A Spatiotemporal Lightning Risk Assessment Using Lightning Mapping Data

2021 ◽  
Author(s):  
Kelley Murphy ◽  
Eric Bruning ◽  
Christopher J. Schultz ◽  
Jennifer Vanos
Keyword(s):  
Risk Assessment ◽  
Standard Method ◽  
Weighted Average ◽  
Lead Times ◽  
International Electrotechnical Commission ◽  
Mapping Data ◽  
West Texas ◽  
Lightning Detection ◽  
Total Lightning ◽  
Lightning Safety

AbstractA lightning risk assessment for application to human safety was created and applied in 10 West Texas locations from 2 May 2016 to 30 September 2016. The method combined spatial lightning mapping data, probabilistic risk calculation adapted from the International Electrotechnical Commission Standard 62305-2, and weighted average interpolation to produce risk magnitudes that were compared to tolerability thresholds to issue lightning warnings. These warnings were compared to warnings created for the same dataset using a more standard lightning safety approach based on National Lightning Detection Network (NLDN) total lightning within 5 nautical miles of each location. Four variations of the calculation as well as different units of risk were tested to find the optimal configuration to calculate risk to an isolated human outdoors.The best performing risk configuration using risk 10min−1 or larger produced the most comparable results to the standard method, such as number of failures, average warning duration, and total time under warnings. This risk configuration produced fewer failures than the standard method, but longer total time under warnings and higher false alarm ratios. Median lead times associated with the risk configuration were longer than the standard method for all units considered, while median down times were shorter for risk 10min−1 and risk 15min−1. Overall, the risk method provides a baseline framework to quantify the changing lightning hazard on the storm-scale, and could be a useful tool to aid in lightning decision support scenarios.

scholarly journals Improvement of Risk Assessment Using Numerical Analysis for an Offshore Plant Dipole Antenna

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 681
Author(s):  
Yun-Jeong Cho ◽  
Kichang Im ◽  
Dongkoo Shon ◽  
Daehoon Park ◽  
Jong-Myon Kim
Keyword(s):  
Risk Assessment ◽  
Numerical Analysis ◽  
High Frequency ◽  
Dipole Antenna ◽  
Effective Field ◽  
Initial Assessment ◽  
International Electrotechnical Commission ◽  
Test Procedures ◽  
High Frequency Structure Simulator ◽  
Site Test

This paper proposes a numerical analysis method for improving risk assessment of radio frequency (RF) hazards. To compare the results of conventional code analysis, the values required for dipole antenna risk assessment, which is widely used in offshore plants based on the British standards (BS) guide, are calculated using the proposed numerical analysis. Based on the BS (published document CENELEC technical report (PD CLC/TR) 50427:2004 and international electrotechnical commission (IEC) 60079 for an offshore plant dipole antenna, an initial assessment, a full assessment, and on-site test procedures are performed to determine if there is a potential risk of high-frequency ignition. Alternatively, numerical analysis is performed using the Ansys high frequency structure simulator (HFSS) tool to compare results based on the BS guide. The proposed method computes the effective field strength and power for the antenna without any special consideration of the structure to simplify the calculation. Experimental results show that the proposed numerical analysis outperforms the risk assessment based on the BS guide in accuracy of the evaluation.

An Electrical and Polarimetric Analysis of the Overland Reintensification of Tropical Storm Erin (2007)

2014 ◽  
Vol 142 (6) ◽  
pp. 2321-2344 ◽  
Author(s):  
Erica M. Griffin ◽  
Terry J. Schuur ◽  
Donald R. MacGorman ◽  
Matthew R. Kumjian ◽  
Alexandre O. Fierro
Keyword(s):  
Tropical Cyclones ◽  
Inner Core ◽  
Open Water ◽  
Tropical Storm ◽  
Sea Level Pressure ◽  
Core Convection ◽  
Lightning Detection ◽  
Mapping Array ◽  
Total Lightning ◽  
Abundant Data

