26
In recent years multi-point lightning location systems have been being ac‑
tively developed in Russia [54–60]. A number of studies have been performed
so as to investigate and improve the precision of LLSs [56,61], new systems and
complexes have been created [54,55,57]. In other studies the LLS data have been
used together with other sources of information about thunderstorm activity [62].
A multi-point LLS developed in the IAP RAS was put into operation in the
Volga-Vyatka region. At the initial stage of development, this LLS covers Nizh‑
ny Novgorod region. During the period from 16 July 2014 until the end of the
convective season the LLS registered about 160000 lightning discharges (includ‑
ing both cloud-to-ground and intracloud discharge types). The system is based
on Boltek Stormtracker devices and special software developed in the IAR RAS.
For validating the precision of the developed LLS, the data obtained from it were
compared with the WWLLN data and the data from a Doppler weather radar;
this validation showed good correlation. In the Nizhny Novgorod LLS a com‑
bined method of lightning detection is applied, including the time-of-arrival and
direction finding methods [55, 63].
In the North Caucasus region the lightning detector LS8000, developed by
Vaisala, was put into operation. LS8000 provides the coordinates, polarity, type
(cloud-to-ground or intracloud) and other characteristics of lightning discharges.
Combined cluster processing is planned of the LS8000 data and the map of the
radio echo from clouds and precipitations, obtained from regional weather radars
network in real time. Since 2008, during the period of LS8000 operation, the
parameters of the currents for detected cloud‑to‑ground
lightning discharges
were studied [57].
During 2011, the Alves 9.07 LLS, developed jointly by Alves Ltd. and the
department of atmospheric electricity of the Voeikov Main Geophysical Obser‑
vatory, was modified. The Alves System is based on the time-of-arrival position‑
ing method and covers the European part of Russia and the Urals. The new
generation of lightning detectors was developed and put into operation. As of
August 2014, the LLS consisted of 70 lightning detectors. During the convective
seasons of 2013–2014 accuracy of the Alves was estimated using the data pro‑
vided by the European LLS Blitzortung [58–60]. Also, the sources of inaccura‑
cies caused by errors in the timing of atmospherics were investigated. Model and
experimental estimates of these errors were made [56, 64]. Model estimates of
the errors of lightning positioning algorithms were carried out for the case of a
high-current lightning stroke represented by an arbitrarily oriented dipole under
the influence of industrial noise [61].
In Eastern Siberia the features of the spatial distribution of positive lightning
discharges detected by a one-point detector with the coverage radius of about
1200 km were studied for 2003–2007 seasons. The spatial distribution of positive
lightning was found to be in general the same as the distribution of the total
E. A. Mareev, V. N. Stasenko, A. A. Bulatov, S. O. Dementyeva, A. A. Evtushenko, N. V. Ilin, ...
27
Atmospheric
Electricity
lightning activity. Areas of thunderstorm activity, where the count of positive
discharges is greater than the
count of negative ones,
were highlighted, and this
fact was accounted for by geographical conditions, such as high altitude and the
proximity of the Sea of Okhotsk; thus the influence of the relief on the inverted
charge distribution inside the cloud was demonstrated [65].
Other lightning activity parameters were investigated in the region of Central
Yakutia in 2009–2012. The percentage of cloud-to-ground discharges was found
to be 40–60%, which agrees with the observations in Western Siberia (40–50%).
Positive cloud-to-ground discharges count was 8–15%. Thunderstorm activity in
Yakutsk was 3 times higher than that in the 400-km vicinity of Yakutsk [66].
An LLS based on three independent lightning detectors have been function‑
ing in Yakutia for a long time; the detectors are located in Yakutsk, Neryungri,
Mirnyi. It operates in the VLF range and has the positioning precision of a few
kilometres. Using the LLS data helps to improve clustering algorithms. The re‑
sults of data processing showed that mature thunderstorm cells are located at the
cluster centre and dissipating cells are located at the downwind part of the clus‑
ter. The time of activity of a single cell is 20–30 minutes, whereas a multi-cell
cluster can exist for several hours. Thunderstorms in a cluster are usually more
intensive than those in isolated cells. According to the study of 227 thunderstorm
cells, average cell area is 12 km
2
, average cell lifetime is about 31 minute and
average count of discharges in a cell is equal to 10. For the first time the data on
thunderstorm climatology in the region are obtained [67].
5. High-altitude discharges and gamma flashes
In recent years high-altitude discharges in the atmosphere are given signifi‑
cant attention in the world. One of the main tools for the direct study of high-al‑
titude discharges are satellite measurements. The main scientific objectives and
engineering designs of the micro-satellite platform Chibis and the scientific
equipment Thunderstorm, which are aimed at exploring new physical mecha‑
nisms of high‑altitude electrical discharges
in the atmosphere, are presented in
[68]. In [69] the data are presented from a space experiment conducted at the
satellite University-Tatiana, in which the UV radiation in the night-time atmos‑
phere and fluxes of electrons with energies above 70 keV were measured simul‑
taneously. Increases in the average intensity of the UV radiation are registered;
presumably, they may be due to the acceleration of electrons in atmospheric
electrical discharges, followed by the capture of electrons by the geomagnetic
field and the electron precipitation at conjugate points of the geomagnetic field.
The statistics of high altitude discharges detected by the university satellite Ta‑
tiana 2 was analyzed in [70]. High-altitude discharges occur most often in equa‑
torial latitudes over land, and their duration is 1–128 ms. Sequences of