accomplished by studying the four-wave mixing (FWM) of dual-wavelength, 200 ps CO2 laser pulses. These measurements indicate that the nonlinearities of the diatomic molecules N2, O2 and the air are dominated by the molecular contribution to the nonlinear refractive index. Supercontinuum (SC) generation covering the infrared spectral range, from 2-20 microm, was realized by propagating 3 ps, 10 microm pulses in an approximately 7 cm long, Cr-doped GaAs crystal. Temporal measurements of the SC radiation show that pulse splitting accompanies the generation of such broadband light in GaAs. The propagation of 3 ps, 10 microm pulses in GaAs was studied numerically by solving the Generalized Nonlinear Schrodinger Equation (GNLSE). These simulations, combined with analytic estimates, were used to determine that stimulated Raman scattering combined with a modulational instability caused by the propagation of intense LWIR radiation in the negative group velocity dispersion region of GaAs are responsible for the SC generation process. The multiple FWM of a 106 GHz, 200 ps CO2 laser beat-wave propagating in GaAs was used to generate a broadband FWM spectrum that was compressed by the negative group velocity dispersion of GaAs and NaCl crystals to form trains of high-power, picosecond pulses at a wavelength near 10 microm. Experimental FWM spectra obtained using 165 and 882</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/993351-prediction-metrics-chemical-detection-long-wave-infrared-hyperspectral-imagery','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/993351-prediction-metrics-chemical-detection-long-wave-infrared-hyperspectral-imagery"><span>Prediction Metrics for Chemical Detection in <span class="hlt">Long-Wave</span> Infrared Hyperspectral Imagery</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chilton, Marie C.; Walsh, Stephen J.; Daly, Don S.</p> <p>2009-01-29</p> <p>A natural or anthropogenic process often generates a signature gas plume whose chemical constituents may be identified using hyperspectral imagery. A hyperspectral image is a pixel-indexed set of spectra where each spectrum reflects the chemical constituents of the plume, the atmosphere, the bounding background surface, and instrument noise. This study explored the relationship between gas absorbance and background emissivity across the <span class="hlt">long-wave</span> infrared (LWIR) spectrum and how they affect relative gas detection sensitivity. The physics-based model for the observed radiance shows that high gas absorbance coupled with low background emissivity at a single wavenumber results in a stronger recorded radiance.more » Two sensitivity measures were developed to predict relative probability of detection using chemical absorbance and background emissivity: one focused on a single wavenumber while another accounted for the entire spectrum. The predictive abilities of these measures were compared to synthetic image analysis. This study simulated images with 499 distinct gases at each of 6 concentrations over 6 different background surfaces with the atmosphere and level of instrument noise held constant. The Whitened Matched Filter was used to define gas detection from an image spectrum. The estimate of a chemical’s probability of detection at a given concentration over a specific background was the proportion of detections in 500 trials. Of the 499 chemicals used in the images, 276 had estimated probabilities of detection below 0.2 across all backgrounds and concentrations; these chemicals were removed from the study. For 92.8 percent of the remaining chemicals, the single channel measure correctly predicted the background over which the chemical had the largest relative probability of detection. Further, the measure which accounted for information across all wavenumbers predicted the background over which the chemical had the largest relative probability of detection for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=335488&Lab=NERL&keyword=forensics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=335488&Lab=NERL&keyword=forensics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">Lightning</span> NOx Production in CMAQ Part I – Using Hourly NLDN <span class="hlt">Lightning</span> Strike Data</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p><span class="hlt">Lightning</span>-produced nitrogen oxides (NOX=NO+NO2) in the middle and upper troposphere play an essential role in the production of ozone (O3) and influence the oxidizing capacity of the troposphere. Despite much effort in both observing and modeling <span class="hlt">lightning</span> NOX during the past dec...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMAE41A..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMAE41A..06S"><span>Combining GOES-16 Geostationary <span class="hlt">Lightning</span> Mapper with the ground based Earth Networks Total <span class="hlt">Lightning</span> Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stock, M.; Lapierre, J. L.; Zhu, Y.</p> <p>2017-12-01</p> <p>Recently, the Geostationary <span class="hlt">Lightning</span> Mapper (GLM) began collecting optical data to locate <span class="hlt">lightning</span> events and flashes over the North and South American continents. This new instrument promises uniformly high detection efficiency (DE) over its entire field of view, with location accuracy on the order of 10 km. In comparison, Earth Networks Total <span class="hlt">Lightning</span> Networks (ENTLN) has a less uniform coverage, with higher DE in regions with dense sensor coverage, and lower DE with sparse sensor coverage. ENTLN also offers better location accuracy, <span class="hlt">lightning</span> classification, and peak current estimation for their <span class="hlt">lightning</span> locations. It is desirable to produce an integrated dataset, combining the strong points of GLM and ENTLN. The easiest way to achieve this is to simply match located <span class="hlt">lightning</span> processes from each system using time and distance criteria. This simple method will be limited in scope by the uneven coverage of the ground based network. Instead, we will use GLM group locations to look up the electric field change data recorded by ground sensors near each GLM group, vastly increasing the coverage of the ground network. The ground waveforms can then be used for: improvements to differentiation between glint and <span class="hlt">lightning</span> for GLM, higher precision lighting location, current estimation, and <span class="hlt">lightning</span> process classification. Presented is an initial implementation of this type of integration using preliminary GLM data, and waveforms from ENTLN.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EP%26S...70...88T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EP%26S...70...88T"><span>Initiation of a <span class="hlt">lightning</span> search using the <span class="hlt">lightning</span> and airglow camera onboard the Venus orbiter Akatsuki</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takahashi, Yukihiro; Sato, Mitsuteru; Imai, Masataka; Lorenz, Ralph; Yair, Yoav; Aplin, Karen; Fischer, Georg; Nakamura, Masato; Ishii, Nobuaki; Abe, Takumi; Satoh, Takehiko; Imamura, Takeshi; Hirose, Chikako; Suzuki, Makoto; Hashimoto, George L.; Hirata, Naru; Yamazaki, Atsushi; Sato, Takao M.; Yamada, Manabu; Murakami, Shin-ya; Yamamoto, Yukio; Fukuhara, Tetsuya; Ogohara, Kazunori; Ando, Hiroki; Sugiyama, Ko-ichiro; Kashimura, Hiroki; Ohtsuki, Shoko</p> <p>2018-05-01</p> <p>The existence of <span class="hlt">lightning</span> discharges in the Venus atmosphere has been controversial for more than 30 years, with many positive and negative reports published. The <span class="hlt">lightning</span> and airglow camera (LAC) onboard the Venus orbiter, Akatsuki, was designed to observe the light curve of possible flashes at a sufficiently high sampling rate to discriminate <span class="hlt">lightning</span> from other sources and can thereby perform a more definitive search for optical emissions. Akatsuki arrived at Venus during December 2016, 5 years following its launch. The initial operations of LAC through November 2016 have included a progressive increase in the high voltage applied to the avalanche photodiode detector. LAC began <span class="hlt">lightning</span> survey observations in December 2016. It was confirmed that the operational high voltage was achieved and that the triggering system functions correctly. LAC <span class="hlt">lightning</span> search observations are planned to continue for several years.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20180001922','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20180001922"><span>ENSO Related Interannual <span class="hlt">Lightning</span> Variability from the Full TRMM LIS <span class="hlt">Lightning</span> Climatology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clark, Austin; Cecil, Daniel J.</p> <p>2018-01-01</p> <p>It has been shown that the El Nino/Southern Oscillation (ENSO) contributes to inter-annual variability of <span class="hlt">lightning</span> production in the tropics and subtropics more than any other atmospheric oscillation. This study further investigated how ENSO phase affects <span class="hlt">lightning</span> production in the tropics and subtropics. Using the Tropical Rainfall Measuring Mission (TRMM) <span class="hlt">Lightning</span> Imaging Sensor (LIS) and the Oceanic Nino Index (ONI) for ENSO phase, <span class="hlt">lightning</span> data were averaged into corresponding mean annual warm, cold, and neutral 'years' for analysis of the different phases. An examination of the regional sensitivities and preliminary analysis of three locations was conducted using model reanalysis data to determine the leading convective mechanisms in these areas and how they might respond to the ENSO phases. These processes were then studied for inter-annual variance and subsequent correlation to ENSO during the study period to best describe the observed <span class="hlt">lightning</span> deviations from year to year at each location.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=channeling&pg=4&id=EJ163429','ERIC'); return false;" href="https://eric.ed.gov/?q=channeling&pg=4&id=EJ163429"><span>CB <span class="hlt">Radios</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Martin, Dick</p> <p>1977-01-01</p> <p>Citizen band <span class="hlt">radios</span> keep trucking across the American scene, and no doubt your students are caught in the folk craze. Provides some suggestions for channeling students' interests with a unit on CBs. (Author/RK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090017890&hterms=epa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Depa','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090017890&hterms=epa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Depa"><span>A NASA <span class="hlt">Lightning</span> Parameterization for CMAQ</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, William; Khan, Maudood; Biazar, Arastoo; Newchurch, Mike; McNider, Richard</p> <p>2009-01-01</p> <p>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, <span class="hlt">lightning</span> modeling for CMAQ is highly oversimplified. This leads to very poor estimates of <span class="hlt">lightning</span>-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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> model, called the <span class="hlt">Lightning</span> Nitrogen Oxides Model (LNOM) that combines state-of-the-art <span class="hlt">lightning</span> measurements, empirical results from field studies, and beneficial laboratory results to arrive at a realistic representation of <span class="hlt">lightning</span> NOx production for CMAQ. NASA satellite <span class="hlt">lightning</span> data is used in conjunction with ground-based <span class="hlt">lightning</span> detection systems to assure that the best representation of <span class="hlt">lightning</span> frequency, geographic location, channel length, channel altitude, strength (i.e., channel peak current), and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1713577H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1713577H"><span>Severe weather detection by using Japanese Total <span class="hlt">Lightning</span> Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hobara, Yasuhide; Ishii, Hayato; Kumagai, Yuri; Liu, Charlie; Heckman, Stan; Price, Colin</p> <p>2015-04-01</p> <p>In this paper we demonstrate the preliminary results from the first Japanese Total <span class="hlt">Lightning</span> Network. The University of Electro-Communications (UEC) recently deployed Earth Networks Total <span class="hlt">Lightning</span> System over Japan to conduct various <span class="hlt">lightning</span> research projects. Here we analyzed the total <span class="hlt">lightning</span> data in relation with 10 severe events such as gust fronts and tornadoes occurred in 2014 in mainland Japan. For the analysis of these events, <span class="hlt">lightning</span> jump algorithm was used to identify the increase of the flash rate in prior to the severe weather events. We found that <span class="hlt">lightning</span> jumps associated with significant increasing <span class="hlt">lightning</span> activities for total <span class="hlt">lightning</span> and IC clearly indicate the severe weather occurrence than those for CGs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/9757','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/9757"><span><span class="hlt">Lightning</span> and its effects on railroad signal circuits</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>1975-12-31</p> <p>This study discusses the occurrence of <span class="hlt">lightning</span>, its effects on railroad signal equipment, and protection of such equipment from <span class="hlt">lightning</span> damage, with special attention to known protective techniques which are employed in a variety of situations in...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012MNRAS.425.2501B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012MNRAS.425.2501B"><span>A search for dispersed <span class="hlt">radio</span> bursts in archival Parkes Multibeam Pulsar Survey data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bagchi, Manjari; Nieves, Angela Cortes; McLaughlin, Maura</p> <p>2012-10-01</p> <p>A number of different classes of potentially extra-terrestrial bursts of <span class="hlt">radio</span> emission have been observed in surveys with the Parkes 64-m <span class="hlt">radio</span> telescope, including 'rotating <span class="hlt">radio</span> transients', the 'Lorimer burst' and 'perytons'. Rotating <span class="hlt">radio</span> transients are <span class="hlt">radio</span> pulsars which are best detectable in single-pulse searches. The Lorimer burst is a highly dispersed isolated <span class="hlt">radio</span> burst with properties suggestive of extragalactic origin. Perytons share the frequency-swept nature of the rotating <span class="hlt">radio</span> transients and Lorimer burst, but unlike these events appear in all 13 beams of the Parkes multibeam receiver and are probably a form of peculiar <span class="hlt">radio</span> frequency interference. In order to constrain these and other <span class="hlt">radio</span> source populations further, we searched the archival Parkes Multibeam Pulsar Survey data for events similar to any of these. We did not find any new rotating <span class="hlt">radio</span> transients or bursts like the Lorimer burst. We did, however, discover four peryton-like events. Similar to the perytons, these four bursts are highly dispersed, detected in all 13 beams of the Parkes multibeam receiver, and have pulse widths between 20 and 30 ms. Unlike perytons, these bursts are not associated with atmospheric events like rain or <span class="hlt">lightning</span>. These facts may indicate that <span class="hlt">lightning</span> was not responsible for the peryton phenomenon. Moreover, the lack of highly dispersed celestial signals is the evidence that the Lorimer burst is unlikely to belong to a cosmological source population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.470..187A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.470..187A"><span><span class="hlt">Lightning</span> chemistry on Earth-like exoplanets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ardaseva, Aleksandra; Rimmer, Paul B.; Waldmann, Ingo; Rocchetto, Marco; Yurchenko, Sergey N.; Helling, Christiane; Tennyson, Jonathan</p> <p>2017-09-01</p> <p>We present a model for <span class="hlt">lightning</span> shock-induced chemistry that can be applied to atmospheres of arbitrary H/C/N/O chemistry, hence for extrasolar planets and brown dwarfs. The model couples hydrodynamics and the STAND2015 kinetic gas-phase chemistry. For an exoplanet analogue to the contemporary Earth, our model predicts NO and NO2 yields in agreement with observation. We predict height-dependent mixing ratios during a storm soon after a <span class="hlt">lightning</span> shock of NO ≈10-3 at 40 km and NO2 ≈10-4 below 40 km, with O3 reduced to trace quantities (≪10-10). For an Earth-like exoplanet with a CO2/N2 dominated atmosphere and with an extremely intense <span class="hlt">lightning</span> storm over its entire surface, we predict significant changes in the amount of NO, NO2, O3, H2O, H2 and predict a significant abundance of C2N. We find that, for the Early Earth, O2 is formed in large quantities by <span class="hlt">lightning</span> but is rapidly processed by the photochemistry, consistent with previous work on <span class="hlt">lightning</span>. The chemical effect of persistent global <span class="hlt">lightning</span> storms are predicted to be significant, primarily due to NO2, with the largest spectral features present at ˜3.4 and ˜6.2 μm. The features within the transmission spectrum are on the order of 1 ppm and therefore are not likely detectable with the James Webb Space Telescope. Depending on its spectral properties, C2N could be a key tracer for <span class="hlt">lightning</span> on Earth-like exoplanets with a N2/CO2 bulk atmosphere, unless destroyed by yet unknown chemical reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/949855-lightning-vulnerability-fiber-optic-cables','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/949855-lightning-vulnerability-fiber-optic-cables"><span><span class="hlt">Lightning</span> vulnerability of fiber-optic cables.