GENERAL CIRCULATION OF THE E-REGION
by
Leonard S.
Fedor
B.S., San Diego State College
(1961)
SUBMITTED IN PARTIAL FULFILLMENT
C
OF THE REQUIREMENTS FOR THE
I
3i
iss.INST. TEcy
DEGREE OF MASTER OF
LIBRARY
SCIENCE
LINDGREN
at the
MASSACHUSETTS INSTITUTE OF
TECHNOLOGY
September, 1964
A
r
i
I
.
Signature of Author ...........
Department
.
.
V.0.*
a
a
. * *, . .
of Meteorology,
August 24,
..
1964
i
.Certified by
*
*
*
*...
*
4;j
;9f
*
60
0
Thesis Supervisor
Accepted by
*
..........
00.*ee
o...
ooooooooo..
...
*
......o..
.*00
Chairman, Departmental Committee
on Graduate Students
GENERAL CIRCULATION OF THE E-REGION
by
Leonard S. Fedor
Submitted to the Department of Meteorology on August 24, 1964
in partial fulfillment of the requirement for the degree of Master
of Science.
ABSTRACT
Ionospheric sounders may be used to determine the motions
in the upper atmosphere by monitoring the reflected waves at
three spaced receivers. The correlation method of determining
the motions in the ionosphere is presented in detail. The data
from fifteen sounders is used to formulate a preliminary picture
of the atmospheric general circulation in the region from 95 km
to 115 km.
The diurnal variations of the wind at selected stations are
shown for various seasons. The data is arranged according to
distribution for each hour and a mean value is given for each hour.
Height profiles of the zonal wind showing the seasonal variation are given at four-hour intervals. A height profile of the
prevailing component of the zonal wind is determined from two sets
of profiles. The height profile of the tidal variations is also
shown. Zonal and meridional prevailing winds are shown in hemispheric maps for both summer and winter.
Thesis Supervisor:
Title:
Reginald E. Newell
Assistant Professor of Meteorology
-ii-
TABLE OF CONTENTS
I
INTRODUCTION
A.
B.
II
..
.
.
.
.
.
.
.
.
.
...
. .
General Circulation
Detection of Motions by Radio Methods
CALCULATION OF THE MOTIONS.
.
.
.
.
.
.
.
.
.
.
1
.
.
.
.
.
.
.
.
.
A.
Introduction .
B.
The Method of Briggs, Phillips and Shinn
.
.
.
.
1.
The Space-Time Ellipse .
.
.
11
.
.
11
.
.
.
16
.
.
.
.
The Connecting Equations
.
.
.
.
.
.
.
Structure Size .
The Velocities in a Two-Dimensional Space
.
.
.
.
Isotropy and Anisotropy .
1.
.
.
.
.
20
22
.
.
24
.
.
24
2.
.
.
Velocity Definitions
.
.
.
.
.
.
3.
4.
C.
.
.
.
.
.
.
.
The V'c Ellipse.
.
.
3. Determining the Fading Velocity and
Characteristic Velocity in Two Dimensions .
4. Concerning a Comparison of the Methods . .
.
.
.
.
.
.
Notes About the Stations . .
2.
D.
III
RESULTS .
A.
B.
C.
D.
E.
IV
11
11
.
.
1
6
.
.
.
.
.
.
.
.
.
.
.
.
.
Diurnal Wind Variations at Individual
Stations . .
.
.
.
.
.
.
.
.
.
.
.
.
Height Profiles of the Zonal Wind .. .
Height Profiles of the Prevailing Zonal Wind
Height-Profiles of the Zonal Wind Without
the Prevailing Component .
.
.
.
.
.
.
Hemispheric Zonal and Meridional Prevailing
Motion .
.
.
.
.
.
.
.
.
.
.
.
.
CONCLUSIONS
.
ACKNOWLEDGEMENTS.
BIBLIOGRAPHY
.
.
24
27
33
34
.
37
.
.
.
37
67
74
.
77
.
84
.
.
.
.
.
.
.
.
.
.
.
89
.
.
.
.
.
.
.
.
.
.
.
91
.
.
.
.
.
.
.
.
.
.
.
92
-iii-
LIST OF ILLUSTRATIONS
1.
Observed Zonal Wind 'Component After Murgatroyd
(westerly components positive, m/sec) .
.
2.
Space-Time Plot of a Sine-Wave Moving Along the
x-axis . . . . . . . . . . . . .
12
Space-Time Plot of Random Signal Moving Along
Positive x-axis .
.
.
.
.
.
.
.
.
.
13
Space-Time Plot of a Contour of the Correlation
Function
.
.
.
.
.........
15
Temporal Cross-Correlation Function Between Two
Receivers Separated by the Distance o
.
17
Space Cross-Correlation Function Between Two
Receivers Separated by the Time Tr .
.
.
19
3.
4.
5.
6.
7.
Possible Receiver Locations
8.
Characteristic Ellipse .
9.
.
.
.
.
25
.
.
.
.
26
Apparent Drift Velocity - Uncorrected for
Anisotropy.
.
.
.
.
...
. .
.
.
.
28
0
..
..
29
30
.
10.
Apparent Drift Velocity - Reduced
11.
Apparent Drift Velocity - Corrected
12a.
.
.
.
Spring (After Harnischmacher, 1963).
..
0
..
..
.
.
.
.
.
0
0
0
0
0
.
.
.
.
.
0
0
0
.
.
.
43
12b.
Summer (After Harnischmacher, 1963).
12c.
Autumn (After Harnischmacher, 1963).
45
12d.
Winter (After Harnischmacher, 1963).
46
13a.
Diurnal Variation of the West-East Component at
Yamagawa (Jan-Feb-Mar) .
.
.
.
.
.
.
.
47
Diurnal Variation of the South-North Component
at Yamagawa (Jan-Feb-Mar) .
.
.
.
.
.
.
48
13b.
-iv-
*
.
44
14a.
14b.
15a.
15b.
16a.
16b.
17a.
17b.
18 a.
18b.
19a.
19b.
20a.
20b.
21a.
21b.
Diurnal Variation of the West-East Component at
Yamagawa (Apr-May-June) .
.
.
.
.
.
49
Diurnal Variation of the South-North Component at
Yamagawa (Apr-May-June) .
.
.
.
.
.
.
50
Diurnal Variation of the West-East Component at
Yamagawa (July-Aug-Sept)
.
.
.
.
.
.
.
51
Diurnal Variation of the South-North Component at
Yamagawa (July-Aug-Sept)
.
.
.
.
.
.
52
Diurnal Variation of the West-East Component at
Yamagawa (Oct-Nov-Dec)
.
.
.
.
a
.
*
S 53
Diurnal Variation of the South-North Component at
Yamagawa (Oct-Nov-Dec) .
.
.
.
.
. .
S 54
Diurnal Variation of the West-East Component at
Waltair (July-Aug-Sept) .
.
.
.
.
.
55
Diurnal Variation of the South-North Component at
Waltair (July-Aug-Sept) .
.
. .* ...
56
Diurnal Variation of the West-East Component at
Waltair (Oct-Nov-Dec)
* * * * * *
*
57
Diurnal Variation of the South-North Component at
Waltair (Oct-Nov-Dec)
*
. . . . . .
58
Diurnal Variation of the West-East Component at
Rostov (Oct-Nov-Dec)
*
*
.
59
Diurnal Variation of the South-North Component at
Rostov (Oct-Nov-Dec) ..........
60
Diurnal Variation of the West-East Component at
Mayaguez (Jan-Feb-Mar)
.
. .....
61
Diurnal Variation of the South-North Component at
Mayaguez (Jan-Feb-Mar) *
*
*
* .
.
62
Diurnal Variation of the West-East Component at
Mayaguez (Apr-May-June) .........
63
Diurnal Variation of the South-North Component at
Mayaguez (Apr-May-June) .
.
.
.
.
.
.
.
64
22a.
22b.
Diurnal Variation 'of the West-East Component at the
Pennsylvania State College (July-Aug-Sept). .
.
Diurnal Variation of the South-North Component at
the Pennsylvania State College (July-Aug-Sept)
65
.
66
Height Profile of the Zonal Wind at 0000 Local
.
.
.
Time
68
Height Profile of the Zonal Wind at 0400 Local
Time .
.
.
*
69
Height Profile of the Zonal Wind at 0800 Local
Time .
70
Height Profile of the Zonal Wind at 1200 Local
Time .
.
.
71
Height Profile of the Zonal Wind at 1600 Local
Time .
.
.
72
Height Profile of the Zonal Wind at 2000 Local
Time .
.
73
24a.
Height Profile of the Prevailing Zonal Wind
75
24b.
Height Profile of the Prevailing Zonal Wind
76
25a.
Height Profile of the Zonal Wind Without the
Prevailing Component at 0000 Local Time
78
Height Profile of the Zonal Wind Without the
Prevailing Component at 0400 Local Time
79
23a.
.
23b.
.
.
#
23c.
23d.
23e.
.
0
23f.
S
25b.
25c.
25d.
25e.
25f.
0
a
0
0
0
.
0
*
&
0
0
0
*
.
0
0
0
0
0
.
0
.
.
0
0
0
0
0
0
0
.
.
.
0
0
0
Height Profile of the Zonal Wind Without the
Prevailing Component at 0800 Local Time
.
.
.
80
Height Profile of the Zonal Wind Without the
Prevailing Component at 1200 Local Time
.
.
.
.
81
Height Profile of the Zonal Wind Without the
Prevailing Component at 1600 Local Time
0
.
82
Height Profile of the Zonal Wind Without the
Prevailing Component at 2000 Local Time
83
26a.
26b.
26c.
26d.
Hemispheric Map of the Prevailing Zonal Winds in
the Winter . .
.
.
.
.
.
.
.
.
.
.
85
Hemispheric Map of the Prevailing Zonal Winds in
the Summer . .
. .* .
*
.
. . . .
.
86
Hemispheric Map of the Prevailing Meridional Winds
in the Winter.
.
.
.
. . . . . .
.
87
Hemispheric Map of the Prevailing Meridional Winds
in the Summer .
