MASSACHUSETTS INSTITUTE OF TECHNOLOGY
LINCOLN LABORATORY
MILLSTONE HILL THOMSON SCATTER RESULTS FOR 1968
J. V. EVANS
Group 21
TECHNICAL REPORT 499
23 JANUARY 1973
Approved for public release; distribution unlimited.
LEXINGTON
MASSACHUSETT5
The work reported in this document was performed at Lincoln Laboratory,
a center for research operated by Massachusetts Institute of Technology.
Tbework issponsored by the Office of the Chief. of Research and Deve@
ment, Department of the Army; it is supported by the Advanced Ballistic
Missile Defense Agency under Air Force Contract F 19628-7>c-0002.
Tbis report may be reproduced to satisfy needs of U.S. Government agencies.
NonLincoln
PLEASE
I
Permission
DO
Recipients
NOT
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is given 10 destroy
when it is no Ionger needed.
this document
I
ABSTRACT
This repat
summarizes
.mdion temperatures
7f.5”W)
(42.6-N,
height interval
ing periods,
complete
electron
twice’
density
30 minutes.
During
i968 the apparatus
flected
signalsvs
in real
which
time,
and with
analyzer
x-ertical
of the plasma.
drift
form,
The density
mer
and winter
discerned
occasions
The average
appears
fewer
there
accuracy
which
observ-
was
of the re-
of the electron
at all altitudes
and
to be
In addition,
at Millstone
are difficult
the
to obtairra
spectrum
than heretofore.
measurements
results,
24-hour
height interval
the estimates
recognized
at sunspot
on all but very
disturbed
previously
Apparently,
were
by chance,
of magnetic
dependence
on solar
the
Hill of the
to condense
hasbeeni
minimum,
into
Office
variation
of sum-
can still
be
A number of dis-
in 1968, albeit on fewer
for observation
than in 1967.
nvestigated.
flux (as defined
explained.
patterns
the days selected
disturbance
a summer-to-winter
Liaison
clear
days.
again detected
the magnetosphere
.4ccepted for the Air Force
Joseph J. Whelan, USAF
.Acti”g Chief, Lincoln Laboratory
this
Hill
data, for
required
the frequency
the separate
instances
remains
over
showthat
behavior,
heat flux from
electron
in the report.
results
maximum
observed
to be a Ckar
emission),
easily
diurnal
than in i967.
in 4968 contained
These
over
The time
the measurements
the first
are not included
at sunspot
turbancepatterns
greater
permitted
and temperature
to measure
These
gathered
profile
in turn yields
permitting
distribution,
system.
month.
and temperature
was rebuilt
radar
800 hm, were
employed
altitude,
density
during 1968 using the Millstone
scatter
calendar
per
new spectrum
summary
obtained
(incoherent)
approximateIy200to
roughly
usuaIly
made
for the electron
in the F-region
Thomson
ion temperatures,
I
the results
While there
by the io.7. mn radio
of 5 to 7 that cannot be
CONTENTS
iii
Abstract
i
1. INTRODUCTION
11. EQUIPMENT,
PROCEDURES
III.
IV.
OBSERVING
AND
PROCESSING
2
2
A,
Equipment
B.
Observing
C.
Data Reduction
3
Procedure
5
7
RESULTS
7
A.
ElectTon
Density
B.
Electron
Temperature
29
53
C.
Ion Temperature
D.
Average
Temperature
E.
Seasonal
Variations
F.
Magnetospheric
Profiles
72
77
Heat Fluxes
77
8i
SUMMARY
82
References
iv
,+
DATA
MILLSTONE
1.
HILL
THOMSON
SCATTER
RESULTS
FOR
i968
INTRODUCTION
Thomson
(incoherent)
scatter
radar
temperatures
were
imately
per month throughout
twice
made at Millstone
rizes
the results
obtained
years
(Table
Earlier
I).
ried out in the years
years
measurements
Hill,
i968 for periods
electron
Massachusetts
usually
(42.6”N,
of 24 hours.
densities
and
7i.5”W),
approx-
This report
and discusses
them in relation to the behavior observed
4-5
in this series
present the results of synoptic
reports
1963 through i967.
arediscussed
West ford,
of F-region
ingreater
detail
Results
obtained
inanurnberof
summa-
in pnrevious
studies
car-
during some of the months in these
jmumalarticles
as referenced
in Table
1.
TABLE I
PUBLICATIONS
(68-cm
CONCERNING
W.velen@h)
Ymr
Month,
February
1963
March,
July,
January
SCATTER
Covered
1963 foJm.my
July,
April,
THE MiLLSTONE
THOMSON
August,
HILL
UHF
RESULTS
Publication
1964
Ref. 1
September
Ref.6
November
Ref. 7
through December
Ref. 2
1964
April,
July,
November
Ref. 8
Jm.ciry through December
Ref. 3
June,
Ref. 9
A.gust,
September
1965
June
Ref. 10
January,
April,
January
July
Ref.11
through December
Ref. 4
1966
Jon.my,
March,
July,
September
J.nuorythr.ugh
December
February,
October,
Ref. 12
Ref.5
1967
In addition to the measurements
tically
directed
E, Pi,
UHF radar
tal drift
here of F-region
a number of measurements
observations
were
made with the ver-
conducted
in 1968 of the
employing the L-hand radar with beam directed obliquely.
These meas13,14
a“d the horizmaimed at determining
the ion composition
in the F+ region
15
in the E and F regions.
In as much as these results have already been reported,
Section
employed
Section
Ref. 12
were
they are not included
signals.
reported
December
and F2 regions
urements
results
system,
J.”e,
11provides
during i968,
and eliminate
in this paper.
a sumnmryof
These
the equipment,
the results
a summary,
observing
changed during the middle
the need for non-real-time
Section 111presents
N provides
were
processing
for electron
density,
and data- processing
of the year to yield
of magnetic
electron
procedures
more reliable
tape records
of the IF
and ion temperatures
a“d
i
>
II.
EQUIPMENT,
A.
OBSERVING
AND
the spectrum
interfaced
analyzer
directly
scatter
portion
In the earliest
a given
mitter
pulse,
briefly
gate applied
because
conducted
integrated
a sample
of gain differences
the signals
available,
it was possible
were
from
to explore
for later
non-real-time
complete
a series
of measurements
that the integrators
spectra
depends
became
preach
in Ref. f6
from
readily
filters.
the analyzer,
set of integrators.
and because
a
scheme
suffered
about an hour
number of integrators
spectrum,
that permitted
This arrangement
spectrum.
reduced
(at the expense
thereby
pre-
the signals
the spectrum
between
by differences
samples.
the signal
analyzer
Unfortunately,
was rebuilt
though not recognized
the signal
As a result,
ratio.3
to
it was arranged
and noise voltage
between
to
post-
samples.
in the gains of the integrators
the difference
signal-to-noise
to be
the time required
of many hours of liter
To cope with this increase,
only the difference
one obtains by integrating
This
it required
with the limited
was constructed
to 30 minutes
upon the predector
outputs were
drifts.
system
and the noise
The filter
To calibrate
only one half of tbe signal
introduced
from
trans-
near the end of the timeba se, to the filters,
Also,
ionospheric
of the signals
in length equal to?he
that
at the
and the noise
the interpretation
of the
uncertain.
