A Review of Positive and Bipolar Lightning Discharges

2003 ◽  
Vol 84 (6) ◽  
pp. 767-776 ◽  
Author(s):  
V. A. Rakov
Keyword(s):  
Forest Fires ◽  
Return Stroke ◽  
Winter Storms ◽  
Convective Systems ◽  
Lightning Channel ◽  
Different Types ◽  
Mesoscale Convective ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning ◽  
Positive Return

Characteristics of lightning discharges that transport either positive charge or both positive and negative charges to the ground are reviewed. These are termed positive and bipolar lightning discharges, respectively. Different types of positive and bipolar lightning are discussed. Although positive lightning discharges account for 10% or less of global cloud-to-ground lightning activity, there are five situations that appear to be conducive to the more frequent occurrence of positive lightning. These situations include 1) the dissipating stage of an individual thunderstorm, 2) winter thunderstorms, 3) trailing stratiform regions of mesoscale convective systems, 4) some severe storms, and 5) thunderclouds formed over forest fires or contaminated by smoke. The highest directly measured lightning currents (near 300 kA) and the largest charge transfers (hundreds of coulombs or more) are thought to be associated with positive lightning. Two types of impulsive positive current waveforms have been observed. One type is characterized by rise times of the order of 10 μs, comparable to those for first strokes in negative lightning, and the other type is characterized by considerably longer rise times, up to hundreds of microseconds. The latter waveforms are apparently associated with very long, 1–2 km, upward negative connecting leaders. The positive return-stroke speed is of the order of 108 m s−1. Positive flashes are usually composed of a single stroke. Positive return strokes often appear to be preceded by significant in-cloud discharge activity, then followed by continuing currents, and involve long horizontal channels. In contrast to negative leaders, which are always optically stepped when they propagate in virgin air, positive leaders seem to be able to move either continuously or in a stepped fashion. The reported percentage of bipolar flashes in summer storms ranges from 6% to 14% and from 5% to 33% in winter storms. Bipolar lightning discharges are usually initiated by upward leaders from tall objects. It appears that positive and negative charge sources in the cloud are tapped by different upward branches of the bipolar-lightning channel.

scholarly journals Comprehensive Analysis of a Coast Thunderstorm That Produced a Sprite over the Bohai Sea

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 718
Author(s):  
Cong Pan ◽  
Jing Yang ◽  
Kun Liu ◽  
Yu Wang
Keyword(s):  
Bohai Sea ◽  
Mesoscale Convective System ◽  
Convective System ◽  
Return Stroke ◽  
Absolute Value ◽  
Transient Luminous Events ◽  
Stratiform Region ◽  
Before And After ◽  
Mesoscale Convective ◽  
Cloud To Ground Lightning

Sprites are transient luminous events (TLEs) that occur over thunderstorm clouds that represent the direct coupling relationship between the troposphere and the upper atmosphere. We report the evolution of a mesoscale convective system (MCS) that produced only one sprite event, and the characteristics of this thunderstorm and the related lightning activity are analyzed in detail. The results show that the parent flash of the sprite was positive cloud-to-ground lightning (+CG) with a single return stroke, which was located in the trailing stratiform region of the MCS with a radar reflectivity of 25 to 35 dBZ. The absolute value of the negative CG (−CG) peak current for half an hour before and after the occurrence of the sprite was less than 50 kA, which was not enough to produce the sprite. Sprites tend to be produced early in the maturity-to-dissipation stage of the MCS, with an increasing percentage of +CG to total CG (POP), indicating that the sprite production was the attenuation of the thunderstorm and the area of the stratiform region.

scholarly journals on the prevention of lighting

1969 ◽  
Vol 50 (7) ◽  
pp. 514-521 ◽  
Author(s):  
C. D. Stow
Keyword(s):  
United States ◽  
Forest Fires ◽  
Western United States ◽  
Agricultural Crops ◽  
Loss Of Life ◽  
The World ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning ◽  
Recreational Resources

