@InProceedings{SaraivaCamCumAntPin:2014:AnFoSt,
author = "Saraiva, Ant{\^o}nio Carlos V. and Campos, Leandro Zanella de
Souza and Cummins, Kenneth L. and Antunes, Larissa and Pinto Jr.,
Osmar",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {The University of
Arizona} and {Instituto Nacional de Pesquisas Espaciais (INPE)}
and {Instituto Nacional de Pesquisas Espaciais (INPE)}",
title = "Analysis of forked strokes characteristics over southeastern
Brazil during the summer season of 2013",
booktitle = "Proceedings...",
year = "2014",
organization = "International Lightning Detection Conference, 23. (ILDC); and
International Lightning Meteorology Conference, 5 (ILMC).",
publisher = "Vaisala",
note = "Informa{\c{c}}{\~o}es Adicionais: The objective of this work is
the analysis of overall characteristics of 35 cloud-to-ground (CG)
strokes that presented two or more contact points to the ground in
a millisecond scale. This dataset includes both the classical
forked strokes (first observed in streak camera records) and the
new class of this type of phenomenon, called upward illumination
strokes, introduced in more recent works. The genesis of the
latter is very similar to the classical forked strokes, i. e., one
branch from the main trunk of a stepped leader produces a second
stroke after the first return stroke occurs. The main difference
from the classical forked stroke events are: a) UI stroke channels
appear to completely disconnect from the main trunk during its
development, b) the time between strokes is longer than in the
case of classical forked strokes and c) the peak currents of the
UI strokes are, usually, very small. From the visual inspection of
the 35 selected events, 22 were classified as forked strokes and
13 UI strokes. A new name was given to the broad class of strokes
that present two or more contact points in a millisecond and
sub-millisecond scale, multi ground contact strokes (MGCS).
Subclasses received the names forked strokes and UI strokes ,
related to the previous findings from the literature. All MGCS
flashes were recorded during the summer season of 2013 in
Southeastern Brazil as part of a five-day campaign employing a
network of high-speed camera sensors known as the RAMMER network.
The high-speed video records were obtained by three identical
cameras installed in S{\~a}o Jos{\'e} dos Campos and a fourth
mobile camera (whose only difference from the other three is its
capability to record colored images). All four cameras were set up
for recording at 1200 x 500 pixels spatial resolution, 2500 frames
per second, and 400- s time interval between frames. A total of
357 negative CG flashes were recorded. The physical processes that
generate either forked strokes and UI st.",
keywords = "atmospheric electricity, lightning, lightning physics, forked
strokes, upward illumination strokes.",
abstract = "The objective of this work is the analysis of overall
characteristics of 35 cloud-to-ground (CG) strokes that presented
two or more contact points to the ground in a millisecond scale.
This dataset includes both the classical forked strokes (first
observed in streak camera records) and the new class of this type
of phenomenon, called upward illumination strokes, introduced in
more recent works. The genesis of the latter is very similar to
the classical forked strokes, i. e., one branch from the main
trunk of a stepped leader produces a second stroke after the first
return stroke occurs. The main difference from the classical
forked stroke events are: a) UI stroke channels appear to
completely disconnect from the main trunk during its development,
b) the time between strokes is longer than in the case of
classical forked strokes and c) the peak currents of the UI
strokes are, usually, very small. From the visual inspection of
the 35 selected events, 22 were classified as forked strokes and
13 UI strokes. A new name was given to the broad class of strokes
that present two or more contact points in a millisecond and
sub-millisecond scale, multi ground contact strokes (MGCS).
Subclasses received the names forked strokes and UI strokes,
related to the previous findings from the literature. All MGCS
flashes were recorded during the summer season of 2013 in
Southeastern Brazil as part of a five-day campaign employing a
network of high-speed camera sensors known as the RAMMER network.
The high-speed video records were obtained by three identical
cameras installed in S{\~a}o Jos{\'e} dos Campos and a fourth
mobile camera (whose only difference from the other three is its
capability to record colored images). All four cameras were set up
for recording at 1200 x 500 pixels spatial resolution, 2500 frames
per second, and 400-\μs time interval between frames. A
total of 357 negative CG flashes were recorded. The physical
processes that generate either forked strokes and UI strokes are
discussed in details. RAW data from BrasilDAT network was used to
identify and give more information about the MGCS, such as: peak
current estimates and precise interstroke intervals in the
microsecond range. Plots of time intervals between strokes versus
peak current added new information on the physical characteristics
and distinctive features of UI and forked strokes.",
conference-location = "Tucson",
conference-year = "mar. 18-19, 2014 / mar. 20-21, 2014",
label = "lattes: 4161737266837399 2 SaraivaCamCumAntPin:2014:AnFoSt",
language = "en",
targetfile = "Saraiva-Analysis of Forked Strokes Characteristics over
Southeastern Brasil-2014-ILDC-ILMC.pdf",
url = "http://www.vaisala.com/en/events/ildcilmc/Documents/2014%20ILDC-ILMC%20Agenda.pdf",
volume = "1",
urlaccessdate = "29 mar. 2024"
}