The problems
soon recognized,
crystal
In addition to this change,
problems
the signal
the spectrum
design that was
the spectrum
RC integrators.
in the integrators,
the entire
would store
This change eliminated
During $968
are fully documented
HiRi,2,
in a second
processing.
of the tape records).
across
narrowband
selected
tape recording
recorded
48 filters
previously.i
by one of newer
changes
of the IF signals,
all heights.
of measuring
In ~965 anmgnetic
stored
These
at Millstone
stored
and drifts
returned
cluding the possibility
processing
was replaced
using analog
of noise,
noise voltages
to explore
distribute
has been described
by gating a portion
into a bank of twenty-four
and the rectified
samples
PROCEDURES
here.
observations
and the voltages
second
equipment
of the receiver
height was determined
rectified
radar
into the SDS 9300 computer.
but will be summarized
hitherto
PROCESSING
Equipment
The UHF incoherent
time,
DATA
inherent
with the tape recorder
and beginning
that was attempted
in 1966 efforts
and analyzer
employed
made to improve
from
the system.
but was abandoned as being too costly
mid-t 965 were
One ambitious
and requiring
ap-
too much develop-
ment would have provided complete computer-processing
through the use of a number of parallel
16
Finally,
in
i967,
construction
began
of
anew spectrum analyzer that obviated
multiplier
units.
most of the difficulties
of the earlier
In the new spectrum
SDS 9300 computer,
tion,
the signals
a bank of 5-pole
analyzer,
thereby
one.
This wasplaced
the integration
eliminating
inoperation
of the echoes
all problems
in July i968 (Ref. i6).
is carried
due to gain differences
but instead
and drift.
are continuously
by the
In addi-
are no longer
gated from
crystal
each of which is matched to the length of the pulse employed
filters
the time base,
out digitally
applied
to
(0.5 or 1.0 msec).
Each of the (two) filter
dar frequency
intervals
sampled
banks available
with i kHz spacing.
so that a spectrum
sequentially
a manner that provides
maybe
(at intervals
obtained
of 20 psec),
exact compensation
takes 480 psec to scan through
employs
ThevoItages
all filters,
24 filters
at the filter
every
spanning +11.5 kHz about the raoutputs are sampled
75 km of altitude.
a tapped delay-line
for tbe delays
between
the outputs correspond
2
at 0.5-msec
Since the filters
is used to drive
samples.
Thus,
to the same real
must be
the filters
in
although it
altitude.
B.
Observing
Procedure
Ouring $968 we attempted
Table
II lists
the dates and times
Included
reduced.
to make observations
in Table
twice
per montb for a period
for which measurements
IIisthe
were
mean of the planetary
successfully
magnetic
of 24 hours.
carried
index Kp over
out and
each period
of observation.
As noted above,
required
to obtain
the observing
a complete
procedures
electron
This was accomplished
byrecord,ing
recording
system,
and playback
were
density
the fF signals
discussed
changed in 1965 to reduce
and temperature
profile
from
for Iater non-real-time
extensively
the amount of time
i hour to 30 minutes.
processing.
in Ref. 3, was employed
The
until the end of
June i968.
In addition
to?his
halves of the signal
change,
spectrum
which,
though not recognized
values
obtained
tbe spectrum
analyzer
to be explored.
at the time,
for ion temperature
was modified
As already
noted,
between
are not included
in this report.
they introduced
in the results
Beginning
first
proved
impossible
II lists
Table
Folbvingthe
the vertical
were
to be incompletely
was placed
recorded.
about
and means of
in Ref. 3 and will
only days for which results
introd”ctionof
were
the new spectrum
above
in operation.
Several
owing to a programming
Other dayfs data were
to read the data tapes owing to the presence
drift of the ionization
conducted
analyzer
could not be analyzed
runs made with this device
which caused the results
Thus,
changes
the
between
here.
in July 4968, the new spectrum
24-hour
These
are discussed
both
out in a way
As a result,
January and June i968 are unreliable
300 and 500 km and, therefore,
not he repeated
this was carried
caused some loss of information.
minimizing
tbe unwanted effects
in June $965 to permit
of either
later
“write-”
of the
error
lost when it
or “read- errors.”
secured.
analyzer,
hmax F2 (Ref. i7).
special
efforts
For this reason,
were made to detect
some observations
in which the measurements
made using the i-msec pulses (’l C mode”) were re16,17
in each cycle.
This raised the time to complete a cycle of measurement
peated four times
to 45 minutes,
In the normal
pulses
in sequence;
in Table
operating
mode,
the complete
II to distinguish
measurements
cycle
a measurement
measurement
stored
were
to he employed
of the F-region
critical
was made by the radar
C-4 ionosonde
was modified
frequency
operator,
on the sounder
and advance
just perceived
at great
This procedure
gathered,
to permit
controlled
the frequency
. i.24 X 104 (fo F2)2 el/cm3
,,
and i. O-msec
runs are termed
of “drift;’
out in each calendar
‘<regularly
Usually
month.
was made a“ailable
in the form
foF2 in NIHz at the start of each cycle.*
frequency
tape.
synthesizer.
of the synthesizer
was intended to eliminate
0.5-,
who then typed the value into the computer
The synthesizer
but could not be reduced
These
the determination
on magnetic
instances
remotely,
Thus,
owing to lack of ionosonde
when foF2 is expressed
which
incoherent
measurements.
in MHz,
would turn
return was
value of foF2.
scatter
the
as well as
the operator
until the F2 ordinary
where
of
This
To make the measurement,
dials then gave the required
3
I
30 minutes.
it to be turned on and monitored
by a remote
range.
carried
made using O.i-,
in the data-reduction
it along with all the other information
have its frequency
*Nmax
occupying
them from those emphasizing
24 hours of each type of measurement
The value of N ~ax
were
data were
TABLE
INCOHERENT
SCATTER
OBSERVATIONS
End
Begin
Date
II
EST
c*
-1968
Mean
Date
c*
EST
Kp
Ob,t
comments
16 January
I 030
17 January
1030
3+
A
23 January
1130
24 January
1100
2+
A
1630
14 February
Q
1600
1+
A
Quiet
1130
28 FebruaV
D
1200
3
A
Disturbed
26 March
1200
27 Mwch
1200
3:
A
Disturbed
16 April
I 000
17 April
1130
2
A
13 February
27 Febr.aty
q
Disturbed
25 April
q
1300
26 April
Q
1300
1:
A
Quiet
23 May
q
0730
24 May
Q
0700
1-
A
Quiet
20 June
1200
21 Jwm
Q
1200
1+
A
Quief
IB July
1630
19 July
0800
2-
Reg
15 Awwt
D
I 000
16 Aw.,t
D
0900
4-
Reg
Distwbed
27 AWIW
q
0830
28 August
Q
0830
I
Drift~
Quiet
29 August
Q
0800
30 August
Q
0800
1:
Drift
Disturbed
3 September
1200
4 September
1200
3+
Drift ~
Disturbed
I I September
1300
12 September
1300
1+
Drift$
Quiet
12 September
1500
13 September
1500
4
Reg
Disfwbed
Quiet
Quiet
0900
1°
o
Drift $
3 October
1530
4 October
1730
I
Reg
8 October
1100
9 October
1300
2:
Drift+
22 October
0800
23 October
0800
m
Reg
Quiet
29 October
1000
30 October
I 000
4-
Drift $
Disturbed
26 September
0900
27 September
14 November
Q
1630
15 November
Q
1030
1+
Reg
19 Nwember
Q
1200
19 November
Q
1800
1-
Drift
I 000
26 November
I 000
2
Reg
0900
30 Ncwember
Q
0900
1:
Drift
Quiet
1200
13
q
1300
}
Drift~
Quiet
0900
18 December
0900
1°
Reg
Quiet
1000
31 December
I 030
2°
o
Reg
?5 Nwember
?9 Nwember
Q
12 December
17 December
Q
~0 December
December
Quiet
<Ccmditicm:
Q
One of Five quietest
q
D
One of ten quietest days in month
most
disturbed days in month
0..
of fi,.