Abstract While passing over central Oklahoma on 18–19 August 2007, the remnants of Tropical Storm Erin unexpectedly reintensified and developed an eyelike feature that was clearly discernable in Weather Surveillance Radar-1988 Doppler (WSR-88D) imagery. During this brief reintensification period, Erin traversed a region of dense surface and remote sensing observation networks that provided abundant data of high spatial and temporal resolution. This study analyzes data from the polarimetric KOUN S-band radar, total lightning data from the Oklahoma Lightning Mapping Array, and ground-flash lightning data from the National Lightning Detection Network. Erin’s reintensification was atypical since it occurred well inland and was accompanied by stronger maximum sustained winds and gusts (25 and 37 m s−1, respectively) and lower minimum sea level pressure (1001.3 hPa) than while over water. Radar observations reveal several similarities to those documented in mature tropical cyclones over open water, including outward-sloping eyewall convection, near 0-dBZ reflectivities within the eye, and relatively large updraft velocities in the eyewall as inferred from single-Doppler winds and ZDR columns. Deep, electrified convection near the center of circulation preceded the formation of Erin’s eye, with maximum lightning activity occurring prior to and during reintensification. The results show that inner-core convection may have played a role in the reinvigoration of the storm.

The Relationship between Total Cloud Lightning Behavior and Radar-Derived Thunderstorm Structure

2013 ◽  
Vol 28 (1) ◽  
pp. 237-253 ◽  
Author(s):  
Eric Metzger ◽  
Wendell A. Nuss
Keyword(s):  
Weather Type ◽  
Severe Weather ◽  
Characteristic Change ◽  
Lightning Flash ◽  
Fort Worth ◽  
Detection Systems ◽  
Lightning Detection ◽  
Rapid Changes ◽  
Total Lightning ◽  
The Relationship

Abstract Total lightning detection systems have been in development since the mid-1980s and deployed in several areas around the world. Previous studies on total lightning found intra- and intercloud lightning (IC) activity tends to fluctuate significantly during the lifetime of thunderstorms and have indicated that lightning jumps or rapid changes in lightning flash rates are closely linked to changes in the vertical integrated liquid (VIL) reading on the National Weather Service’s Weather Surveillance Radar-1988 Doppler (WSR-88D) systems. This study examines the total lightning and its relationship to WSR-88D signatures used operationally to determine thunderstorm severity to highlight the potential benefit of a combined forecast approach. Lightning and thunderstorm data from the Dallas–Fort Worth, Texas, and Tucson, Arizona, areas from 2006 to 2009, were used to relate total lightning behavior and radar interrogation techniques. The results indicate that lightning jumps can be classified into severe wind, hail, or mixed-type jumps based on the behavior of various radar-based parameters. In 25 of 34 hail-type jumps and in 18 of 20 wind-type jumps, a characteristic change in cloud-to-ground (CG) versus IC lightning flash rates occurred prior to the report of severe weather. For hail-type jumps, IC flash rates increased, while CG flash rates were steady or decreased. For wind-type jumps, CG flash rates increased, while IC flash rates either increased (12 of 18) or were steady or decreased (6 of 18). Although not every lightning jump resulted in a severe weather report, the characteristic behavior in flash rates adds information to radar-based approaches for nowcasting the severe weather type.

scholarly journals New Lightning Detection Networks in Poland – LINET and LLDN

2009 ◽  
Vol 3 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Marek Loboda ◽  
Hans D. Betz ◽  
Piotr Baranski ◽  
Jan Wiszniowski ◽  
Zdzislaw Dziewit
Keyword(s):  
Detection System ◽  
High Sensitivity ◽  
Lightning Flash ◽  
Time Operation ◽  
Lightning Detection ◽  
Time Signals ◽  
Real Time Operation ◽  
Basic Characteristics ◽  
Total Lightning ◽  
The Cost