The destructive nature of cloud-to-ground lightning strokes is well known. Loss of life and damage to buildings and other man-made structures may to a large extent be prevented by the judicial use of lightning conductors and screens but no comparable protection may be offered to expanses of agricultural crops or forests. According to Fuquay (1967) lightning is the greatest single cause of forest fires in the western United States: during the period 1946–1962, 140,000 such fires occurred causing severe losses of timber, wildlife, watershed, and recreational resources. Comparable losses occur regularly in other parts of the world. The only solution is the suppression or modification of cloud-to-ground lightning discharges. Methods of suppression are described, some of which may turn out to be practical ways of achieving this aim.

Characteristics of Sprite-Producing Positive Cloud-to-Ground Lightning during the 19 July 2000 STEPS Mesoscale Convective Systems

2003 ◽  
Vol 131 (10) ◽  
pp. 2417-2427 ◽  
Author(s):  
Walter A. Lyons ◽  
Thomas E. Nelson ◽  
Earle R. Williams ◽  
Steven A. Cummer ◽  
Mark A. Stanley
Keyword(s):  
Mesoscale Convective Systems ◽  
Convective Systems ◽  
Mesoscale Convective ◽  
Cloud To Ground Lightning

scholarly journals Some characteristics of cloud-to-ground lightning in mesoscale convective systems

1998 ◽  
Vol 103 (D12) ◽  
pp. 14011-14023 ◽  
Author(s):  
Donald R. MacGorman ◽  
Carolyn D. Morgenstern
Keyword(s):  
Mesoscale Convective Systems ◽  
Convective Systems ◽  
Mesoscale Convective ◽  
Cloud To Ground Lightning

scholarly journals First versus subsequent return-stroke current and field peaks in negative cloud-to-ground lightning discharges

2008 ◽  
Vol 113 (D19) ◽  
Author(s):  
Amitabh Nag ◽  
Vladimir A. Rakov ◽  
Wolfgang Schulz ◽  
Marcelo M. F. Saba ◽  
Rajeev Thottappillil ◽  
...  
Keyword(s):  
Return Stroke ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning

scholarly journals Mesoscale convective systems observed during AMMA and their impact on the NO<sub>x</sub> and O<sub>3</sub> budget over West Africa

2010 ◽  
Vol 10 (10) ◽  
pp. 22765-22853
Author(s):  
H. Huntrieser ◽  
H. Schlager ◽  
M. Lichtenstern ◽  
P. Stock ◽  
T. Hamburger ◽  
...  
Keyword(s):  
Production Rate ◽  
Mass Flux ◽  
Mesoscale Convective Systems ◽  
Trace Gas ◽  
Stroke Rate ◽  
Convective Systems ◽  
Mixing Ratios ◽  
Convective Core ◽  
Different Types ◽  
Mesoscale Convective