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martinez, Leonard E.; Caldwell, Michele</p> <p>2008-06-01</p> <p>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 <span class="hlt">lightning</span> strike representing an extreme but very importantmore » 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 <span class="hlt">lightning</span> conditions at the Sandia <span class="hlt">Lightning</span> Simulator (SLS). Simulated <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> tests performed at the Sandia <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> conditions.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090017685&hterms=information+technology+trend&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dinformation%2Btechnology%2Btrend','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090017685&hterms=information+technology+trend&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dinformation%2Btechnology%2Btrend"><span>An Operational Perspective of Total <span class="hlt">Lightning</span> Information</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nadler, David J.; Darden, Christopher B.; Stano, Geoffrey; Buechler, Dennis E.</p> <p>2009-01-01</p> <p>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 <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> networks across the country, have shown distinct correlations between the time rate-of-change of total <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> can be compared to corresponding damage reports. This presentation will emphasize</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880019875','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880019875"><span>The 1983 direct strike <span class="hlt">lightning</span> data, part 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, Mitchel E.</p> <p>1985-01-01</p> <p>Data waveforms are presented which were obtained during the 1983 direct strike <span class="hlt">lightning</span> tests utilizing the NASA F106-B aircraft specially instrumented for <span class="hlt">lightning</span> electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached <span class="hlt">lightning</span>. Part 1 contains 435 pages of <span class="hlt">lightning</span> strike data in chart form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880019876','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880019876"><span>The 1983 direct strike <span class="hlt">lightning</span> data, part 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, Mitchel E.</p> <p>1985-01-01</p> <p>Data waveforms are presented which were obtained during the 1983 direct strike <span class="hlt">lightning</span> tests utilizing the NASA F106-B aircraft specially instrumented for <span class="hlt">lightning</span> electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached <span class="hlt">lightning</span>. Part 2 contains 443 pages of <span class="hlt">lightning</span> strike data in chart form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990108685&hterms=self+harm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dself%2Bharm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990108685&hterms=self+harm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dself%2Bharm"><span><span class="hlt">Lightning</span> Launch Commit Criteria for America's Space Program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roeder, W. P.; Sardonia, J. E.; Jacobs, S. C.; Hinson, M. S.; Harms, D. E.; Madura, J. T.; DeSordi, S. P.</p> <p>1999-01-01</p> <p>The danger of natural and triggered <span class="hlt">lightning</span> significantly impacts space launch operations supported by the USAF. The <span class="hlt">lightning</span> Launch Commit Criteria (LCC) are used by the USAF to avoid these <span class="hlt">lightning</span> threats to space launches. This paper presents a brief overview of the LCC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec57-12065.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec57-12065.pdf"><span>30 CFR 57.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec56-12065.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec56-12065.pdf"><span>30 CFR 56.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 56... Electricity § 56.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec57-12065.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec57-12065.pdf"><span>30 CFR 57.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec56-12065.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec56-12065.pdf"><span>30 CFR 56.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 56... Electricity § 56.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec57-12065.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec57-12065.pdf"><span>30 CFR 57.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec56-12065.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec56-12065.pdf"><span>30 CFR 56.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 56... Electricity § 56.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec57-12065.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec57-12065.pdf"><span>30 CFR 57.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec56-12065.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec56-12065.pdf"><span>30 CFR 56.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 56... Electricity § 56.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=338768&Lab=NERL&keyword=forensics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=338768&Lab=NERL&keyword=forensics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>A Performance Evaluation of <span class="hlt">Lightning</span>-NO Algorithms in CMAQ</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>In the Community Multiscale Air Quality (CMAQv5.2) model, we have implemented two algorithms for <span class="hlt">lightning</span> NO production; one algorithm is based on the hourly observed cloud-to-ground <span class="hlt">lightning</span> strike data from National <span class="hlt">Lightning</span> Detection Network (NLDN) to replace the previous m...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec56-12065.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec56-12065.pdf"><span>30 CFR 56.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 56... Electricity § 56.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec57-12065.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec57-12065.pdf"><span>30 CFR 57.12065 - Short circuit and <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit and <span class="hlt">lightning</span> protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and <span class="hlt">lightning</span> protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and <span class="hlt">lightning</span>. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec25-1316.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec25-1316.pdf"><span>14 CFR 25.1316 - System <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... airplane; (5) Establishing the susceptibility of the systems to the internal and external <span class="hlt">lightning</span>...) Determining the <span class="hlt">lightning</span> strike zones for the airplane; (2) Establishing the external <span class="hlt">lightning</span> environment for the zones; (3) Establishing the internal environment; (4) Identifying all the electrical and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title14-vol1/pdf/CFR-2013-title14-vol1-sec23-954.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title14-vol1/pdf/CFR-2013-title14-vol1-sec23-954.pdf"><span>14 CFR 23.954 - Fuel system <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-01-01</p> <p>... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system <span class="hlt">lightning</span> protection. 23.954... Fuel System § 23.954 Fuel system <span class="hlt">lightning</span> protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct <span class="hlt">lightning</span> strikes to areas having a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title14-vol1/pdf/CFR-2012-title14-vol1-sec23-954.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title14-vol1/pdf/CFR-2012-title14-vol1-sec23-954.pdf"><span>14 CFR 23.954 - Fuel system <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-01-01</p> <p>... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system <span class="hlt">lightning</span> protection. 23.954... Fuel System § 23.954 Fuel system <span class="hlt">lightning</span> protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct <span class="hlt">lightning</span> strikes to areas having a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec23-954.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec23-954.pdf"><span>14 CFR 23.954 - Fuel system <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system <span class="hlt">lightning</span> protection. 23.954... Fuel System § 23.954 Fuel system <span class="hlt">lightning</span> protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct <span class="hlt">lightning</span> strikes to areas having a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol1/pdf/CFR-2011-title14-vol1-sec23-954.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol1/pdf/CFR-2011-title14-vol1-sec23-954.pdf"><span>14 CFR 23.954 - Fuel system <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system <span class="hlt">lightning</span> protection. 23.954... Fuel System § 23.954 Fuel system <span class="hlt">lightning</span> protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct <span class="hlt">lightning</span> strikes to areas having a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title14-vol1/pdf/CFR-2014-title14-vol1-sec23-954.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title14-vol1/pdf/CFR-2014-title14-vol1-sec23-954.pdf"><span>14 CFR 23.954 - Fuel system <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-01-01</p> <p>... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system <span class="hlt">lightning</span> protection. 23.954... Fuel System § 23.954 Fuel system <span class="hlt">lightning</span> protection. The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by— (a) Direct <span class="hlt">lightning</span> strikes to areas having a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840002593','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840002593"><span>How to protect a wind turbine from <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dodd, C. W.; Mccalla, T., Jr.; Smith, J. G.</p> <p>1983-01-01</p> <p>Techniques for reducing the chances of <span class="hlt">lightning</span> damage to wind turbines are discussed. The methods of providing a ground for a <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> strikes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=The+AND+lightning&pg=5&id=EJ244606','ERIC'); return false;" href="https://eric.ed.gov/?q=The+AND+lightning&pg=5&id=EJ244606"><span>Production of Artificial <span class="hlt">Lightning</span> in An Ordinary Clear Light Bulb.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Zaffo, Peter Alfred</p> <p>1981-01-01</p> <p>Reported is a method of producing artificial <span class="hlt">lightning</span> in an ordinary clear lightbulb. The appearance of sparks produced is that of a miniature stroke of forked <span class="hlt">lightning</span> seen in natural thunderstorms. The sparks also show the intricate branching patterns often seen in natural <span class="hlt">lightning</span>. (JT)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol1/pdf/CFR-2011-title14-vol1-sec25-1316.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol1/pdf/CFR-2011-title14-vol1-sec25-1316.pdf"><span>14 CFR 25.1316 - System <span class="hlt">lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... systems to perform these functions are not adversely affected when the airplane is exposed to <span class="hlt">lightning</span>... these functions can be recovered in a timely manner after the airplane is exposed to <span class="hlt">lightning</span>. (c) Compliance with the <span class="hlt">lightning</span> protection criteria prescribed in paragraphs (a) and (b) of this section must...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMAE13A0368Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMAE13A0368Z"><span>Statistical Evolution of the <span class="hlt">Lightning</span> Flash</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zoghzoghy, F. G.; Cohen, M.; Said, R.; Inan, U. S.</p> <p>2012-12-01</p> <p>Natural <span class="hlt">lightning</span> is one of the most fascinating and powerful electrical processes on Earth. To date, the physics behind this natural phenomenon are not fully understood, due primarily to the difficulty of obtaining measurements inside thunderstorms and to the wide range of timescales involved (from nanoseconds to seconds). Our aim is to use accurate <span class="hlt">lightning</span> geo-location data from the National <span class="hlt">Lightning</span> Detection Network (NLDN) to study statistical patterns in <span class="hlt">lightning</span>, taking advantage of the fact that millions of <span class="hlt">lightning</span> flashes occur around the globe every day. We present two sets of results, one involving the patterns of flashes in a storm, and a second involving the patterns of strokes in a flash. These patterns can provide a surrogate measure of the timescales and the spatial extents of the underlying physical processes. First, we study the timescales of charge buildup inside thunderstorms. We find that, following a <span class="hlt">lightning</span> flash, the probability of another neighboring flash decreases and takes tens of seconds to recover. We find that this suppression effect is a function of flash type, stroke peak current, cloud-to-ground (CG) stroke multiplicity, and other <span class="hlt">lightning</span> and geographical parameters. We find that the probabilities of subsequent flashes are more suppressed following oceanic <span class="hlt">lightning</span>, or following flashes with higher peak currents and/or higher multiplicities (for CG flashes). Second, we use NLDN data to study the evolution of the strokes within a CG flash. A CG flash typically includes multiple return strokes, which can occur in the same channel or in multiple channels within a few kilometers. We cluster NLDN stroke data into flashes and produce the probability density function of subsequent strokes as a function of distance and time-delays relative to the previous stroke. Using this technique, we investigate processes which occur during the CG <span class="hlt">lightning</span> flash with nanosecond to millisecond timescales. For instance, our results suggest</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100002101&hterms=climate+facts&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dclimate%2Bfacts','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100002101&hterms=climate+facts&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dclimate%2Bfacts"><span>Climate Change and Tropical Total <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Albrecht, R.; Petersen, W.; Buechler, D.; Goodman, S.; Blakeslee, R.; Christian, H.</p> <p>2009-01-01</p> <p>While global warming is regarded as a fact by many in the scientific community, its future impact remains a challenge to be determined and measured. The International Panel on Climate Change (IPCC) assessment report (IPCC, 2007) shows inconclusive answers on global rainfall trends and general agreement on a future drier climate with increased global warming. The relationship between temperature, humidity and convection is not linear and is strongly dependent on regional scale features, such as topography and land cover. Furthermore, the relationship between convective <span class="hlt">lightning</span> production (thunderstorms) and temperature is even more complicated, being subjected to the cloud dynamics and microphysics. Total <span class="hlt">lightning</span> (intracloud and cloud-to-ground) monitoring is a relatively new field of observation. Global and tropical total <span class="hlt">lightning</span> began to be more extensively measured by satellites in the mid 90s. In this scope, the <span class="hlt">Lightning</span> Imaging Sensor (LIS) onboard of the Tropical Rainfall Measurement Mission (TRMM) has been operational for over 11 years. Here we address total <span class="hlt">lightning</span> trends observed by LIS from 1998 to 2008 in different temporal (annual and seasonal) and spatial (large and regional) scales. The observed 11-year trends are then associate to different predicted/hypothesized climate change scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511245D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511245D"><span>Solar wind modulation of UK <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davis, Chris; Harrison, Giles; Lockwood, Mike; Owens, Mathew; Barnard, Luke</p> <p>2013-04-01</p> <p>The response of <span class="hlt">lightning</span> rates in the UK to arrival of high speed solar wind streams at Earth is investigated using a superposed epoch analysis. The fast solar wind streams' arrivals are determined from modulation of the solar wind Vy component, measured by the Advanced Composition Explorer (ACE) spacecraft. <span class="hlt">Lightning</span> rate changes around these event times are then 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 day rate of the Sun. Arrival of the high speed stream at Earth also coincides with a rapid decrease in cosmic ray flux and an increase in <span class="hlt">lightning</span> rates over the UK, persisting for around 40 days. The <span class="hlt">lightning</span> rate increase is corroborated by an increase in the total number of thunder days observed by UK Met stations, again for around 40 days after the arrival of a high speed solar wind stream. This increase in <span class="hlt">lightning</span> may be beneficial to medium range forecasting of hazardous weather.