Lightning detection in Poland is performed by means of a PERUN (Safir 3000) system operated by the Institute of Meteorology and Water Management. Poland is also partly covered by a VLF/LF lightning detection system (CLDN, Central Lightning Detection Network). Both sources of lightning data have their limitations resulting from detection technique, limited number of sensors and geographical configuration, with the consequence of shortcomings in the data quality. For this reason, a new network has been installed in Poland and started continuous real-time operation in May 2006. It is LINET that covers entire Poland and is complemented by numerous sensors positioned in surrounding countries. In 2007 additional LINET sensors have been installed in Poland in order to allow exploitation of reduced baselines for efficient achievement of total lightning. In the frame of the COST P18 Action “Physics of Lightning Flash and Its Effects” another new Polish project started in 2006 related to regional lightning location. At present, the Local Lightning Detection Network (LLDN) undergoes installation in the region of Warsaw. LLDN will consist of six individual stations equipped with E-field antennae and digital recorders synchronized with GPS time signals. The aim of LLDN installation is complement other networks covering region of Warsaw (PERUN, LINET) and to provide an additional source of lightning CG data with high sensitivity in a relatively small area. In the paper are described general characteristics of LINET in Poland, as well as basic characteristics and assumed performance of LLDN, which will start operation in 2008.

scholarly journals The Intracloud Lightning Fraction in the Contiguous United States

2017 ◽  
Vol 145 (11) ◽  
pp. 4481-4499 ◽  
Author(s):  
Gina Medici ◽  
Kenneth L. Cummins ◽  
Daniel J. Cecil ◽  
William J. Koshak ◽  
Scott D. Rudlosky
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Central California ◽  
The Pacific ◽  
Lightning Detection ◽  
Maximum Period ◽  
Total Lightning ◽  
Imaging Sensor ◽  
Optical Transient

This work addresses the long-term relative occurrence of cloud-to-ground (CG) and intracloud (IC; no attachment to ground) flashes for the contiguous United States (CONUS). It expands upon an earlier analysis by Boccippio et al. who employed 4-yr datasets provided by the U.S. National Lightning Detection Network (NLDN) and the Optical Transient Detector (OTD). Today, the duration of the NLDN historical dataset has more than tripled, and OTD data can be supplemented with data from the Lightning Imaging Sensor (LIS). This work is timely, given the launch of GOES-16, which includes the world’s first geostationary lightning mapper that will observe total lightning (IC and CG) over the Americas and adjacent ocean regions. Findings support earlier results indicating factor-of-10 variations in the IC:CG ratio throughout CONUS, with climatological IC fraction varying between 0.3 and greater than 0.9. The largest values are seen in the Pacific Northwest, central California, and where Colorado borders Kansas and Nebraska. An uncertainty analysis indicates that the large values in the northwest and central California are likely not due to measurement uncertainty. The high IC:CG ratio (>4) throughout much of Texas reported by Boccippio et al. is not supported by this longer-term climatology. There is no clear evidence of differences in IC fraction between land and coastal ocean. Lightning characteristics in six selected large regions show a consistent positive relationship between IC fraction and the percent of positive CG flashes, irrespective of lightning incidence (flash density), dominant season, or diurnal maximum period.

The 29 June 2000 Supercell Observed during STEPS. Part II: Lightning and Charge Structure

2005 ◽  
Vol 62 (12) ◽  
pp. 4151-4177 ◽  
Author(s):  
Kyle C. Wiens ◽  
Steven A. Rutledge ◽  
Sarah A. Tessendorf
Keyword(s):  
Positive Charge ◽  
Lightning Activity ◽  
Structure Evolution ◽  
Severe Thunderstorm ◽  
Charge Structure ◽  
Flash Rate ◽  
Lightning Detection ◽  
Mapping Array ◽  
Total Lightning ◽  
Mexico Tech