Abstract. During the "African Monsoon Multidisciplinary Analysis" (AMMA) field phase in August 2006, a variety of measurements focusing on deep convection were performed over West Africa. The German research aircraft Falcon based in Ouagadougou (Burkina Faso) investigated the chemical composition in the outflow of large mesoscale convective systems (MCS). Here we analyse two different types of MCS originating north and south of the intertropical convergence zone (ITCZ, ~10° N), respectively. In addition to the airborne trace gas measurements, stroke measurements from the Lightning Location Network (LINET), set up in Northern Benin, are analysed. The main focus of the present study is 1) to analyse the trace gas composition (CO, O3, NO, NOx, NOy, and HCHO) in the convective outflow as a function of distance from the convective core, 2) to investigate how different trace gas compositions in the boundary layer (BL) and ambient air may influence the O3 concentration in the convective outflow, and 3) to estimate the rate of lightning-produced nitrogen oxides per flash in selected thunderstorms and compare it to our previous results for the tropics. The MCS outflow was probed at different altitudes (~10–12 km) and distances from the convective core (<500 km). Trace gas signatures similar to the conditions in the MCS inflow region were observed in the outflow close to the convective core, due to efficient vertical transport. In the fresh MCS outflow, low O3 mixing ratios in the range of 35–40 nmol mol−1 were observed. Further downwind, O3 mixing ratios in the outflow rapidly increased with distance, due to mixing with the ambient O3-rich air. After 2–3 h, O3 mixing ratios in the range of ~65 nmol mol−1 were observed in the aged outflow. Within the fresh MCS outflow, mean NOx (=NO+NO2) mixing ratios were in the range of ~0.3–0.4 nmol mol−1 (peaks ~1 nmol mol−1) and only slightly enhanced compared to the background. Both lightning-produced NOx (LNOx) and NOx transported upward from the BL contributed about equally to this enhancement. On the basis of Falcon measurements, the mass flux of LNOx in the investigated MCS was estimated to be ~100 g(N) s−1. The average stroke rate of the probed thunderstorms was 0.04–0.07 strokes s−1 (here only strokes with peak currents ≥10 kA contributing to LNOx were considered). The LNOx mass flux and the stroke rate were combined to estimate the LNOx production rate. For a better comparison with other published results, LNOx estimates per LINET stroke were scaled to Lightning Imaging Sensor (LIS) flashes. The LNOx production rate per LIS flash was estimated to 1.0 and 2.5 kg(N) for the MCS located south and north of the ITCZ, respectively. If we assume, that these different types of MCS are typical thunderstorms occurring globally (LIS flash rate ~44 s−1), the annual global LNOx production rate was estimated to be ~1.4 and 3.5 Tg(N) a−1.

Cloud-to-Ground Lightning in Linear Mesoscale Convective Systems

2001 ◽  
Vol 129 (5) ◽  
pp. 1232-1242 ◽  
Author(s):  
Matthew D. Parker ◽  
Steven A. Rutledge ◽  
Richard H. Johnson
Keyword(s):  
Mesoscale Convective Systems ◽  
Convective Systems ◽  
Mesoscale Convective ◽  
Cloud To Ground Lightning

scholarly journals Modeling the Flash Rate of Thunderstorms. Part I: Framework

2011 ◽  
Vol 139 (10) ◽  
pp. 3093-3111 ◽  
Author(s):  
Johannes M. L. Dahl ◽  
Hartmut Höller ◽  
Ulrich Schumann
Keyword(s):  
Radar Data ◽  
Mesoscale Convective Systems ◽  
New Approach ◽  
Flash Rate ◽  
Convective Systems ◽  
Cloud Properties ◽  
Lightning Detection ◽  
Mesoscale Convective ◽  
Lightning Discharges ◽  
New Framework

Abstract In this study a straightforward theoretical approach to determining the flash rate in thunderstorms is presented. A two-plate capacitor represents the basic dipole charge structure of a thunderstorm, which is charged by the generator current and discharged by lightning. If the geometry of the capacitor plates, the generator-current density, and the lightning charge are known, and if charging and discharging are in equilibrium, then the flash rate is uniquely determined. To diagnose the flash rate of real-world thunderstorms using this framework, estimates of the required relationships between the predictor variables and observable cloud properties are provided. With these estimates, the flash rate can be parameterized. In previous approaches, the lightning rate has been set linearly proportional to the electrification rate (such as the storm’s generator power or generator current), which implies a constant amount of neutralization by lightning discharges (such as lightning energy or lightning charge). This leads to inconsistencies between these approaches. Within the new framework proposed here, the discharge strength is allowed to vary with storm geometry, which remedies the physical inconsistencies of the previous approaches. The new parameterization is compared with observations using polarimetric radar data and measurements from the lightning detection network, LINET. The flash rates of a broad spectrum of discrete thunderstorm cells are accurately diagnosed by the new approach, while the flash rates of mesoscale convective systems are overestimated.