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023322','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023322"><span>The Sandia transportable triggered <span class="hlt">lightning</span> instrumentation facility</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schnetzer, George H.; Fisher, Richard J.</p> <p>1991-01-01</p> <p>Development of the Sandia Transportable Triggered <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> facility for specialized test applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=522088','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=522088"><span>Isolation of <span class="hlt">Lightning</span>-Competent Soil Bacteria</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cérémonie, Hélène; Buret, François; Simonet, Pascal; Vogel, Timothy M.</p> <p>2004-01-01</p> <p>Artificial transformation is typically performed in the laboratory by using either a chemical (CaCl2) or an electrical (electroporation) method. However, laboratory-scale <span class="hlt">lightning</span> has been shown recently to electrotransform Escherichia coli strain DH10B in soil. In this paper, we report on the isolation of two “<span class="hlt">lightning</span>-competent” soil bacteria after direct electroporation of the Nycodenz bacterial ring extracted from prairie soil in the presence of the pBHCRec plasmid (Tcr, Spr, Smr). The electrotransformability of the isolated bacteria was measured both in vitro (by electroporation cuvette) and in situ (by <span class="hlt">lightning</span> in soil microcosm) and then compared to those of E. coli DH10B and Pseudomonas fluorescens C7R12. The electrotransformation frequencies measured reached 10−3 to 10−4 by electroporation and 10−4 to 10−5 by simulated <span class="hlt">lightning</span>, while no transformation was observed in the absence of electrical current. Two of the isolated <span class="hlt">lightning</span>-competent soil bacteria were identified as Pseudomonas sp. strains. PMID:15466589</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGRA..115.0E09F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGRA..115.0E09F"><span>Relativistic runaway breakdown in low-frequency <span class="hlt">radio</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Füllekrug, Martin; Roussel-Dupré, Robert; Symbalisty, Eugene M. D.; Chanrion, Olivier; Odzimek, Anna; van der Velde, Oscar; Neubert, Torsten</p> <p>2010-01-01</p> <p>The electromagnetic radiation emitted by an electron avalanche beam resulting from relativistic runaway breakdown within the Earth's atmosphere is investigated. It is found from theoretical modeling with a computer simulation that the electron beam emits electromagnetic radiation which is characterized by consecutive broadband pulses in the low-frequency <span class="hlt">radio</span> range from ˜10 to 300 kHz at a distance of ˜800 km. Experimental evidence for the existence of consecutive broadband pulses is provided by low-frequency <span class="hlt">radio</span> observations of sprite-producing <span class="hlt">lightning</span> discharges at a distance of ˜550 km. The measured broadband pulses occur ˜4-9 ms after the sprite-producing <span class="hlt">lightning</span> discharge, they exhibit electromagnetic radiation which mainly spans the frequency range from ˜50 to 350 kHz, and they exhibit complex waveforms without the typical ionospheric reflection of the first hop sky wave. Two consecutive pulses occur ˜4.5 ms and ˜3 ms after the causative <span class="hlt">lightning</span> discharge and coincide with the sprite luminosity. It is concluded that relativistic runaway breakdown within the Earth's atmosphere can emit broadband electromagnetic pulses and possibly generates sprites. The source location of the broadband pulses can be determined with an interferometric network of wideband low-frequency <span class="hlt">radio</span> receivers to lend further experimental support to the relativistic runaway breakdown theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130014258','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130014258"><span><span class="hlt">Lightning</span> NOx Statistics Derived by NASA <span class="hlt">Lightning</span> Nitrogen Oxides Model (LNOM) Data Analyses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, William; Peterson, Harold</p> <p>2013-01-01</p> <p>What is the LNOM? The NASA Marshall Space Flight Center (MSFC) <span class="hlt">Lightning</span> Nitrogen Oxides Model (LNOM) [Koshak et al., 2009, 2010, 2011; Koshak and Peterson 2011, 2013] analyzes VHF <span class="hlt">Lightning</span> Mapping Array (LMA) and National <span class="hlt">Lightning</span> Detection Network(TradeMark) (NLDN) data to estimate the <span class="hlt">lightning</span> 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" <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> return stroke; (7) NOx computed for several other <span class="hlt">lightning</span> 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).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15...32P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15...32P"><span>Visual Analytics approach for <span class="hlt">Lightning</span> data analysis and cell nowcasting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peters, Stefan; Meng, Liqiu; Betz, Hans-Dieter</p> <p>2013-04-01</p> <p>Thunderstorms and their ground effects, such as flash floods, hail, <span class="hlt">lightning</span>, strong wind and tornadoes, are responsible for most weather damages (Bonelli & Marcacci 2008). Thus to understand, identify, track and predict <span class="hlt">lightning</span> cells is essential. An important aspect for decision makers is an appropriate visualization of weather analysis results including the representation of dynamic <span class="hlt">lightning</span> cells. This work focuses on the visual analysis of <span class="hlt">lightning</span> data and <span class="hlt">lightning</span> cell nowcasting which aim to detect and understanding spatial-temporal patterns of moving thunderstorms. <span class="hlt">Lightnings</span> are described by 3D coordinates and the exact occurrence time of <span class="hlt">lightnings</span>. The three-dimensionally resolved total <span class="hlt">lightning</span> data used in our experiment are provided by the European <span class="hlt">lightning</span> detection network LINET (Betz et al. 2009). In all previous works, <span class="hlt">lightning</span> point data, detected <span class="hlt">lightning</span> cells and derived cell tracks are visualized in 2D. <span class="hlt">Lightning</span> cells are either displayed as 2D convex hulls with or without the underlying <span class="hlt">lightning</span> point data. Due to recent improvements of <span class="hlt">lightning</span> data detection and accuracy, there is a growing demand on multidimensional and interactive visualization in particular for decision makers. In a first step <span class="hlt">lightning</span> cells are identified and tracked. Then an interactive graphic user interface (GUI) is developed to investigate the dynamics of the <span class="hlt">lightning</span> cells: e.g. changes of cell density, location, extension as well as merging and splitting behavior in 3D over time. In particular a space time cube approach is highlighted along with statistical analysis. Furthermore a <span class="hlt">lightning</span> cell nowcasting is conducted and visualized. The idea thereby is to predict the following cell features for the next 10-60 minutes including location, centre, extension, density, area, volume, lifetime and cell feature probabilities. The main focus will be set to a suitable interactive visualization of the predicted featured within the GUI. The developed visual</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LPICo2063.3017L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LPICo2063.3017L"><span>The Deep Space Gateway <span class="hlt">Lightning</span> Mapper (DLM) — Monitoring Global Change and Thunderstorm Processes through Observations of Earth's High-Latitude <span class="hlt">Lightning</span> from Cis-Lunar Orbit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lang, T. J.; Blakeslee, R. J.; Cecil, D. J.; Christian, H. J.; Gatlin, P. N.; Goodman, S. J.; Koshak, W. J.; Petersen, W. A.; Quick, M.; Schultz, C. J.; Tatum, P. F.</p> <p>2018-02-01</p> <p>We propose the Deep Space Gateway <span class="hlt">Lightning</span> Mapper (DLM) instrument. The primary goal of the DLM is to optically monitor Earth's high-latitude (50° and poleward) total <span class="hlt">lightning</span> not observed by current and planned spaceborne <span class="hlt">lightning</span> mappers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA486684','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA486684"><span>Calibrated Mid-wave Infrared (IR) (MidIR) and <span class="hlt">Long-wave</span> IR (LWIR) Stokes and Degree-of-Liner Polarization (DOLP)</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2008-09-01</p> <p>LWIR <span class="hlt">long-wave</span> IR MCT mercury cadmium telluride MidIR mid-wave IR NUC nonuniformity corrections ROI regions-of-interest 22 No. of Copies...Calibrated Mid-wave Infrared (IR) (MidIR) and <span class="hlt">Long-wave</span> IR ( LWIR ) Stokes and Degree-of-Liner Polarization (DOLP) by Kristan P. Gurton and... LWIR ) Stokes and Degree-of-Liner Polarization (DOLP) Kristan P. Gurton and Melvin Felton Computational and Information Sciences Directorate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001SPIE.4198...96S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4198...96S"><span>Thermal and ghost reflection modeling for a 180-deg. field-of-view <span class="hlt">long-wave</span> infrared lens</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Weimin; Couture, Michael E.</p> <p>2001-03-01</p> <p>Optics 1, Inc. has successfully designed and developed a 180 degree(s) field of view <span class="hlt">long</span> <span class="hlt">wave</span> infrared lens for USAF/AFRL under SBIR phase I and II funded projects in support of the multi-national Programmable Integrated Ordinance Suite (PIOS) program. In this paper, a procedure is presented on how to evaluate image degradation caused by asymmetric aerodynamic dome heating. In addition, a thermal gradient model is proposed to evaluate degradation caused by axial temperature gradient throughout the entire PIOS lens. Finally, a ghost reflection analysis is demonstrated with non-sequential model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011OExpr..1915803W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011OExpr..1915803W"><span><span class="hlt">Long-wave</span> infrared 1 × 2 MMI based on air-gap beneath silicon rib waveguides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Yuxin; Li, Guoyi; Hao, Yinlei; Li, Yubo; Yang, Jianyi; Wang, Minghua; Jiang, Xiaoqing</p> <p>2011-08-01</p> <p>The undercut <span class="hlt">long-wave</span> infrared (LWIR) waveguide components with air-gap beneath are analyzed and fabricated on the Si-wafer with simple manufacturing process. A 1 × 2 multimode interference (MMI) splitter based on this structure is presented and measured under the 10.6μm wavelength experimental setup. The uniformity of the MMI fabricated is 0.76 dB. The relationship among the output power, slab thickness and air-gap width is also fully discussed. Furthermore, undercut straight waveguides based on SOI platform are fabricated for propagation loss evaluation. Ways to reduce the loss are discussed either.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1770c0018T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1770c0018T"><span>Determination of the mode composition of <span class="hlt">long-wave</span> disturbances in a supersonic flow in a hotshot wind tunnel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsyryulnikov, I. S.; Kirilovskiy, S. V.; Poplavskaya, T. V.</p> <p>2016-10-01</p> <p>In this paper, we describe a new method of mode decomposition of disturbances on the basis of specific features of interaction of <span class="hlt">long-wave</span> free-stream disturbances with the shock wave and knowing the trends of changing of the conversion factors of various disturbance modes due to variations of the shock wave incidence angle. The range of admissible root-mean-square amplitudes of oscillations of vortex, entropy, and acoustic modes in the free stream generated in IT-302M was obtained by using the pressure fluctuations measured on the model surface and the calculated conversion factors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.2925V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.2925V"><span>Validation and Comparison of 2D and 3D Codes for Nearshore Motion of <span class="hlt">Long</span> <span class="hlt">Waves</span> Using Benchmark Problems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Velioǧlu, Deniz; Cevdet Yalçıner, Ahmet; Zaytsev, Andrey</p> <p>2016-04-01</p> <p>Tsunamis are huge waves with <span class="hlt">long</span> <span class="hlt">wave</span> periods and wave lengths that can cause great devastation and loss of life when they strike a coast. The interest in experimental and numerical modeling of tsunami propagation and inundation increased considerably after the 2011 Great East Japan earthquake. In this study, two numerical codes, FLOW 3D and NAMI DANCE, that analyze tsunami propagation and inundation patterns are considered. Flow 3D simulates linear and nonlinear propagating surface waves as well as <span class="hlt">long</span> <span class="hlt">waves</span> by solving three-dimensional Navier-Stokes (3D-NS) equations. NAMI DANCE uses finite difference computational method to solve 2D depth-averaged linear and nonlinear forms of shallow water equations (NSWE) in <span class="hlt">long</span> <span class="hlt">wave</span> problems, specifically tsunamis. In order to validate these two codes and analyze the differences between 3D-NS and 2D depth-averaged NSWE equations, two benchmark problems are applied. One benchmark problem investigates the runup of <span class="hlt">long</span> <span class="hlt">waves</span> over a complex 3D beach. The experimental setup is a 1:400 scale model of Monai Valley located on the west coast of Okushiri Island, Japan. Other benchmark problem is discussed in 2015 National Tsunami Hazard Mitigation Program (NTHMP) Annual meeting in Portland, USA. It is a field dataset, recording the Japan 2011 tsunami in Hilo Harbor, Hawaii. The computed water surface elevation and velocity data are compared with the measured data. The comparisons showed that both codes are in fairly good agreement with each other and benchmark data. The differences between 3D-NS and 2D depth-averaged NSWE equations are highlighted. All results are presented with discussions and comparisons. Acknowledgements: Partial support by Japan-Turkey Joint Research Project by JICA on earthquakes and tsunamis in Marmara Region (JICA SATREPS - MarDiM Project), 603839 ASTARTE Project of EU, UDAP-C-12-14 project of AFAD Turkey, 108Y227, 113M556 and 213M534 projects of TUBITAK Turkey, RAPSODI (CONCERT_Dis-021) of CONCERT</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ResPh...9.1403L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ResPh...9.1403L"><span>Applications of exact traveling wave solutions of Modified Liouville and the Symmetric Regularized <span class="hlt">Long</span> <span class="hlt">Wave</span> equations via two new techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Dianchen; Seadawy, Aly R.; Ali, Asghar</p> <p>2018-06-01</p> <p>In this current work, we employ novel methods to find the exact travelling wave solutions of Modified Liouville equation and the Symmetric Regularized <span class="hlt">Long</span> <span class="hlt">Wave</span> equation, which are called extended simple equation and exp(-Ψ(ξ))-expansion methods. By assigning the different values to the parameters, different types of the solitary wave solutions are derived from the exact traveling wave solutions, which shows the efficiency and precision of our methods. Some solutions have been represented by graphical. The obtained results have several applications in physical science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023704','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023704"><span><span class="hlt">Radio</span> astronomy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kellermann, Kenneth I.; Heeschen, David; Backer, Donald C.; Cohen, Marshall H.; Davis, Michael; Depater, Imke; Deyoung, David; Dulk, George A.; Fisher, J. R.; Goss, W. Miller</p> <p>1991-01-01</p> <p>The following subject areas are covered: (1) scientific opportunities (millimeter and sub-millimeter wavelength astronomy; meter to hectometer astronomy; the Sun, stars, pulsars, interstellar masers, and extrasolar planets; the planets, asteroids, and comets; <span class="hlt">radio</span> galaxies, quasars, and cosmology; and challenges for <span class="hlt">radio</span> astronomy in the 1990's); (2) recommendations for new facilities (the millimeter arrays, medium scale instruments, and small-scale projects); (3) continuing activities and maintenance, upgrading of telescopes and instrumentation; (4) long range programs and technology development; and (5) social, political, and organizational considerations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988JAP....63.3191G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988JAP....63.3191G"><span>Magnetic field generated by <span class="hlt">lightning</span> protection system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geri, A.; Veca, G. M.</p> <p>1988-04-01</p> <p>A <span class="hlt">lightning</span> protection system for today's civil buildings must be electromagnetically compatible with the electronic equipment present in the building. This paper highlights a mathematic model which analyzes the electromagnetic effects in the environment in which the <span class="hlt">lightning</span> protection system is. This model is developed by means of finite elements of an electrical circuit where each element is represented by a double pole circuit according to the trapezoidal algorithm developed using the finite difference method. It is thus possible to analyze the electromagnetic phenomena associated with the transient effects created by the <span class="hlt">lightning</span> stroke even for a high-intensity current. Referring to an elementary system comprised of an air terminal, a down conductor, and a ground terminal, numerical results are here laid out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22580490','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22580490"><span><span class="hlt">Lightning</span> and severe thunderstorms in event management.