Geoscience Reference
In-Depth Information
Fig. 11
Chapman elec-
tron density profile and the
ionospheric layers D, E, and F
for both night and day condi-
tions at mid-latitudes (Cravens
1997
)
1000
500
400
F2 Layer
300
200
F1 Layer
100
E Layer
D Layer
50
1
8
10
9
10
10
10
11
10
12
10
Electron density [elec/m
3
]
position of the transition height (at which the concentration of
O
+
and
H
+
are equal)
varies from around 800km on a winter night at low solar activity to around 4000km
during a summer day at high solar activity (Feltens et al.
2009
). Since there is almost
no plasma production in the plasmasphere, the ionized particles diffuse up from
the ionosphere to plasmasphere. The plasmasphere takes ionized particles from the
ionosphere by day, acting like a reservoir and stores them in a loss-free environment.
At nighttime this procedure gets inversed and the plasmasphere returns the ions
back to the ionosphere. Thus the nighttime F layer is maintained in the ionosphere
(Fig.
11
).
4.3.2 Latitude Dependent Spatial Variations
Due to the Earth's magnetic field the behavior of the ionosphere can be divided
into three latitudinal regions: low latitude (equatorial), mid latitude and high latitude
regions (Fig.
12
). The boundaries between the regions are not constant, but vary
according to local time, geomagnetic condition and solar activity.
0
o
-180
o
180
o
90
o
90
o
c
45
o
45
o
M
id l
r
E
-45
o
-45
o
ar
-90
o
-90
o
-180
o
180
o
0
o
Fig. 12
Latitude dependent regions of the ionosphere (modified from Hobiger
2005
)