.
.
.
.
.
.
.
.
.
88
LIST OF TABLES
1,.
Stations Used in the Analysis
2.
The 24-, 12-, and 8-Hour Harmonics Obtained by
&.
.
.
.
Fourier Analysis (from Aono, et.al., 1961)
-vii-
0
.
.
.
.
40
CHAPTER I.
A.
INTRODUCTION
General Circulation
Initial studies of the general circulation of the atmos-
phere have been concerned with the troposphere, where the
weather systems form.
As data became available the studies
were extended to include the stratosphere.
It is natural to
continue the general circulation investigations into the upper
atmosphere.
Physicists have been determining the motions in
the ionosphere for many years at various stations.
It is the
purpose of this thesis to use the more recent data to obtain
a picture of the circulation in the region from 95 km to 115 km.
A survey article by Murgatroyd (1957) proposed a model for
the zonal motions in the upper atmosphere (up to 100 km) using
measurements made by a variety of methods.
For the high alti-
tudes these methods include the use of noctilucent clouds,
ionized meteor trails, ejection of sodium from rockets, radio
propagation, and others.
given in Figure 1.
The results of Murgatroyd's study are
Above 80 km the results were obtained from
the data of nine stations and include data from both hemispheres.
Kochanski (1963) proposed models of the general circulation at
80 km and 100 km based mainly on the meteor trail measurements
at Jodrell Bank and Adelaide.
Such a model necessarily suffers
-1-
Summer
120
Winter
120
E
100
I
Pole
80*
600
400
200
Equator
20*
408
Figure 1:
I~Cbs
600
80* Pole
Latitude
Latitude
Observed Zonal Wind Component After Murgatroyd (1957)
(westerly components positive, m/sec)
=;-iZ. -ru i~i--~ C---~P-i
~-~-51~-FliJYasZGill~-BIClt~P-IIL
L-
1-
_1~1_~1 _~_~_
_1__
_~_1~1~11_~~...__ ~.~_~
I
for its lack of observations and number of stations.
However,
there has been information gained from the data at the individual meteor wind stations.
For example, this data shows that
internal gravity waves are present (Hines, 1960) and the Jodrell
Bank data shows strong tidal components.
A source of much information in the studies of the general
circulation at lower altitudes has been the separation of the
motions into harmonic components (see, for example, Teweles,.
1963).
Four groupings of the resultant waves are made; the
zonal flow (n = 0), long or planetary waves (n = 1 to 4), cyclone
waves (n = 5 to 8), and short waves (n = 9 to 15).
In the trop-
osphere the cyclone waves provide the largest energy contribution to the zonal flow (Teweles, 1963), while in the stratosphere
the planetary waves contribute the most energy to the zonal flow
(Teweles, 1963).
In particular, at 100 mb, eddies of wave
number 1 and 2 contribute the bulk of the energy to the zonal flow.
There is energy exchanged among the eddies of different wave
number.
The eddy of wave number 3 receives the most energy from
the other eddies.
Charney and Drazin (1961) considered the
vertical propagation of planetary-scale waves.
The damping of
these waves with altitude is dependent upon the magnitude of the
zonal winds in the stratosphere.
They concluded that these waves
probably could not be propagated above the stratosphere, except
-3-
possibly in the spring after the breakdown of the polar night
jet, and for a short time in the autumn.
Hines (1963) points
out that in the winter when the transmission coefficient increases (he determines from Charney and Drazin that the transmission coefficient for a horizontal wavelength of 10
10
- 3
km is
in the winter) more than enough energy needed to support
prevailing motions can be propagated to 95 km.
Hines' calcu-
lations were approximations but they point out that planetaryscale motions propagated from below may be a source of energy
for the motions in the upper atmosphere.
Internal gravity waves generated in the troposphere may
propagate into the ionosphere.
Gossard (1962) discussed the
generation of internal gravity waves in connection with tropospheric weather.
Jones (1963) proposes that internal gravity
waves may be generated as secondary waves resulting from the
interaction of the tides with geographic undulations.
Hines
(1960, 1963) has shown that the lower ionosphere is a permissible region for the existence of these waves.
His discussion
included experimental evidence of their existence in this
region.
The waves should not be in evidence much above 100 km
because of the increasing importance of molecular viscosity
(Jones, 1963).
-4-
The influence of the tides in the lower ionosphere is well
documented.
The data from meteor trail measurements at Jodrell
Bank (530 N) show that there is a prevailing wind of about
15 m/sec, with a 24-hour tidal component of about 10 m/sec, and
a 12-hour tidal component of about 20 m/sec (Greenhow and
Neufeld, 1961).
Meteor trail measurements at Adelaide (350S)
show that the 24-hour tidal component is directed northward at
1730 LT (local time) with a magnitude of 27 m/sec and it
is
directed eastward at 0930 LT with a magnitude of 25 m/sec.
The
12-hour tidal component at Adelaide is directed northward at
0000 LT with a magnitude of 20 m/sec in the summer and northward at 0530 LT with a magnitude of 5 m/sec in the winter; the
12-hour tidal component is directed eastward at 0720 LT with a
magnitude of 12 m/sec.
at Brisbane (270S)
tude of 7 m/sec.
Radio waves reflected from the ionosphere
show a 24-hour tidal component with a magniThe 12-hour tidal component at Brisbane is
directed northward at 0930 LT with a magnitude of 10 m/sec in
the summer and at 0230 LT with a magnitude of 15 m/sec in the
winter; it is directed eastward at 0840 LT with a magnitude of
8 m/sec (Burke and Jenkinson, 1957).
The observations at
Freiburg (510 N) were analyzed according to the distribution in
the percentage of times each value occurs (Harnischmacher, 1963).
The data was arranged to occur with both solar time and lunar time.
-5-
Harnischmacher then found that the solar and lunar phase shifts
of the 12-hour tidal component were quite similar.
On the
average both go through north at 0300 hours and 1500 hours
solar or lunar time.
He concluded that gravitational forces
were the cause of the solar and lunar 12-hour terms.
Harnischmacher defines the term engagement to describe the
importance and concentration of the distribution maximum.
An engagement of 100% would exist for a delta-function distribution, an engagement of 0% would indicate that no preference
can be found for the distribution.
In solar time the engage-
ment is 25% for the prevailing component, 3% for the 24-hour
tidal component, and 25% for the 12-hour tidal component.
In
lunar time the engagement is 5% for the prevailing component,
9% for the 24-tidal component, and 15% for the 12-hour tidal
component.
B.
Detection of Motions by Radio Methods
The measurements used in this thesis are all derived from
the fading of radio waves reflected from the ionosphere.
It
is important to know what relation the measurements have to
the actual winds at ionospheric heights.
-6-
Radio waves transmitted from the ground interact with the
free electrons in the ionosphere resulting in the waves being
reflected back to the ground.
The reflection coefficient is
dependent upon the frequency of the waves, electron density,
the magnitude and direction of the earth's magnetic field,
and the electron-neutral particle collision frequency (see,
for example, Ratcliffe, 1959a).
Depending upon the time of
day and angle of incidence very low frequency (3 kc/s to
30 kc/s) and low frequency (30 kc/s to 300 kc/s) radio waves
are reflected from the D-region (below 95 km) and the lower
E-region.
Medium frequency (300 kc/s to 3 mc/s) radio waves
are reflected in the lower E-region.
In the D-region the
collision frequency is high so that waves reflected here are
strongly absorbed.
The collision frequency is considerably
reduced in the E-region but waves reflected here will suffer
some absorption in passing through the D-region.
Since the
electron density varies throughout the day the radio waves
will be reflected at different heights during the day.
*At any particular frequency the ionosphere does not behave
as a perfect reflector.
The direction of propagation bends as
the waves traverse the medium until they emerge from the bottom
-7-
of the ionosphere.
When the time of travel is known and the
free-space velocity is assumed an apparent reflection height
results (Ratcliffe, 1959a).
Uncertainty of this height in
relation to the true height is about 10 km (Briggs, 1960) and
will depend upon the frequency and the angle of incidence.
The reflected signal is.variable in amplitude and phase.
This is true because the electron density is irregular, the
electrons having a tendency to form "clouds".
The radio waves
will be scattered from these irregularities and form a diffraction pattern.
The reflected signal received at the ground will
vary with time if an unchanging diffraction pattern moves with
a steady drift, if random changes occur within the diffraction
pattern, or if there is a combination of steady drift and random
changes (Briggs, et.al., 1950; Bowhill, 1956a).
Determination
of the velocities of drift will be discussed in detail in succeeding paragraphs.
An extensive study of the relationship
between the diffraction pattern at the ground and the diffraction pattern at the diffracting screen has been made by Bowhill
(1956b).
In terms of wavelength the higher frequency waves
give the appearance that the screen is a very long distance from
the ground.
The structure size (to be defined) and the fading
speed of the pattern at the ground have a one-to-one correspondence
with the pattern at the screen.
-8-
For long waves (VLF and LF) the
relation between the pattern at the screen and the pattern at
the ground is not simple but it is determinable.
Fooks (1962)
shows that the irregularities have their greatest effect on
the reflected signal when they are just below the height of
reflection.
This agrees with experiment results (Jones, 1958).
The relationship between the motions determined by radio
methods and the neutral wind is still not clearly understood.
Electrodynamics may play an important role in determining the
motions at the altitudes considered here.
From a summary
article by Ratcliffe (1959b) electromagnetic effects are negligible in the D-region and the motion of the electrons is
identical to the neutral wind.
In the E-region the winds and
the electric fields (set up by the winds and by polarization
effects) have equal effect on the ionization drifts.
The exact
height where the electric-field effect becomes important is
not known.
Jones (1958) has compared the results from the radio
wave fading technique with the meteor trails technique and concluded that the ionization irregularities move with the neutral
wind up to 110 km.
E-region sounders determine the motions of densely ionized
electron clouds (sporadic E) at night.
Axford (1963) proposes
a model which shows that the sporadic E may be formed by the
-9-
motion of electrons along the earth's magnetic field lines.