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walsh, Katie M</p> <p>2012-01-01</p> <p>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, <span class="hlt">lightning</span>, 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. <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023331','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023331"><span>A survey of laser <span class="hlt">lightning</span> rod techniques</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barnes, Arnold A., Jr.; Berthel, Robert O.</p> <p>1991-01-01</p> <p>The work done to create a laser <span class="hlt">lightning</span> rod (LLR) is discussed. Some ongoing research which has the potential for achieving an operational laser <span class="hlt">lightning</span> rod for use in the protection of missile launch sites, launch vehicles, and other property is discussed. Because of the ease with which a laser beam can be steered into any cloud overhead, an LLR could be used to ascertain if there exists enough charge in the clouds to discharge to the ground as triggered <span class="hlt">lightning</span>. This leads to the possibility of using LLRs to test clouds prior to launching missiles through the clouds or prior to flying aircraft through the clouds. LLRs could also be used to probe and discharge clouds before or during any hazardous ground operations. Thus, an operational LLR may be able to both detect such sub-critical electrical fields and effectively neutralize them.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GID.....4..213C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GID.....4..213C"><span>Protection against <span class="hlt">lightning</span> on the geomagnetic observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Čop, R.; Milev, G.; Deželjin, D.; Kosmač, J.</p> <p>2014-04-01</p> <p>The Sinji Vrh Geomagnetic Observatory was built on the brow of the mountain Gora, above Ajdovščina, and all over Europe one may hardly find an area which is more often struck by <span class="hlt">lightning</span> than this south-western 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 the additional electrical charge of stormy clouds. The reliability of operations performed in the every building of observatory could be increased by understanding the formation of <span class="hlt">lightning</span> in the thunderstorm cloud, the application of already proven methods of protection against a strike of <span class="hlt">lightning</span> and against its secondary effects. To reach this goal the following groups of experts have to co-operate: the experts in the field of protection against lightening phenomenon, the constructors and manufacturers of equipment and the observatory managers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880034919&hterms=thunderstorm+protection&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthunderstorm%2Bprotection','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880034919&hterms=thunderstorm+protection&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthunderstorm%2Bprotection"><span><span class="hlt">Lightning</span> threat extent of a small thunderstorm</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nicholson, James R.; Maier, Launa M.; Weems, John</p> <p>1988-01-01</p> <p>The concern for safety of the personnel at the Kennedy Space Center (KSC) has caused NASA to promulgate strict safety procedures requiring either termination or substantial curtailment when ground <span class="hlt">lightning</span> threat is believed to exist within 9.3 km of a covered operation. In cases where the threat is overestimated, in either space or time, an opportunity cost is accrued. This paper describes a small thunderstorm initiated over the KSC by terrain effects, that serves to exemplify the impact such an event may have on ground operations at the Center. Data from the Air Force <span class="hlt">Lightning</span> Location and Protection System, the AF/NASA Launch Pad <span class="hlt">Lightning</span> Warning System field mill network, radar, and satellite imagery are used to describe the thunderstorm and to discuss its impact.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120003408','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120003408"><span>Objective <span class="hlt">Lightning</span> Probability Forecast Tool Phase II</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lambert, Winnie</p> <p>2007-01-01</p> <p>This presentation describes the improvement of a set of <span class="hlt">lightning</span> probability forecast equations that are used by the 45th Weather Squadron forecasters for their daily 1100 UTC (0700 EDT) weather briefing during the warm season months of May-September. This information is used for general scheduling of operations at Cape Canaveral Air Force Station and Kennedy Space Center. Forecasters at the Spaceflight Meteorology Group also make thunderstorm forecasts during Shuttle flight operations. Five modifications were made by the Applied Meteorology Unit: increased the period of record from 15 to 17 years, changed the method of calculating the flow regime of the day, calculated a new optimal layer relative humidity, used a new smoothing technique for the daily climatology, and used a new valid area. The test results indicated that the modified equations showed and increase in skill over the current equations, good reliability, and an ability to distinguish between <span class="hlt">lightning</span> and non-<span class="hlt">lightning</span> days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5393793-horizontal-electric-fields-from-lightning-return-strokes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5393793-horizontal-electric-fields-from-lightning-return-strokes"><span>Horizontal electric fields from <span class="hlt">lightning</span> return strokes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Thomson, E.M.; Uman, M.A.; Johnson, J.</p> <p>1985-01-01</p> <p>Measurements are presented of simultaneous horizontal and vertical electric fields from both close and distant <span class="hlt">lightning</span> return strokes. The data were obtained during summer 1984 at the Kennedy Space Center, Florida, using an electrically isolated spherical antenna having a system bandwidth of 3 Hz to 5 MHz. <span class="hlt">Lightning</span> signals were obtained from flashes at distances from a few to 100 kilometers. Since the horizontal electric field is in part determined by the local ground conductivity, that parameter was measured as a function of depth. The horizontal fields from <span class="hlt">lightning</span> return strokes had typically 1/50 the peak amplitude of the verticalmore » fields and waveshapes which were consistant with available theory, as expressed by the ''wavetilt'' formula.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1157093-augmenting-satellite-precipitation-estimation-lightning-information','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1157093-augmenting-satellite-precipitation-estimation-lightning-information"><span>Augmenting Satellite Precipitation Estimation with <span class="hlt">Lightning</span> Information</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mahrooghy, Majid; Anantharaj, Valentine G; Younan, Nicolas H.</p> <p>2013-01-01</p> <p>We have used <span class="hlt">lightning</span> information to augment the Precipitation Estimation from Remotely Sensed Imagery using an Artificial Neural Network - Cloud Classification System (PERSIANN-CCS). Co-located <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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.more » 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.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920045362&hterms=Global+warming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGlobal%2Bwarming','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920045362&hterms=Global+warming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGlobal%2Bwarming"><span>The effect of global warming on <span class="hlt">lightning</span> frequencies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Price, Colin; Rind, David</p> <p>1990-01-01</p> <p>The first attempt to model global <span class="hlt">lightning</span> distributions by using the Goddard Institute for Space Studies (GISS) GCM is reported. Three sets of observations showing the relationship between <span class="hlt">lightning</span> frequency and cloud top height are shown. Zonally averaged <span class="hlt">lightning</span> frequency observed by satellite are compared with those calculated using the GISS GCM, and fair agreement is found. The change in <span class="hlt">lightning</span> frequency for a double CO2 climate is calculated and found to be nearly 2.23 x 10 exp 6 extra <span class="hlt">lightning</span> flashes per day.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090033131','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090033131"><span>Developing an Enhanced <span class="hlt">Lightning</span> Jump Algorithm for Operational Use</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schultz, Christopher J.; Petersen, Walter A.; Carey, Lawrence D.</p> <p>2009-01-01</p> <p>Overall Goals: 1. Build on the <span class="hlt">lightning</span> jump framework set through previous studies. 2. Understand what typically occurs in nonsevere convection with respect to increases in <span class="hlt">lightning</span>. 3. Ultimately develop a <span class="hlt">lightning</span> jump algorithm for use on the Geostationary <span class="hlt">Lightning</span> Mapper (GLM). 4 <span class="hlt">Lightning</span> jump algorithm configurations were developed (2(sigma), 3(sigma), Threshold 10 and Threshold 8). 5 algorithms were tested on a population of 47 nonsevere and 38 severe thunderstorms. Results indicate that the 2(sigma) algorithm performed best over the entire thunderstorm sample set with a POD of 87%, a far of 35%, a CSI of 59% and a HSS of 75%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170011702','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170011702"><span><span class="hlt">Lightning</span>-Related Indicators for National Climate Assessment (NCA) Studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koshak, W.</p> <p>2017-01-01</p> <p>Changes in climate can affect the characteristics of <span class="hlt">lightning</span> (e.g., number of flashes that occur in a region, return stroke current and multiplicity, polarity of charge deposited to ground, and the <span class="hlt">lightning</span> cloud-top optical energy emission). The NASA/MSFC <span class="hlt">Lightning</span> Analysis Tool (LAT) monitors these and other quantities in support of the National Climate Assessment (NCA) program. Changes in <span class="hlt">lightning</span> characteristics lead to changes in <span class="hlt">lightning</span>-caused impacts to humans (e.g., fatalities, injuries, crop/property damage, wildfires, airport delays, changes in air quality).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMAE53A..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMAE53A..05G"><span>Artificial Neural Network applied to <span class="hlt">lightning</span> flashes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gin, R. B.; Guedes, D.; Bianchi, R.</p> <p>2013-05-01</p> <p>The development of video cameras enabled cientists to study <span class="hlt">lightning</span> discharges comportment with more precision. The main goal of this project is to create a system able to detect images of <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>, 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 <span class="hlt">lightning</span> events (one image can have more than one <span class="hlt">lightning</span>). 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 <span class="hlt">lightning</span> discharges previously manually detected. Results showed that all the <span class="hlt">lightning</span> 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</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020078320','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020078320"><span>System and Method of Locating <span class="hlt">Lightning</span> Strikes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Medelius, Pedro J. (Inventor); Starr, Stanley O. (Inventor)</p> <p>2002-01-01</p> <p>A system and method of determining locations of <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> strikes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ERL.....9e5004S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ERL.....9e5004S"><span>Evidence for solar wind modulation of <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scott, C. J.; Harrison, R. G.; Owens, M. J.; Lockwood, M.; Barnard, L.</p> <p>2014-05-01</p> <p>The response of <span class="hlt">lightning</span> 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. <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> rates. These changes persist for around 40 d in all three quantities. The <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730023587','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730023587"><span>Automatic <span class="hlt">lightning</span> detection and photographic system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wojtasinski, R. J.; Holley, L. D.; Gray, J. L.; Hoover, R. B. (Inventor)</p> <p>1972-01-01</p> <p>A system is presented for monitoring and recording <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APJAS..50..133S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APJAS..50..133S"><span>Statistical analysis of <span class="hlt">lightning</span> electric field measured under Malaysian condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salimi, Behnam; Mehranzamir, Kamyar; Abdul-Malek, Zulkurnain</p> <p>2014-02-01</p> <p><span class="hlt">Lightning</span> is an electrical discharge during thunderstorms that can be either within clouds (Inter-Cloud), or between clouds and ground (Cloud-Ground). The <span class="hlt">Lightning</span> characteristics and their statistical information are the foundation for the design of <span class="hlt">lightning</span> protection system as well as for the calculation of <span class="hlt">lightning</span> radiated fields. Nowadays, there are various techniques to detect <span class="hlt">lightning</span> signals and to determine various parameters produced by a <span class="hlt">lightning</span> flash. Each technique provides its own claimed performances. In this paper, the characteristics of captured broadband electric fields generated by cloud-to-ground <span class="hlt">lightning</span> discharges in South of Malaysia are analyzed. A total of 130 cloud-to-ground <span class="hlt">lightning</span> flashes from 3 separate thunderstorm events (each event lasts for about 4-5 hours) were examined. Statistical analyses of the following signal parameters were presented: preliminary breakdown pulse train time duration, time interval between preliminary breakdowns and return stroke, multiplicity of stroke, and percentages of single stroke only. The BIL model is also introduced to characterize the <span class="hlt">lightning</span> signature patterns. Observations on the statistical analyses show that about 79% of <span class="hlt">lightning</span> signals fit well with the BIL model. The maximum and minimum of preliminary breakdown time duration of the observed <span class="hlt">lightning</span> signals are 84 ms and 560 us, respectively. The findings of the statistical results show that 7.6% of the flashes were single stroke flashes, and the maximum number of strokes recorded was 14 multiple strokes per flash. A preliminary breakdown signature in more than 95% of the flashes can be identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.2128L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.2128L"><span>Nowcasting and forecasting of <span class="hlt">lightning</span> activity: the Talos project.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lagouvardos, Kostas; Kotroni, Vassiliki; Kazadzis, Stelios; Giannaros, Theodore; Karagiannidis, Athanassios; Galanaki, Elissavet; Proestakis, Emmanouil</p> <p>2015-04-01</p> <p>Thunder And <span class="hlt">Lightning</span> Observing System (TALOS) is a research program funded by the Greek Ministry of Education with the aim to promote excellence in the field of <span class="hlt">lightning</span> meteorology. The study focuses on exploring the real-time observations provided by the ZEUS <span class="hlt">lightning</span> 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: - <span class="hlt">lightning</span> climatology over the Mediterranean focusing on <span class="hlt">lightning</span> spatial and temporal distribution, on the relation of <span class="hlt">lightning</span> with topographical features and instability and on the importance of aerosols in <span class="hlt">lightning</span> initiation and enhancement. - nowcasting of <span class="hlt">lightning</span> activity over Greece, with emphasis on the operational aspects of this endeavour. The nowcasting tool is based on the use of <span class="hlt">lightning</span> data complemented by high-time resolution METEOSAT imagery. - forecasting of <span class="hlt">lightning</span> activity over Greece based on the use of WRF numerical weather prediction model. - assimilation of <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......146T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......146T"><span>Mathematical Formulation of the Remote Electric and Magnetic Emissions of the <span class="hlt">Lightning</span> Dart Leader and Return Stroke</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thiemann, Edward M. B.