2000 July 17: cPbL: INSPEC SEARCH: Find SUBJECT NLDN OR SUBJECT ANOMALOUS LIGHT OUTPUT LIGHTNING OR SUBJECT OPTICAL RADIATION SIGNATURES LIGHTNING % The following is a clever subject-only way to find Uman87 OR SUBJECT LIGHTNING DISCHARGE STEPPED LEADER PLANETARY ATMOSPHERES JUNCTION PROCESSES or TITLE EFFECTS CLOUDS LIGHT PRODUCED LIghtning OR TITLE PEAK ELECTROMAGNETIC RADIATED LIGHTNING or Find TITLE CLOUD GROUND LIGHTNING CONTIGUOUS or TITLE ELECTRIC FIELD MEASUREMENTS MESOSCALE CONVECTIVE SYSTEMS citations: 27+3 % NO I DONT NEED THIS ONE. %still needed: Brook, 82: electrical structure Hokuriku winter tstorms ========================================================== /usr/tmp/citation.tmp.26235 @ARTICLE{LyonsAug98, author={Lyons, W.A. and Uliasz, M. and Nelson, T.E.}, title={ Large peak current cloud-to-ground lightning flashes during the summer months in the contiguous United States }, journal={Monthly Weather Review}, volume={126}, number={8}, year={1998}, month={Aug}, pages={2217-33}, abstract={ A clear association between large peak current cloud-to-ground (CG) lightning flashes of positive polarity and sprites and elves in the stratosphere and mesosphere has been previously demonstrated. This paper reports on the first climatology of large peak current CG (LPCCG) lightning flashes compiled from the U.S. National Lightning Detection Network. Analysis of almost 60 million CG flashes from 14 boreal summer months (1991-95) reveals distinct geographic differences in the distribution of positive and negative polarity LPCCGs, arbitrarily defined as flashes with peak currents >or=75 kA. Large peak current positive CGs (LPC+CGs) are concentrated in the High Plains and upper Midwest, the region in which a large majority of optical sprite and elves observations have been obtained. By contrast, large peak current negative CGs (LPC-CGs) preferentially occur over the coastal waters of the Gulf of Mexico and the southeastern United States. A total of 1.46 million LPCCGs were found, of which only 13.7% were +CGs. Almost 70% of the LPC+CGs, however, occurred in the central United Stares (30 degrees -50 degrees N, 88 degrees -110 degrees W). The percentage of all LPCCGs that were positive approached 30% in the central United States compared to 4.5% for the remainder of the country. Over a half million negative CGs and over 1000 positive CGs were found with multiplicity }, keywords={ lightning mesosphere stratosphere large peak current cloud-to-ground lightning flashes boreal summer months contiguous United States positive polarity sprites elves stratosphere mesosphere US National Lightning Detection Network AD 1991 to 1995 geographic distribution peak currents High Plains Midwest Gulf of Mexico multiplicity USA }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.26235 @ARTICLE{MarshallMar96, author={Marshall, T.C. and Stolzenburg, M. and Rust, W.D.}, title={ Electric field measurements above mesoscale convective systems }, journal={Journal of Geophysical Research}, volume={101}, number={D3}, year={1996}, month={Mar}, pages={6979-96}, abstract={ The authors show that electric field discontinuities occur above the stratiform clouds associated with mesoscale convective systems. Above cloud top, 12 discontinuities were observed at altitudes between 10 and 16 km. The field changes of the discontinuities ranged from -1.1 to -4.0 kV m/sup -1/. The data suggest that the electric field discontinuities were caused by coincident, positive, cloud-to-ground lightning flashes. The coincident ground flashes included both single and multiple return stroke flashes, with first-stroke peak currents between 20 and 154 kA. The authors modeled the electric field change that would occur if lightning discharged a horizontally extensive positive charge layer within the stratiform cloud. In the model, disks with charge densities of 1 and 3 nC m/sup -3/, a thickness of 400 m, and diameters ranging from 20 to 200 km were discharged and produced field changes similar to the observed above-cloud field discontinuities. The authors results support the idea that sprites may be initiated by above-cloud field changes caused by positive cloud-to-ground lightning flashes that discharge a horizontally extensive charge region in the stratiform cloud of a mesoscale convective system. During the time between the electric field discontinuities the electric field above the stratiform clouds was -0.5 to -1.0 kV m/sup -1/; this field may be important in the global electrical circuit because the stratiform clouds have large horizontal extents (10/sup 4/ km/sup 2/) }, keywords={ atmospheric electricity lightning mesosphere stratosphere thunderstorms atmosphere troposhere stratosphere storm cloud electricity cloud-to-ground lightning mesoscale convective system electric field discontinuity stratiform cloud model sprite mesosphere middle atmosphere thunderstorm 8 to 20 km }, mynotes={UNREAD}, } @ARTICLE{OrvilleMay94, author={Orville, R.E.}, title={ Cloud-to-ground lightning flash characteristics in the contiguous United States: 1989-1991 }, journal={J. Geophys. Res. (USA), Journal of Geophysical Research}, volume={99}, number={D5}, year={1994}, month={May}, pages={10833-41}, abstract={ Wideband magnetic direction finders have been used to obtain a cloud-to-ground lightning flash count for the contiguous United States, an area of 7.7*10/sup 6/ km/sup 2/, for the period 1989 through 1991. Over 46 million flashes to ground were recorded and are divided among the three years, 13.4 million in 1989, 15.9 million in 1990, and 16.9 million in 1991. Maximum flash densities occur in Florida and increase each year, from 9 flashes km/sup -2/ (1989) to 13 flashes km/sup -2/ (1991). The database contains 1.7 million positive flashes divided among the three years, 0.4 million in 1989, 0.6 million in 1990, and 0.7 million in 1991. In 1990 and 1991 the positive flash density maximum occurred in Florida but elsewhere in 1989. Secondary maximum positive flash densities occur throughout the Midwest. The annual mean percentage of positive flashes in the total lightning count is 3.7% for the period 1989-1991. The interannual variation is small, ranging from 3.1% (1989) to 4.0% (1991). However, in any given year the geographical variation of the percentage of positive flashes is large. The percentage of positive flashes is 2% (1989) at the latitude of Florida but near 25% and higher at the latitudes of the upper Midwest, Maine, and Oregon }, keywords={ lightning cloud-to-ground lightning flash count contiguous United States AD 1989 to 1991 maximum flash densities Florida database Midwest interannual variation geographical variation Maine Oregon USA wideband magnetic direction finder recordings }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{JekerFeb00, author={Jeker, D.P. and Pfister, L. and Thompson, A.M. and Brunner, D. and Boccippio, D.J. and Pickering, K.E. and Wernli, H. and Kondo, Y. and Staehelin, J.