Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systems
Thunderstorm activity takes place in the eastern Mediterranean mainly through the boreal fall and winter seasons during synoptic systems of Red Sea Trough (RST), Red Sea Trough that closed a low over the sea (RST-CL), and Cyprus Low (during fall – FCL and winter – WCL). In this work we used the Isra...
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doaj-ebc6865bedae46328da2ba89abfae6982020-11-25T00:03:08ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812015-11-0115112449245910.5194/nhess-15-2449-2015Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systemsY. Ben Ami0O. Altaratz1Y. Yair2I. Koren3Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, IsraelDepartment of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, IsraelSchool of Sustainability, Interdisciplinary Center (IDC), Herzliya, IsraelDepartment of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, IsraelThunderstorm activity takes place in the eastern Mediterranean mainly through the boreal fall and winter seasons during synoptic systems of Red Sea Trough (RST), Red Sea Trough that closed a low over the sea (RST-CL), and Cyprus Low (during fall – FCL and winter – WCL). In this work we used the Israeli Lightning Location System ground strokes data set, between October 2004 and December 2010, for studying the properties of lightning strokes and their link to the thermodynamic conditions in each synoptic system. <br><br> It is shown that lightning activity dominates over sea during WCL and FCL systems (with maximum values of 1.5 in WCL, and 2.2 km<sup>−2</sup> day<sup>−1</sup> in FCL) and have a dominant component over land during the RST and RST-CL days. The stronger instability (high Convective Available Potential Energy (CAPE) values of 762 ± 457 J kg<sup>−1</sup>) during RST-CL days together with the higher altitude of the clouds' mixed-phase region (3.6 ± 0.3 km), result in a slightly higher density of ground strokes during this system but a lower fraction of positive ground strokes (3 ± 0.5 %). In general the fraction of positive strokes was found to be inversely correlated with the sea surface temperature: it increases from 1.2 % in early fall to 17.7 % in late winter, during FCL and WCL days. This change could be linked to the variation in the charge center's vertical location during those months. <br><br> The diurnal cycle in the lightning activity was examined for each synoptic system. During WCL conditions, no preferred times were found through the day, as it relates to the random passage timing of the frontal systems over the study region. During the fall systems (FCL and RST-CL) there is a peak in lightning activity during the morning hours, probably related to the enhanced convection driven by the convergence between the eastern land breeze and the western synoptic winds. The distributions of peak currents in FCL and WCL systems also change from fall to winter and include more strong negative and positive strokes toward the end of the winter.http://www.nat-hazards-earth-syst-sci.net/15/2449/2015/nhess-15-2449-2015.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Y. Ben Ami O. Altaratz Y. Yair I. Koren |
spellingShingle |
Y. Ben Ami O. Altaratz Y. Yair I. Koren Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systems Natural Hazards and Earth System Sciences |
author_facet |
Y. Ben Ami O. Altaratz Y. Yair I. Koren |
author_sort |
Y. Ben Ami |
title |
Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systems |
title_short |
Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systems |
title_full |
Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systems |
title_fullStr |
Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systems |
title_full_unstemmed |
Lightning characteristics over the eastern coast of the Mediterranean during different synoptic systems |
title_sort |
lightning characteristics over the eastern coast of the mediterranean during different synoptic systems |
publisher |
Copernicus Publications |
series |
Natural Hazards and Earth System Sciences |
issn |
1561-8633 1684-9981 |
publishDate |
2015-11-01 |
description |
Thunderstorm activity takes place in the eastern Mediterranean mainly through
the boreal fall and winter seasons during synoptic systems of Red Sea Trough
(RST), Red Sea Trough that closed a low over the sea (RST-CL), and Cyprus
Low (during fall – FCL and winter – WCL). In this work we used the Israeli
Lightning Location System ground strokes data set, between October 2004 and
December 2010, for studying the properties of lightning strokes and their link
to the thermodynamic conditions in each synoptic system.
<br><br>
It is shown that lightning activity dominates over sea during WCL and
FCL systems (with maximum values of 1.5 in WCL, and
2.2 km<sup>−2</sup> day<sup>−1</sup> in FCL) and have a dominant component over land during the RST
and RST-CL days. The stronger instability (high Convective Available Potential
Energy (CAPE) values of 762 ± 457 J kg<sup>−1</sup>)
during RST-CL days together with the higher altitude of the
clouds' mixed-phase region (3.6 ± 0.3 km), result in a slightly higher
density of ground strokes during this system but a lower fraction of positive
ground strokes (3 ± 0.5 %). In general the fraction of positive
strokes was found to be inversely correlated with the sea surface
temperature: it increases from 1.2 % in early fall to 17.7 % in late
winter, during FCL and WCL days. This change could be linked to the
variation in the charge center's vertical location during those months.
<br><br>
The diurnal cycle in the lightning activity was examined for each synoptic
system. During WCL conditions, no preferred times were found through the day,
as it relates to the random passage timing of the frontal systems over the
study region. During the fall systems (FCL and RST-CL) there is a peak in
lightning activity during the morning hours, probably related to the
enhanced convection driven by the convergence between the eastern land
breeze and the western synoptic winds. The distributions of peak currents in
FCL and WCL systems also change from fall to winter and include more strong
negative and positive strokes toward the end of the winter. |
url |
http://www.nat-hazards-earth-syst-sci.net/15/2449/2015/nhess-15-2449-2015.pdf |
work_keys_str_mv |
AT ybenami lightningcharacteristicsovertheeasterncoastofthemediterraneanduringdifferentsynopticsystems AT oaltaratz lightningcharacteristicsovertheeasterncoastofthemediterraneanduringdifferentsynopticsystems AT yyair lightningcharacteristicsovertheeasterncoastofthemediterraneanduringdifferentsynopticsystems AT ikoren lightningcharacteristicsovertheeasterncoastofthemediterraneanduringdifferentsynopticsystems |
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