</p> <p></p> <p><span class="hlt">Lightning</span> detection and geolocation networks have found widespread use by the utility, air traffic control and forestry industries as a means of locating strikes and predicting imminent recurrence. Accurate <span class="hlt">lightning</span> geolocation requires detecting VLF <span class="hlt">radio</span> emissions at multiple sites using a distributed sensor network with typical baselines exceeding 150 km, along with precision time of arrival estimation to triangulate the origin of a strike. The trend has been towards increasing network accuracy without increasing sensor density by incorporating precision GPS synchronized clocks and faster front-end signal processing. Because <span class="hlt">lightning</span> <span class="hlt">radio</span> waveforms evolve as they propagate over a finitely conducting earth, and that measurements for a given strike may have disparate propagation path lengths, accurate models are required to determine waveform fiducials for precise strike location. The transition between the leader phase and return stroke phase may offer such a fiducial and warrants quantitative modeling to improve strike location accuracy. The VLF spectrum of the ubiquitous downward negative <span class="hlt">lightning</span> strike is able to be modeled by the transfer of several Coulombs of negative charge from cloud to ground in a two-step process. The <span class="hlt">lightning</span> stepped leader ionizes a plasma channel downward from the cloud at a velocity of approximately 0.05c, leaving a column of charge in its path. Upon connection with a streamer, the subsequent return stroke initiates at or near ground level and travels upward at an average but variable velocity of 0.3c. The return stroke neutralizes any negative charge along its path. Subsequent dart leader and return strokes often travel smoothly down the heated channel left by a preceding stroke, lacking the halting motion of the preceding initial stepped leader and initial return stroke. Existing <span class="hlt">lightning</span> models often neglect the leader current and rely on approximations when solving for the return stroke. In this thesis, I present an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/976609','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/976609"><span>Global optical <span class="hlt">lightning</span> flash rates determined with the Forte satellite</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Light, T.; Davis, S. M.; Boeck, W. L.</p> <p>2003-01-01</p> <p>Using FORTE photodiode detector (PDD) observations of <span class="hlt">lightning</span>, we have determined the geographic distribution of nighttime flash rate density. We estimate the PDD flash detection efficiency to be 62% for total <span class="hlt">lightning</span> through comparison to <span class="hlt">lightning</span> observations by the TRMM satellite's <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> in both high and low flash rate environments, and find that while <span class="hlt">lightning</span> occurs less frequently over ocean, oceanic <span class="hlt">lightning</span> flashes are somewhat moremore » powerful, on average, than those over land.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMAE23A..01L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMAE23A..01L"><span>Toward a Time-Domain Fractal <span class="hlt">Lightning</span> Simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, C.; Carlson, B. E.; Lehtinen, N. G.; Cohen, M.; Lauben, D.; Inan, U. S.</p> <p>2010-12-01</p> <p>Electromagnetic simulations of <span class="hlt">lightning</span> are useful for prediction of <span class="hlt">lightning</span> properties and exploration of the underlying physical behavior. Fractal <span class="hlt">lightning</span> models predict the spatial structure of the discharge, but thus far do not provide much information about discharge behavior in time and therefore cannot predict electromagnetic wave emissions or current characteristics. Here we develop a time-domain fractal <span class="hlt">lightning</span> simulation from Maxwell's equations, the method of moments with the thin wire approximation, an adaptive time-stepping scheme, and a simplified electrical model of the <span class="hlt">lightning</span> channel. The model predicts current pulse structure and electromagnetic wave emissions and can be used to simulate the entire duration of a <span class="hlt">lightning</span> discharge. The model can be used to explore the electrical characteristics of the <span class="hlt">lightning</span> channel, the temporal development of the discharge, and the effects of these characteristics on observable electromagnetic wave emissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002931','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002931"><span><span class="hlt">Lightning</span> criteria relative to space shuttles: Currents and electric field intensity in Florida <span class="hlt">lightning</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Uman, M. A.; Mclain, D. K.</p> <p>1972-01-01</p> <p>The measured electric field intensities of 161 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> properties relative to space vehicle design as given in NASA TMX-64589 (Daniels, 1971). The small sample of <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.C31A0294S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.C31A0294S"><span><span class="hlt">Long-wave</span> Irradiance Measurement and Modeling during Snowmelt, a Case Study in the Yukon Territory, Canada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sicart, J.; Essery, R.; Pomeroy, J.</p> <p>2004-12-01</p> <p>At high latitudes, <span class="hlt">long-wave</span> radiation emitted by the atmosphere and solar radiation can provide similar amounts of energy for snowmelt due to the low solar elevation and the high albedo of snow. This paper investigates temporal and spatial variations of <span class="hlt">long-wave</span> irradiance at the snow surface in an open sub-Arctic environment. Measurements were conducted in the Wolf Creek Research Basin, Yukon Territory, Canada (60°36'N, 134°57'W) during the springs of 2002, 2003 and 2004. The main causes of temporal variability are air temperature and cloud cover, especially in the beginning of the melting period when the atmosphere is still cold. Spatial variability was investigated through a sensitivity study to sky view factors and to temperatures of surrounding terrain. The formula of Brutsaert gives a useful estimation of the clear-sky irradiance at hourly time steps. Emission by clouds was parameterized at the daily time scale from the atmospheric attenuation of solar radiation. The inclusion of air temperature variability does not much improve the calculation of cloud emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25493863','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25493863"><span>Multicomponent <span class="hlt">long-wave</span>-short-wave resonance interaction system: Bright solitons, energy-sharing collisions, and resonant solitons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sakkaravarthi, K; Kanna, T; Vijayajayanthi, M; Lakshmanan, M</p> <p>2014-11-01</p> <p>We consider a general multicomponent (2+1)-dimensional <span class="hlt">long-wave</span>-short-wave resonance interaction (LSRI) system with arbitrary nonlinearity coefficients, which describes the nonlinear resonance interaction of multiple short waves with a <span class="hlt">long</span> <span class="hlt">wave</span> in two spatial dimensions. The general multicomponent LSRI system is shown to be integrable by performing the Painlevé analysis. Then we construct the exact bright multisoliton solutions by applying the Hirota's bilinearization method and study the propagation and collision dynamics of bright solitons in detail. Particularly, we investigate the head-on and overtaking collisions of bright solitons and explore two types of energy-sharing collisions as well as standard elastic collision. We have also corroborated the obtained analytical one-soliton solution by direct numerical simulation. Also, we discuss the formation and dynamics of resonant solitons. Interestingly, we demonstrate the formation of resonant solitons admitting breather-like (localized periodic pulse train) structure and also large amplitude localized structures akin to rogue waves coexisting with solitons. For completeness, we have also obtained dark one- and two-soliton solutions and studied their dynamics briefly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMAE44A..08R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMAE44A..08R"><span>Lighting Observations During the Mt. Augustine Volcanic Eruptions With the Portable <span class="hlt">Lightning</span> Mapping Stations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rison, W.; Krehbiel, P.; Thomas, R.; Edens, H.; Aulich, G.; O'Connor, N.; Kieft, S.; McNutt, S.; Tytgat, G.; Clark, E.</p> <p>2006-12-01</p> <p>Following the initial eruptions of Mt. Augustine on January 11-17 2006, we quickly prepared and deployed a first contingent of two portable mapping stations. This was our first use of the newly-developed portable stations, and we were able to deploy them in time to observe the second set of explosive eruptions during the night of January~27-28. The stations were located 17~km apart on the west coast of the Kenai Peninsula, 100~km distant from Augustine on the far western side of Cook Inlet. The stations comprised a minimal network capable of determining the azimuthal direction of VHF radiation sources from electrical discharges, and thus the transverse location of the electrical activity relative to the volcano. The time series data from the southern, Homer station for the initial, energetic explosion at 8:31 pm on January~27 revealed the occurrence of spectacular <span class="hlt">lightning</span>, which from the two-station data drifted southward from Augustine with time, in the same direction as the plume from the eruption. About 300 distinct <span class="hlt">lightning</span> discharges occurred over an 11-minute time interval, beginning 2-3~min after the main explosion. The <span class="hlt">lightning</span> quickly became increasingly complex with time and developed large horizontal extents. One of the final discharges of the sequence lasted 600~ms and had a transverse extent of 15~km, extending to 22~km south of Augustine's summit. In addition to this more usual form of <span class="hlt">lightning</span>, continuous bursts of <span class="hlt">radio</span> frequency radiation occurred during the explosion itself, indicating that the tephra was highly charged upon being ejected from the volcano. A completely unplanned and initially missed but one of several fortuitous aspects of the observations was that the Homer station functioned as a 'sea-surface interferometer' whose interference pattern can be used to determine the altitude variation with time for some discharges. The station's VHF antenna was located on the edge of a bluff 210~m above Cook Inlet and received both the direct</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMAE11A..05V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMAE11A..05V"><span>Automated analysis of <span class="hlt">lightning</span> leader speed, local flash rates and electric charge structure in thunderstorms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Van Der Velde, O. A.; Montanya, J.; López, J. A.</p> <p>2017-12-01</p> <p>A <span class="hlt">Lightning</span> Mapping Array (LMA) maps <span class="hlt">radio</span> pulses emitted by <span class="hlt">lightning</span> leaders, displaying <span class="hlt">lightning</span> flash development in the cloud in three dimensions. Since the last 10 years about a dozen of these advanced systems have become operational in the United States and in Europe, often with the purpose of severe weather monitoring or <span class="hlt">lightning</span> research. We introduce new methods for the analysis of complex three-dimensional <span class="hlt">lightning</span> data produced by LMAs and illustrate them by cases of a mid-latitude severe weather producing thunderstorm and a tropical thunderstorm in Colombia. The method is based on the characteristics of bidrectional leader development as observed in LMA data (van der Velde and Montanyà, 2013, JGR-Atmospheres), where mapped positive leaders were found to propagate at characteristic speeds around 2 · 104 m s-1, while negative leaders typically propagate at speeds around 105 m s-1. Here, we determine leader speed for every 1.5 x 1.5 x 0.75 km grid box in 3 ms time steps, using two time intervals (e.g., 9 ms and 27 ms) and circles (4.5 km and 2.5 km wide) in which a robust Theil-Sen fitting of the slope is performed for fast and slow leaders. The two are then merged such that important speed characteristics are optimally maintained in negative and positive leaders, and labeled with positive or negative polarity according to the resulting velocity. The method also counts how often leaders from a <span class="hlt">lightning</span> flash initiate or pass through each grid box. This "local flash rate" may be used in severe thunderstorm or NOx production studies and shall be more meaningful than LMA source density which is biased by the detection efficiency. Additionally, in each grid box the median x, y and z components of the leader propagation vectors of all flashes result in a 3D vector grid which can be compared to vectors in numerical models of leader propagation in response to cloud charge structure. Finally, the charge region altitudes, thickness and rates are summarized</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140008582','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140008582"><span><span class="hlt">Lightning</span> Jump Algorithm Development for the GOES·R Geostationary <span class="hlt">Lightning</span> Mapper</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schultz. E.; Schultz. C.; Chronis, T.; Stough, S.; Carey, L.; Calhoun, K.; Ortega, K.; Stano, G.; Cecil, D.; Bateman, M.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20140008582'); toggleEditAbsImage('author_20140008582_show'); toggleEditAbsImage('author_20140008582_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20140008582_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20140008582_hide"></p> <p>2014-01-01</p> <p>Current work on the <span class="hlt">lightning</span> jump algorithm to be used in GOES-R Geostationary <span class="hlt">Lightning</span> Mapper (GLM)'s data stream is multifaceted due to the intricate interplay between the storm tracking, GLM proxy data, and the performance of the <span class="hlt">lightning</span> jump itself. This work outlines the progress of the last year, where analysis and performance of the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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/<span class="hlt">lightning</span> 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).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70039773','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70039773"><span>Combining satellite-based fire observations and ground-based <span class="hlt">lightning</span> detections to identify <span class="hlt">lightning</span> fires across the conterminous USA</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bar-Massada, A.; Hawbaker, T.J.; Stewart, S.I.; Radeloff, V.C.</p> <p>2012-01-01</p> <p><span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> detections from the National <span class="hlt">Lightning</span> Detection Network to identify <span class="hlt">lightning</span> fires across the conterminous US from 2000 to 2008. The algorithm searches for spatiotemporal conjunctions of MODIS fire clusters and NLDN detected <span class="hlt">lightning</span> strikes, given a spatiotemporal lag between <span class="hlt">lightning</span> strike and fire ignition. The algorithm revealed distinctive spatial patterns of <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> fire occurrence, and especially <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> fire activity, and can be used to identify the broad scale factors controlling fire occurrence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21570915-number-lightning-discharges-causing-damage-lightning-arrester-cables-aerial-transmission-lines-power-systems','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21570915-number-lightning-discharges-causing-damage-lightning-arrester-cables-aerial-transmission-lines-power-systems"><span>Number of <span class="hlt">lightning</span> discharges causing damage to <span class="hlt">lightning</span> arrester cables for aerial transmission lines in power systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nikiforov, E. P.</p> <p>2009-07-15</p> <p>Damage by <span class="hlt">lightning</span> discharges to <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> arrester cables occur when a tensile force acts on a cable heated to the melting point by a <span class="hlt">lightning</span> current. The <span class="hlt">lightning</span> currents required to heat a cable to this extent are greater for larger cable cross sections. The probability that a <span class="hlt">lightning</span> discharge will develop decreases as the amplitude of the <span class="hlt">lightning</span> current increases, which greatly reduces themore » number of <span class="hlt">lightning</span> discharges which damage TK-70 cables compared to TK-50 cables. In order to increase the reliability of <span class="hlt">lightning</span> arrester cables for 110 kV aerial transmission lines, TK-70 cables should be used in place of TK-50 cables. The number of <span class="hlt">lightning</span> discharges per year which damage <span class="hlt">lightning</span> 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.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AtmRe.172....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AtmRe.172....1M"><span>The verification of <span class="hlt">lightning</span> location accuracy in Finland deduced from <span class="hlt">lightning</span> strikes to trees</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mäkelä, Antti; Mäkelä, Jakke; Haapalainen, Jussi; Porjo, Niko</p> <p>2016-05-01</p> <p>We present a new method to determine the ground truth and accuracy of <span class="hlt">lightning</span> location systems (LLS), using natural <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>. 