Observ.fi.m:
A - Data gathered
Reg
Dot.
days in month
and cm.lyzed
gathered
Drift } Reg = Regular;
os described
and analyzed
in Line.in
.s described
in Li”c.in
Labcwat.ry
Laboratory
Report TR-474.
Repwt TR-477.
Drift = Drift Measurement.
These data have been inde~nde”tly
reduced and p.bl ished by Carpenter
4
and 8owhill !8
C.
Data Reduction
The measurements
with the exception
viously
these profiles
formed
by a graphical
for the altitude variation
in the electron-to-ion
Beginning
in July *968,
of interest
The computer
(2) removed
the results
“power”
profiles
were
It was,
however,
of the scattering
ratio
produced5
cross
Te/Ti
section
in Ref. 3
:.n place of those pre-
still necessary
to correct
of the electrons
with height.
spurious
employed
echoes
of Te/Ti,
CalCOmP plotter
Ti were
effects
introduced
This correction
due to satellites,
(3) adjusted
o“ the immsonde,
This profile
was per-
reduced
to that employed
We have compared
agreement.
.ss a graph plotted by a
ik
Estimates of Te and
Table
cycle.
i.e.,
for the
had also been
111contrasts
in Table
by Carpenter
II),
the manner
the data have
and Bowhilli8
using graphical
are presented
corrected
since i963.
by the daggers
with those obtained
reductions
methods
at Millstone
in the report
in a manner
and hand calcula-
and fcmnd generally
in order
to preser”e
consistency.
TABLE
OBSERVING
PROGWM
Year
(h..,,)
1963
30
111
AS A FUNCTION
OF YEAR
Number of
Time Token
tO Me.,.,.
Number of
Observing Periods
Per Month
One PrOfile
(h..,,)
Profi Ies Obt. i“ed
Per M.nth
Reducti.n Method
Employed
4
1.5
80
Mean hourly profiles
cwmtr.cted
for each
Length of
Each Observing
Period
pro-
on altitude var-
this correction
in each year
of lIlinois
these reductions
The lIillstone
density
value to yield the correct
the dependence
of Te were
(Preciously
(indicated
results,
the absolute
was available
for one complete
at the University
for the earlier
the electron
all the
possible.
made with the thz’ee pulse lengths,
The values
made and reduced
observations
became
as log< ~Ne vs altitude.
Debye length with altitude. ‘6
were
reduction
Basically,
and (4) removed
on plots a“d o“ the print-out.
? shows results
machine
in Ref. 16.
also provided
seven of the ,,drifts”
in a manner that placed together
measurements
of the changing
been independently
tions.
are described
Fig. 4), and m a print-out
in which the measurements
similar
gathered
(4 ) combined
and (5) o“ Debye length.
(e. g.,
made hy hand. ) Figure
For
were
data tape so that complete
in a way that,
of Xmax F2 as measured
iations
good
in the manner described
method.
temperature
on a single
programs
,vere obtained
value
overlay
reduced
by hand.5
quantities
files
to July 1968 were
that computer-drawn
obtained
by changes
made prior
c.lendar
month (Ref.]).
1964
30
2
1.0
60
As in 1963
1965
48
I
0.5
96
As in 1963
I ?66
24
2
0.5
96
Each pr.file
sepr.tely
1967
24
2
0.5
96
As in 1966
1968
24
2
0.5 or 0.75
96 .r 64
..al’yzed
(Ref. 3).
As in 1965 until July
when COrnplete
nmchime reduction
beg..
(Ref. 16).
I
I
.
1
I
1
t
6
1
f
- .
The measurement
of the vertical
tion of the new frequency
not been resolved
ude
synthesizer
adequately
of the drift velocity
certainty
not presented
III.
at this time.
Ne,
here,
Te,
that became
Owing to the large
of height and the,
(especially
has yet been devised
used to present
f6, i7
has posed some problems
as functions
in the measurements
presentation
drift velocity
possible
variability
comparable
to the contour diagrams
of height and time.
but will be made available
in tabular form
that have
in the sign and magnit-
as well as the large
at high altitudes i 7), m simple
and Ti as functions
with the introduc-
of data presentation
experimental
un-
means of data-
that have routinely
Accordingly,
to interested
been
these results
users
are
on request.
.
RESULTS
A.
Electron
Contours
~f electron
during the period
in the balance
llensity
density
of the year
are. presented
beled by the corresponding:
We have discussed
at Millstone.
(expressed
January- June i968 a=
as plasma
presented
as Figs.3(a)
frequent y in O.5-MHz intervals)
ti” “Figs. 2(.a.)through
through.(s).
(i). while
obtained
thOse Obtafned
~ Fig. 3, the cOntOurs are la-
value of log, ONe; and are in stePS Of fJ.2.
in previous
Quiet days exhibit
.reports2-5
a cbarscteri
tbe principal
types ofdiznmal
stic ,,w?nter,, or ‘tsummer”
behavior
variation.
observed
There is a
fairly abrupt transition between the two in the equinoxes.
.For the results presented here,
,,winter!! pattern prevails
“p.to i6-17 April [Fig. ~(f)] and after 3-4 october
[Fig. 3(i)!.
I
,
mm
I
OBca
,20)
Km
mea
,.
EST
EST
b)
(.)
Fig. 2(a - i). COntour diagmms
of censtan; plcwma frequency (in 0.5 MHz
of height and time g.the red d.ring the first six months of 1968.
7
steps) os f...tnsns
the
ES,
(d)
(c)
I
EsT
,3,
(f)
(e)
,,
Fig. 2(a-i).
:1
:,:1
,,.
I
I
,.
1
Continued.
n~i
)
Wca
,
,,CO
G9cu
$
,.ca
,
mm
24..
E$,
(9)
,,,
E,7
(h)
O)
Continued.
Fig.2 (a-i),
9
contour diagrams Of co.sfa.t
foglo electron density (in fOgloNe
Fig. 3(a-s).
os functions of height and time gathered during the last six months of 1968.
= o.2 ‘fe~)
...
:
g
:
me
403
,..
,00
I
EST
(b)
Fig.3 (a-s).
Continued.
/
\
au
,0.
EST
(.)
Fig. 3(.-s).
Continued
/
\
\ \
J
ES,
(d)
Fig.3(a-s).
Continued.
,,
I
L
Fi5..3 (a-s).
Continued.
1
I
!
I
I
,!
~
!
*—.
14
\
///’———’—’———.—
‘“ ‘“d
,
X0
me
E,7
(f)
~
{
,,:
{
!
fig. 3(.-s).
Cc.ntin.ed.
:He%”
““:”A,“...e
“-”’’”/’
.:..A“
EST
(9)
fig.
‘!
I
3(0-s).
C.ntin.ed,
EST
(h)
Fig.
I
:
,
i
3(0-s).
C.ntin.ed.
EST
(1)
Fig. 3(c-s).
Continued.
21
,4.,5.0”,,6,
I,,,ON.
I
! ,0.
la
EST
(m)
fig.
3(0-s).
Continued.
,,.
1+—————’
I
1==7
.@
,5
,,,
(n)
fig.
Continued.
3(0-s).
23
(0)
Fig,
Continued.
3(a-s).
24
“
/J
!’::G’+
k
4..
,Ce
,.,
,,
/.
, I
/
/“
/
(P)
fig.
3(.-s).
Continued.
1
1
I
25
(q)
Fig. 3(a-s).
Continued.
26
,00
\\
“ ‘z -.
,
,00
400
3..
ZOO
E5T
(r)
Fig. 3(.-s).
Continued.
27
.
,.
I
‘“/
I
0000
O*,.
0,0.
Wcu
UL
\--0,.0
{m
, ,C6
L-,400
ES,
(s)
Fig. 3(0-s).
28
Continued.
