Geoscience Reference
In-Depth Information
coecient
α
1
(
R
) is obtained by the Fernald formula
6
as
S
S
2
α
1
(
R
)=
−
α
2
(
R
)
X
(
R
)exp
»
2
„
S
S
2
−
1
«Z
R
f
α
2
(
R
)
dR
-
R
+
+2
Z
R
f
R
X
(
R
)exp
»
2
„
S
S
2
−
1
«Z
R
f
α
2
(
r
)
dr
-
dR
.
X
(
R
f
)
α
1
(
R
f
)+
S
S
2
α
2
(
R
f
)
R
(2)
In the present analysis, we assume
S
2
= 30 sr for aerosols and 17 sr for
clouds. In Sec. 6, the PAL data are depicted using the time-height
indication (THI): the abscissa shows time, the ordinate shows the height,
and the signal intensity is shown in the brightness (color or gray) scale.
Because of the elevation angle (38
◦
), the height resolution is improved by
a factor of sin 38
◦
=0
.
62.
5. Features of Meteorological Data
Before comparing PAL lidar data and meteorological conditions, the aspects
of average meteorological conditions in 2004 and 2005 are overviewed.
Monthly average of weather parameters of Chiba observatory is shown in
Figs. 2(a) and 2(b).
From Figs. 2(a) and 2(b), it is found that in 2004, the precipitation
amount of October was exceptionally large, while in July it was quite
small. Usually in Chiba, precipitation is small from November to May, and
large from August to October (except September, 2005). From the graph,
Fig. 2. Meteorological parameters at Chiba Observatory in 2004 and 2005. (a) Monthly
precipitation (mm), sunshine hour (h), and relative humidity (%), (b) temperature (
◦
C),
relative humidity (%), wind speed (m/s), and temperature difference in a day (
◦
C).