scholarly journals Mesoscale convective systems observed during AMMA and their impact on the NO<sub>x</sub> and O<sub>3</sub> budget over West Africa

2011 ◽  
Vol 11 (6) ◽  
pp. 2503-2536 ◽  
Author(s):  
H. Huntrieser ◽  
H. Schlager ◽  
M. Lichtenstern ◽  
P. Stock ◽  
T. Hamburger ◽  
...  
Keyword(s):  
Production Rate ◽  
Mass Flux ◽  
Mesoscale Convective Systems ◽  
Trace Gas ◽  
Stroke Rate ◽  
Convective Systems ◽  
Mixing Ratios ◽  
Convective Core ◽  
Different Types ◽  
Mesoscale Convective

Abstract. During the "African Monsoon Multidisciplinary Analysis" (AMMA) field phase in August 2006, a variety of measurements focusing on deep convection were performed over West Africa. The German research aircraft Falcon based in Ouagadougou (Burkina Faso) investigated the chemical composition in the outflow of large mesoscale convective systems (MCS). Here we analyse two different types of MCS originating north and south of the intertropical convergence zone (ITCZ, ~10° N), respectively. In addition to the airborne trace gas measurements, stroke measurements from the Lightning Location Network (LINET), set up in Northern Benin, are analysed. The main focus of the present study is (1) to analyse the trace gas composition (CO, O3, NO, NOx, NOy, and HCHO) in the convective outflow as a function of distance from the convective core, (2) to investigate how different trace gas compositions in the boundary layer (BL) and ambient air may influence the O3 concentration in the convective outflow, and (3) to estimate the rate of lightning-produced nitrogen oxides per flash in selected thunderstorms and compare it to our previous results for the tropics. The MCS outflow was probed at different altitudes (~10–12 km) and distances from the convective core (<500 km). Trace gas signatures similar to the conditions in the MCS inflow region were observed in the outflow close to the convective core, due to efficient vertical transport. In the fresh MCS outflow, low O3 mixing ratios in the range of 35–40 nmol mol−1 were observed. Further downwind, O3 mixing ratios in the outflow rapidly increased with distance, due to mixing with the ambient O3-rich air. After 2–3 h, O3 mixing ratios in the range of ~65 nmol mol−1 were observed in the aged outflow. Within the fresh MCS outflow, mean NOx (=NO+NO2) mixing ratios were in the range of ~0.3–0.4 nmol mol−1 (peaks ~1 nmol mol−1) and only slightly enhanced compared to the background. Both lightning-produced NOx (LNOx) and NOx transported upward from the BL contributed about equally to this enhancement. On the basis of Falcon measurements, the mass flux of LNOx in the investigated MCS was estimated to be ~100 g(N) s−1. The average stroke rate of the probed thunderstorms was 0.04–0.07 strokes s−1 (here only strokes with peak currents ≥10 kA contributing to LNOx were considered). The LNOx mass flux and the stroke rate were combined to estimate the LNOx production rate. For a better comparison with other published results, LNOx estimates per LINET stroke were scaled to Lightning Imaging Sensor (LIS) flashes. The LNOx production rate per LIS flash was estimated to 1.0 and 2.5 kg(N) for the MCS located south and north of the ITCZ, respectively. If we assume, that these different types of MCS are typical thunderstorms occurring globally (LIS flash rate ~44 s−1), the annual global LNOx production rate was estimated to be ~1.4 and 3.5 Tg(N) a−1.

Positive Cloud-to-Ground Lightning in Mesoscale Convective Systems

1990 ◽  
Vol 47 (17) ◽  
pp. 2085-2100 ◽  
Author(s):  
Steven A. Rutledge ◽  
Chungu Lu ◽  
Donald R. MacGorman
Keyword(s):  
Mesoscale Convective Systems ◽  
Convective Systems ◽  
Mesoscale Convective ◽  
Cloud To Ground Lightning
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