}, title={ Measurements of nitrogen oxides at the tropopause: attribution to convection and correlation with lightning }, journal={Journal of Geophysical Research}, volume={105}, number={D3}, year={2000}, month={Feb}, pages={3679-700}, abstract={ NO/sub x/ (NO and NO/sub 2/) and ozone were measured on 98 flights during August to November 1997 in the framework of the projects Pollution From Aircraft Emissions in the North Atlantic Flight Corridor (POLINAT 2) and Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX). The fully automated measurement system Nitrogen Oxides and Ozone Along Air Routes (NOXAR) was permanently installed aboard an in-service Swissair B-747 airliner operating in the North Atlantic Flight Corridor. Below the tropopause, predominantly over the U.S. east coast, the patchy occurrence of NO/sub x/ enhancements up to 3000 parts per trillion by volume (pptv) was observed frequently and led to a lognormal probability density function of NO/sub x/. These plumes extend over several hundred kilometers. In three case studies the origin of such plumes was investigated using back trajectories, satellite infrared images, and lightning observations from the U.S. National Lightning Detection Network (NLDN) and the Optical Transient Detector (OTD) satellite instrument. In the case of frontal activity above the continental United States, the location of NO/sub x/ plumes was explained with maps of convective influence. In another case, NO/sub x/ seems to have been produced by lightning in a marine thunderstorm over the eastern Atlantic. Lightning activity triggered over the warm Gulf Stream is found to be an important source for the regional upper tropospheric NO/sub x/ budget, at least for the time period considered. With a method that the authors call "lightning tracing" the authors show for the first time that (in some cases) the number of lightning flashes, accumulated along back trajectories, was proportional to the NO/sub x/ concentrations observed several hundred kilometers downwind of the anvil outflows }, keywords={ air pollution atmospheric composition lightning nitrogen compounds stratosphere troposphere atmosphere stratosphere chemical composition air pollution troposphere tropopause convection lightning POLINAT 2 North Atlantic Flight Corridor AD 1997 United States USA Subsonic Assessment Ozone and Nitrogen Oxide Experiment SONEX Nitrogen Oxides and Ozone Along Air Routes NOXAR patchy occurrence NO/sub x/ plume back trajectory anvil outflow NO NO/sub 2/ O/sub 3/ }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{GoodmanFeb00, author={Goodman, S.J. and Buechler, D.E. and Knupp, K. and Driscoll, K. and McCaul, E.W., Jr.}, title={ The 1997-98 El Nino event and related wintertime lightning variations in the southeastern United States }, journal={Geophysical Research Letters}, volume={27}, number={4}, year={2000}, month={Feb}, pages={541-4}, abstract={ The El Nino Southern Oscillation (ENSO) is a climate anomaly responsible for worldwide weather impacts ranging from droughts to floods. In the United States, warm episode years are known to produce above normal rainfall along the Southeast U.S. Gulf Coast and into the Gulf of Mexico, with the greatest response observed in the October-March period of the warm episode year. The 1997-98 warm episode is notable for being the strongest event since 1982-83. With the recent launch of a lightning sensor on NASA's Tropical Rainfall Measuring Mission (TRMM) in November 1997 and the detailed coverage of the U.S. National Lightning Detection Network (NLDN), such interannual changes in lightning activity can be examined with far greater detail than ever before. For the 1997-98 ENSO event the most significant year-to-year changes in lightning frequency worldwide occurred along the Gulf Coast and within the Gulf of Mexico basin during the Northern Hemisphere winter. Within a broad swath across the northern Gulf of Mexico basin there is a 100-150% increase in lightning days year-to-year (a peak of 33 days in the winter of 1997-98 vs. only 15 days or fewer in both the 1996-97 and 1998-99 winter). In addition, there is a nearly 200% increase in lightning hours (a peak of 138 hours in 1996-97 vs. 50 hours in both 1996-97 and 1998-99). The increase in lightning activity during ENSO occurs in association with a 100% increase in the number of synoptic scale cyclones that developed within or moved through the Gulf basin. The primary variables controlling these enhancements in thunderstorm activity are the position and strength of the jet stream }, keywords={ El Nino Southern Oscillation lightning thunderstorms atmosphere teleconnection United States USA AD 1997 AD 1998 El Nino wintertime winter temporal variation season El Nino Southern Oscillation ENSO warm episode years interannual change synoptic scale cyclone thunderstorm activity storm jet stream strength }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{CumminsJan00, author={Cummins, K.L.}, title={ Continental-scale detection of cloud-to-ground lightning }, journal={Transactions of the Institute of Electrical Engineers of Japan, Part B}, volume={120-B}, number={1}, year={2000}, month={Jan}, pages={2-5}, abstract={ The US National Lightning Detection Network (NLDN) has provided US national-scale information about cloud-to-ground (CG) lightning to industrial and scientific communities since 1989. The electric power industry, one of the principal user groups, utilizes real-time data as well as archived data for operation, fault analysis and transmission line design. Beginning in 1998 with the completion of the Canadian Lightning Detection Network (CLDN), continental-scale lightning information has been available through the integration of these two networks. The combined network is known as the North American Lightning Detection Network (NALDN). This large network provides a unique opportunity to study lightning characteristics over a wide range of climate and terrain, and to evaluate the behavior of lightning detection sensors in response to very-high peak current CG discharges }, keywords={ atmospheric techniques clouds electricity supply industry lightning continental-scale detection cloud-to-ground lightning electric power industry real-time data archived data fault analysis transmission line design North American Lightning Detection Network lightning characteristics lightning detection sensors USA Canada }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{BeasleyJan00, author={Beasley, W.H. and Eack, K.B. and Morris, H.E. and Rust, H.D. and MacGorman, D.R.