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 <span class="hlt">lightning</span> location network for that period was 600 m. In addition, we show that the 50% confidence ellipse calculated by the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900004088','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900004088"><span>Systems tunnel linear shaped charge <span class="hlt">lightning</span> strike</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cook, M.</p> <p>1989-01-01</p> <p>Simulated <span class="hlt">lightning</span> strike testing of the systems tunnel linear shaped charge (LSC) was performed at the Thiokol <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> strikes with peak current levels within 71 percent of the worst-case <span class="hlt">lightning</span> strike condition of NSTS-07636, is adequate to prevent LSC ignition. It is therefore recommended that the design remain unchanged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA496692','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA496692"><span>Z-M in <span class="hlt">Lightning</span> Forecasting</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-03-01</p> <p>hydrometers create a charge separation. Inductive processes rely on a preexisting external electric field to induce charges on polarized particles, which...frozen hydrometers . A. FLORIDA CLIMATE Florida is often referred to as the <span class="hlt">lightning</span> capital of the United States (Hodanish et al. 1997) or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20134678','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20134678"><span>The laser <span class="hlt">lightning</span> rod system: thunderstorm domestication.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ball, L M</p> <p>1974-10-01</p> <p>An unusual application of the laser, namely protection of life and property from <span class="hlt">lightning</span>, 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.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol4/pdf/CFR-2010-title14-vol4-sec420-71.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol4/pdf/CFR-2010-title14-vol4-sec420-71.pdf"><span>14 CFR 420.71 - <span class="hlt">Lightning</span> protection.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false <span class="hlt">Lightning</span> protection. 420.71 Section 420.71 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... path connecting an air terminal to an earth electrode system. (iii) Earth electrode system. An earth...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950045227&hterms=emp&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Demp','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950045227&hterms=emp&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Demp"><span><span class="hlt">Lightning</span> driven EMP in the upper atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rowland, H. L.; Fernsler, R. F.; Huba, J. D.; Bernhardt, P. A.</p> <p>1995-01-01</p> <p>Large <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090033796','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090033796"><span><span class="hlt">Lightning</span> Pin Injection Testing on MOSFETS</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>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</p> <p>2009-01-01</p> <p><span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> transients; and to understand the interplay between <span class="hlt">lightning</span>-induced surges and aging (i.e. humidity, vibration thermal stress, etc.) on component degradation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMAE13A0417M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMAE13A0417M"><span><span class="hlt">Lightning</span> spectra at 100,000 fps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McHarg, M. G.; Harley, J.; Haaland, R. K.; Edens, H. E.; Stenbaek-Nielsen, H.</p> <p>2016-12-01</p> <p>A fundamental understanding of <span class="hlt">lightning</span> can be inferred from the spectral emissions resulting from the leader and return stroke channel. We examine an event recorded at 00:58:07 on 19 July 2015 at Langmuir Laboratory. We recorded <span class="hlt">lightning</span> spectra using a 100 line per mm grating in front of a Phantom V2010 camera with an 85mm Nikon lens recording at 100,000 frames per second. Coarse resolution spectra (approximately 5nm resolution) are produced from approximately 400 nm to 800 nm for each frame. Electric field data from the Langmuir Electric Field Array for the 03:19:19 event show 10 V/m changes in the electric field associated with multiple return strokes visible in the spectral data. We used the spectral data to compare temperatures at the top, middle and bottom of the <span class="hlt">lightning</span> channel. <span class="hlt">Lightning</span> Mapping Array data at Langmuir for the 00:58:07 event show a complex flash extending 10 km in the East-West plane and 6 km in the North-South plane. The imagery data imply that this is a bolt-from-the-blue event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009pcms.confE..98P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009pcms.confE..98P"><span>Relationship between convective precipitation and <span class="hlt">lightning</span> activity using radar quantitative precipitation estimates and total <span class="hlt">lightning</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pineda, N.; Rigo, T.; Bech, J.; Argemí, O.</p> <p>2009-09-01</p> <p>Thunderstorms can be characterized by both rainfall and <span class="hlt">lightning</span>. The relationship between convective precipitation and <span class="hlt">lightning</span> activity may be used as an indicator of the rainfall regime. Besides, a better knowledge of local thunderstorm phenomenology can be very useful to assess weather surveillance tasks. Two types of approach can be distinguished in the bibliography when analyzing the rainfall and <span class="hlt">lightning</span> activity. On one hand, rain yields (ratio of rain mass to cloud-to-ground flash over a common area) calculated for long temporal and spatial domains and using rain-gauge records to estimate the amounts of precipitation. On the other hand, a case-by-case approach has been used in many studies to analyze the relationship between convective precipitation and <span class="hlt">lightning</span> in individual storms, using weather radar data to estimate rainfall volumes. Considering a local thunderstorm case study approach, the relation between rainfall and <span class="hlt">lightning</span> is usually quantified as the Rainfall-<span class="hlt">Lightning</span> ratio (RLR). This ratio estimates the convective rainfall volume per <span class="hlt">lightning</span> flash. Intense storms tend to produce lower RLR values than moderate storms, but the range of RLR found in diverse studies is quite wide. This relationship depends on thunderstorm type, local climatology, convective regime, type of <span class="hlt">lightning</span> flashes considered, oceanic and continental storms, etc. The objective of this paper is to analyze the relationship between convective precipitation and <span class="hlt">lightning</span> in a case-by-case approach, by means of daily radar-derived quantitative precipitation estimates (QPE) and total <span class="hlt">lightning</span> data, obtained from observations of the Servei Meteorològic de Catalunya remote sensing systems, which covers an area of approximately 50000 km2 in the NE of the Iberian Peninsula. The analyzed dataset is composed by 45 thunderstorm days from April to October 2008. A good daily correlation has been found between the radar QPE and the CG flash counts (best linear fit with a R^2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900005749&hterms=thunderstorm+protection&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dthunderstorm%2Bprotection','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900005749&hterms=thunderstorm+protection&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dthunderstorm%2Bprotection"><span>Effects of <span class="hlt">lightning</span> on operations of aerospace vehicles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fisher, Bruce D.</p> <p>1989-01-01</p> <p>Traditionally, aircraft <span class="hlt">lightning</span> strikes were a major aviation safety issue. However, the increasing use of composite materials and the use of digital avionics for flight critical systems will require that more specific <span class="hlt">lightning</span> protection measures be incorporated in the design of such aircraft in order to maintain the excellent <span class="hlt">lightning</span> safety record presently enjoyed by transport aircraft. In addition, several recent <span class="hlt">lightning</span> mishaps, most notably the loss of the Atlas/Centaur-67 vehicle at Cape Canaveral Air Force Station, Florida in March 1987, have shown the susceptibility of aircraft and launch vehicles to the phenomenon of vehicle-triggered <span class="hlt">lightning</span>. The recent findings of the NASA Storm Hazards Program were reviewed as they pertain to the atmospheric conditions conducive to aircraft <span class="hlt">lightning</span> strikes. These data are then compared to recent summaries of <span class="hlt">lightning</span> strikes to operational aircraft fleets. Finally, the new launch commit criteria for triggered <span class="hlt">lightning</span> being used by NASA and the U.S. Defense Department are summarized. The NASA Research data show that the greatest probability of a direct strike in a thunderstorm occurs at ambient temperatures of about -40 C. Relative precipitation and turbulence levels were characterized as negligible to light for these conditions. However, operational fleet data have shown that most aircraft <span class="hlt">lightning</span> strikes in routine operations occur at temperatures near the freezing level in non-cumulonimbus clouds. The non-thunderstorm environment was not the subject of dedicated airborne <span class="hlt">lightning</span> research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NatCC...8..210F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NatCC...8..210F"><span>A projected decrease in <span class="hlt">lightning</span> under climate change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Finney, Declan L.; Doherty, Ruth M.; Wild, Oliver; Stevenson, David S.; MacKenzie, Ian A.; Blyth, Alan M.</p> <p>2018-03-01</p> <p><span class="hlt">Lightning</span> strongly influences atmospheric chemistry1-3, and impacts the frequency of natural wildfires4. Most previous studies project an increase in global <span class="hlt">lightning</span> with climate change over the coming century1,5-7, but these typically use parameterizations of <span class="hlt">lightning</span> that neglect cloud ice fluxes, a component generally considered to be fundamental to thunderstorm charging8. As such, the response of <span class="hlt">lightning</span> to climate change is uncertain. Here, we compare <span class="hlt">lightning</span> projections for 2100 using two parameterizations: the widely used cloud-top height (CTH) approach9, and a new upward cloud ice flux (IFLUX) approach10 that overcomes previous limitations. In contrast to the previously reported global increase in <span class="hlt">lightning</span> based on CTH, we find a 15% decrease in total <span class="hlt">lightning</span> flash rate with IFLUX in 2100 under a strong global warming scenario. Differences are largest in the tropics, where most <span class="hlt">lightning</span> occurs, with implications for the estimation of future changes in tropospheric ozone and methane, as well as differences in their radiative forcings. These results suggest that <span class="hlt">lightning</span> schemes more closely related to cloud ice and microphysical processes are needed to robustly estimate future changes in <span class="hlt">lightning</span> and atmospheric composition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC33E1125K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC33E1125K"><span><span class="hlt">Lightning</span>-Related Indicators for National Climate Assessment (NCA) Studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koshak, W. J.</p> <p>2017-12-01</p> <p>With the recent advent of space-based <span class="hlt">lightning</span> mappers [i.e., the Geostationary <span class="hlt">Lightning</span> Mapper (GLM) on GOES-16, and the <span class="hlt">Lightning</span> Imaging Sensor (LIS) on the International Space Station], improved investigations on the inter-relationships between <span class="hlt">lightning</span> and climate are now possible and can directly support the goals of the National Climate Assessment (NCA) program. <span class="hlt">Lightning</span> nitrogen oxides (LNOx) affect greenhouse gas concentrations such as ozone that influences changes in climate. Conversely, changes in climate (from any causes) can affect the characteristics of <span class="hlt">lightning</span> (e.g., frequency, current amplitudes, multiplicity, polarity) that in turn leads to changes in <span class="hlt">lightning</span>-caused impacts to humans (e.g., fatalities, injuries, crop/property damage, wildfires, airport delays, changes in air quality). This study discusses improvements to, and recent results from, the NASA/MSFC NCA <span class="hlt">Lightning</span> Analysis Tool (LAT). It includes key findings on the development of different types of <span class="hlt">lightning</span> flash energy indicators derived from space-based <span class="hlt">lightning</span> observations, and demonstrates how these indicators can be used to estimate trends in LNOx across the continental US.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25650360','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25650360"><span>Acute transient hemiparesis induced by <span class="hlt">lightning</span> strike.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rahmani, Seyed Hesam; Faridaalaee, Gholamreza; Jahangard, Samira</p> <p>2015-07-01</p> <p>According to data from the National Oceanic and Atmospheric Administration,in the years from 1959 to 1994, <span class="hlt">lightning</span> was responsible for more than 3000 deaths and nearly 10,000 casualties. The most important characteristic features of <span class="hlt">lightning</span> injuries are multisystem involvement and widely variable severity. <span class="hlt">Lightning</span> strikes are primarily a neurologic injury that affects all 3 components of the nervous system: central, autonomic,and peripheral. Neurologic complications of <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRD..119.1455M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRD..119.1455M"><span><span class="hlt">Lightning</span> discharges produced by wind turbines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montanyà, Joan; van der Velde, Oscar; Williams, Earle R.</p> <p>2014-02-01</p> <p>New observations with a 3-D <span class="hlt">Lightning</span> Mapping Array and high-speed video are presented and discussed. The first set of observations shows that under certain thunderstorm conditions, wind turbine blades can produce electric discharges at regular intervals of 3 s in relation to its rotation, over periods of time that range from a few minutes up to hours. This periodic effect has not been observed in static towers indicating that the effect of rotation is playing a critical role. The repeated discharges can occur tens of kilometers away from electrically active thunderstorm areas and may or may not precede a fully developed upward <span class="hlt">lightning</span> discharge from the turbine. Similar to rockets used for triggering <span class="hlt">lightning</span>, the fast movement of the blade tip plays an important role on the initiation of the discharge. The movement of the rotor blades allows the tip to "runaway" from the generated corona charge. The second observation is an uncommon upward/downward flash triggered by a wind turbine. In that flash, a negative upward leader was initiated from a wind turbine without preceding <span class="hlt">lightning</span> activity. The flash produced a negative cloud-to-ground stroke several kilometers from the initiation point. The third observation corresponds to a high-speed video record showing simultaneous upward positive leaders from a group of wind turbines triggered by a preceding intracloud flash. The fact that multiple leaders develop simultaneously indicates a poor shielding effect among them. All these observations provide some special features on the initiation of <span class="hlt">lightning</span> by nonstatic and complex tall structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100021010','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100021010"><span>Assessing Operational Total <span class="hlt">Lightning</span> Visualization Products</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stano, Geoffrey T.; Darden, Christopher B.; Nadler, David J.</p> <p>2010-01-01</p> <p>In May 2003, NASA's Short-term Prediction Research and Transition (SPoRT) program successfully provided total <span class="hlt">lightning</span> data from the North Alabama <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> networks to streamline training and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060022021','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060022021"><span>Bringing Thunder and <span class="hlt">Lightning</span> Indoors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2005-01-01</p> <p>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 <span class="hlt">Lightning</span>. This same sandwiched piezoelectric wafer can also convert electrical energy into</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100026450&hterms=astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dastronomy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100026450&hterms=astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dastronomy"><span>The <span class="hlt">Radio</span> JOVE Project - Shoestring <span class="hlt">Radio</span> Astronomy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.