The motion of electrons along the field lines may be caused by
neutral wind shears set up by internal gravity waves (Hines,
1960).
The vertical movement of the internal gravity waves can
cause a vertical transport of these clouds (Axford, 1963).
Gossard and Paulson (1964) have proposed that electron cloud
projections extend into the D-region causing the rapid phase
changes "seen" by ionospheric sounders.
These projections may
remain for some time before attachment and recombination
processes dissipates them.. The projections may separate into
smaller clouds before they finally disappear.
This may be
why the ratio of random vzlocity to drift velocity (to be
defined) in the D-region (Sales and Bowhill, 1962) is greater
than that in the E-region (Fooks and Jones, 1961).
CHAPTER II.
A.
CALCULATION OF THE MOTIONS
Introduction
The motions in the ionosphere may be determined from radio
waves that have been reflected from the ionosphere and received
at three spaced receivers.
motions are presented here.
The methods of determining the
There are three methods presently
being used by various workers.
The time-delay method (see, for
example, Sales, 1960) has been called the spaced receiver or
Mitra method after its originator.
The method devised by Briggs,
Phillips, and Shinn (1950) uses statistical functions and is
called the correlation method.
Yerg (1959) has proposed a
statistical method that gives results that are similar to those
given by the correlation method.
The correlation method with
modifications by Phillips and Spencer (1955) and by Sales and
Bowhill (1962) is presented in this chapter.
The limit of the
time-delay method is shown.
B.
The Method of Briggs, Phillips, and Shinn
1.
The Space,Time Ellipse
Consider a two-dimensional diagram where the coordinates
are space and time as in Figure 2.
-11-
t (time)
4-.
At
x *spoce
Figure 2. Space-Time Plot of a Sine Wave Moving Along the x-axis.
Suppose that a receiver has been placed at A and another at B
on the x-axis, at a distance, e, apart.
If a sine wave travels
along the x-axis its temporal record at A would be indicated by
the maxima and minima (crosses and circles) along the line parallel to the t-axis passing through A in Figure 2. The same
sine wave would arrive at B but its time record is displaced by
a time, At, the time it takes the sine wave to travel from A to
B.
Therefore, knowing e it is possible to determine the speed
at which the sine wave is traveling along the x-axis, i.e., VAt.
-12-
If, instead of a simple sine wave, the received signals
were a diffraction pattern of radio waves that resulted from
the reflection of the waves from the ionosphere, then a similar
space-time plot may be made.
In order to obtain a more complete
picture consider that there are an infinite number of receivers
situated along the x-axis.
The space-time plot then might
appear as in Figure 3.
)
7
'2$
I
Figure 3.
r-
i
•
I
I
I
--
Space-Time Plot of Random Signal Moving Along
Positive x-axis.
-13-
The closed contours are isolines of amplitude and are shown
sloping corresponding to the time delay of the signal as it
travels from A to B as in Figure 2.
The contours of the
diffraction pattern are shown irregular since the ionospheric
diffracting screen causing the pattern will be irregular.
The
exact nature of the diffraction pattern cannot be determined
since it is impossible to have an infinite number of receivers
and impractical. to have more than a few.
This is as far as the Mitra method carries the analysis.
Three receivers are set up to form a triangle.
The temporal
records of a pair of receivers are compared for similar maxima.
The time displacements determined over a length of the record,
usually about fifteen minutes, are then averaged to give a
fading.time.
Knowing the distance between the two receivers
gives a component of the drift velocity in the direction of
the line joining them.
A similar procedure is made using a
second pair of receivers of the triangle.
The two components
are added vectorially to find the drift velocity.
The errors
possible with this method will soon become apparent.
Consider a two-dimensional correlation function defined
such that, p(a,O)
is the spatial auto-correlation function
and p(0,T) is the temporal auto-correlation function.
-14-
There
is experimental evidence that p(e,0) and p(0,7) have similar
shapes (Bowhill, 1956a).
The cross-correlation function is
P(o,-7) where eo is the spatial separation between itwo
receivers.
The three-dimensional picture of the correlation
function would be a surface whose maximum value occurs at zero
time lag and zero space lag, given by p(O,O) = 1.
'Considering
that the correlation function is fairly well behaved near the
origin (
=
0, 7 = 0), to a first approximation an isopleth
will have the form of an ellipse.
An isopleth, Po, of the
correlation function is shown in Figure 4.
The slope of the
ellipse is due to the time required for an event to move from
one point to the next.
axis (line 00')
is
Thb inverse of the slope of the major
the drift velocity component in
the
x-direction, Ax/At..
#o--
o-
x
,/
'
0,0)
/
Io
(Eo,To)
(xo,O
!
00
Figure 4.
Space-Time Plot of a Contour of the Correlation
Function.
-15-
X
2.
Velocity Definitions
The preceding discussion has been limited to the effect a
stable diffraction pattern has on a space-time plot.
If the
diffraction pattern changes form as it drifts the velocity of
drift cannot be found simply, as by the Mitra method.
changes of form will be called random changes.
These
In effect .it
will induce a random component (random velocity, to be defined)
on the drift velocity.
It will be assumed that the random
velocity and the drift velocity do not change during the length
of a time record, i.e., the record is statistically stationary.
The record is assumed to-be short with respect to long period
changes such as tidal oscillations.
Lee (1962) has made an
analysis for a vertical ionospheric sounder at a frequency of
300 kc/s and determined that a record of fourteen minutes with
84 scaling points gave satisfactory results.
This was a com-
promise between a long record less subject to sampling errors
and a short record that will give better resolution of the
movements.
The following definitions will be used to describe the
motions of the diffraction pattern (Briggs, et.al., 1950).
-16-
1.0
p(Co,
T)
TO
Figure 5.
a.
Temporal Cross-Correlation Function Between Two
Receivers Separated by the Distance to.
Apparent Drift Velocity (V')
This is the velocity obtained when the records of
two receivers, separated by a known distance,
are examined for the best cross-correlation.
eo,
If
Figure 5 is the cross-correlation function for the
two receivers then the time lag for maximum correlation is To.
Therefore
V' = to/To
This is identical to the velocity obtained by the
time-delay method.
-17-
(I)
b.
Fading Velocity (V')
This is the ratio of the space shift to the time
shift needed to produce the same change in value of
the received signal.
If for a time lag, to, the
temporal correlation is Po, then one finds the space
lag, xo,
such that p(xo,O) = Po = p(O,to),
then
Vt = xo/to
(2)
The fading velocity is the overall drift velocity,
that is, its components include the drift velocity
and the randomness of the diffraction pattern.
c. Drift Velocity (V)
This is the velocity an observor would have to move
at in order to experience the minimum amount of
fading of the signal.
For a given time displacement,
r , one finds the spatial displacement that will give
the maximum value of the spatial correlation function.
From Figure 6
v =
The e-axis is parallel to the x-axis.
(3)
xJ
p ({1Tj)
%I
Space Cross-Correlation Function Between Two Receivers
Separated by the Time T7.
Figure 6.
d.
Characteristic Velocity (V0 )
This is the fading velocity (V') found by the observer
-
moving with a velocity V.
that p(e,, T7)
p(xo,0) = p(,,).
Since T. may be chosen such
= Po = P(VT7,
7),
then,
Therefore
Vc = xo/Ti
(4)
The fading velocity (V') and the apparent drift velocity
(V') are easily found from the auto- and cross-correlation
functions.
in Figure
But it is impractical to obtain the function shown
6, since
it would require an infinite number of
-19-
receivers.
Therefore, connecting equations must be found in
order to determine the drift velocity (V) of the pattern and
the characteristic velocity (Vc) which is a measure of the
randomness of the pattern.
3.
The Connecting Equations
By suitable choice of xo,
(0,to),
(~o,T0 )
and
to,
o, and 71 the points
j,7T
1 ) may be located on the po ellipse,
These points are shown
a contour of the correlation surface.
in Figure 4.
The general equation for an ellipse is
Ae 2 4 2B47 + C
2
= 1
A, B, and C may be found from Figure 3.
equation (5)
(5)
At the point (O,to)
becomes
C=
/t2
(6)
The ellipse has a vertical tangent at the point (,oo).
Therefore A
=
0 at (o,To).
So that proper substitutions
at the point (toTo) gives
B = -ro/oto
-20-
(7)
and
2)/t2
S2
A = (to
+ ro)/tI T
(8)
A, B, and C may also be found using the points (xo,O) and
dr
(~r,r
1 ) where there is a horizontal tangent such that, d-
0
at (41~7 1). This procedure gives
(9)
A = 1/x2
B = -41/x1
c =(x0 +
1)/x~
(10)
(11)
Rearranging equations (9) and (10)
x
7T
Combining equations (11),
=
(12),
= 1l/A
12)
(13)
-ejA/B
and (13)
6. = B 2 /A(AC-B
-21-
2)
(14)
then
72 = A/(AC-B 2 )
(15)
dividing equation (12) by equation (15)
2) = (C/A) - (B 2 /A 2 )
(x2
but from equation (4), Ve = Xo/7
and (9),
C/A = x/t2
(~
1
.
And from equations (6)
by equation (2).
and equation (3) B2 /A 2 = V2 .
(16)
From equation (13)
Therefore equation (16) may now
be written
(v')2 = v 2 + V2
(17)*
Combining equations (6) and (7) and making use of equation (1)
gives eo/To = -C/B = V'.
VV'
4.
=
Therefore
(-B/A)(-c/B) = C/A = (V ) 2
(18)
Structure Size
So far the discussion has been concerned with the motion of
a one-dimensional diffraction pattern resulting from the reflection of radio waves from the ionosphere.
It is important to
define a quantity that will describe the extent of the ionospheric
-22-
irregularities.
The structure size may be defined as the dis-
tance, or time, where the correlation function falls to some
arbitrary value.
Bowhill (1956a) used a value of 0.61 (e)
while Fooks and Jones used 0.50.
Let the time lag where the
auto-correlation function falls to 0.50 be called the fading
period and be designated by b, i.e., p(0,b) = 0.50.