Abstract This second part of a two-part study examines the lightning and charge structure evolution of the 29 June 2000 tornadic supercell observed during the Severe Thunderstorm Electrification and Precipitation Study (STEPS). Data from the National Lightning Detection Network and the New Mexico Tech Lightning Mapping Array (LMA) are used to quantify the total and cloud-to-ground (CG) flash rates. Additionally, the LMA data are used to infer gross charge structure and to determine the origin locations and charge regions involved in the CG flashes. The total flash rate reached nearly 300 min−1 and was well correlated with radar-inferred updraft and graupel echo volumes. Intracloud flashes accounted for 95%–100% of the total lightning activity during any given minute. Nearly 90% of the CG flashes delivered a positive charge to ground (+CGs). The charge structure during the first 20 min of this storm consisted of a midlevel negative charge overlying lower positive charge with no evidence of an upper positive charge. The charge structure in the later (severe) phase was more complex but maintained what could be roughly described as an inverted tripole, dominated by a deep midlevel (5–9 km MSL) region of positive charge. The storm produced only two CG flashes (both positive) in the first 2 h of lightning activity, both of which occurred during a brief surge in updraft and hail production. Frequent +CG flashes began nearly coincident with dramatic increases in storm updraft, hail production, total flash rate, and the formation of an F1 tornado. The +CG flashes tended to cluster in or just downwind of the heaviest precipitation, which usually contained hail. The +CG flashes all originated between 5 and 9 km MSL, centered at 6.8 km (−10°C), and tapped LMA-inferred positive charge both in the precipitation core and (more often) in weaker reflectivity extending downwind. All but one of the −CG flashes originated from >9 km MSL and tended to strike near the precipitation core.

scholarly journals A Bayesian Approach to Assess the Performance of Lightning Detection Systems

2016 ◽  
Vol 33 (3) ◽  
pp. 563-578 ◽  
Author(s):  
Phillip M. Bitzer ◽  
Jeffrey C. Burchfield ◽  
Hugh J. Christian
Keyword(s):  
North America ◽  
Detection System ◽  
Optical Detectors ◽  
Bayesian Techniques ◽  
Detection Systems ◽  
Lightning Detection ◽  
Spatial Domains ◽  
Stroke Type ◽  
Total Lightning ◽  
Imaging Sensor

AbstractHistorically, researchers explore the effectiveness of one lightning detection system with respect to another system; that is, the probability that system A detects a discharge given that system B detected the same discharge is estimated. Since no system detects all lightning, a more rigorous comparison should include the reverse process—that is, the probability that system B detects a discharge given that system A detected it. Further, the comparison should use the fundamental physical process detected by each system. Of particular interest is the comparison of ground-based radio frequency detectors with space-based optical detectors. Understanding these relationships is critical as the availability and use of lightning data, both ground based and space based, increases. As an example, this study uses Bayesian techniques to compare the effectiveness of the Earth Networks Total Lightning Network (ENTLN), a ground-based wideband network, and the Lightning Imaging Sensor (LIS), a space-based optical detector. This comparison is completed by matching LIS groups and ENTLN pulses, each of which correspond to stroke-type discharges. The comparison covers the period from 2009 to 2013 over several spatial domains. In 2013 LIS detected 52.0% of the discharges ENTLN reported within the LIS field of view globally and 53.2% near North America. Conversely, ENTLN detected 5.9% of the pulses detected by LIS globally and 26.9% near North America in 2013. Using these results in the Bayesian-based methodology outlined, the study finds that LIS detected 80.1% of discharges near North America in 2013, while ENTLN detected 40.1%.

A Research on the Characteristics of Lightning in Hailstorms of Beijing Area by the Method of Analysis the Lightning Detection Data and Numerical Simulation

2013 ◽  
Vol 416-417 ◽  
pp. 1993-1996
Author(s):  
Chuang Chuang Zhang ◽  
Ming Ma
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Two Dimensional ◽  
Beijing Area ◽  
Variation Trend ◽  
Lightning Detection ◽  
The Mean ◽  
Total Lightning ◽  
The Relationship ◽  
Cg Lightning

In this paper, by using lightning detection material of Beijing area, we analyzing the characteristics of lightning in four hailstorms. The results show that the mean percentage of cloud-to-ground (CG) lightning accounting for the total lightning is 8.28%, which is lower than the normal thunderstorms. On the contrary, the CG lightning has a higher proportion of positive CG than the normal thunderstorms. All cases variation trend of lightning frequency show a conspicuous intensive increase before the hail reaches the ground. The peak lightning frequency usually occurs 5 to 80min earlier than hailstone falling. These characteristics may have contribution to the forecasting of hailstorms of Beijing area. Another work was done by using a two-dimensional numerical model which includes dynamic, microphysics, electrification and discharge to simulate these four instances. The results present similar characteristics with the actual detection data. This will lay a foundation for the continuing studies of the relationship between hailstorm and lightning and the inherent reason of the relationship by using the method of numerical simulation.

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