}, title={ Electric-field changes of lightning observed in thunderstorms }, journal={Geophysical Research Letters}, volume={27}, number={2}, year={2000}, month={Jan}, pages={189-92}, abstract={ During the Summer and Fall of 1998 the authors launched five balloon-borne instruments into thunderstorms to observe changes in the vertical component of electric field caused by lightning. Four of these were for measurement of field change only. The fifth was part of a larger package that included a gamma radiation detector and a GPS receiver on board. The authors have processed electric-field-change data from two of these flights. They discuss examples of field changes observed at altitude and compare them with data from the National Lightning Detection Network (NLDN) for cloud-to-ground lightning flashes that were coincident in time. Limits on time resolution and timing accuracy prevent unambiguous identification of the lightning processes that caused the field changes. It appears that they may have been caused by charge movements relatively near the instruments as compared with the ground-strike location of coincident flashes }, keywords={ atmospheric electricity clouds lightning thunderstorms atmosphere electricity electric-field change lightning thunderstorm thundercloud vertical component electric charge movement ground-strike location AD 1998 United States USA Oklahoma }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @CONFERENCE{Longo99, author={Longo, V.J. and Hickman, C.}, title={ Lightning research update including new uses of lighting data }, booktitle={IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)}, volume={}, number={}, year={1999}, month={}, pages={1285-6 vol.2}, abstract={ The 1989 implementation of a National Lightning Detection Network (NLDN) was a joint effort of the National Severe Storms Laboratory, the Bureau of Land Management, the State University of New York at Albany and EPRI. That event followed about five years of research and development activities which paved the way for such a network to be feasible. Further, this network offered the possibility of a depth of understanding of lightning phenomena which was previously only dreamed about. The National Lightning Detection Network has been commercialized-it is no longer a research project, it is a business. And, as we head toward the network's tenth anniversary, a glimpse of the data obtained and some of the uses to which the data is being applied is provided. When NLDN started operations, location accuracy of flashes was advertised as one kilometer and the location technology in use tracked lightning flashes (a lightning flash could have one or more subsequent strokes). Today, using advanced sensor technology, detection accuracy is on the order of one hundred meters and the unit of lightning location (and other data) is the stroke. In fact, using a Fault And Lightning Location System (FALLS/sup TM/) Workstation, location accuracy and other characteristics of individual strokes can be determined for both macro and micro geographic locations. For the utility engineer, the equipment manufacturer and the scientist, a whole new level of insight into lightning is available. The use of this data in several research venues is highlighted. Further, two novel uses of this data by electric utilities is also presented }, keywords={ atmospheric measuring apparatus atmospheric techniques electricity supply industry lightning lightning protection power system protection electric utilities National Lightning Detection Network USA research update lightning phenomena flash location accuracy advanced sensor technology FALLS/sup TM/ Workstation power system lightning protection }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{WackerJan99, author={Wacker, R.S. and Orville, R.E.}, title={ Changes in measured lightning flash count and return stroke peak current after the 1994 U.S. National Lightning Detection Network upgrade. 1. Observations }, journal={Journal of Geophysical Research}, volume={104}, number={D2}, year={1999}, month={Jan}, pages={2151-7}, abstract={ A total of more than 134 million cloud-to-ground lightning flashes (127 million negative, 7 million positive), occurring during 1989-1995 in the continental United States, have been studied on a monthly and yearly basis for variations in flash count, first stroke peak current, and polarity. The years 1989-1993 cover a period in which similar instrumentation was used throughout the United States. In 1994 the National Lightning Detection Network (NLDN) underwent a system-wide upgrade to improve location accuracy and detection efficiency. As a result of this upgrade, the authors observe in the NLDN that the negative mean peak current decreased from a preupgrade (1989-1993) mean of 37.5 kA to a 1995 value of 30.2 kA, a decrease of 3.4 standard deviations. The positive mean peak current decreased from 54.4 to 31.6 kA, a 5.0 standard deviation decrease. The NLDN negative flash count increased 1.2 standard deviations, from a preupgrade mean of 16.7 million flashes yr/sup -1/ to 20.6 million flashes in 1995. The positive flash count increased 6.2 standard deviations, from an average of 696000 flashes yr/sup -1/ before the upgrade to 2.1 million flashes in 1995. Both the negative and the positive flash count increases were predominantly at low peak currents }, keywords={ atmospheric measuring apparatus atmospheric techniques lightning AD 1994 AD 1995 atmosphere lightning United States USA flash count return stroke peak current electric current National Lightning Detection Network upgrade detection efficiency location accuracy measurement technique }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{WackerJan99, author={Wacker, R.S. and Orville, R.E.}, title={ Changes in measured lightning flash count and return stroke peak current after the 1994 U.S. National Lightning Detection Network upgrade. 2. Theory }, journal={Journal of Geophysical Research}, volume={104}, number={D2}, year={1999}, month={Jan}, pages={2159-62}, abstract={ For pt.1 see ibid., vol.104, no.D2, p.2151-7 (1999). A model of return stroke detection by the U.S. National Lightning Detection Network (NLDN) magnetic direction finder (MDF) sensors is used to approximate the pulse width criterion modification made to the sensors during the 1994 upgrade. Decreasing the pulse width detection criterion used by the MDF sensors increases their effective detection range, which increases their sensitivity to weak flashes (because of NLDN network geometry, increasing sensitivity has little effect on detection of strong flashes). Consequently, the authors observe an increase in the weak flash counts. The increased detection of weak flashes accounts, in part, for the decrease in mean peak currents observed in subsequent years to 1994. In addition to decreasing the mean peak current of detected positive and negative flashes, the NLDN-upgrade has apparently had the unwanted effect of increasing the contamination of the positive CG flash data with cloud flashes }, keywords={ atmospheric techniques lightning atmosphere measurement technique United States USA lightning flash count return stroke peak current change AD 1994 National Lightning Detection Network upgrade return stroke detection model magnetic direction finder pulse width criterion modification weak flash count }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{CumminsNov98, author={Cummins, K.L. and Krider, E.P. and Malone, M.D.