/27
, .@
//
/’c
,,0.
mm—
1
,,w
,4..
1
The winter
somewhat
behavior
after.
the early
is characterized
At sunspot minimum,
morning
as many of the days presented
3(P) through (r)].
A number of nights do show an early
The summer
values
than in winter.
midday
June [Figs.
I
~
‘/
abnormally
storm!s
gathered
on 29-3o October
it appears
whfle
occurrence
inside the plasmasphere.
instances
magnetically
disturbed
over
F- region
netic storms
behavior
densities
conditions
5,12
on i7 January
densities,
before
Electron
From
to
that are
by
of the local
appear to have been observed
than normal,
more
than the F2 peak (G condition).
thermospheric
time of
magnetic
in i968.
field.
Irregular
winds and
near sunspot maximum
to the motion of the mid-latitude
1968 [Fig. 2(a)] represents
a
of magnetospheric
of event has a preferred
increases
on
the drift information
directed
seem to be caused by thermospheric
19
of such an event.
and attributed
to be on 27 March
rise
or early evening.
These
emP1OYing the ‘esults
caused by penetration
with marked
on these days and the F* layer
in 1968 appears
noon giving
On
that has been seen,
are caused by southward
during
trough of low
often during 4968 and Pos-
the only case.
are frequently
phase ) on the day (or days) following
larger
2(g)].
which is followed
in tbe late afternoon
separately
have been encountered
lower
2(f),
have been recognized
This does not seem to have occurred
somewhat
(negative
is lower
Contours
through
is usu-
1972 [Figs.
above normal,
This last class
much of the day,
the station.
Fi peak becomes
B.
over
low nighttime
sibly the behavior
1
20
is thought to be an example
Abnormally
corded
and the peak density
are found to occur up to i8 hours after
motions
of this type of disturbance
extending
29-30 October
h~axF2
to horizontal
I).
nighttime
One type of variation
usually
near 1700 LT and is associated
increases,
ionization
(Table
of foF2 and Larger
maximum
3968 [Fig. 3(l)] and in July $969 (Ref. i9 ).
are related
25-26 November
Examples
density
that some of the increases
others
fields
NO clear
values
these patterns
increases
sudden commencement,
3(i) through (k),
e.g.,
than seen at sunspot minimum,
ph~~~llportionsof the storm have been examined
obtained,
electric
from
conditions.
These
Figs.
in
absent at
them here.
in the daytime
values.
largely
of this behavior are to be found
ii, iz
the probable
We have discussed elsewhere
2(i)].
deviations
disturbed
is an increase
low nighttime
magnetic
,!positive.
winds,
2(h),
it [cf.,
increase,
and 25-26 April
“bite- out.”
and will not repeat
with magnetically
16-i7
near noon or
peak in the density
seems
disturbed
daytime
a second weaker
the so-called
A number of cham.cte=istic
many occasions,
morning
less diurnal variation,
e.g.,
Nmax reaches
minimum,
of these variations
associated
here do not exhibit
by lower
therefore,
ground sunset,
for 23-24 May and 20-2i
causes
is,
There
at local
smaller
This feature
thi8 is less pronounced
is characterized
many days in the summer,
a shallow
[Fig. 3(s)fi
peak in foF2 centered
a second
that these nights tend to be magnetically
behavior
ally encountered
,,
is usually
sunspot maximum
and it is noteworthy
N
there
daytime
hours (0200- 0400 ) that is anomalous.
[Fig, 3(0 )] and 30-31 December
I
by a single
encountered
the positive
pronounced
than
increase.
Usual.
The only instance
On
during magusually
OcCU?iOn
of this behavior
the
re-
[Fig. 2(e)].
Temperature
of constant electron
(i) and 5(a) through (s).
for summer
and winter
the simplest
pattern.
with altitude
at all times
In these
temperature
at 200eK intervals are presented in Figs. 4(a)
2-5
the characteristic
temperature
We have discussed previously
observed
months,
(indicating
at Millstone.
the electron
the presence
29
The summer
temperature
of a source
months usually
usually
increases
exhibit
monotonically
of heat in the magnetosphere).
I
E,,
(c)
Fig. 4(.-T).
Contour
diagrams of COnst.a.t electron
of height and time gathered
temperature
during the first six nmnths of 1968.
30
(in 200”K
steps) as functions
,,,
,,,
w
,U3
200
OCea
0400
0..0
,200
600
mm
?400
EN
,$,
(.)
(f)
Fig. 4(a-i).
Continued.
3i
EN
(9)
]
,
EST
EST
(i)
(h)
fig.
4(a-i).
Continued.
1
32
48-!9
d“,
T.
?s68
‘/L///l/
Iil
I
E $,
(o)
Fig. 5(.-s).
Contcwr diagrams of constant electron
of he!ght and time gathered
temperature
during the last six months of 1968.
33
(i. 200”K
steps) as functi.ns
1
I
m
,,0
mm
Cdca
1
C6co
1
mm
I
!KOo
,,CO
I
!...
EST
(b)
Fig.
5(.-s).
Ccmtinued.
34
1
,.CC
!..0
am.
,,ca
,.,0
... .
.
!
em
ma
.m
7
.
:
g
,..
,,;:
,Ca
.Cc
\
,.,
j
EST
(c)
.,!
:1
fig.
5(.-s).
Continued.
1
‘“!
(
,i
35
ES
(d)
Fig. 5(0-s).
Ccmtin.ed.
!
36
..
7C0 —
ma —
;
:
*
r
,0? —
30. —
ma —
EST
(e)
Fig. 5(.-s).
C.mt!nued.
37
fig. 5(a-s).
Continued.
38
—...
9@
/ /1
.
!,
u!!
\
1.
I
/
[
1!
‘h Wrw’=-’+
Eii-ECO.o
0,0.
..ca
OWa
mm
,,m
!mo
,4.0
EST
(9)
fig.
5(.-s).
Ccmtinued.
39
I
II
“m
CcOo
.2.
m
.03
///4
///
R=-ja
es.
w
,0,.
!2.0
EST
h)
Fig. 5(a-s).
40
Ccmtinued.
,...
,.CU
,,..
m.
2,0,
,.CO
,,
I
I
I
~
,.1
~i)EsT
Fig, 5(a-s).
I
(
Continued.
Fig. 5(a-s).
C.ntin.ed.
42
!0.
,KO
;,0
,0.
.
_.
+--’--’
\
,s1
(k)
Fig. 5(0-s).
Continued.
43
‘~
1
f
,...
\
\l /-
/=--’l
,m.
I
,!
,:
EST
(1)
Fig. 5(0-s).
,.
,,
Continued.
ESr
(m)
fig.
5(.-s).
Continued.
45
EST
(n)
Fig. 5(.-s).
C~ntin.ed.
46
I
Fig. 5(0-s).
Continued.
I
47
I /f-----+\lF”.lF
-----7A
,,,
(P)
Fig. 5(0-s).
(
Cotitinued.
I
m
02m
1
@m
1
O.CM
f
mm
I
1
lm
!?CO
1
!4..
EST
(q)
Fig. 5(.-s).
Continued.
49
1
!m
1
IOca
1
I
mea
=@
I
,.~
“Ldx
m
OCa
C.m
mm
mm
E,.
(r)
Fig. 5(.-s).
Continued.
50
1
““m
,Cc
\
NW
I
I
I
Wco
1
mm
EST
(s)
Fig. 5(a-s).
Continued.
,-,
R-//l
,, ...,.
