Features of Ground Flashes before and after the Massive Earthquake Observed from Kathmandu, Nepal

Tiwari

2021

BIBECHANA

In Nepal, the main disasters are floods, lightning, fire, epidemics, and landslides. Among the several disasters in the Himalayan region, lightning is an important one. Because of the short distance (about 160 km) between the low land and peak Mount Everest from South to North, there is a variation of about 950C temperature in these regions. The topographical features of the southern slopes and variation of temperature within this short distance influences the features of lightning and in this scenario, we get the positive cloud to ground lightning frequently which is more dangerous for human beings, animals, and property. In the Himalayan region, thunderstorms occur near the mountains due to which more positive charge can easily transfer from cloud to ground. Hence positive lightning occurs in the Himalayan region. The majority of the lightning-affected people are unaware of lightning safety and they should know the measures to protect life and property from lightning hazards. Hence by conducting awareness programs for the people of potential hazard areas, the number of injured people can be reduced as well as electrical, medical, military equipment can be somewhat protected from lightning. BIBECHANA 18 (2) (2021) 116-128

Section: Instrumentation and Methodologymentioning

confidence: 99%

Effects of lightning as a disaster in Himalayan region

Tiwari

2021

BIBECHANA

“…In this paper, the digitizer volts are used to measure the electric field signatures. A similar electric field measuring system is described in various other experiments also [ 25 – 30 ].…”

Section: Instrumentationmentioning

confidence: 99%

Section: Instrumentationmentioning

confidence: 99%

Comparing the Wave Characteristics of Breakdown Pulses of the Lightning Waveforms in the Himalayan Region

The Scientific World Journal

2021

Self Cite

We have analyzed the breakdown pulse train with or without the main event in this paper. Among the selected 81 flashes, 36 flashes are starting positively, and 45 are starting negatively. Also, 58 flashes contain positive pulses, and 67 flashes contain negative pulses, whereas 44 flashes contain both positive and negative pulses. Among these 81 flashes, 22 flashes follow the main events, and the rest are isolated events. In this study, we got the main duration of PB pulses as 1.94 ms and the time interval between the breakdown pulse and return stroke as 61.49 ms. On taking each pulse train, we found the rise time to be 2.6 μs, zero-crossing time 14.95 μs, and the time interval between pulses 199.3 μs. The largest pulse amplitude ratio in the preliminary breakdown pulse to the main event return stroke was 0.43.

“…To find the discovered properties, researchers used different instruments with the help of fast optical and electromagnetic instruments. Some previously unrecognized lightning signatures have been identified later on, such as, Compact Intra-Cloud Discharges (CIDs) [1,2]; Narrow Bipolar Pulses (NBPs) [3]; Isolated Breakdown Pulses (IBPs) [4,5]; Transient luminous sig-natures observed in the middle and upper atmosphere [6,7]; Unusual lightning [8]; Different features of cloud flashes [9,10,11]; Preliminary breakdown pulses [12,13]; Different features of positive CG lightning [14,15] and so on. A sudden occurrence of a violent discharge of steam and volcanic material from certain regions of land, mountains, or water bodies is known as a volcanic eruption.…”

Section: Introductionmentioning

confidence: 99%

Discharging Phenomena in different types of Lightning

2022

J. Nep. Phys. Soc.

There are two charge regions and charges can transfer from one region to another region. For lightning discharging process, the centers of two charges are separated by different distances and air as an insulator between them. The methods of the process of charge formation in differ-ent types of lightning are different. In volcanic lightning, it form closer to the ground and dis-charging process occurs between the two charge regions as the normal thunderstorm lightning does. The steeped leader starts at the structure and propagates upward in nuclear lightning. Their direction of branching is also upward and the return strokes do not initiate from upward moving leaders. It is similar to upward initiated thunderstorm lightning flashes from tall struc-tures and forms in several kilometers. In Earthquake lightning, a shifting of the positive and negative charge centers in the material, which then results in an external electric field. Even the different lightning signatures have been observed in our scientific community, the thunderstorm lightning is frequently observed and measured by the different methods such as electric field measurement, magnetic field measurement, photography and so on. Here, the method of elec-tric field measurement is used to measure the thunderstorm lightning. In all cases of lightning, the discharge phenomena take place between two different charged regions. The two regions of positive charges and negative charges are separated by a certain distance and the air between them is an insulator. When the sufficient charges store in the two charge regions, voltage is de-veloped between them. If the potential developed is sufficient for the electric breakdown of the air, then lightning phenomena occur. Hence, the discharging phenomena occur between the positive and negative charge regions for the different types of lightning.