}, title={ The US National Lightning Detection Network/sup TM/ and applications of cloud-to-ground lightning data by electric power utilities }, journal={IEEE Transactions on Electromagnetic Compatibility}, volume={40}, number={4}, year={1998}, month={Nov}, pages={465-80}, abstract={ Lightning is a significant cause of interruptions or damage in almost every electrical or electronic system that is exposed to thunderstorms. The problem is particularly severe for electric power utilities that have exposed assets covering large areas. We summarize the basic properties of cloud-to-ground (CG) lightning, the primary hazard to structures on the ground, and then we discuss methods of detecting and locating such discharges. We describe the US National Lightning Detection Network/sup TM/ (NLDN), a system that senses the electromagnetic fields that are radiated by individual return strokes in CG flashes. This network provides data on the time of such strokes, their location and polarity and an estimate of the peak current. We discuss the network detection efficiency and location accuracy and some of the limitations that are inherent in any detection system that operates with a finite number of sensors with fixed trigger thresholds. We also discuss how NLDN data have benefited utilities by providing lightning warnings in real time and information on whether CG strokes are the cause of faults, documenting the response of fixed assets that are exposed to lightning, and quantifying the effectiveness of lightning protection systems. We conclude with some general observations on the use of lightning data by power utilities and we provide some guidelines on the uncertainties in lightning parameters that are acceptable in the industry }, keywords={ electricity supply industry electromagnetic fields lightning lightning protection power system faults reviews thunderstorms US National Lightning Detection Network cloud-to-ground lightning data electric power utilities electronic system electrical system thunderstorms electromagnetic fields return strokes polarity peak current network detection efficiency location accuracy fixed trigger thresholds NLDN data cloud-to-ground strokes lightning protection systems lightning parameters uncertainties }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{WescottMay98, author={Wescott, E.M. and Sentman, D.D. and Heavner, M.J. and Hampton, D.L. and Lyons, W.A. and Nelson, T.}, title={ Observations of columniform' sprites }, journal={Journal of Atmospheric and Solar-Terrestrial Physics}, volume={60}, number={7-9}, year={1998}, month={May}, pages={733-40}, abstract={ This paper reports observations of a distinctive form of sprites associated with positive CG flashes carrying currents of 23 or less to about 100 kA in mesoscale thunderstorms. The sprites are characterized by long vertical columns about 10 km long, less than 1 km in diameter, and show virtually no variation in brightness along their length. Three dimensional triangulation of what the authors define as a columniform' sprite (c-sprite) event on the evening of 19 June 1995 showed that the individual elements had an average terminal altitude of 86.7 km and an average bottom of 76.2 km. Some show faint diffuse hair' or tendrils extending above and below the column. The sprite columns are nearly vertical, in video imagery. On some evenings, c-sprites are the dominant form of sprite activity above thunderstorms but, on other nights with many sprites, they may not be observed at all. Comparison of c-sprite forms vs National Lightning Detection Network (NLDN) positive cloud-to-ground current, shows a progression from simple thin vertical forms to brighter and more complicated forms. Theoretical explanations which predict the form and vertical structure of the classical sprites do not at present account for these different forms }, keywords={ airglow lightning mesosphere stratosphere thermosphere thunderstorms thermosphere mesosphere middle atmosphere stratosphere thunderstorm lightning airglow columniform sprite positive cloud to ground flash mesoscale thunderstorm long vertical column AD 1995 06 19 terminal altitude faint diffuse hair tendrils c-sprite New Mexico United States USA }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{BoccippioMay98, author={Boccippio, D.J. and Wong, C. and Williams, E.R. and Boldi, R. and Christian, H.J. and Goodman, S.J.}, title={ Global validation of single-station Schumann resonance lightning location }, journal={Journal of Atmospheric and Solar-Terrestrial Physics}, volume={60}, number={7-9}, year={1998}, month={May}, pages={701-12}, abstract={ Global measurements of large, optically bright lightning events from the Optical Transient Detector (OTD) satellite are used to validate estimates of lightning location from single-station Schumann resonance (SR) data. Bearing estimates are obtained through conventional magnetic direction-finding techniques, while source range is estimated from the range-dependent impedance spectrum of individual SR transients. An analysis of 40 such transients suggests that single-station techniques can locate lightning globally with an accuracy of 1-2 Mm. This is confirmed by further validation at dose ranges from flashes detected by the National Lightning Detection Network (NLDN). Observations with both OTD and SR systems may be useful for globally locating lightning with necessary, if not sufficient, characteristics to trigger mesospheric sprites }, keywords={ atmospheric techniques Earth-ionosphere waveguide lightning mesosphere Earth ionosphere waveguide ELF single-station Schumann resonance lightning location Schumann resonance lightning global validation optically bright lightning Optical Transient Detector satellite OTD magnetic direction-finding source range measurement technique position determination mesosphere sprite }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{IdoneApr98, author={Idone, V.P. and Davis, D.A. and Moore, P.K. and Yan Wang and Henderson, R.W. and Ries, M. and Jamason, P.F.}, title={ Performance evaluation of the U.S. National Lightning Detection Network in eastern New York. 2. Location accuracy }, journal={Journal of Geophysical Research}, volume={103}, number={D8}, year={1998}, month={Apr}, pages={9057-69}, abstract={ For pt.I see ibid., vol.103, no.D8, p.9057-69 (1998). The authors have evaluated the location accuracy of the U.S. National Lightning Detection Network (NLDN) via comparison of individual NLDN stroke locations with their corresponding stroke terminations as determined from multiple-site video recordings of local cloud-to-ground lightning flashes. The video records used in this analysis were acquired in the vicinity of Albany, New York, during the summers of 1994 and 1995, seasons corresponding to the initial and final phases of the upgrade of the NLDN to the improved accuracy from combined technology (IMPACT) configuration. For 1994 a total of 751 strokes were located in common between the video and NLDN data sets, yielding median and mean values of the NLDN-video location separation of 2.21 km and 3.74 km, respectively. Constraint of the 1994 data to the best video locations (those with a semimajor axis value of the 50% error ellipse less than 500 m) yielded a subset of 53 strokes with median and mean values of the NLDN-video location separation of 2.61 km and 4.74 km, respectively. For 1995 a total of 219 strokes were located in common, yielding median and mean values of the NLDN-video location