There
is a large
lasting
increase
in temperature
until sunset when the temperature
the temperature
decreases,
temperatures
hibit a shallow
minimum
through
caping from
remains
following
ature may
then increase
the temperature
morning
density
(s )].
that occurs
These
At sunset,
at sunrise.
during the day and usually
are presented
ex-
in Figs. 4(b)
local
electron
development
density
density
by strong
depending
of the demsity,
4(g),
condition
The electron
bas been observed
as ?t.smnmer.’,
rather
on 16-{7
smwise
cm 26-27 March
of the ionospheric
than normal
storm
densities,
These
ion-cyclotron
fluxes
then in progress.
An impressive
for i2-i
temperature
increase
occurring
low electron
densities
[Fig.
high E-region
densities
increase
at sunset.
In summer,
statement,
In part,
to be produced
are provided
indicator
condition
by 25-26 April,
of abnormal
heating,
result
the protonosphere
from
phase
lower
also contrib-
particles
for nighttime
probably
of ionizing
The very
are associated
with tbe negative
during the period
is precipitation
the
during
the high temperatures
to be responsible
[Fig. 5(g)]
behavior.
we believe
by the decay of ring current
of nocturnal
with
in the density,
only encountered
the higher temperatures
from
23-24 May
should be associated
at this time does not appear to be associated
when there
for the
about 7-8 X
through
mid-
caused by this process
2200-2400.
The large
with particularly
3(g)] as would be the case when the trough lies overhead,
that occur
when-
that a
based cm the present
to be associated
heat fluxes
that appears
example
This
which occurs
shcmld exceed
near 0230 [Fig. 4(a)],
12
Millstone.
Similarly,
large
350 km.
we reported
to be the necessary
better
of the day, of
5(q) through (s).
temperature
Previously,5
and at Millstone
are believed
3 September
5(o),
Owing to the annual variation
trough over
but in some storms
by the results
(h),
this feature
to be a sensitive
[Fig. 4(e)]
are presumed
Thus,
than summer,
damping - the same process
red arcsyi
is provided
Examples
January beginning
with the motion of the mid- latitude
following
5(p)
on days that, based on the diurnal variation
[Fig. 5(f)].
than season.
appears
high.
A somewhat
on the exact aItitude.
temperature
[Figs.
during portions
at the height of the minimmn
more
observed
with the
for 23-24 January
i. e., typically
of the electron
at 300 km appeared
often in winter
4,5,32
near sunspot maximum.
high values
cooling
minimum
condition
than the decrease
above hmaxF2,
somewhat
would be classed
is reached
es-
the elec-
At sunspot
tend to cause the temperature
is particularly
minimum.
density
4(h)] and 41-12 September
the above density
4(b)].
in association
the end of the year
4(e) and Figs. 5(e) through
local
Ne & 106 el/cm3
This temperature
the lowering-of
near 2000, and the temper-
midnight
is the appearance,
somewhat
4(d),
of this temperature
i 05 el/cm3
by photo-electrons
Thus,
can be seen most clearly
pronounced
behavior
at this altitude
might be that the local
At night,
amplitude.
at an altitude
is produced
complex.
[see Figs. 4(a),
after
days toward
“a=iations
much more
of the winter
minimum
the electron
more
arrested
to decrease
cm several
temperature
to appear
can be seen in Figs. 4(a),
This minimmn
continues
This phenomenon
nocturnal
sunlit.
is usually
is usually found to decrease
less markedly
feature
ever
latitude
increase
and time is frequently
sunset in winter
are of comparable
Yet another
a temperature
local
increase.
at sunrise
the two usually
ute:”
observed
of this bebavior
which then remains
as the density
[Fig. 4(b)] and somewhat
years
than those
by a period
constant with time.
than the corresponding
Examples
both with altitude
ionosphere
minimum,
results,
essentially
that is followed
high owing to the heating of the magnetosphere
the conjugate
tron temperature
[Figs.
are much lower
near midnight.
the variation
the temperature
feature
rapidly
at sunrise
(d).
In winter,
through
remains
albeit less
The nighttime
early
at all levels
b“t with
particles.
52
,——-.
—
In general,
behavior
the results
than i967,
this simply
reflects
for i 968 appear to contain fewer
despite
the increase
the fact that,
in sunspot level
by chance,
fewer
instances
and magnetic
of anomalous
activity.
of the days of observation
temperature
We believe
were
that
magnetically
disturbed.
C.
Ion Temperature
Ion temperature
results
through
(s) as isotherms
reaches
a nearly
fluctuation
for the period
at i OO-K intervals
isothermal
level
350 km, the ion temperature
Thus,
the ion temperature
hibits a similar
shallow
between
in the height of the isotherms)
is largely
as functions
in the afternoon
are presented
of height and time.
in Figs. 6(a)
The ion temperature
250 and 35o km, and this gives rise to the er!’atic
Below about
[e. g., Figs. 6(r), 6(s)].
in this interval
governed
is usually only slightly
diurnal variation.
maximum
July through December
by the thermal
greater
than the neutral
Thws, the ion temperature
and a minimum
coupling
just before
with neutral
particles.
temperature
at these le”els
usually
and exreaches
sunrise.
l\w/
3..
L
—\\
,\
\
--1..-
1/–
1,
(.)
~g. 6(a-s).
Contour diagrams of c.anstant ion tempemture
and time gathered during the last six months of 1968.
53
(in 100”K step)
.S functions
of heighi
a
54
i
I
EST
(c)
fig.
6(0-s).
Continued.
55
—
—
1
1
(d)
Fig. 6(0-s).
Continued.
56
woo
mm
o.ca
C6cu
mm
!.
~ca
EST
(.)
fig. 6(a-s).
C.ntin.ed.
57
I
1,‘i
,,-,2
2,.
SErp
!,,,
—
~
moo
I
.200
I
..00
1
I
m
.,,.
I
1
f,,,
i,,.
EST
1
~~oo
(f)
I
“’l
Hg. 6(.-s).
Continued.
58
1
I
1
““”
““”
I
I
200”
““”
“w
(9)
fig.
6(.-s).
Continued.
59
!!.0
,
,Cu
:
~
.
,00
●u
,. .
m.
.,0.
.*OO
..00
0.0.
0=
,...
:,0:
‘-
(h)
,1
fig.
6(.-s).
Continued.
60
‘ ‘“O
‘“0”
moo
2ZO0
I
k\
\
//
\
\\
,..”
i
I
\
,,
/,
+
O“/. -/
//
I \\
1
(i)
Fig. 6(0-s).
62
Continued.
‘4
I
!
(k)
Fig. 6(a-s).
63
C.ntinued.
,..
,,00
-w
F
,200
w,,
7.6
(1)
Fig. 6(a-s).
Continued.
,!
64
6
,00
z!ca
,00
. . .
;
~
:
❑ ,@
,
!4-,5 .0”
400 —
!,,,
,,
,Ce
. ..
,.0
—
—
-
TimTim
OCcu
o,ca
6.0
,00
o.ca
mm
OWO
I
‘ma
{mu
1
,.00
EST
(m)
FFg.
6(.-s).
Continued.
65
1
,6C0 —
,.m
,mo
,,00
I
Fig. 6(0-s).
Continued.
66
.-. ...
.--,-.
i
!,
.....Af-+-””
~.
2’00
(0)
Fig.
6(0-s).
Continued.
1
67
\
-!,
‘“m /’p,/
,
.. .=.,.,, “
.“..
1
“/’--
/
\
‘“”B
0000
.2..
.4C0
omu
c-o
fsr
(P)
Fig. 6(.-s).
Continued.
,/-=
(q)
Fig. 6(0-s).
Continued.
“,,,”,
(k”, )
,,,
(s)
Fig. 6(0-s).
Continued.
.—.
—
Above
perature.
their
about 400 km altitude,
At these
temperature
crease
altitudes,
D.