Then the
structure size, d, is given by p(d,O) = p(0,b) = 0.50.
fading velocityis defined by equation (2).
The
Therefore
VI = d/b
(19)
The value of the correlation function p(eo,7) at 7 = 0, where
to is the separation between two receivers, will give one point
on the spatial correlation function.
T2
,
such that p(0,'7)
= p(o,O).
Then choose a time lag,
This assumes that the temporal
and spatial correlation functions have similar shapes.
d = (eo/r 2 )b
-23-
Then
(20)
C.
The Velocities in a Two-Dimensional Space
1.
Isotropy and Anisotropy
Suppose that the diffraction pattern is frozen in time.
A central point is arbitrarily chosen and the spatial correlation function is determined.
If the structure size is found
for each direction and is found to be constant, independent of
direction, the diffraction pattern is said to be statistically
isotropic.
If the equations given in Part B are used to deter-
mine the velocities in two dimensions, isotropy is assumed.
This is essentially the Briggs, Phillips, and Shinn method.
If the pattern deviates from this defined isotropy it is an
anisotropic pattern.
Phillips and Spencer (1955) made the
modifications that will include anisotropic patterns.
It will
be assumed that space lags are sufficiently close to the origin
of the spatial correlation function so that, to a first approximation, isopleths will be ellipses.
This means that receiver
separations must be sufficiently small.
It has been determined
that the best separation is about one wavelength of the transmitted frequency (Sales, 1960).
2.
The V'
c Ellipse
Since only three points are needed to determine the
equation of an ellipse, only three receivers are needed to
-24-
1
Figure 7.
Possible Receiver Locations.
completely describe the extent of the received ionospheric
irregularities.
in Figure 7.
One possible triangle of receivers is shown
Considering the records from two of the receivers
at a time, a structure size may be determined from each pair
of records.
Figure 8 shows the three structure sizes obtained
with an ellipse drawn through the end points.
By dividing each
structure size by the fading period a fading velocity for each
direction is determined.
The resultant ellipse will be called
ellipse.
the fading velocity (V')
C
-25-
A general equation for the
0Q
d/I
\
0
Ob = m a Semi-minor axis
\bo
= tilt angle of ellipse
/O
ratio
ROo=AxiSem
Figure 8.
Characteristic Ellipse.,
ellipse shown in Figure 8 is Ax2 - Bxy + Cy 2 = 1, where
A = (Cos
2
'/M 2 ) + (Sin 2 "'/m2 )
B = (m-2 - M-2 ) Sin29
C = (Sin2 /M 2 ) + (Cos
2 9 /m 2 )
Tan2* = B/(C-A)
-26-
(21)
(22)
(23)
(24)
From equations (21),
(22),
and (23)
M2
2
(A+C)
-
(25)
B2 + (A-C)2}
(26)
2
m2 _
(A+)
+ B2+
(A-C)2}2
R2 = M2 /m2
3.
(27)
Determining the Fading Velocity and Characteristic
Velocity in Two Dimensions
Since the fading velocity is dependent on direction a
receiver triangle different from the one shown in Figure 7
will result in different values for the drift velocity and
characteristic velocity.
The following method (Phillips and
Spencer) will be used to eliminate the effect of anisotropy.
Suppose receivers ro and r, are used to find the apparent
drift velocity by equation (1).
Then call this velocity V .
Similarly, receivers ro and r 2 will give an apparent drift
velocity, VA.
The resultant of VA and VB will be called VD.
The three velocities are shown in Figure 9.
TaneD =
V~Cosp + VASina
V Cosa + VBSinp
-27-
(28)
4
0001X
V8
I,
Figure 9.
Apparent Drift Velocity - Uncorrected for Anisotropy.
VD = VBCos(eD+P) = vAsin(eD-a)
(29)
The major axis of the VI ellipse shown in Figure 8 lies along
the line 00'
shown in Figure 9.
If all values of V' parallel
to the major axis are reduced by a factor 1/R, R = axial ratio
of the ellipse, the ellipse becomes a circle and the fading
velocity is independent of direction.
Figure 10 shows VA, VB,
and VD transformed to the new coordinate system where all
velocity components parallel to the 00' direction have been
reduced by 1/R.
coordinates.
The subscript T refers to the transformed
V# is the apparent drift velocity in transformed
-28-
I
d
VAT
/
TXT
SVBT
Figure 10.
coordinates.
Apparent Drift Velocity - Reduced.
Since the pattern is isotropic the same value
will always be obtained no matter what the original receiver
triangle configuration.
Expanding to the original coordinate
system from Figure 10 will give Figure 11.
Figure 11 is iden-
tical to Figure 10 except for the presence of V'
and e.
V' is
the apparent drift velocity found by considering motion in two
dimensions, and by taking into account anisotropy; if the
pattern is isotropic than V' = Vb.
From the geometry of
Figure 11
V'
= V/Cos(eD-e)
-29-
(30)*
0O f
Figure 11.
Apparent Drift Velocity - Corrected.
From the geometry of Figure 10
VT = vnCos(e -
The relationship between V
V
=
VI
(31)
T)
and V' is
(1/R2)Cos 2 (e-*) + Sin2 (e-)
-30-
2i
I
(32)
and between e and eT
Tan(eT-9
)
= RTan(e-v9)
(33)
Similarly
V
= V{ (1/R2) Cos2(eD-*) + Sin 2 (
D-
(34)
and
Tan( eDT-9) = RTan(9 D - V9)
Combining equations (33)
Cos(eDT-eT ) =
(35)
and (35)
1 + R2 Tan(nD-))Tan(0--)
1 + R2 Tan 2 ( eD-V) fl
and combining equations (31),
(32),
Cos(eDT-T) =
1 + R2Tan2(eP)J
(36)
and (35)
(37)
-31-
By combining equations (30), (36),
and (37),
suitable manip-
ulation gives
Tan(e-9) = (1/R
2
)Tan(eD-9))
(38)
*
The fading velocity in the transformed coordinate system is
independent of direction.
Its magnitude is the length of the
semi-minor axis of the fading ellipse.
Therefore, its value is
Vc = m{(1/2)Cos2(e-*) + Sin2(e-*)}
(39)*
Equations (17) and (18) now can be used to find the drift
velocity (V) and characteristic velocity (Vc).
Sales (1960)
shows that there must also be a correction made in the determination of the characteristic velocity.
If V*C is the correct
value then
+ R2Tan 2 (0-_)
so that equation (17)
(40)*
becomes
(v)
2
= v 2 + (v*) 2
-32-
(17a) *
It needs to be pointed out that .the drift velocity (V) measured
at the ground is one-half the ionospheric drift velocity.
4.
Concerning a Comparison of the Methods
Yerg (1959) gives the theory for determining the drifts
using the total derivatives and partial derivatives of the
amplitude of the received signal.
Although the method will
not be presented here its accuracy is comparable to the Briggs,
Phillips, and Shinn (1950) method.
The time-delay method uses
the apparent drift velocity (V') only in determining the magnitude of the motions.
The advantage of this method is that it
easily and quickly arrives at a value.
It was used by the
In fact,
majority of the workers whose data is used here.
Harnischmacher (1963) has obtained 20,000 values over a period
of five years by this method.
The correlation method is more
accurate but it is more laborious.
However, except for deter-
mining the points on the fading ellipse (see Figure 3),
analysis can be readily applied to a computer.
the
Fooks and
Jones (1961) have compared V' with V for the E and F regions.
For the E region V' was greater than V in the majority of cases,
with an average value of their ratio of about 1.4.
no systematic difference between 0 and OD
majority of values of (e D-)
.
However, the
were within +200.
-33-
There was
D.
Notes About the Stations
The locations of the stations used in the analysis are
listed in Table 1.
The methods used by each station to deter-
mine the winds are noted by T, C, and Y.
T is for the time-
delay method, C is for the correlation method, and Y is for the
Yerg method.
The last column in Table 1 shows the number of
observations obtained by each station for the listed period.
Data was received for only two stations in the southern hemisphere (Johannesburg and Brisbane).
Therefore, motions in
the southern hemisphere will not be considered in the analysis.
The number of stations reporting data is twice the number
available to Murgatroyd (1957) above 95 km.
Murgatroyd com-
bined the data from both hemispheres and several different
methods of observation.
There still remains a major portion
of the hemisphere not covered by any observations.
made available in varying amounts.
Data was
The Freiburg data actually
covered a period of four years during which time approximately
15,000 observations were made.
not given for Freiburg.
Individual observations were
Instead, results were obtained from
distributions of magnitude and phase of the motions for each
month.
Since this was time consuming only one year's data
was used in the analysis.
The data at Yuma is limited to three
-34-
Table 1 - Stations Used in the Analysis
Station Station
Name
Number
1
Yamagawa
2
Swansea
3
Gorky
4
Irkutsk
Ibaden
6
Waltair
7
Tomsk
8
Murmansk
9
Rostov
10
Simeiz
11
Kharkov
12
Mayaguez
Location
130.6 0 E
31.2 0 N
4.0 W
51.6 0 N
44. 3 0 E
56.1 0 N
104.0 0 E
52.5 0 N
'Period of
Coverage.
Type of*
Analysis
7/57-12/60
1343
7/57-6/58
137
8/57-3/60
103
4/58-1/60
349
8/58-12/58
244
6/57-5/60
865
9/57-6/59
128
11/58-1/60
180
7/58-12/59
456
1/58-11/58
235
8/57-1/60
386
66.oow 2/58-9/58
357
4.00E
7.4 0 N
83.3 0 E
17.7 0 N
85.0oE
56.5 0 N
33. OOE
69.0 0 N
39.6 0 E
47.2 0 N
34. OE
44.6 0 N
36.3 0 E
50.0 0 N
18.OoN
13
14
15
Pennsylvania
77.9 00 W
State College 40.8 N
Yuma
114.7 0 W
32.7 0N
Freiburg
13. 33E
50.9 0 N
*T = time-delay method
Total No.
of Obs.