separation of 442 m and 865 m, respectively. Constraint of the 1995 data to that year's best video locations (those with a semimajor axis value of the 50% error ellipse less than 200 m) yielded a subset of 79 common strokes with median and mean values of the NLDN-video location separation of 435 m and 625 m, respectively. The IMPACT upgrade of the NLDN apparently has resulted in about a fivefold increase in location accuracy. A special subset of 11 strokes occurred in 1995; these were located by the NLDN and observed to terminate on local structures of accurately known location. For these 11 strokes, the median and mean values of the NLDN location error are 518 m and 484 m, respectively, a result quite consistent with the overall NLDN-video location comparison and the claim }, keywords={ atmospheric measuring apparatus atmospheric techniques lightning meteorological instruments atmosphere meteorology measurement technique instrument United States USA performance evaluation National Lightning Detection Network New York location accuracy NLDN lightning stroke termination Albany AD 1994 AD 1995 }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{IdoneApr98, author={Idone, V.P. and Davis, D.A. and Moore, P.K. and Yan Wang and Henderson, R.W. and Ries, M. and Jamason, P.F.}, title={ Performance evaluation of the U.S. National Lightning Detection Network in Eastern New York. 1. Detection efficiency }, journal={Journal of Geophysical Research}, volume={103}, number={D8}, year={1998}, month={Apr}, pages={9045-55}, abstract={ The detection efficiency (DE) of the U.S. National Lightning Detection Network (NLDN) has been evaluated using a large data set of video observations of cloud-to-ground lightning activity in the vicinity of Albany, New York. These data were acquired during the summers of 1993, 1994, and 1995, the latter being the year of completion of a major upgrade of the network to the improved accuracy from combined technology (IMPACT) configuration. For 1993, the authors find a flash DE value of 67% based upon 517 cloud-to-ground flashes documented on video. The latter two years yielded both flash and stroke DEs: in 1994, 86% of 893 flashes and 67% of 2162 strokes were detected; in 1995, 72% of 433 flashes and 47% of 1242 strokes were detected. The higher DEs of 1994 relative to 1995 are likely due to additional sensors deployed locally during the initial stage of the IMPACT upgrade. Detection efficiencies were found to vary significantly from storm to storm in each season, likely due to the inherent variability of return stroke characteristics between storms. For a special subset of 92 strokes of known location and measured electric-field change, peak current estimates were generated using the transmission-line model and a return stroke speed of 1.2*10/sup 8/ m/s. This speed was selected, as it is the effective speed used in present NLDN peak current estimates. For this 92-stroke data subset, the stroke DE depended upon peak current: strokes with peak currents greater than 14 kA were almost always detected (39 of 40), below 14 kA, the DE dropped until by 6-10 kA, the stroke DE was only 18% (three of 17). None of 14 strokes with estimated peak currents below 6 kA was detected. If the IMPACT design constraint of an effective 5-kA minimum peak current is applied to the authors' 92-stroke subset, the respective flash and stroke DEs are 84% and 69%; this is consistent with NLDN model predicted performance in this area }, keywords={ atmospheric measuring apparatus atmospheric techniques lightning meteorological instruments atmosphere meteorology lightning United States USA measurement technique instrument apparatus New York performance evaluation National Lightning Detection Network detection efficiency NLDN Albany AD 1993 AD 1994 AD 1995 upgrade improved accuracy from combined technology IMPACT peak current return stroke }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{CumminsApr98, author={Cummins, K.L. and Murphy, M.J. and Bardo, E.A. and Hiscox, W.L. and Pyle, R.P. and Pifer, A.E.}, title={ A combined TOA/MDF technology upgrade of the U.S. National Lightning Detection Network }, journal={Journal of Geophysical Research}, volume={103}, number={D8}, year={1998}, month={Apr}, pages={9035-44}, abstract={ The U.S. National Lightning Detection Network/sup TM/ (NLDN) has provided lightning data covering the continental United States since 1989. Using information gathered from more than 100 sensors, the NLDN provides both real-time and historical lightning data to the electric utility industry, the National Weather Service, and other government and commercial users. It is also the primary source of lightning data for use in research and climatological studies in the United States. In this paper the authors discuss the design, implementation, and data from the time-of-arrival/magnetic direction finder (TOA/MDF) network following a recent system-wide upgrade. The location accuracy (the maximum dimension of a confidence region around the stroke location) has been improved by a factor of 4 to 8 since 1991, resulting in a median accuracy of 500 m. The expected flash detection efficiency ranges from 80% to 90% for those events with peak currents above 5 kA, varying slightly by region. Subsequent strokes and strokes with peak currents less than 5 kA can now be detected and located; however, the detection efficiency for these events is not quantified in this study because their peak current distribution is not well known }, keywords={ atmospheric measuring apparatus lightning meteorological instruments atmosphere meteorology measurement technique instrument apparatus TOA MDF technology upgrade National Lightning Detection Network USA United States NLDN lightning design time-of-arrival magnetic direction finder stroke location flash detection efficiency detection efficiency peak current distribution }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{ZuelsdorfFeb98, author={Zuelsdorf, R.S. and Casler, C. and Strangeway, R.J. and Russell, C.T. and Franz, R.}, title={ Ground detection of trans-ionospheric pulse pairs by stations in the National Lightning Detection Network }, journal={Geophysical Research Letters}, volume={25}, number={4}, year={1998}, month={Feb}, pages={481-4}, abstract={ Trans-ionospheric pulse pairs (TIPPs), as detected by the Blackbeard instrument on board the ALEXIS satellite, correlate with signals that the National Lightning Detection Network (NLDN) classifies as "cloud" lightning with a positive signal polarity (+IC). Correlation is only found for +IC pulses occurring in the 10 ms interval prior to TIPP occurrence. Apart from this single peak, there is no general change in lightning rates around TIPP time. Correlation between TIPPs and +IC strokes is statistically significant with 99.94% confidence. The amplitudes of +IC pulses that are associated with TIPPs are indistinguishable from the amplitudes of pulses that are not. The rise time of +IC pulses correlating with TIPPs, however, does appear to be longer than the noncorrelating +IC pulses, the median value being about 3 times greater than all other +IC pulses. By assuming TIPPs to be generated close to the detecting ground station, the pulse separation time can be used to calculate the source heights for the ground reflection model. The calculated height of TIPPs is consistent with a cloud source }, keywords={ atmospherics ionospheric electromagnetic wave propagation lightning trans-ionospheric pulse pairs ground detection National Lightning Detection Network stations TIPPs Blackbeard instrument ALEXIS satellite NLDN cloud lightning positive signal polarity lightning rates pulse rise time pulse separation time source heights ground reflection model cloud source VHF 28 to 95 MHz 108 to 166 MHz }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{ReisingDec96, author={Reising, S.C. and Inan, U.S. and Bell, T.F. and Lyons, W.A.