Average
Temperature
At sunspot minimum,
results,
and nighttime
averaging
it was fomd
detecting
with electrons,
and
the increase
and de-
Thus,
Figs. 6(b) through
~e.g.,
tem-
(d)] and
Fig. 6 (g )].
of average
Two averages
EST ).
temperature
were
As sunspot maximum
curves
constructed,
viz.,
was approached,
in em attempt
daytime
to better
(1 000-i 500 EST)
the justification
for
yet the practice was continued as it provided a useful way of
22
and smmpot cycle trends.
These average temperature
curves were con-
seasonal
structed
after,
tbe electron
that for large portions of the day and the night the eleci-3
appreciably.
Owing to the poor quality of >ome of the
the mnstructicm
(21 00-0300
encounters
temperature.
[e. g.,
toward
Profiles
with altitude.
the resdts
and converges
and set can be quite marked
did not vary
this encouraged
the variation
in electron
heating can be recognized
tron and ion temperatures
define
changes
at sunrise
of nocturnal
rapidly
the ions are heated by Coulomb
tends to follow
in temperature
instances
Ti incpeases
was reduced,
for the data gathered
prior
to July i 968 and are shown in Figs. 7(a) through
(i);
there-
this work was discontinued.
The curves
shown in Figs.
i. e., by computing
original
curves
Figs. 7(a),
7(d),
7(a) through (i) were
the average
obtained
7(e)]
of the electron
in these two time
clearly
obtained
in the manner
temperatures
intervals.
show the temperature
employed
previously,5
read (at i 00 km intervals)
several
mininmrn
of the winter
daytime
off the
curves
that then develops.
~
!6-,7
,.0
JAN
,,6,
-
600 .,0”,
:
:
:
:
4,,
–
,00
-
1
o
1
I
40,
,
1
1
,00
1
I
,
,,00
,,,,
I
,
1
,,,.
I
,..0
1
1
,,.,
TEMPERATURE
(*K)
(.)
Fig. 7(a-i).
vs
altitude
Aver.ge
daytime
(1000-1500
EST) and ni9httirne
cbserved during the first six months of 1968.
72
(2100-0300)
electron
fernpemf.res
I
[e. g.,
,000
23-24
,00
-
,00
–
J4N
~
196B
F
:
.,s”,
:
:
:
4,,
-
*OO -
1
1
400
0
1
)
*,O
t
1
,,m
,,00
,EM,E.A,
I
.OOO
URE
,
,400
r
,,00
1
,
,200-
,..,
(b)
,00.
,3-,4
FEB
TEmIL
,968
.
800 -
“,.
”T
,.0z
:
s
~
!
40.
-
*OO -
,
0
,
4,.
1
1
80,
I
,,,.
1
,
,,00
K.,,..,
,
”,,
,000
(..
(c)
Fig. 7(a-i).
Cc.ntin.ed.
73
}
,
I
,400
c
,
,800
I
,200
.
1
1
1
.00
1
,
,00
1
1
1
1
,s00
,,00
I
TFMPER4TURE
1
,000
{..
I
!
2.00
1
!
2..0
1
)
(d)
.;
,1
‘OOOY
o
1
.,0
I
,00
Tmm
(
,200
mm
,s00
,EMP,
RA*”,
F
(..
(.)
Fig. 7(a-i).
Continued.
74
)
I
,400
2,00
I
,,00
o
I
1
1
400
,
!
8.0
I
,
,,00
,
1
,.00
,,.,,.,,
”.,
t
moo
,..
(9)
I
Fig. 7(a-i).
Continued.
I
75
)
1
1
,400
!
1
,,00
I
—
.,.,
,000
~
23-24
MAY 49S8
t
o
[
I
I
.00
,
1
,00
,
4,00
,
I
,600
1
1
2.,0
T,..,..,”,?,
I
1
,40.
I
I
2m.
1
1
!
,2,.
,,0
(..,
(h)
,
0
1
.00
1
1
,00
1
1
,200
1
I
,,00
,,!+.,..,
Fig. 7(a-i).
I
”,S
1
moo
,..1
Continued.
76
1
!
,.00
1
I
2000
1
1
,,00
E.
Seasonal
Variations
The seasonal variations that may be inferred from these results have been discussed pre22
Thus, for example,
the nighttime winter temperatures
are high, as noted above, as
viously.
a result
of pbcdoelectron
heating of the magnetosphere
be seen in Figs. 8 and 9, which represent
different
by the conjugate
T.’
700
to present
seasonal
This may
trends.
In
,8-2 -!{!!3
-
600
ionosphere.
n
attempts
:0
-
0
:“
-E
5
z~
?
,00
p“”
400
-
300 -
200
/
-
TEMPERATURE
so o
~
40
,0
,020
,0
,s.
JAM
20
,0
,0
,0
APR
MAR
20
,0
MAY
ll!ll
,0
20
M1l!lll
20
10 Zo
,..
J“.
,,8
1111111111,,,,
w 20
40 20
MAR
(°Kl
t$,
40 20
AP,
m 20
M?.”
,“.
[968
1966
(b)
(a)
Fig. 8(a-b).
Contour diagrams of OVemge electron tem~r.ature
(in 500”K step) w height and months
for the first six months in 1968; (.) daytime (1000-1500
EST), (b) nighttime (2100-0300
EST).
Figs.
8(a) and 8(b),
contours
are drawn of electron
of height and month for the daytime
(Fig. 7).
In Figs. 9(a) and (b),
(1000-1500
the electron
temperatm’e
at 500SK intervals
EST) and nighttime
temperature
as a function
(21 00-0300 EST) averages
at 300 and 500 km is plotted
as a func-
tion of month.
Figures
This variation
8(a) and 9(a) show that the daytirr e temperatures
is much less prormmmed near ,mmpot mi”immr
duced by the appearmce
of the temperatu~e
minimum
are larger in summer than winter.
22
and, in large part, is intro-
near 350 km altitude
chiefly
in the winter
months.
F.
Magnetospheric
The positive
temperate
of a heat flux from
a“erage
Heat Fluxes
temperature
gradient
difference
independent
estimates
The magnitude
~
500 km implies
500-600,
600-700
the existence
computed
wez.e then awraged
and are plotted
in Figs.
from
the
and 700-800 km “ia
si”21eV/cm2/sec
77
A
above
of the flmi has bee”
over the height intervals
Gp . 7.7X 105 T~/2
These
in Fig. 7 at altitudes
the magnetosphere,
lo(a)
and (b).
‘~’’’’’’’’’’’’’’’’
-iEEcL
~:~
I
so..
2800
“!
1
ooo~
!.00
530
it
4,00
dAN
!0 20
FE,
,0 m
. . .
,0 20
,,,
!0 20
MA,
i
‘“o~
,0 ,0
4“.
$0 m
JAN
m ?0
,,,
,0 20
. . .
4968
F;g.
9(o-b).
111111,
,0 m
.,”
,0 20
,“.
4968
(b)
(.)
Average
six months i. 1968;
m m
APR
electron
(.)
daytime
twnpemtwe
(1 000-1500
! 111111111,1,,,,,,,,,,,
af 3000,
EST),
l,ri
(b
I 500 km altitude vs mcmth for the first
nighttime (21 00-0300
EST).
111111
!llllllllll
] 1111111111
~
Illrrr
~
~
,0
,,!4
,,,
f 96e
Fig. 10(a-b).
Magnet.
(1000-1500
m
. . .
,0
,,,
2,
,0
..”
m
,0
,..
(b)
spheric heat flux cwnputed
EST), (b) nighttime
frcnn the temperature
(21 00-0300
78
,
,0
1968
(.)
(.) daytime
,0
EST).
curves in Fig, 7;
m
At night the heat flux is considerably
can be accounted
opacity
for in terms
of the field
time fluxes
larger
of the conjugate
tube is quite high.