2/61-1/62
451
3/62, 10/62,
2/63
7/60-6/61
Y = Yerg method
-35-
=3718
C = correlation method
EXLU~
1L^.--"-~~
-----
-~-I-XLI
~PXI
-YIIWI---I ~---I~C--LL-L
months of observations (March and October, 1962; February 1963).
Stations reporting data for only part of the day are Yuma,
Pennsylvania State College, Ibaden, Gorky, and Simeiz.
The height range for which the data apply is from about
95 km to 115 km.
The height of reflection of radio waves was
not given for the following stations; Swansea, Ibaden, Freiburg,
Mayaguez, Pennsylvania State College, and Yuma.
A reflection
height may be assigned based on the frequency used at each
station and/or the time of day when most of the data was obtained at each station.
The height of reflection was assumed
to be 95 km at Swansea, Ibaden, Pennsylvania State College,
and Yuma.
The height of reflection was assumed to be 100 km
at Mayaguez and Freiburg.
The remaining stations gave a
reflection height for each observation.
-36-
CHAPTER III.
A.
RESULTS
Diurnal Wind Variations at Individual Stations
Figures 12a through 22b show the diurnal wind variation
at selected stations.
Stations that were chosen had ten or
more observations at the time indicated, plus a series of such
times in a given season.
Observations were chosen if they
referred to motion in the height range, 95 km through 115 km.
The shaded areas indicate those values where there is a concentration of 10% or more of the observations.
This procedure is
similar to that used by Harnischmacher (1963).
Figures 12a
through 12d show Harnischmacher's results from five years of
data obtained at Freiburg.
The magnitude and direction (clock-
wise from north) of the motion is presented in these figures.
The remaining figures in this set have been determined from
the observations taken at other stations under the conditions
described above.
A summary of the results obtained at Freiburg is presented
in Figures 12a through 12d.
Harnischmacher (1963) did not
determine average values since the distributions sometimes
became complicated.
Thus, average values would often occur
where there is a minimum number of observations.
The distri-
bution was limited to every 300 in direction and every 10 m/sec
-37-
in magnitude.
Figure 12a presents the distributions for spring.
The magnitude
A 12-hour variation in direction is well defined.
shows some variability but no tidal component is evident.
The magni-
distributions for summer are presented in Figure 12b.
tude is very steady and lacks any tidal variations.
The
The summer
magnitude is generally smaller in comparison to the spring magnitude.
The direction is fairly steady having components towards
the east and towards the north.
Superimposed on this steady
component may be seen a 24-hour tidal component.
In the autumn
the magnitude is about the same as it is in the summer (Figure 12c).
The return of the 12-hour tidal component in direction is shown.
Figure 12d presents the distributions for winter.
There is a
marked increase in magnitude with a wider distribution, which is
comparable to the spring distribution.
tion indicate
The variations in direc-
the influence of more than one tidal component.
The diurnal wind distributions determined in this thesis
were separated into westerly and southerly components.
values at each hour of the day were also determined.
Mean
A prevailing
wind in each season was found by averaging all observations.
Figures 13a through 16b show the diurnal wind variation at
Yamagawa for the four seasons.
In winter there is a 2 m/sec
-38-
prevailing westerly component (Figure 13a).
There is a lack
of continuity in the distribution resulting from day-to-day
variabilities.
The concentration of values indicates that
these variabilities may have comparable magnitude in either
direction.
There may be tidal influences but they are not
easily discernable.
The south-north component for winter is
shown in Figure 13b.
The prevailing component is northerly
with a magnitude of 25 m/sec.
in the distribution.
Again, there is a variability
A strong prevailing westerly component
of 37 m/sec may be seen in Figure 14a.
The distribution is
continuous with a median some 20 m/sec greater than the mean
values.
Figure 14b shows the diurnal distribution of the south-
north component.
in the afternoon.
The distribution is fairly continuous except
The prevailing component is northerly with
a 17 m/sec magnitude.
seen in this figure.
A strong 24-hour tidal component may be
During the summer both components have
widespread discontinuities (Figures 15a and 15b).
The prevail-
ing components are 17 m/sec westerly and 26 m/sec northerly.
The mean value variations in both wind components show a strong
12-hour tidal component.
In the autumn there is a return to
continuous distributions, which is shown by Figures 16a and 16b.
The prevailing components are 17 m/sec easterly and 20 m/sec
northerly.
It is difficult to determine the tidal influence in
these figures.
-39-
~--xlrrrrarr~-mrr-
A Fourier analysis of the data from Yamagawa has been
made (Aono, Tsukamoto, and Ichinose, 1961).
results are shown in Table 2.
A portion of the
The velocities and times of
maximum northward and eastward are given in local time.
Table 2
The 24-, 12-, and 8-Hour Harmonics Obtained
By Fourier Analysis (from Aono, et.al., 1961)
Season
Northward
Velocity
Time
(hours)
(m/sec)
Eastward
Velocity
Time
(hours)
(m/sec)
24-Hour
Summer
23.4
1236
4.2
1542
Harmonic
Autumn
33.0
1300
21.8
0254
Spring
13.5
1730
16.5
0400
12-Hour
Summer
25.6
0524
13.6
0924
Harmonic
Autumn
30.9
0418
19.4
0724
Spring
8.3
0518
13.3
0754
8-Hour
Summer
6.3
0618
2.8
0100
Harmonic
Autumn
1.4
0124
1.8
0254
Spring
14.0
1400
3.2
0512
-40-
.1,1
1inw1,1ill
awl
~yULUll__i~J___YII~
Two seasons of data from Waltair were analyzed.
for summer are shown in Figures 17a and 17b.
The results
Both figures show
the distribution variability that was in evidence at Yamagawa
during the same season.
The prevailing wind components are
Tidal motion is present
1 m/sec westerly and 24 m/sec northerly.
in both figures.
The variability of the distribution makes it
difficult to determine this tidal influence.
Unlike Yamagawa,
the data from Waltair for the autumn retains the variability in
its distribution (Figures 18a and 18b).
However, there is a
summer-to-autumn reduction in the magnitude of the tidal effects
at Waltair, similar to the summer-to-autumn change at Yamagawa.
The prevailing wind components are 14 m/sec easterly and 12 m/sec
northerly.
Rostov had only one season (Figures 19a and 19b) with a
sufficient number of observations to show diurnal wind variations.
A variability of the distribution, similar to that seen at
Waltair, is shown for this season.
The prevailing winds are
13 m/sec easterly and 14 m/sec northerly.
are present in both figures.
Tidal influences
It is difficult to estimate which
tidal components are present because of the limited number of
hours represented and the variability of the distribution.
The
main influences appear to be from the higher order components
of the tide.
-41-
Two seasons of data from Mayaguez are shown in Figures 20a
through 21b.
The diurnal wind distributions are for the daytime
for both seasons.
In each figure the distributions are fairly
well concentrated.
The prevailing wind components are 5 m/sec
westerly and 25 m/sec northerly in the winter; they are 18 m/sec
westerly and 16 m/sec northerly in the spring.
A nighttime wind variation for summer at the Pennsylvania
State College is shown in Figures 22a and 22b.
The prevailing
wind components are 11 m/sec westerly and 1 m/sec northerly.
Some evidence of tidal effects may be seen in both figures.
However, the period of coverage is too short to give a clear
picture of the tidal influence.
-42-
N
00
E
900
Spring
S 1800
W 270"
N 3600
S 200
LA
I
1'80.
12
14
11,30 Fi-guroe
11,00
12a:
16
18
20
(After IIarnischmachor,
2?
24 MEZ
1)93)
23,30 MOZ.
23,00 T. U
N 0Summer
S
!
4-,
K''44"
4
1
44-e
41
,ll
7
.&
44 K'
,..
W270*
'
pI
3
I
*
I
II
3
71~----~-(~~
9--
g
,,
4
2#
sec. 200-
4
160 -
~
~
-
Al1
--
-
3
I
,I -.~1
CcJ;
C,;
-'
-
F-.
'.
-
--r.
I
1
r
t
I
1 4
)
)-,
S"
~i
.. S.
I
-I
L-(
I~
;45I
-- --~ I~--k--l~-~-t-~Y--"~-V-~LYG-~~
!
---i----~---
77
q
- ,'
'
I I
A#
q
1
i
iYljjiZIi77lllllf
I (i Z
4..
I
i
r 1, ...... ..
r
'--
-i-
I
~ I
7,11
~ I
4
1~(;1~1L~IZ131-ICf
----
140-
II
--r
Aal
1
TT~~
ii
IF
I
100
~ I r.l.
r
r,€.
At
26
1
'44
-'--r-4-
L4g
60.
r7
l
40
'fli
,)
W
I
2
.
4I +..<.D.
,.,-, -3
14
41.
I
II
I
I
------
1
I'-'--ii
--
I
r I i i
"'f
-- 4 -- -- +-
-fr-
4-
11
i 3i.
'10
t
"7 i
2',
4q
S
Ak_
~9.
,
4,
-
I
in,-i
45
I70
-- -- ~--I
I
4t~'71,
41:t
---Al
.4JA
.
I ~ I
lEa. I
V
(
&
i
---- i-----l-----,- '
Al
.
I
,,
'- "
I
i
-4--
43
L
f ~..- ;-f------1i7~F7i77V717
L
2A; -9-
I,
I
20
~~YIZ
P
1._
A
I
80-
(-.--~-
)----1---~--1----I---E---I---
i VJ-~C-l '-I 'I-tTrt~T-l-T~-ll.~~-~~---rpl-1--~-l--r-I . j.l,
I '~ t
1----~
'
1------1-----1------1
1 ---~---1---1----1---r
I
I
I
J
~-----i-----~----I------I
I
I --2 II
I I.
-I
_.-I" - I
1 r- -I
I
-
---
I --. -I------i-----l
r
-- 1--
120-
0
,
,
''
r
,i;ce
4)1, l.i'
;L"
q
i
I,
I~-I
t.
c--;
I ~ll-;l-i~
.;--r--r
I
".
--
S...
VL
180 -
o0
!:
1 -~rr -1
3
ii
Vi
I:-
.4'
4t
-~1
t-5.
$
IT
1--_
• I
i '.I- '
--
-,1:
t
,A&
.