}, title={ Evidence for continuing current in sprite-producing cloud-to-ground lightning }, journal={Geophysical Research Letters}, volume={23}, number={24}, year={1996}, month={Dec}, pages={3639-42}, abstract={ Radio atmospherics launched by sprite-producing positive cloud-to-ground lightning flashes and observed at Palmer Station, Antarctica, exhibit large ELF slow tails following the initial VLF portion, indicating the presence of continuing currents in the source lightning flashes. One-to-one correlation of sferics with NLDN lightning data in both time and arrival azimuth, measured with an accuracy of +or-1 degrees at \12,000 km range, allows unambiguous identification of lightning flashes originating in the storm of interest. Slow-tail measurements at Palmer can potentially be used to measure continuing currents in lightning flashes over nearly half of the Earth's surface }, keywords={ atmospherics lightning thunderstorms atmosphere troposphere electric field electric current continuing current sprite-producing cloud-to-ground lightning thunderstorm atmospherics positive cloud-to-ground lightning flash Palmer Station Antarctica large ELF slow tail source lightning flash sferics NLDN lightning }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @CONFERENCE{Malone95, author={Malone, M.D. and Tuel, J.V. and Hagberg, D.J., Jr.}, title={ Improving power quality with lightning notification: "customer defined alert" }, booktitle={Official Proceedings of the Eighth International Power Quality Solutions'95. Presented at Powersystems World '95 Conference and Exhibit}, volume={}, number={}, year={1995}, month={}, pages={235-45}, abstract={ With the advent of state-of-the-art systems introduced into the mainstream of the National Lightning Detection Network (NLDN), Global Atmospherics, Inc. can now provide a means to improve overall facility power quality utilizing real-time lightning alert and notification strategies. Remotely sensed lightning strike data are collected at the NLDN Control Center in Tucson, Arizona and are queried for spatial proximity to an end-user defined "Area of Exposure" (AOE). The local utility power delivery assets that supply energy to the commercial and industrial end-users can be included as an integral part of the AOE so as not to exclude any elements that can contribute to a lightning-induced transient or interruption at their facility. The AOE geometry can be sophisticated, allowing unique customization to the facility's individual utility layout. NLDN real-time systems monitor the commercial and industrial facility's defined AOE for threatening lightning ground strike activity. Upon detecting lightning strikes within the defined AOE region, an immediate notification to the end-user is provided via a digital pager or other means. With advanced notification of the potential for power interruptions or facility damage now available, the facility manager can pro-actively initiate precautionary measures such as data back-up, warm standby of back-up generators, temporarily delay or suspend batch processes, or completely eliminate risks by decoupling from the utility and transferring to an alternate power source }, keywords={ lightning lightning protection power supply quality power system protection weather forecasting lightning notification customer defined alert power quality improvement National Lightning Detection Network Global Atmospherics real-time lightning alert remotely sensed lightning strike data Tucson Arizona lightning-induced transient lightning ground strike activity Area of Exposure digital pager power interruptions facility damage data back-up warm standby back-up generators }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{BiazarNov95, author={Biazar, A.P. and McNider, R.T.}, title={ Regional estimates of lightning production of nitrogen oxides }, journal={Journal of Geophysical Research}, volume={100}, number={D11}, year={1995}, month={Nov}, pages={22861-74}, abstract={ Summertime distribution of lightning over the United States and the potential importance of lightning-generated NO/sub x/ (NO+NO/sub 2/) was investigated by using data from the National Lightning Detection Network (NLDN) for June, July, and August 1989 through 1992. The data were compiled and gridded to yield hourly and monthly flash densities. Without correcting the data for the networks detection efficiency, on the average, 10 million flashes occur over the United States each summer with 2.6 strokes occurring per flash. The densest concentration of flashes is over the Southeast. In 1989 the summertime lightning activity (9.4 million flashes) accounted for 70% of the annual flashes. To investigate the regional characteristics of lightning, the data were also compiled for the eastern United States and a smaller subdomain of the southeastern United States. NO/sub x/ production rates of 0.36*10/sup 26/, 4*10/sup 26/, and 30*10/sup 26/ molecules/flash were chosen to represent the low, median, and high end of estimates suggested by different investigators. Using these three production rates and hourly gridded flash densities, lightning-generated NO/sub x/ emissions were calculated. These estimates were compared to anthropogenic emissions derived from the 1985 National Acid Precipitation Assessment Program (NAPAP) inventory. Based on the high production rate, NO/sub x/ emissions produced by lightning are comparable to monthly anthropogenic NO/sub x/ emissions in the Southeast during the summer. Even for the low production rate, hourly emissions of lightning produced NO/sub x/ frequently exceed anthropogenic emissions, with the highest frequencies in the Southeast. These results suggest that estimates of lightning-generated NO/sub x/ in the rural southeastern United States are not negligible and that this natural source of NO/sub x/ could play a significant role in summertime tropospheric ozone production in the Southeast. Given the importance of NO/sub x/ in ozone photoc }, keywords={ atmospheric chemistry atmospheric composition lightning nitrogen compounds troposphere atmosphere troposphere chemical composition concentration production United States USA regional estimate lightning summer NO/sub x/ AD 1989 AD 1990 AD 1991 AD 1992 monthly flash density natural source season NO NO/sub 2/ }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @CONFERENCE{Smith95, author={Smith, E.A. and Farrar, M. and Xuwu Xiang and Turk, J.