maxima of the comparison period and critical frequencies were consistentiy leas than the frequency minima.
However, the extreme rise
in virtual height which occurred after Shots 1 and 2 and Shot Mike
(Operation IVY) was not observed at. Rongerik following Shot 4.
If there was a region of mrked upward displacement of the F2
layer resulting from Shot 4, as seems likely, then it occurred above
another geographical location. Ths most pronounced evidence of |
abnormal conditions occurred in the Jonograms recorded during the per=
iod from plus 40 min, when the F2 layer emerged from absorptive
obscuration, to about plus 11/2 hr. The weak and irregular echoes
from plus 40 to plus 55 min are shown in Fig. 3.16. A series of
‘Lonograms from plus 57 to plus 70 minshows an F2 return apparently —
rising to 500 ln (Fig. 3.17).
_
7
Kn
cet pp
cae
“ab
Sete
Eee:
800 ere?
‘
x2 A
dda
“2B
Se
Er
it
EERE:
‘
~*~
45.+40M
600
-
400
200
qa
+
a
fi
THEE
an: beck:
bict
? ome
0
ra
POPE
46+ 42M
oe
800
OY 49.536
i
ee
Sart
600
400
200 dina fninn
KM
i
pepe
800 Bik
47.4456q
Fe
i
Fie
op
Ks
600 §
ph
pore
2 00 tmmerer
a
ow
2
:
:
Pi:
Be
Bo s
*
pe
are
bent
0
~
ene te een
80.455M
a:
aa.
eer
mi
5.
sh
at
:
a
me
:
| TTS
i
oe
3
4
Ria
be
i
6 60
eek ee OL 8 te te“se
Figo 3.16 « Ionospheric Resords at, Rongerik Following Shot 4 ty
40 to 55 min, Showing Weak and Irregular F2 Echoes
43
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