</p> <p>2010-01-01</p> <p><span class="hlt">Radio</span> JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning <span class="hlt">radio</span> astronomy. They can do this through building a <span class="hlt">radio</span> telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (<span class="hlt">Radio</span> Skypipe) and other reference materials</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130004497','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130004497"><span>Space Telecommunications <span class="hlt">Radio</span> System STRS Cognitive <span class="hlt">Radio</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Briones, Janette C.; Handler, Louis M.</p> <p>2013-01-01</p> <p><span class="hlt">Radios</span> today are evolving from awareness toward cognition. A software defined <span class="hlt">radio</span> (SDR) provides the most capability for integrating autonomic decision making ability and allows the incremental evolution toward a cognitive <span class="hlt">radio</span>. This cognitive <span class="hlt">radio</span> technology will impact NASA space communications in areas such as spectrum utilization, interoperability, network operations, and <span class="hlt">radio</span> resource management over a wide range of operating conditions. NASAs cognitive <span class="hlt">radio</span> will build upon the infrastructure being developed by Space Telecommunication <span class="hlt">Radio</span> System (STRS) SDR technology. This paper explores the feasibility of inserting cognitive capabilities in the NASA STRS architecture and the interfaces between the cognitive engine and the STRS <span class="hlt">radio</span>. The STRS architecture defines methods that can inform the cognitive engine about the <span class="hlt">radio</span> environment so that the cognitive engine can learn autonomously from experience, and take appropriate actions to adapt the <span class="hlt">radio</span> operating characteristics and optimize performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMAE13A0414L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMAE13A0414L"><span>High Speed Video Observations of Natural <span class="hlt">Lightning</span> and Their Implications to Fractal Description of <span class="hlt">Lightning</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, N.; Tilles, J.; Boggs, L.; Bozarth, A.; Rassoul, H.; Riousset, J. A.</p> <p>2016-12-01</p> <p>Recent high speed video observations of triggered and natural <span class="hlt">lightning</span> flashes have significantly advanced our understanding of <span class="hlt">lightning</span> initiation and propagation. For example, they have helped resolve the initiation of <span class="hlt">lightning</span> leaders [Stolzenburg et al., JGR, 119, 12198, 2014; Montanyà et al, Sci. Rep., 5, 15180, 2015], the stepping of negative leaders [Hill et al., JGR, 116, D16117, 2011], the structure of streamer zone around the leader [Gamerota et al., GRL, 42, 1977, 2015], and transient rebrightening processes occurring during the leader propagation [Stolzenburg et al., JGR, 120, 3408, 2015]. We started an observational campaign in the summer of 2016 to study <span class="hlt">lightning</span> by using a Phantom high-speed camera on the campus of Florida Institute of Technology, Melbourne, FL. A few interesting natural cloud-to-ground and intracloud <span class="hlt">lightning</span> discharges have been recorded, including a couple of 8-9 stroke flashes, high peak current flashes, and upward propagating return stroke waves from ground to cloud. The videos show that the propagation of the downward leaders of cloud-to-ground <span class="hlt">lightning</span> discharges is very complex, particularly for the high-peak current flashes. They tend to develop as multiple branches, and each of them splits repeatedly. For some cases, the propagation characteristics of the leader, such as speed, are subject to sudden changes. In this talk, we present several selected cases to show the complexity of the leader propagation. One of the effective approaches to characterize the structure and propagation of <span class="hlt">lightning</span> leaders is the fractal description [Mansell et al., JGR, 107, 4075, 2002; Riousset et al., JGR, 112, D15203, 2007; Riousset et al., JGR, 115, A00E10, 2010]. We also present a detailed analysis of the high-speed images of our observations and formulate useful constraints to the fractal description. Finally, we compare the obtained results with fractal simulations conducted by using the model reported in [Riousset et al., 2007</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24487887','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24487887"><span>Single-image-based solution for optics temperature-dependent nonuniformity correction in an uncooled <span class="hlt">long-wave</span> infrared camera.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cao, Yanpeng; Tisse, Christel-Loic</p> <p>2014-02-01</p> <p>In this Letter, we propose an efficient and accurate solution to remove temperature-dependent nonuniformity effects introduced by the imaging optics. This single-image-based approach computes optics-related fixed pattern noise (FPN) by fitting the derivatives of correction model to the gradient components, locally computed on an infrared image. A modified bilateral filtering algorithm is applied to local pixel output variations, so that the refined gradients are most likely caused by the nonuniformity associated with optics. The estimated bias field is subtracted from the raw infrared imagery to compensate the intensity variations caused by optics. The proposed method is fundamentally different from the existing nonuniformity correction (NUC) techniques developed for focal plane arrays (FPAs) and provides an essential image processing functionality to achieve completely shutterless NUC for uncooled <span class="hlt">long-wave</span> infrared (LWIR) imaging systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24085086','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24085086"><span>Shutterless solution for simultaneous focal plane array temperature estimation and nonuniformity correction in uncooled <span class="hlt">long-wave</span> infrared camera.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cao, Yanpeng; Tisse, Christel-Loic</p> <p>2013-09-01</p> <p>In uncooled <span class="hlt">long-wave</span> infrared (LWIR) microbolometer imaging systems, temperature fluctuations of the focal plane array (FPA) result in thermal drift and spatial nonuniformity. In this paper, we present a novel approach based on single-image processing to simultaneously estimate temperature variances of FPAs and compensate the resulting temperature-dependent nonuniformity. Through well-controlled thermal calibrations, empirical behavioral models are derived to characterize the relationship between the responses of microbolometer and FPA temperature variations. Then, under the assumption that strong dependency exists between spatially adjacent pixels, we estimate the optimal FPA temperature so as to minimize the global intensity variance across the entire thermal infrared image. We make use of the estimated FPA temperature to infer an appropriate nonuniformity correction (NUC) profile. The performance and robustness of the proposed temperature-adaptive NUC method are evaluated on realistic IR images obtained by a 640 × 512 pixels uncooled LWIR microbolometer imaging system operating in a significantly changed temperature environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1323900','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1323900"><span>Auger recombination in <span class="hlt">long-wave</span> infrared InAs/InAsSb type-II superlattices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Olson, B. V.; Grein, C. H.; Kim, J. K.</p> <p>2015-12-29</p> <p>The Auger lifetime is a critical intrinsic parameter for infrared photodetectors as it determines the longest potential minority carrier lifetime and consequently the fundamental limitations to their performance. Here, Auger recombination is characterized in a <span class="hlt">long-wave</span> infrared InAs/InAsSb type-II superlattice. Auger coefficients as small as 7.1×10 –26 cm 6/s are experimentally measured using carrier lifetime data at temperatures in the range of 20 K–80 K. The data are compared to Auger-1 coefficients predicted using a 14-band K•p electronic structure model and to coefficients calculated for HgCdTe of the same bandgap. In conclusion, the experimental superlattice Auger coefficients are found tomore » be an order-of-magnitude smaller than HgCdTe.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27140581','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27140581"><span>Idler-efficiency-enhanced <span class="hlt">long-wave</span> infrared beam generation using aperiodic orientation-patterned GaAs gratings.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gürkan Figen, Ziya; Aytür, Orhan; Arıkan, Orhan</p> <p>2016-03-20</p> <p>In this paper, we design aperiodic gratings based on orientation-patterned gallium arsenide (OP-GaAs) for converting 2.1 μm pump laser radiation into <span class="hlt">long-wave</span> infrared (8-12 μm) in an idler-efficiency-enhanced scheme. These single OP-GaAs gratings placed in an optical parametric oscillator (OPO) or an optical parametric generator (OPG) can simultaneously phase match two optical parametric amplification (OPA) processes, OPA 1 and OPA 2. We use two design methods that allow simultaneous phase matching of two arbitrary χ<sup>(2)</sup> processes and also free adjustment of their relative strength. The first aperiodic grating design method (Method 1) relies on generating a grating structure that has domain walls located at the zeros of the summation of two cosine functions, each of which has a spatial frequency that equals one of the phase-mismatch terms of the two processes. Some of the domain walls are discarded considering the minimum domain length that is achievable in the production process. In this paper, we propose a second design method (Method 2) that relies on discretizing the crystal length with sample lengths that are much smaller than the minimum domain length and testing each sample's contribution in such a way that the sign of the nonlinearity maximizes the magnitude sum of the real and imaginary parts of the Fourier transform of the grating function at the relevant phase mismatches. Method 2 produces a similar performance as Method 1 in terms of the maximization of the height of either Fourier peak located at the relevant phase mismatch while allowing an adjustable relative height for the two peaks. To our knowledge, this is the first time that aperiodic OP-GaAs gratings have been proposed for efficient <span class="hlt">long-wave</span> infrared beam generation based on simultaneous phase matching.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023383','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023383"><span>A system for mapping sources of VHF and electric field pulses from in-cloud <span class="hlt">lightning</span> at KSC</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomson, Ewen M.; Medelius, Pedro J.</p> <p>1991-01-01</p> <p>The literature concerning VHF radiation and wideband electric fields from in-cloud <span class="hlt">lightning</span> is reviewed. VHF location systems give impressive <span class="hlt">radio</span> images of <span class="hlt">lightning</span> in clouds with high spatial and temporal resolution. Using systems based on long and short baseline time-or-arrival and interferometry, workers have detected VHF sources that move at speeds of 10(exp 5) to 10(exp 8) m/s. The more slowly moving sources appear to be associated with channel formation but the physical basis for the higher speeds is not clear. In contrast, wideband electric fields are directly related to physical parameters such as current and tortuosity. A long baseline system is described to measure simultaneously VHF radiation and wideband electric fields at five stations at Kennedy Space Center. All signals are detected over remote, isolated ground planes with fiber optics for data transmission. The modification of this system to map rapidly varying dE/dt pulses is discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9614008','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9614008"><span><span class="hlt">Lightning</span>-associated deaths--United States, 1980-1995.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p></p> <p>1998-05-22</p> <p>A <span class="hlt">lightning</span> 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, <span class="hlt">lightning</span> causes more deaths than do most other natural hazards (e.g., hurricanes and tornadoes), although the incidence of <span class="hlt">lightning</span>-related deaths has decreased since the 1950s. The cases described in this report illustrate diverse circumstances in which deaths attributable to <span class="hlt">lightning</span> can occur. This report also summarizes data from the Compressed Mortality File of CDC's National Center for Health Statistics on <span class="hlt">lightning</span> fatalities in the United States from 1980 through 1995, when 1318 deaths were attributed to <span class="hlt">lightning</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100033708&hterms=Pollution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPollution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100033708&hterms=Pollution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPollution"><span>Weekly Cycle of <span class="hlt">Lightning</span>: Evidence of Storm Invigoration by Pollution</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bell, Thomas L.; Rosenfeld, Daniel; Kim, Kyu-Myong</p> <p>2009-01-01</p> <p>We have examined summertime 1998 2009 U.S. <span class="hlt">lightning</span> data from the National <span class="hlt">Lightning</span> Detection Network (NLDN) to look for weekly cycles in <span class="hlt">lightning</span> activity. As was found by Bell et al. (2008) for rain over the southeast U.S., there is a significant weekly cycle in afternoon <span class="hlt">lightning</span> activity that peaks in the middle of the week there. The weekly cycle appears to be reduced over population centers. <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030111776&hterms=quantitative+data+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dquantitative%2Bdata%2Banalysis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030111776&hterms=quantitative+data+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dquantitative%2Bdata%2Banalysis"><span><span class="hlt">Lightning</span> and Precipitation: Observational Analysis of LIS and PR</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adamo, C.; Solomon, R.; Goodman, S.; Dietrich, S.; Mugnai, A.</p> <p>2003-01-01</p> <p><span class="hlt">Lightning</span> flash rate can identify areas of convective rainfall when the storms are dominated by ice-phase precipitation. Modeling and observational studies indicate that cloud electrification and microphysics are very closely related and it is of great interest to understand the relationship between <span class="hlt">lightning</span> and cloud microphysical quantities. Analyzing data from the <span class="hlt">Lightning</span> Image Sensor (LIS) and the Precipitation Radar (PR), we show a quantitative relationship between microphysical characteristics of thunderclouds and <span class="hlt">lightning</span> flash rate. We have performed a complete analysis of all data available over the Mediterranean during the TRMM mission and show a range of reflective profiles as a function of <span class="hlt">lightning</span> activity for both convective and stratiform regimes as well as seasonal variations. Due to the increasing global coverage of <span class="hlt">lightning</span> detection networks, this kind of study can used to extend the knowledge about thunderstorms and discriminate between different regimes in regions where radar measurements are readilly available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860003852','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860003852"><span>Interpretation of F-106B in-flight <span class="hlt">lightning</span> signatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Trost, T. F.; Grothaus, M. G.; Wen, C. T.</p> <p>1985-01-01</p> <p>Various characteristics of the electromagnetic data obtained on a NASA F-106B aircraft during direct <span class="hlt">lightning</span> strikes are presented. Time scales of interest range from 10 ns to 400 microsecond. The following topics are discussed: (1) <span class="hlt">Lightning</span> current, I, measured directly versus I obtained from computer integration of measured I-dot; (2) A method of compensation for the low frequency cutoff of the current transformer used to measure I; (3) Properties of fast pulses observed in the <span class="hlt">lightning</span> time-derivative waveforms; (4) The characteristic D-dot signature of the F-106B aircraft; (5) An RC-discharge interpretation for some <span class="hlt">lightning</span> waveforms; (6) A method for inferring the locations of <span class="hlt">lightning</span> channel attachment points on the aircraft by using B-dot data; (7) Simple, approximate relationships between D-dot and I-dot and between B and I; and (8) Estimates of energy, charge, voltage, and resistance for a particular <span class="hlt">lightning</span> event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820058794&hterms=rust&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Drust','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820058794&hterms=rust&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Drust"><span>Doppler radar echoes of <span class="hlt">lightning</span> and precipitation at vertical incidence</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zrnic, D. S.; Rust, W. D.; Taylor, W. L.</p> <p>1982-01-01</p> <p>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, <span class="hlt">lightning</span> echoes were observed as increased reflectivity on an oscilloscope display. Simultaneously, <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> discharges. Spectra from locations where <span class="hlt">lightning</span> occurred show peaks, due to the motion of the <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ems..confE.192G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ems..confE.192G"><span>Ten years of <span class="hlt">Lightning</span> Imaging Sensor (LIS) data: Preparing the way for geostationary <span class="hlt">lightning</span> imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grandell, J.; Stuhlmann, R.