}, title={ Prospects for advanced radar-radiometer precipitation retrieval algorithms during the TRMM era }, booktitle={Conference Proceedings. Second Topical Symposium on CombinedOptical-Microwave Earth and Atmosphere Sensing (Cat. No.95TH8015)}, volume={}, number={}, year={1995}, month={}, pages={177}, abstract={ The upcoming Tropical Rainfall Measuring Mission (TRMM) to be launched in August, 1997, will offer a much improved instrumentation. In addition to a cloud-radiation budget instrument (CERES) and a lightning detection instrument (LIS) which were developed as part of the Earth Observing System (EOS), the TRMM satellite will carry a set of three new instruments principally devoted to rainfall estimation. This package includes a visible-infrared radiometer called VIRS, a multi-channel dual-polarization passive microwave radiometer called TMI (with a 10.7 GHz capability), and a 14 GHz radar which will represent the first use of a precipitation radar (PR) in space. The addition of the PR instrument creates a new space-based capability for rainfall measurement, particularly when coupled with the TMI radiometer. The two types of measuring systems are based on entirely different physical principles and thus generate markedly different signatures of the hydrometeor profile. Either type of measuring approach by itself presents certain difficulties in retrieving vertically distributed rainrate information, but combined together present various new approaches for more accurate rainfall estimation. This presentation outlines a new type of combined algorithm scheme being developed within the TRMM project called the "Tall Vector" algorithm, representing the emerging technology for the TRMM era insofar as rainfall and latent heating estimation. The basic framework of this approach, which can be considered as a type of physical inversion scheme using incongruent measurement vectors, is presented }, keywords={ atmospheric measuring apparatus atmospheric techniques inverse problems meteorological instruments microwave measurement radar applications radiometry rain remote sensing remote sensing by radar spaceborne radar atmosphere meteorology radar remote sensing microwave radiometry SHF spaceborne radar measurement technique advanced radar-radiometer precipitation retrieval algorithm TRMM Tropical Rainfall Measuring Mission cloud-radiation budget instrument visible-infrared radiometer VIRS multi-channel dual-polarization passive microwave radiometer TMI instrument Tall Vector rain rainfall inversion scheme 10.7 GHz 14 GHz }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @CONFERENCE{Diaz94, author={Diaz, H. and Loorya, J.}, title={ Large system power quality analysis at MCI }, booktitle={Power Quality '94 USA. Official Proceedings of the Seventh InternationalPower Quality Telecomputer Infrastructure Conference (Power Quality)}, volume={}, number={}, year={1994}, month={}, pages={31-6}, abstract={ MCI, the telecommunications company, bills 16.5 billion calls annually. To ensure the integrity of their switching centers, power, and back-up power systems supporting that business, the company developed the SARA (Surge Activity Risk Assessment) system. The system uses ESIDS (Electrical Storm Identification Device), NLDN (National Lightning Detection Network), and the BMI PQNode distributed power monitoring system }, keywords={ electronic switching systems power measurement power supply quality surge protection telecommunication power supplies power quality analysis MCI Telecommunications switching center integrity power systems back-up power systems SARA system Surge Activity Risk Assessment system ESIDS Electrical Storm Identification Device NLDN National Lightning Detection Network BMI PQNode distributed power monitoring system }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{IdoneOct93, author={Idone, V.P. and Saljoughy, A.B. and Henderson, R.W. and Moore, P.K. and Pyle, R.B.}, title={ A reexamination of the peak current calibration of the National Lightning Detection Network }, journal={Journal of Geophysical Research}, volume={98}, number={D10}, year={1993}, month={Oct}, pages={18323-32}, abstract={ The peak current calibration of the National Lightning Detection Network (NLDN) reported by Orville (1991) has been reexamined with 57 directly measured stroke peak currents, I/sub peak/ (kiloamperes), and their corresponding NLDN mean normalized magnetic signal strengths, M/sub peak/(LLP units). Identification of corresponding I/sub peak/ and M/sub peak/ measurements was verified through accurate coincidence in absolute time of the two independent data sets. The I/sub peak/-M/sub peak/ data (with one point excluded as an outlier) are apparently linearly related with a correlation coefficient of 0.881, consistent with that predicted by application of the transmission line model of the lightning return stroke. The regression equation for prediction of I/sub peak/ from NLDN M/sub peak/ measurements is given. Examination of the overall I/sub peak/-M/sub peak/ data set for the possible influence of two different models of signal strength attenuation with distance,D, (power law, D/sup beta /, and exponential, (exp/sup /( alpha D))/sup -/) indicates negligible sensitivity to the proposed variations; other larger error sources likely mask the true attenuation effect. Twelve flashes were detected with four or more direction finders; a power law fit to the direction finder signal strength variation with distance of these individual flashes yields a mean beta value of -1.09. Examination of the overall I/sub peak/-M/sub peak/ data set for the possible effect of a nonlinear relation between the source stroke peak current and return stroke propagation speed indicates no obvious influence }, keywords={ lightning peak current calibration National Lightning Detection Network stroke peak currents mean normalized magnetic signal strengths transmission line model lightning return stroke regression equation signal strength attenuation direction finder signal strength variation nonlinear relation propagation speed source stroke }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{KriderOct92, author={Krider, E.P.}, title={ On the electromagnetic fields, Poynting vector, and peak power radiated by lightning return strokes }, journal={Journal of Geophysical Research}, volume={97}, number={D14}, year={1992}, month={Oct}, pages={15913-17}, abstract={ The initial radiation fields, Poynting vector, and total electromagnetic power that a vertical return stroke radiates into the upper half space have been computed when the speed of the stroke, nu , is a significant fraction of the speed of light, c, assuming that at large distances and early times the source is an infinitesimal dipole. The initial current is also assumed to satisfy the transmission-line model with a constant nu and to be perpendicular to an infinite, perfectly conducting ground. The effect of a large nu is to increase the radiation fields by a factor of (1- beta /sup 2/ cos/sup 2/ theta )/sup -1/, where beta = nu /c and theta is measured from the vertical, and the Poynting vector by a factor of (1- beta /sup 2/ cos/sup 2/ theta )/sup -2/ }, keywords={ atmospheric radiation lightning atmosphere EM power radiowave emission initial electric current electromagnetic fields Poynting vector peak power lightning initial radiation fields vertical return stroke }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @BOOK{Uman87, author={Uman, M.A.