\vhich are only a factor
in winter
than in summer
This appears
of 2 smaller
to be necessaryin
cated in Table
to expectation,
This bebavior
IV which summarizes
and this
provided
that the
order
than those observed
During the day, cm tbe other hand, the flux tends to be larger
and this is contrary
[Fig. iO(b)]
heating of the magnetosphere,
in winter
has been observed
the mean seasonal
values
to account for night-
during the day.
than summer
in previous
of the daytime
years
average
[Fig. ~O(a)],
as indi-
heat fluxes
TABLE IV
AVERAGE
DAYTIME
(100-1500)
PROTON
OSPHERE
HEAT
FLUXES
(109 eV/cm2/see)
Summer
Winter
Yeor
(April-September)
I 964
3.66+1.06
5.16
+ 1.28
1965
2.03*0.57
3.23
* 0.88
1966
3.74+
1.56
4.42*1.11
1967
5.08+
1.42
7.74
1968*
4.64
(January -M.rch,
& 0.74
October-December)
* 3.33
8.81+1.79
* first six m.nths only.
observed
each year
observed
in winter
is higher.
since 4964 (Ref. 22].
despite
There
that the summer
the fact that the temperature
is also a clear
in Fig. ii
This is illustrated
It is clear
trendof
increasing
where the fluxes
(
[W.,ww
(,!
.,,,
.,,..,,
Table
M,T,
are lower
the thermal
as sunspot maximum
IV are plotted
1
s,0.,
ME
{!O-,,
HEAT
1
)”,s
FL”
X
z
~
‘J
i
~
9
i’[
:
–,
o–
00
— .0
,3..
,96.
,9.,
,967
!,,,
‘ 0
YEAR
Fig. Il.
V.riati.”
.f the average winter (Jo..a~-March,
cmd summer (April -September) daytime average (1000-1500
Oct. ber-December)
EST) magne tospheric
heat flux si”ce
10.7
averaged
1964.
AISO shcxvn i. fhesolar
over three solcir mtatio”s,
7
10.7’
79
radio fl..xat
than those
conductivity)
is approached.
against time together
,,,,
PRO IONOSPHERIC
e
(and, therefore,
values
giveni”
fluxes
crnw.velength
with the solar
the large
(Fig.
flux at iO.7 cm,
winter
values
averaged
in 1967
over three
and 4968 appear
solar
rotations,
to be associated
~lo.,.
It cm be seen that
with peaks in the solar
flux
Ii).
;(O,,
Fig. 12.
Dependence
As a quantitative
in solar
radiation,
spread,
average
heat fl.xes
test of the dependeme
over
it seems
(fig.
ll).n~lo,,
of the average
we have plotted the valms
flux F10,7 when averaged
somewhat
ofse.sonal
given
annual daytime
in Table
the same 6 month periods
that both summer
and winter.
heat flux on changes
IV as functions
(Fig. i2).
and winter
f.rs.mme,
Although
days obey a simple
of the mean solar
the results
linear
are
dependence
of the form
—
Gp ‘a
Flo.7
where
asummer
awinter
Reasons
(winter)
photoelectron
changes
- 5.4 X ~07
-
for the possible
the annual variation
the colder
. 3.65 x $07 eV/cm2/sec/flux
summer
in the F-region
hemisphere
production
in the composition
eV,/cm2/sec/flux
to winter
““it
difference
temperature
of the neutral
have been considered.
is not capable
is different
atmosphere
80
It appears
of causing more
that
heat to flow to
these results. 22 Possibly the
in the two hemispheres
as a ccmseqwmce of
to the extent necessary
and/or escape
unit, and
to explain
and this can account for the difference.
Iv.
SUMMARY
Incoherent
atures
were
scatter
synoptic
made at the Millstone
per month in i968 (Table
in a manner
I
H).
established
method of measuring
Hill Field
where.i6
system
include
drift velocity
measurements
disturbed
(Ref. 5).
fell
conditions
We attribute
‘!summer,,
Several
!
tbe received
as a satisfactory
albeit
Uegi”ning
compl$te
signals
i-eal -
on mag-
has been described
method of presenting
else-
the data
this,
a greater
amount of magnet-
for the measmwrnents
made in i967
to the fact that most of the days chosen for observation
confined
recognizable
Despite
to baws been encountered
quiet periods.
The remits
in 1968 confirm that the character2,3
at near sunspot minimum
persists through
identified
quiet periods.
fro,m the quiet day beha”ior
and negative
in 1968
gathered
to magnetically
departures
include both the positive
I
in this report.
that provided
was capable of detecting small frequency shifts in the
*6-$8
However,
we have not attempted to
sunspot cycle.
and 1,winte r,, beha”ior
sunspot maximum,
1
the
the determination
in the plasma.
in this report
appears
this simply
during magnetically
istic
Unfortunately,
rendering
of this new system
twice
and reduced
fashion has not been found.
i 968 was tbe peak of the current
ically
gathered
previously.3
distortion
the need for recording
The implementation
caused by drifts
in a useful and compact
introduced
and ion temper-
of 24 hours app~oximately
the data were
was put into operation
and obviated
It was found that the new system
of the signals
electron
and these data have not been included
processing.
spectra
six months,
of the signals
uncertain,
of the signals
netic tape for later
densities,
in June i965 that has been described
in July 1968, a new data-processing
time processing
electron
Station for periods
During the first
the spectra
of the ion temperature
j
studies of F-region
phases of magnetic
have been identified,
storms.
Elsewhere,
4,5
These
we have proposed
that there
are two separate mechanisms that can give rise to increases
of electron density during
i9
the positi”e
phase.
Cases in which the increase is irregular
and persists for a large part of
the day appear
to be caused by lifting
blowing
toward
the equator
velocity
observations
of positi”e
events
appear
an increase
Marked
magnetic
over
decreases
Instances
The electron
densities
fields
density
increase
temperature
were
of ionization
occurring
trough moves
common
on 27 March
results
have been employed
into the ionosphere
during the daytime.
to the iO. 7 cm solar flux averaged
reasOns for this difference
necm 1700 LT coincident
are found usmilly
over
3 solar
and -3.65
cm the second
southward
with
overhead
during a minor
day of the
to m cupy a position
in <967, but were
to have been present
encomtered
--5.4 X f07 eV/Cm2/5e C/flux unit in winter,
Satisfactory
density
of this behavior
were
winds
and the start of a substorm.
electron
trough appears
mmtral
in the dusk sector caused
i5, 19,20 These
inside the plasmasphere.
electric
field
about by thernmspheric
The density and
19
Another cause
with this explanation.
$968 are consistent
and at night when the mid- Iatit”de
The mid-latitude
F-region
the magnetosphere
related
to a single
in F-region
brought
heating of the atmosphere.
to be a redistribution
in the local total magnetic
storm
in 3968.
daytime
appears
of magnetospheric
to give rise
Millstone.
to am-oral
for 29-3o October
phase increases
by the penetration
of the F-1ayer
in response
seen only once each
on 17 January a“d low
magnetic
to study the average
storm.
heat flux from
We find that the flux appears
rotations,
~lo
linearly
~ with a dependence
X 107 eV/cm2/sec/flm+
of
tmit in summer.
have not been fcmnd.
81
.—.,
—
ACKNOWLEDGMENTS
W.A.
Reid,
R.F.
modifications
The
for
equipment
new data- amlysis
assistance
and Mrs.
J.H.
Corporation).
largely
program
responsible
software
in gathering
and others
these
for
the
that resulted
achieved
during
was the work of R. F. Julian
The author is indebted to these individ-
R. J. Cicerone
McNally
A. Freeman
were
and associated
computer
and to L. A. Carpenter,
A. Beauregard,
Ffanson
in the quality of the measurements
improvement
and J. K. Upham (Azrex
uals
and L.B.
to the radar
in the large
i968.
