Geoscience Reference
In-Depth Information
Calculations made by Marshall and Stolzenburg (2002) showed that in the case
of positive CG strikes at which Q-
fl
ashes occur, the level of energy constitutes
40 km
2
. An estimation of total
electrostatic energy stored in two stratus clouds of mesoscale convective cloud
system gave values 5
10
10
J, and the area of strike is
about 1
×
40
×
*
10
11
and 2
10
12
J. These levels of energy are suf
×
×
cient to
provide hundreds or thousands of typical lightning strikes but only 10
100 positive
-
CG strikes with the accompanying Q-
ashes.
Using the Pockels sensors (Miki et al. 2002) in the International Center for
Lightning Research and Testing (ICLRT) in the State of Florida, Miki et al. (2002)
carried out measurements of the shape of the electric
fl
field wave at horizontal
distances from 0.1 to 1.5 m from the lightning channel. The dynamic range of the
measuring system varied between 20 kW m
−
2
and 5 MW m
−
2
, and the band width
in the interval from 50 GHz to 1 MHz. Also, electric
fields were measured near the
bottom of the channel and at distances 5, 15, and 30 m from the lightning channel.
Using the Pockels sensors, measurements of electric
fields were made for 36 strikes
in 9
“
trigger
”
fl
flashes. 8 of 36 strikes measurements were also made of horizontal
electric
field wave
looks like an impulse with its front edge determined by the strike leader, and the
rear edge determined by the inverse strike. Six of 36 studied shapes of the electric
fields. According to the results obtained, the shape of the electric
field wave were close the V-shape, whereas the other 30 were characterized by
much slower variations in the phase of reverse strike than at the leader stage. The
vertical electric field reached a maximum in the interval from 176 kW m
−
1
to
1.5 MW m
−
1
(an average of 577 kW m
−
1
), and the horizontal electric
in the
range between 495 kW m
−
1
and 1.2 MW m
−
1
(an average of 821 kW m
−
1
). These
values are characterized by a 40 % underestimation.
eld
—
5.7 The Numerical Modeling of the 3-D Distribution
of Aerosol and Climate
Developments concerning the 3-D
field of concentration and properties of aerosol
in the context of substantiation of air quality models have contributed much to
numerical modeling of the role of aerosol in the formation of climate.
The aerosol component of CMAQ model described by Binkowski and Roselle
(2003) for multiscale assessments of air quality, is aimed at ef
cient and time-
saving simulation of the atmospheric aerosol dynamics. The aerosol size distribu-
tion is represented as a superposition of three log-normal modes of aerosol which
include the small-sized mode PM-2.5 (D < 2.5
ʼ
m) consisting of two sub-modes
—
Aitken nuclei (D < 0.1
ʼ
m) and accumulation sub-mode (D = 0.1
-
2.5
ʼ
m), as well
ʼ
as large-sized mode PM-10 (D = 2.5
m). The process of the aerosol properties
evolution is described with coagulation, growth and formation of new particles.
In consideration of the aerosol components, the PM-2.5 and PM-10 modes of
primary emissions of elemental and organic carbon, as well as dust and other
-
10
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