}, title={ Lightning discharge }, volume={}, address={London, UK}, publisher={Academic Press}, number={}, year={1987}, keywords={ atmospheric electricity lightning meteorology thunderstorms lightning phenomenology junction processes cloud-ground discharges planetary atmospheres thunderstorms lightning discharge electric charges clouds preliminary electric breakdown stage stepped leader attachment process conducting object return stroke dart leader continuing flow electric current J-processes K-processes positive lightning upward lightning cloud discharges Venus Jupiter Saturn thunder electromagnetic theory statistics experimental techniques lightning measurement }, } /usr/tmp/citation.tmp.4901 @ARTICLE{VampolaJun88, author={Vampola, A.L. and LaBelle, J.}, title={ Comment on: 'Are fast atmospheric pulsations optical signatures of lightning-induced electron precipitation?' by J. LaBelle (with reply) }, journal={Geophysical Research Letters}, volume={15}, number={6}, year={1988}, month={Jun}, pages={633-8}, abstract={ For original paper see ibid., vol.14, p.1023-6 (1987) and for a correction see ibid., vol.15, p.277-82 (1988). Shows that the occurrence of unexplained fast atmospheric light pulsations (FAPs) observed at L=1.5-2.2 in the northern hemisphere cannot be produced by >or=2 MeV electrons in the inner radiation belt except during artificially enhanced electron fluxes such as immediately after the STARFISH explosion. The more general question, whether FAPs are optical manifestations of lightning-induced electron precipitation, is shown to remain valid }, keywords={ atmospheric electron precipitation atmospheric radiation lightning magnetosphere ionosphere magnetosphere optical signatures lightning-induced electron precipitation fast atmospheric light pulsations northern hemisphere electrons inner radiation belt artificially enhanced electron fluxes STARFISH explosion 2 MeV }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{LaBelleOct87, author={LaBelle, J.}, title={ Are fast atmospheric pulsations optical signatures of lightning-induced electron precipitation? }, journal={Geophysical Research Letters}, volume={14}, number={10}, year={1987}, month={Oct}, pages={1023-6}, abstract={ Fast Atmospheric Light Pulsations (FAP's) consist of millisecond time-scale bursts of light which have been observed at L=1.5-2.2 during searches for atmospheric light emissions associated with supernovae. Their statistics of occurrence resemble those of Lightning-induced Electron Precipitation (Trimpi events) observed at somewhat higher L-shells. The present author proposes that FAP's are in fact optical signatures of LEP events associated with the >or=2 MeV electrons of the inner radiation belt (L approximately=1.4). These electrons would precipitate at low altitudes and could be modulated with time scales the order of 1 ms. The total loss rate of electrons from the inner belt resulting from these events would be comparable to, but somewhat smaller than, the loss rate due to Coulomb scattering }, keywords={ atmospheric optics atmospheric radiation ionosphere lightning magnetosphere radiation belts magnetosphere ionosphere FAP light burst atmosphere optics fast atmospheric pulsations optical signatures lightning-induced electron precipitation millisecond LEP events inner radiation belt }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{GuoDec85, author={Guo, C. and Krider, E.P.}, title={ Anomalous light output from lightning dart leaders }, journal={Journal of Geophysical Research}, volume={90}, number={D7}, year={1985}, month={Dec}, pages={13073-5}, abstract={ About 5% of the multiple-stroke cloud-to-ground lightning discharges recorded at the NASA Kennedy Space Center during the summer of 1981 contained dart leaders that produced an unusually large light output. An analysis of these cases indicates that the average peak light output per unit length in the leader may be comparable to or even exceed that of the return stroke that follows }, keywords={ atmospheric optics lightning atmosphere optics intensity optical emission anomalous light output AD 1981 Florida USA lightning dart leaders }, mynotes={UNREAD}, } /usr/tmp/citation.tmp.4901 @ARTICLE{Changming-GuoOct82, author={Changming Guo and Krider, E.P.}, title={ The optical and radiation field signatures produced by lightning return strokes }, journal={Journal of Geophysical Research}, volume={87}, number={C11}, year={1982}, month={Oct}, pages={9813-22}, abstract={ The optical signals radiated by Florida lightning in the 0.4- to 1.1- mu m wavelength interval have been recorded in correlation with wide-band electric field signatures. The initial light signal from a return stroke tends to be linear for about 15 mu s and then rises more slowly to a peak that is delayed about 60 mu s from the electric field peak. The transition between the fast linear portion and the slower rise may be due to the return stroke entering the cloud base. A small percentage of the records indicate that two different branches of the same stepped leader can initiate separate return strokes. The light pulses from cloud discharges tend to be smaller and more slowly varying than those from return strokes. The total optical power radiated by first strokes in the 5- to 35-km range has a mean and standard deviation of 2.3+or-1.8*10/sup 9/ W at peak }, keywords={ atmospheric radiation atmospheric spectra atmospherics lightning radiowave emission atmosphere atmospherics spectra USA visible infrared optical radiation field signatures lightning return strokes Florida electric field power }, mynotes={UNREAD}, } @ARTICLE{ThomasonSep82, author={Thomason, L.W. and Krider, E.P.}, title={ The effects of clouds on the light produced by lightning }, journal={Journal of the Atmospheric Sciences}, volume={39}, number={9}, year={1982}, month={Sep}, pages={2051-65}, abstract={ A Monte Carlo method has been used to simulate the transport of visible (0.45 mu m) and near-infrared (0.87 mu m) photons which are produced by transient light sources, such as lightning, within cubic, spherical and cylindrical clouds. Computations of the total absorption, the fractions of photons which escape various cloud surfaces, the flux density of photons at the cloud surface, and the angular distributions of the photons are given for various source locations. The delay and time-broadening of a light impulse by multiple scattering is discussed }, keywords={ clouds lightning clouds lightning Monte Carlo method transport visible near-infrared transient light sources flux density angular distributions time-broadening light impulse multiple scattering }, mynotes={UNREAD}, }