SC
.7-
IC
,
,44
,I
-4
.
S 10so
I
S,
l
sA
B
.
- -
t1-
S.
43
E Sommer
0
1 --
4C
-t
,
0
-., AO--,
--
3.
0'lt~
AR.
-e--
"94
4
-4--,
---
At
\
'41, /
.4
4*4
*
t
I
--- 1Y
I
1
.4i-
f --
..I
.
i
- _____
I
10
12
11,30
11,00
14
Fi'i
t
r
16
o
12b:
18
(Afto
20
Iarnischoacher,
2'
1933)
24 MEZ.
23,30 MOZ.
23,00 T.U.
Autumn
E
N
9
900 -
-fo-
S 18O
E Herbst
-
W2700 -
N 3600 (-a)200 sec.
I
180 -
12
11,30
11,00
14
Figur
i.
k8
12c:
20
(After Harnischmacher,
22
24 MEZ.
.2330 MOZ.
1953) 23,00 T. U.
E Winter
N
E
WS,
(m
I
se
.
/
1- o
02
4
6
8
10
12
0
11,00
14
Figure 12d:
16
18
20
(After Harnischmachr,
22
1953)
24 MEZ
MOZ.
23
23,00 T U
Number of Observations:
18
i
160
20
17
11
I
i
1
12
11
15
1
E
22
25
broken line: mean values
westerly motion: positive
t
7
(0
80.
0
1
-Irtlsocj
.
[
1
I
-80o
-80
1
I
2
9
8
10
(local Time)
Figure 13a:
Diurnal Variation of the West-East Component at Yamagawa (Jan-Feb-Mar)
4P
4
0
O
18
Number of Observations:
~--~ --
18
20
17
1
12
11
15
25
22
14
i--? -~
broken line: mean values
southerly motion: positive
16o
120
&
0'
0
-
q
e
0
( M/ec)
-40
-80
0e
7 .
'V
0
0
-120
-.160
10
(Iocal Time)
Figure 13b:
Diurnal Variation of the South-North Component at Yamagawa (Jan-Feb-Mar)
'
66
eca'
0g
Number of Observations:
28
25
37
35
12
15
15
21
17
17
21
22
22
22
17
14
16
broken line: mean values
westerly motion: positive
160
120
80
40-6._--
9
*
S
7
+
; .,.,++
+ +,.
-
-
•
. .--+
-
~ia-.iY
hC-.
I
),.
I
4o040 J,/-
.+_,"Ce
,
C
c
el
e,
+
7
C-
+
o
e.,
,
e
,
i;
c
3.
9
-40
C
c
e,
vc
V
+
,+
I-~:,
C'
e
C
3
~
C
+++'
•
o@.
3
5r
tL
g-
.
C
co
---
-~
I
+
it
c
r--C~C~~r
$1
v
el
t
a
.80
-120
Figure 14 a:
12
14
16
(local Time)
18
20
Diurnal Variation of the West-East Component at Yamagava (Apr-May-June)
I+C+
c
VY
(FC
10
C'+
,
24
H
H r
0
050
C''-
co'
Z
4Q
oasil.
cj
44)
0i
j-H
00
t-
;4
-.
*
cu
OpI
,
cu
V :
1i
co>
4)
*r
r
0
1*
A
i
2S
(oas/m)
-51-
u a
m
O0
..
o (,*
(o0 00
b
*
*
.-#
B
I
I
'be
a
t
i
i
i
r
i
A
u
0
0
43
I
41
41
o i-I
0
cu
t
r(
avi
W4
Eso
043
ii,
H
cn
cv.
p
,r
a
0d
Sb
-
a
9..
Vl.
~Q
o
a
.bfJ..
a
. A
DOOO~c
C~
tco
*
Bkok
oa
4
w
Cs
o
::
'P4
*.0
so
-b
o
b..
-
0
1.
a0wp
oes
**oo
amrn e
***
~
1G4~sa aou
~.
C
o4.0q
*
e~a
s
94
E
. .b'4 4.
o%v
.4N
~00Q~~~OhEs
S*
kbo~oioobkkbb
*aoQj
' a~
i"o~e
*00
)
DO.
go
. . .
0/
-52-
4
0
*
o
0*
.
..
.
o
o
II
+3
P4
:04
*i
;
1
Thn~bez, of Observations:
20
20
U
23
22
19
3T
20
14
11
10
broken Ane:
*1*
veBterl.y
i6o
J20.-~
b
e
I
*
*
*
I
0
'I
o
*
6
0
0
*
0
o
*
I
1&
5
~
I
8.
0
e
*
.
0
0
V.-.
-40
-80
0
.0
~
0-
0
6
-g
3
0
0
-120
0
9
*
S
4
5
.0
*.
-i6o
8
12
Figure 1 6 a:
14
16
(local Time)
18
20
mean values
positive
lIDtiofl:
22
Diurnal Variation of t~ie West-East Component at Yamagawa (0ct-Nov-L~c)
00
n
0
a
Ar
u-I:
- r.
Cu,
I
8
43
..
FA
V,4
a0
IioO
~
0
....
410,0
ge oressehone
.......
**
o
O~
\ess
~
00
0
o o
Q 40
o
000o
(0-/m
-54-
'
Of-t
1v
o V
1,
'O4
e
\Eb C
,
0
0
. r4
'a
Co
i-I-
o
0
qiCApS
rqU
Cot OD
i
alr~k
too
f
48 03 10
-a u
cj 0 4b r
a to
ca
OM1
4
iW~
.
*Cu
0 i~~tbo
oo o
o
03
oo
00
0010
I toO
~Q
QUij
*~
I,-L
Ot o?
".43 f;
.31
~pO9
4
L~h
Q to
hlfr
ai
Tio Lo to 0
00
iir
6~c
oc
.OHr
(Dos/m)
-55-
a
*r
4bY
D
O
*
..
e
16%0
&.9I
Lo 40
0
3
3
c
4-1
g
4,
)
c1*iu
Number of Observations
18
1
188
218
17
13
10
13
17
18
16
9
12
17
l
~------- ll~----~-- r~-----CII
~ ----
12
14
---I-LC --- CI~--~-CC
_ -
13T~-- - 10
-
broken line: mean values
southerly motion: positive
c...-c-
160
- -
120
----------- -
I
------
T
o
80
a
00
.0
bI
C
o
o
a
8
*
0.
a
a
-40o
6- .0
v
17
-120
o
o
sd
*
---v.*
0
o
*
a
*'
o
o
*
%:
,
Lv
0
4
0
*
--.
*
Lv
4
6
-
I
a
~~~
6
o
*
-
8
S4
a
'-
o
*o
a
-
0
-16o
If
Figure 1To:
6
8
10
12
14
(local Time)
Diurnal Variation of the South-North Component at Waltair (July-Aug-Sept)
16
18
20
U'%
a'.
'.D
IS
M
0>
4
4-
g'd
2
a.A.
-
l lwt
(a
Du
*
to
lob
0
L o
so
**064 OS>
e*
0*0
r
f'. 0. #
~,
I
too
0 60
p. o .
..-
(oas/uz)
-57-
~I
g tat
r.
La
\r
'a 0
I4--
0
*N
-*
H
-41
01
A
0
4-1
0o
440
4.,
CA
4
CY
0
43
0
0
~;
100
(1
P(4.C0
0
oo
~t..
-58
1*0
0'4
apo u
S l
0
~
S3
0
q4
.1-I0
I
Number of Observations:
22-
23
17
23
19
12
22
11
broken line: mean values
vesterly motion: positive
160
120
80
I
V
40
*
4
*
4
*
4
o
0
4O
0
LD
LO
I
.
1
-80
4
0
e
&
*
0
-120
5
-160
8
10
12
14
16
(local Time)
Figure 19a:
Diurnal Variation of the West-East Component at Rostov (Oct-Nov-Dec)
- --
~'~~I~~ --- ~
--- ~~"
~~-'-'~-- '~~ "'~
''
18
Number of Observations:
22
23
19
23
17
12
22
11
broken line: mean values
southerly motion: positive
1o
320
C
--
e
*C
SC
*
-40
eLLT
o
C
-120
*
Ch
C
5,
a
a
c
4
r
4,
j i83
o
5
ca
I
S
S
.
-160
10
(local Time)
Figure 19b:
Diurnal Variation of the South-North Component at Rostov (Oct-Nov-Dec)
Number of Observations:
15
14
14
12
19
broken line: mean values
westerly motion: positive
160
120
40
0r
7
7
1
-3y
7
-4o
-80
-120
10
(local Time)
Figure 20a:
Diurnal Variation of the West-East Component at Mayaguez (Jan-Feb-4ar)
Nunber of Observations:
14
__)_
_I _
12
19
broken line: mean values
southerly motion: positive
16o
120
80
t
-80
7
0
0c
7
0
5
-120
10
(Local Time)
2
Figure 20b:
(Jan-Feb-Mar)
Diurnal Variation of the South-North Component at Mayaguez
I
Number of ObBervations:
11
11
13
16
I
*
.~
~:
1t~
broken line: mean valueB
vesterly ~tion: pouitive
.
*
120
*
.
4
*
'p
4.
'4
'p
I
-80
If
6
10
(local Time)
-
12
21a:Vaxiation of the West-East Component at Msye~uez (Apr-MEIy-June)
Figure
1)iurnal
.
p
I
I
Nunber of Observations:
I.
broken line:
..
16
I
,
120
18
11
11
13
16
*
.
i
.
I
.
!
"I.
mean vilues
southerly motion:
....
positive
•
•
.l!,I.,__~C-C-i
.
0
I*
'
!r
.
,
"
-- r.~--
_..
.. . ...
---
.
C-~
Cl
--
.. .
~I-l--
.
-
-C-
0o
.
-----
--
t
-
-80..,
-
°
6
2
Figure 21b:
80
2"
8
8
10
(Incal Time)
2
1
(Apr-May-June)
Diurnal Variation of the South-North Component at Mayagruez
_ ___ ,
~..- .~ --------------- --
--
--
- -
-"-
Nmber of Observations:
11
15
14
I...