Julian
(both of the University
at the
data.
Millstone
Thanks
and Miss F. Angier
of Illinois),
Field
Station
are also due to Mrs.
L. Bill,
who assisted
Hill
with the preparation
of the figm-es.
REFERENCES
i.
J, V. ~an~
Reuort
2.
Report
3.
Report
!ulono~pheric
Back~catter
ob~ervation~
at Mi118tone Hill,,, Technical
374: Lincoln Laboratory, .
M. I.T. (22 January *965), DDC AD-646607.
!VMi~l~tone HiII Thomson Scatter Re~~lt~ for i964,,~ Technical
430,’
Lincoln Laboratory,
M. LT. (i5 November
i967). DDC AD-668436.
!NMi~I~tone Hi~~ Thom~On scatter Results for i965,~~ Technical
474:
Lincoln
Laboratory. .
!!Mi~~~tOne
4.
M. LT.
~i~~ ~hOm~~n
(18 December
scatter
Results
1969), DDC AD-70750f.
for i966,q1 Technical
Report
481,’ Lincoln Laboratory, .
M. LT. (i5 December *9713). DDC AD-725742.
,NMil~~tone HiII Thomson scatter Results fo~ 1967,,, Technical
Report
482,’ Lincoln
5.
Laboratory,
6.
Planet.
7.
J. Geophys.
M.l. T.
Space Sci. Q,
8.
planet.
9.
J. Geophys.
Res.
D,
M,
10.
J. Atmos.
$1.
planet.
Space Sci. M,
f2.
Planet.
Space Sci.,
43.
and L. P. Cox,
i 4.
L.P.
Cox and J.V.
15.
J.V.
Evans,
46.
Terr.
Evans,
i03i
(i965),
ii75
Space Sci. ~,
Res.
(22 July t97f).
Phys.
DDCAD-6i6607.
(i965),
DDC AD-6i43i0.
i387 (i967).
4083 and 4845 (i970)t
Z
$629 (t970).
t225 (i970),
in press
J. Geophys.
J. Geophys.
DDC AD-714447.
DDC AD-7161357.
DDCAD-7~6056.
(1973).
Res.,
Res.
@
i59 (497f3)4 DDC AD-7133492.
ZZ. 627f (i970),
J. Geophys.
Res. V, 234i (1972).
, R, ~. Julian and w, A, Reid, ftlncoheFent
scatter
DDC AD-7229~i.
Meas”retnents
of
F-Region
Density, Temperatures,
and Vertical
Velocity at Millstone Hill:’
Technical
Report 447, Lincoln Laboratory,
M. I.T. (6 February 4970),
DDC AD-706863.
i 7.
, R. A. Brockelman,
Radio Science~,
27 (1970).
18.
LA.
Carpenter and S.A.
Processes
intbe Topside
(i5 September i97i).
J.V.
M.D.
21.
22.
Evans,
J. Atmos.
Papagiannis
R. F. Julian,
W. A. Reid and L. A. Carpenter,
,,lnve~tigation
Bowhill,
F-Region, ,, ~niver~ity
Terr.
of the Physics Of Dynamical
of Illinois AeronomY RePOrt %4
..2
Sci.,
and M. Mendillo,
~,
593 (4973).
Planet.
Spat sci.
1?, 503 (497i).
Res.
7A. 4428
J.M. Cornwall,
F.V. Coroniti and R.M. Thorne. J. Geophys.
(i97i).
Variations
of F-Region
Electron TemJ, V, Evans, ,!SeaSon=I snd sunspot Cycle
peratures and Protonsopberic
Heat Fluxes,” J. GeOphys. Res., ?8. 2344 (4973).
82
UNCLASSIFIED
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. . . .!.;,”
.. ., Pi...;
. .. . . ...’;.=,;..
.. . .. . ..
DOCUMENT
[S. . ..ityeajflcft
1.
ORIGINATING
?.n?.n .1 title, b.*y Of**etr..t
(Cotpo,a,e.
.4 CT, V,TY
CONTROL
md!nd.xj.g
DATA
mnOt.tl..
.
R3,D
mt6t6.
en feredwhe.
u,ho,)
fheoverallc.p.rtf.
2..
REPORT
?b.
GROUP
.Ias.>l?.d>
SECURITY
CLASSIFICATION
Unclassified
Lincoln Labmatory,
M. I.T.
None
I
3.
I? EPOI?7
TITLE
Millstone Hill Thomson
I
a,
DE.5CR,
PT,
VE
NOTE,
Scatter
wype.,fr.P.,,
and
Results
for 1968
f”clua,va
da,..>
Technical Report
S, &llT. OFll$l.(La.t “me, f,,., name,,.,,; .,)
Evans, JohnV.
6, REPOR, DATE
23 January
7..
‘3..
8..
CONTRACT
b,
PROJECT
0.
NO.
TOTAL
NO.
0,
‘/b.
PAGES
NO.
0,
REFS
1973
GRANT
NO.
F19628-73-C-OO02
OS1.l..,O,,
S
Tec,bnical
REPORT
M“MBERIs1
Report
499
7X263304D215
9b,
..
07..,
a,.ik.ned
REPoRT
.01S1
this ,..0.,,,
(A,,,
.,h.r,,
umb.,s
,h.,
”,ayb.
ESD-TR -73-55
d.
!0.
AVA,
LA.,
ApwOved
L, T” IL IM(, A,, ON
N’07’ICES
for public release;
distribution mlimited.
,2. S,O. $0.,..
1, 5UPFLEME.,. RY NOT, S
~lLl,..
Y ... (.1,”
Office of the Chief of Research and Development
Department of the Army
None
,. ABSTRACT
This repcmf s“mrmmizes
the results
for the electron density distzibntion,
electron a“d ion temperatures
i“ tbe
scatter radar s ys F -re@on obtained during 1968 using the Millstone Hill (42. 6“N, 71. 5“W) Thomson (incoherent)
These data, for tbe hei@ interval approximate
y 200 to 800 km, were gathered over 24-hour observing petern.
riods, roughly fwice per calendar month.
Tbe time required to obtain a complete elect..”
density and temperature
profile over this height interval was “suall y 30 minutes.
tiring
1968 the apparatus
employed to measure
the frquenc y s~ctrum
of the reflected
signals vs altitude,
wbicb in turn yields the estimates
of the electron a“d ion temperatures,
was rebuilt permitting
tbe measurements
1“ addition, cbe new spectrum
at all altitudes to k made in real time, and with greater
acc.rac y than heretofore.
analyzer permitfed
the first measurements
at Millstone fill of the vertical driti of the plasma.
These results,
which are difficult to condense into summary form, are not included in the reporf.
Tbe densify and temperamre
results show that the separate clear patterns of summer and winter diurnal behavior, recognized
at sunspot minimum,
.8” still be dkxer”ed
at ..”spot
maximum on all b“t very disturbed days.
A number Of disturbance
pa fterns observed previously
were again detected in 1968, albeit cm fewer occasions than
i“ 1967. Apparently,
by chance, the days selected for observation
i“ 1968 contained fewer imtances
of magmetic
disturbance
than in 1967.
Tbe average heat flux fr.m rbe ma@etosphere
has been investigated.
While there appears
mce on solar flUX (as defined by the 10. 7+m radio emission),
there remains
a summer-to-winter
that cannot be easily explained.
.
KEY
to be a clear depe”dvariation
of 5 m 7
WOROS
MillsroPe radar
F-region
diurnal variations
electron density
ionospheric
scmfer
seasonal variations
83
temperamre
effects
spctmm
analyzers
UNCLASSIFIED
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