</p> <p>2010-09-01</p> <p>The <span class="hlt">Lightning</span> Imaging Sensor (LIS) onboard the Tropical Rainfall Measurement Mission (TRMM) platform has provided a continuous source of <span class="hlt">lightning</span> observations in the +/- 35 deg latitude region since 1998. LIS, together with its predecessor Optical Transient Detector (OTD) have established an unprecedented database of optical observations of <span class="hlt">lightning</span> from a low-earth orbit, allowing a more consistent and uniform view of <span class="hlt">lightning</span> that has been available from any ground-based system so far. The main disadvantage of LIS is that, since it operates on a low-earth orbit with a low inclination, only a small part of the globe is viewed at a time and only for a duration of ~2 minutes, and for a rapidly changing phenomenon like convection and the <span class="hlt">lightning</span> related thereto this is far from optimal. This temporal sampling deficiency can, however, be overcome with observations from a geostationary orbit. One such mission in preparation is the <span class="hlt">Lightning</span> Imager on-board the Meteosat Third Generation (MTG) satellite, which will provide service continuation to the Meteosat Second Generation (MSG) system from 2018 onwards. The current MSG system has become the primary European source of geostationary observations over Europe and Africa with the start of nominal operations in January 2004, and will be delivering observations and services at least until 2017. However, considering the typical development cycle for a new complex space system, it was already for a longer time necessary to plan for and define the MTG system. MTG needs to be available around 2016, before the end of the nominal lifetime of MSG-3. One of the new missions selected for MTG is the previously mentioned <span class="hlt">Lightning</span> Imager (LI) mission, detecting continuously over almost the full disc the <span class="hlt">lightning</span> discharges taking place in clouds or between cloud and ground with a resolution around 10 km. The LI mission is intended to provide a real time <span class="hlt">lightning</span> detection (cloud-to-cloud and cloud-to-ground strokes) and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/4112611','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4112611"><span><span class="hlt">RADIO</span> ALTIMETERS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bogle, R.W.</p> <p>1960-11-22</p> <p>A <span class="hlt">radio</span> ranging device is described which utilizes a superregenerative oscillator having alternate sending and receiving phases with an intervening ranging interval between said phases, means for varying said ranging interval, means responsive to an on-range noise reduction condition for stopping said means for varying the ranging interval and indicating means coupled to the ranging interval varying means and calibrated in accordance with one-half the product of the ranging interval times the velocity of light whereby the range is indicated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMAE43B0273H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMAE43B0273H"><span>Combined VLF and VHF <span class="hlt">lightning</span> observations of Hurricane Rita landfall</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henderson, B. G.; Suszcynsky, D. M.; Wiens, K. C.; Hamlin, T.; Jeffery, C. A.; Orville, R. E.</p> <p>2009-12-01</p> <p>Hurricane Rita displayed abundant <span class="hlt">lightning</span> in its northern eyewall as it made landfall at 0740 UTC 24 Sep 2005 near the Texas/Louisiana border. For this work, we combined VHF and VLF <span class="hlt">lightning</span> data from Hurricane Rita, along with radar observations from Gulf Coast WSR-88D stations, for the purpose of demonstrating the combined utility of these two spectral regions for hurricane <span class="hlt">lightning</span> monitoring. <span class="hlt">Lightning</span> is a direct consequence of the electrification and breakdown processes that take place during the convective stages of thunderstorm development. As Rita approached the Gulf coast, the VHF <span class="hlt">lightning</span> emissions were distinctly periodic with a period of 1.5 to 2 hours, which is consistent with the rotational period of hurricanes. VLF <span class="hlt">lightning</span> emissions, measured by LASA and NLDN, were present in some of these VHF bursts but not all of them. At landfall, there was a significant increase in <span class="hlt">lightning</span> emissions, accompanied by a significant convective surge observed in radar. Furthermore, VLF and VHF <span class="hlt">lightning</span> source heights clearly increase as a function of time. The evolution of the IC/CG ratio is consistent with that seen in thunderstorms, showing a dominance of IC activity during storm development, followed by an increase in CG activity at the storm’s peak. The periodic VHF <span class="hlt">lightning</span> events are correlated with increases in convective growth (quantified by the volume of radar echo >40 dB) above 7 km altitude. VLF can discriminate between <span class="hlt">lightning</span> types, and in the LASA data, Rita landfall <span class="hlt">lightning</span> activity was dominated by Narrow Bi-polar Events (NBEs)—high-energy, high-altitude, compact intra-cloud discharges. The opportunity to locate NBE <span class="hlt">lightning</span> sources in altitude may be particularly useful in quantifying the vertical extent (strength) of the convective development and in possibly deducing vertical charge distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900001191','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900001191"><span>The 1984 direct strike <span class="hlt">lightning</span> data, part 3</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, Mitchel E.; Carney, Harold K.</p> <p>1986-01-01</p> <p>Data waveforms are presented which were obtained during the 1984 direct-strike <span class="hlt">lightning</span> tests utilizing the NASA F106-B aircraft specially instrumented for <span class="hlt">lightning</span> electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached <span class="hlt">lightning</span>. This is part 3, consisting entirely of charts and graphs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19345842','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19345842"><span>When <span class="hlt">lightning</span> strikes: bolting down the facts & fiction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Usatch, Ben</p> <p>2009-04-01</p> <p>MYTH: There's no danger from <span class="hlt">lightning</span> until the rain starts. FACT: <span class="hlt">Lightning</span> often precedes the storm by up to 10 miles. A reasonable guideline is the "30-30 rule," by which you count the seconds between the flash and the thunder. If the time span is less than 30 seconds, seek shelter. Additionally, wait a full 30 minutes from last <span class="hlt">lightning</span> flash to resume outdoor activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080037560','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080037560"><span>GOES-R Geostationary <span class="hlt">Lightning</span> Mapper Performance Specifications and Algorithms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>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.</p> <p>2008-01-01</p> <p>The Geostationary <span class="hlt">Lightning</span> Mapper (GLM) is a single channel, near-IR imager/optical transient event detector, used to detect, locate and measure total <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>. The mission objectives for the GLM are to: (1) Provide continuous, full-disk <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>. The GLM owes its heritage to the NASA <span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> activity. GOES-R Risk Reduction Team and Algorithm Working Group <span class="hlt">Lightning</span> Applications Team have begun to develop the Level 2 algorithms and applications. The science data will consist of <span class="hlt">lightning</span> "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 <span class="hlt">lightning</span> data from the NASA <span class="hlt">Lightning</span> Imaging Sensor on the Tropical Rainfall Measuring Mission (TRMM) satellite and regional test beds (e.g., <span class="hlt">Lightning</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT.......302K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT.......302K"><span><span class="hlt">Lightning</span> Strike Induced Damage Mechanisms of Carbon Fiber Composites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kawakami, Hirohide</p> <p></p> <p>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 <span class="hlt">lightning</span> has been rising. Main task of this study is to clarify the <span class="hlt">lightning</span> damage mechanism of carbon fiber reinforced epoxy polymer composites to help further development of <span class="hlt">lightning</span> strike protection. The research on <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> intensity, and <span class="hlt">lightning</span> current waveforms. It revealed that the thermal resistance capability of polymer matrix was one of the most influential parameters on <span class="hlt">lightning</span> damage resistance of CFRPs. Based on the experimental findings, the semi-empirical analysis model for predicting the extent of <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> tests were performed to explore more practical situations. Specifically, filled-hole CFRP plates and patch</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820052191&hterms=comprehensive+review&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DThis%2Bcomprehensive%2Breview%2Bwill','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820052191&hterms=comprehensive+review&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DThis%2Bcomprehensive%2Breview%2Bwill"><span>A review of natural <span class="hlt">lightning</span> - Experimental data and modeling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Uman, M. A.; Krider, E. P.</p> <p>1982-01-01</p> <p>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 <span class="hlt">lightning</span>. 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 <span class="hlt">lightning</span>/aircraft interactions. The state-of-the-art of the modeling of <span class="hlt">lightning</span> currents and fields is discussed in detail. A comprehensive bibliography is given of all literature relating to both <span class="hlt">lightning</span> measurements and models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24054789','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24054789"><span>"Thunderstruck": penetrating thoracic injury from <span class="hlt">lightning</span> strike.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Waes, Oscar J F; van de Woestijne, Pieter C; Halm, Jens A</p> <p>2014-04-01</p> <p><span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> strike and its treatment, which has not been described prior in (kerauno)medicine. Penetrating injury due to blast from <span class="hlt">lightning</span> strike is extremely rare. These "shrapnel" injuries should however be ruled out in all patients struck by <span class="hlt">lightning</span>. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22902106','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22902106"><span>Cochlear implantation for severe sensorineural hearing loss caused by <span class="hlt">lightning</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Myung, Nam-Suk; Lee, Il-Woo; Goh, Eui-Kyung; Kong, Soo-Keun</p> <p>2012-01-01</p> <p><span class="hlt">Lightning</span> 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 <span class="hlt">lightning</span> injury. The exact pathogenetic mechanisms of auditory lesions in <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> strike, who was successfully rehabilitated after a cochlear implantation. Copyright © 2012 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6487I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6487I"><span>Nowcasting of <span class="hlt">Lightning</span>-Related Accidents in Africa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ihrlich, Laura; Price, Colin</p> <p>2016-04-01</p> <p>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 <span class="hlt">lightning</span> strikes. This region of the globe also has little <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span>-caused accidents that got wide press coverage: A <span class="hlt">lightning</span> 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 <span class="hlt">Lightning</span> Location Network (WWLLN) we show that the <span class="hlt">lightning</span> data alone can provide important early warning information that can be used to reduce risks and damages and loss of life from <span class="hlt">lightning</span> 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 <span class="hlt">lightning</span> alone. Furthermore, our analysis can be used in forensic meteorology for determining if such accidents are caused by <span class="hlt">lightning</span> strikes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMAE33A2524B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMAE33A2524B"><span>A first look at <span class="hlt">lightning</span> energy determined from GLM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bitzer, P. M.; Burchfield, J. C.; Brunner, K. N.</p> <p>2017-12-01</p> <p>The Geostationary <span class="hlt">Lightning</span> Mapper (GLM) was launched in November 2016 onboard GOES-16 has been undergoing post launch and product post launch testing. While these have typically focused on <span class="hlt">lightning</span> metrics such as detection efficiency, false alarm rate, and location accuracy, there are other attributes of the <span class="hlt">lightning</span> discharge that are provided by GLM data. Namely, the optical energy radiated by <span class="hlt">lightning</span> may provide information useful for <span class="hlt">lightning</span> physics and the relationship of <span class="hlt">lightning</span> energy to severe weather development. This work presents initial estimates of the <span class="hlt">lightning</span> optical energy detected by GLM during this initial testing, with a focus on observations during field campaign during spring 2017 in Huntsville. This region is advantageous for the comparison due to the proliferation of ground-based <span class="hlt">lightning</span> instrumentation, including a <span class="hlt">lightning</span> mapping array, interferometer, HAMMA (an array of electric field change meters), high speed video cameras, and several long range VLF networks. In addition, the field campaign included airborne observations of the optical emission and electric field changes. The initial estimates will be compared with previous observations using TRMM-LIS. In addition, a comparison between the operational and scientific GLM data sets will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HGSS....9...79D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HGSS....9...79D"><span>An early record of ball <span class="hlt">lightning</span>: Oliva (Spain), 1619</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Domínguez-Castro, Fernando</p> <p>2018-05-01</p> <p>In a primary documentary source we found an early record of ball <span class="hlt">lightning</span> (BL), which was observed in the monastery of Pi (Oliva, southeastern Spain) on 18 October 1619. The ball <span class="hlt">lightning</span> was observed by at least three people and was described as a <q>rolling burning vessel</q> and a <q>ball of fire</q>. The ball <span class="hlt">lightning</span> appeared following a <span class="hlt">lightning</span> flash, showed a mainly horizontal motion, crossed a wall, smudged an image of the Lady of Rebollet (then known as Lady of Pi) and burnt her ruff, and overturned a cross.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/372254-electromagnetic-field-radiation-model-lightning-strokes-tall-structures','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/372254-electromagnetic-field-radiation-model-lightning-strokes-tall-structures"><span>Electromagnetic field radiation model for <span class="hlt">lightning</span> strokes to tall structures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Motoyama, H.; Janischewskyj, W.; Hussein, A.M.</p> <p>1996-07-01</p> <p>This paper describes observation and analysis of electromagnetic field radiation from <span class="hlt">lightning</span> strokes to tall structures. Electromagnetic field waveforms and current waveforms of <span class="hlt">lightning</span> strokes to the CN Tower have been simultaneously measured since 1991. A new calculation model of electromagnetic field radiation is proposed. The proposed model consists of the <span class="hlt">lightning</span> current propagation and distribution model and the electromagnetic field radiation model. Electromagnetic fields calculated by the proposed model, based on the observed <span class="hlt">lightning</span> current at the CN Tower, agree well with the observed fields at 2km north of the tower.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.loc.gov/pictures/collection/hh/item/hi0364.photos.332805p/','SCIGOV-HHH'); return false;" href="https://www.loc.gov/pictures/collection/hh/item/hi0364.photos.332805p/"><span>BLDG 101, OVERVIEW WITH <span class="hlt">LIGHTNING</span> POLES Naval Magazine Lualualei, ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>BLDG 101, OVERVIEW WITH <span class="hlt">LIGHTNING</span> POLES - Naval Magazine Lualualei, Headquarters Branch, Operational Storage Building, Fifteenth Street near Kolekole Road intersection, Pearl City, Honolulu County, HI</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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