I
80
12
14
13
8
13
. --
13
-
9
broken line: mean values
westerly motion: positive
60-
20-
-20 -.
07*~- o'V-If-)
7
0
7.o
a
~~~
-tll
i.
S
Q
-80
2
(Local Time)
Figure 22a:
Diurnal Variation of the West-East Component at the Pennsylvania State College (July-Aug-Sept)
Ilumber of Observations:
U
15
14
13
14
U
8
12
13
9
13
I
I
I
I
.
~
brdkeii1Im~
1
Ue8Z1V~lUO8
r "DDtiQfl
£0'
:1:.
a
I...
*1
*1
I
40
.7
.
.
...
1
*'2
..
-
I;
.I.
.
,
1*'
.
0~
0V%
IC,
6)
-
-
---.--- ~---
-.
.:
....
-#-
I
~I
18
-
(local Time)
Figure 22b:
77,
I1171~~*~~*~~~~~i~
Diurnal Variation of the South-North Con~onent at the Peimaylvania State College (July-Aug-Sept)
B.
Height Profiles of the Zonal Wind
Figures 23a through 23f were obtained by averaging the
observations at a particular station over the summer (April
through September) and winter (October through March) at the
local time of each station.
The averaging was accomplished for
each height starting at 95 km and continuing for each 5 km up
to 115 km.
The results were then averaged around every
latitudinal circle.
and 700 latitude.
O1
All observations occur between 70 latitude
Isolines refer to zonal motion in m/sec and
are positive for westerlies.
During the morning the motion is generally easterly in
the winter and westerly in the summer at 95 km (Figures 23b and
23c).
In the afternoon the motion is easterly in both seasons
below the 500 latitude (Figures 23d and 23e).
In all figures
except as shown in Figure 23d, the motion at 100 km and 105 km
is independent of season below the 400 latitude.
The figures
show more variability at 110 km and 115 km with a generally
westerly motion in both seasons.
This variability should be
expected since the number of observations are least at 110 km
and 115 km.
-67-
Winter
Smrer
, ,_ ...
-
115
.
u4
43l
N100
.
.
6D
40
(tite.!
-
.. 0-6
,
+11
-,.:, ,-. .r : :.:h.""
:Lttue
i'
20 (0e
20
-
40
(Der~esof Latitude )
Figure 23a:
-
..
20
.. ..
.
.:..
It's
6.
. :.:.,
"
..
11
>
-.
e..
:
-
.
,)..
110
I~~E
no
_I
.
Height Profile of the Zonal Wind at 0000 Local Time
60.
-
Sumer
Winter
115
e
L"
''
i"
,,I-43 ,...
-
:.i!
t
..
- •--:.
_
i6,
- ,- . .
....
iC.:TS
:;Y
___
. .- .-
95
"
"Cf"j
.....
•.:
,4"--
,
-
....
-
i
.-
0
t. ..
-..
i
- ,.
..; - . ,
--
-
,
.j,.-,=i; _.
.- ... . ...
at
#AIfore p.ud
-403
6-b10
FigueHightProfle
23:
0
cT
V.
2
(Degres
of Ltitude
f th . ZnalWhidat 000
ocalTim
i
l
-
-5.
., .
. __
4
'77:
..
~*~*
~ ~Q
r
4.
0r
UTHBT
HM~
-70-
,.
.
00
~:~4V
0q
cu
3
Winter
oUmner
115
-,,
no
105
-7
,
.77
100
.,
I
.
i
• "'4.":''
'"*. ..-'
-r
r
:"
..
f4
" .
"
-.
.~
3
/
A-a
;!
:.
95
6o
4o
20
o
20
(Degrees of Latitude)
Figire 23d:
Height Profile of the Zonal Wind at 1200 Local Time
40
60
Winter
Summer
Figure 23e:
ILI
Height Profile of the Zonal Wind at 1600
l
100
local Time
-.7
zooo
2e:
Figue
High
(Degrees of Latitude)*
Proileof te Znal indat 100 ocalTim
gr
3-15
... f y
60 io io
"
7. -,t
,t
'L
"
4l
?rr
o
•(Degrees
...
_.
.
...._
of Latitude)
.7.
Io
bo
o
Summer
Winter
115
110
,
0o5
100
95
(Degrees of Latitude)
Figure 23f:
Height Profile of the Zonal Wind at 2000 local Time
C.
Height Profile of the Prevailing Zonal Wind
A height profile of the zonal winds in the lower E-region
is shown in Figure 24a.
It was obtained by taking the point-
for-point average of Figures 23a through 23f.
A set of height
profiles was also made from observations grouped according to
universal time.
The average of these figures is shown in
The two sets of observations were generally dis-
Figure 24b.
The differences between Figures 24a and 24b give an
similar.
estimate of the error caused by incomplete coverage.
The sim-
ilarities give an estimate of the prevailing zonal wind in the
lower E-region.
Figure 24a was obtained from 2441 observations
and Figure 24b was obtained from 2463 observations.
At 95 km the motion is westerly above 200 latitude in
summer.
It is easterly at all latitudes in the winter with a
maximum at about 200 latitude.
The prevailing wind at 100 km
between 200 and 500 latitude is westerly in both summer and
winter.
Maxima of the westerlies occur about 500 latitude in
the summer and about 300 latitude in the winter.
There is a
westerly maximum about 300 latitude in both seasons at 105 km.
In winter the motion is easterly above 400 latitude.
At 110 km
the motion is westerly in summer with a maximum about 400
latitude.
It
is not clear which zonal motion predominates in
winter although it is probably westerly to 400 latitude.
The
motion is generally westerly in summer and easterly in winter
at 115 km.
-74-
Sunmer
Winter •
115
110
-
105
100
95
60
Figure 24 a:
40
20
0
20
(Degrees of Latitude)
Height Profile of the Prevailing Zonal Wind
___
_
_I
__
I_
Winter
Sumer
.. .....
:q:
,.F..
"--:
. " -,--".-i-'=
110
*1
.........-:......................".................
~14
Z11
7
!
d.
-
.
0., 7
:7
a4:
10)
c-I
;-I
. ..
.
-.
I?;: tJ1 i i:.1.'.J;Y
-:
95
I"
.. . .
t"
"lR . . . .IT":jY
'
,
<
;
1 7-. !
(Degrees of Latitude)
0
":1-B.~Fl~i e
II
60
Figure 24b:
40
20
(Dges
0fItiue
20
Height Profile of the Prevailing Zonal Wind
..~
40
.I.
60
D.
Height Profiles of the Zonal Motion Without the Prevailing
Component
The prevailing wind (Figure 24a) is subtracted point for
point from the total wind (Figures 23a through 23f) to give the
diurnal variation of the tidal motion (Figures 25a through 25f).
In the summer the large region of easterly motion at 0000 LT
(Figure 25a) is considerably reduced in magnitude and scope by
At 0800 LT (Figure 25c) this region shows
0400 LT (Figure 25b).
strong westerlies.
The westerlies are weaker at 1200 LT
(Figure 25d) with parts of the region becoming easterly again.
At 1600 LT (Figure 25e) the region of westerly motion intensifies
but the general shape of the region remains the same.
A strong
easterly region appears at 2000 LT replacing the westerly region
in the previous figure.
Figure 25a shows that the motion is westerly below 400 latitude in the winter.
the summer.
This is basically opposite to the motion in
There is almost a complete reversal in the motion
four hours later above 105 km, as shown in Figure 25b.
the easterly region intensifies.
Below 105 km
At 0800 LT (Figure 25c) the motion
is strong easterly below 300 latitude.
By 1200 LT (Figure 25d) the
motion is almost entirely easterly and of lessened intensity.
Figure 25e shows that easterly motion again becomes intensified
with a strong westerly motion appearing at low latitudes above
100 km.
The motion is almost entirely westerly in Figure 25f.
-77-
Winter
Summer
115
110
.105
1./
100
95
60
60
Figure 25a:
40
20
20
0
(Degrees of
atitude)
Height Profile of the Zonal Wind Without the Prevailing Component
at 0000 Local Time
Winter
Summer
17;
.,3
sy
110
s",
r.
,: •
.
-w
l
43
105 L..
"i
.
-..4- "'
:r
o
,-
-
,.
i
100
-9
at0400 local
-
4
--.
Time
i
95
60
(Degrees of Latitude)
Figure 25b:
Height Profile of the Zonal Wind Without the Prevailin
at o400 Local Time
Component
Summer
Winter
"
115
t.:
•
'..t -- '.-:
110
,, . ..T ,.7P.;'
r~
~ lo
i
II
- -,a i
i
"
.... ..
t
,.
;
-4-
r
-4
"I.
105
V:4
----i-woo
-",
100
.
95
60
40
0
20
20
40
60
(Degrees of Latitude)
Figure 25c:
l-L
Height Profile of the Zonal Wind Without the Prevailing Component
at 0800 Iocal Time
f
_1L
J
Winter
Sumer
....
.1 ...
4..
315
~
___
7::3t
i ,,,t ':
1711Il~i t
eAV
4.,1 -rr-?
_4.4
"ftr-~ii
I L1:
1
"L
4-'-
ii tiii4i ~
"
- r-r11t''~ t r?;li
...
I
I i
''.rcry:
e
i,
tr;
tt )(t
~l
ft~jIi-, i iii
i I I I
IiiP~
C
-:t
{Z7
: i RA
RIL
1C1'
ii JLiiliFi
........
.. .
....
..
-..
.
:: .-
.19
105
i. I
100
.
~~ .
95
.
.
~...
..
~
..4 =
~
,!
~
,.
_7
At
t.
.
I~ J4~+Ji~
1
I
Ic
t:
1:-I
----
i
.
..~ 1 ,k1
..
zlI . , .
'
i.":
'
"
.
.......f:: ...........
--
t,Tf ii
"t ,
- t
r
I
I 11i
.
~~lf;
1~11-t:k; iil::
0
(Degrees of Latitude)
Figure 25d:
Height Profile of the Zonal Wind Without the Prevailing Component
at 1200 local Time
jtfrl
Winter
Summer
Pit
115 --
i
it
i.
t
i t.... lP'
'TT
1101
. .. .......
95..
Figure 25e:
...
P-
off
-- i
. ..
Latitude
L
Height Profile of the Zonal Wind Without the Prevailing Component
at 1600 Local Time
Summer
LIB
115
-T,
I1.k
r- ? -r-
-
Winter
- -r--~----
-- ---.
r4
w
-
I-- I- 11
110
40
*9 105
100
95
0
20
40
60
(Degrees of Latitude)
Figure 25f: Height Profile of the Zonal Wind Without the Prevailing Component
at 2000 Local Time
E.
Hemispheric Zonal and Meridional Prevailing Motion
Figures 26a and 26b show the hemispheric zonal prevailing
wind in winter and summer.
Figures 26c and 26d show the pre-
vailing meridional wind for the same periods.
The location of
each station given in Table 1 is shown along with the number of
observations and value of the motion.
In addition, the results
from Jodrell Bank (Greenhow and Neufeld, 1961) have also been
placed on the figures.
This has been labeled JB in the figures.
It is seen in all figures that the results obtained from Jodrell
Bank are in good agreement with the data analyzed in this thesis.
The general outline of the zonal prevailing wind is towards
strong easterlies or weak westerlies in winter.
The summer zonal
motion becomes strong westerly or in some cases weak easterly
where it had been strong easterly (Figure 26b).
There was a
certain amount of freedom in drawing the isolines.
However,
there is the appearance of standing waves in the figures.
This
is more true in Figures 26c and 26-d, which show the meridional
prevailing wind.
The position of the standing wave remains
consistent from winter to summer.
or two (or both).
-84-
The wave number may be one
Figure 26a.
Hemispheric Map of the Prevailing
Zonal Winds in the Winter
-85-
Figure 26b.
Hemispheric Map of the Prevailing
Zonal Winds in the Summer
-86-
Figure 26c.
Hemispheric Map of the Prevailing
Meridional Winds in the Winter
-87-
Figure 26d.
Hemispheric Map of the Prevailing
Meridional Winds in the Summer
-88-
CHAPTER IV.
CONCLUSIONS
The data from fifteen ionospheric sounders has been used
to determine the general circulation in the lower E-region.
Evidence was presented to indicate that the motion determined
by radio propagation techniques coincides with the neutral
wind up to approximately 110 km.
The diurnal variations of the wind determined at selected
stations show that the wind is
fairly stable from day to day
during the spring and autumn.
There is considerable variability
of the wind during the summer and winter.
is implied from the data.
Strong tidal influence
A more complete analysis must be made,
however, to determine the magnitude of this influence.
The height profiles of the wind show the variations with
latitude throughout the day.
Superimposed on the prevailing
component of the zonal wind is motion that shows considerable
variability throughout the day.
the tidal oscillations.
These variable motions are
The prevailing zonal wind is generally
westerly in the summer and easterly in the winter.
-89-
With due consideration for the number of stations, the
hemispheric maps show the apparent existence of standing waves
of low wave number in both summer and winter.
The magnitude of
the prevailing motion is generally greater in winter than in
summer.
The hemispheric maps also show that the prevailing
wind is easterly in the winter and westerly in the summer.
This has been a preliminary study of the general circulation in the E-region.
No definite statement may be inade about
the upward propagation of energy due to the limited number of
observations available.
Further studies are definitely needed.
More observations at individual stations, such as obtained by
Harnischmacher (1963), will allow the study of the momentum
transports in this region,as Jones (1963) was able to do with
the meteor wind data.
-90-
ACKNOWLEDGEMENTS
The writer would like to express his gratitude to
Dr. K. Tsukamoto, Professor D. G. Yerg, Professor B. R. Rao,
and Professor H. S. Lee for providing their data.
Special thanks are due to Professor R. E. Newell for his
guidance and useful suggestions during the course of this study.
The writer would like to thank his wife, Jo-Anne Fedor,
who reviewed and typed the manuscript.
-91-
BIBLIOGRAPHY
Aono, Y., K. Tsukamoto, and M. Ichinose, (Ed. Com.), 1961:
IGY data of ionospheric drifts at Yamagawa in Japan.
Nat. Committee for the Internat. Geophy. Coord. Sci.
Coun. of Japan, December, 1961.
1963: The formation and vertical movement
Axford, W. I.,
of dense ionized layers in the ionosphere due to
neutral wind shears. J. Geophy. Res., V. 68, 3,
pp. 769-779.
Bowhill, S. A., 1956a: The fading of radio waves of frequencies
between 16 and 2400 kc/s. J. Atmos. Terr. Phys., V. 8,
pp. 129-145.
Bowhill, S. A., 1956b: The ionospheric irregularities causing
fading of low-frequency radio waves. Scientific Report
No. 89, Ionosphere Res. Lab., The Penn. St. U.
The
Briggs, B. H., G. J. Phillips, and D. H. Shinn, 1950:
analysis of observations on spaced receivers of the fading
of radio signals. Proceed. of the Phys. Soc. of London
Series B, V. 63, pp. 106-121.
Briggs, B.H., and M. Spencer, 1954: Horizontal movements in
the ionosphere. Rep . on Prog. in Phys., V. 17, pp. 245-
280.
Briggs, B. H., 1960: Survey of ionospheric drifts.
General Assembly, London, pp. 219-239.
URSI XII
Ionospheric drifts
Burke, M. J., and I. S. Jenkinson, 1957:
3, pp. 378-386.
10,
V.
Phys.,
J.
Aust.
at Brisbane.
Propagation of
Charney, J. G., and P. G. Drazin, 1961:
planetary-scale disturbances from the lower into the
upper atmosphere. J. Geophys. Res., V. 66, 1, pp. 83-109.
Correlation analysis of
Fooks, G. F., and I. L. Jones, 1961:
the fading of radio waves reflected vertically from the
ionosphere. J. Atmos. Terr. Phys., V. 20, pp. 229-242.
-92-
Ionospheric irregularities and the phase
Fooks, G. F., 1962:
J. Atmos. Terr. Phys., V. 24,
waves.
paths of radio
pp. 937-947.
Gossard, E. E., 1962: Vertical flux of energy into the lower
ionosphere from internal gravity waves generated in the
troposphere. J. Geophy. Res., V. 67, 2, pp. 745-757.
The nighttime electron
Gossard, E. E., and M. Paulson, 1964:
density profile through the D-region of the ionosphere in
summer over the southwestern United States. Radio Science,
J. Res. NBS/USNC-URSI, V. 68D, 3, pp. 265-273.
Greenhow, J. S., and E. L. Neufeld, 1961: Winds in the upper
atmosphere. Quart. J. Roy. Met. Soc., V. 87, pp. 472-489.
Hargreaves, J. K., 1961: Random fluctuations in very low frequency signals reflected obliquely from the ionosphere.
J. Atmos. Terr. Phys., V. 20, pp. 155-166.
Harnischmacher, E., 1963: Results of E-region drift measurements.
Proceedings of the International Conference on the Ionosphere
held at Imperial College, London, July, 1962, The Institute
of Physics and the Physical Society, London, pp. 348-356.
Hines, C. 0., 1960:
Internal atmospheric gravity waves at
ionospheric heights.
Can. J.
Phys., V. 38, pp. 1441-1481.
Hines, C. 0., 1963: The upper atmosphere in motion.
J. Roy. Met. Soc., V. 89, 379, pp. 1-42.
Quart.
The height variation of drift in the EJones, I. L., 1958:
region. J. Atmos. Terr. Phys., V. 12, pp. 68-76.
Energetics of the solar semidiurnal tide
Jones, W. L., 1963:
in the atmosphere. Scientific Report No. 2, Planet.
Circ. Proj., Meteor. Dept., Mass. Inst. of Tech.
Kochanski, A., 1963:
Circulation and temperatures at 70 to
100 kilometer height. J. Geophys. Res., V. 68, 1,
pp. 213-226.
A statistical study of apparent horizontal
Lee, H. S., 1962:
ionospheric movements using 300 kc/s radio waves. Scientific
Report No. 170, Ionosphere Res. Lab., The Penn. St. Univ.
-93-
Murgatroyd, R. J., 1957: Winds and temperatures between 20 km
and 100 km - a review. Quart. J. Roy. Met. Soc., V. 83,
358, pp. 417-458.
Phillips, G. J.,
and M. Spencer,
1955:
The effects of aniso-
metric amplitude patterns in the measurement of ionospheric
drifts. Proc. Phys. Soc. of London, Series B, V. 68, pp. 481492.
Ratcliffe, J. A., 1959b: Ionizations and drifts in the ionosphere.
J. Geophys. Res. V. 64, 12, pp. 2102-2111.
*
Ratcliffe, J. A., 1959a: The Magneto-lonic Theory and its
Applications to the Ionosphere. University Press, Cambridge.
Sales, G. S., 1960: Low frequency radio studies of apparent
ionospheric motions. Scientific Report No. 131, Ionosphere
Res. Lab., The Penn. St. Univ.
Sales, G. S., and S. A. Bowhill, 1962: Apparent ionospheric
motion in the night-time D-region. J. Atmos. Terr. Phys.,
V. 24, pp. 451-465.
Teweles, S., 1963: Spectral aspects of the stratospheric circulation during the IGY. Report No. 8, 7 January 1963, Plan.
Circ. Proj. Meteor. Dept., Mass. Inst. of Tech.
Yerg, D. G., 1959: An analysis of drifts of the signal pattern
associated with ionospheric reflections. J. Geophys. Res.,
V. 64, 1, pp. 27-31.
Yerg, D. G., 1961a: Analysis of diffraction patterns on the
ground caused by ionospheric irregularities. Scientific
Report No. 1, Mich. College of Mining and Tech., ..March 1961.
Yerg, D. G., 1961b: Analysis of diffraction patterns on the
ground caused by ionospheric irregularities. Scientific
Report No. 2, Final Report, Mich. College of Mining and
Tech., June 1961.
-94-