COMMON SCALE MAGNETGGRAMS
BY STATION DAY
8 APRIL 1976

a a a ee a a a
LON | INT ne
LR ow
N.P.O. = 025.90
E.LONG. = 338.30

FC uw ne pn a ee
N.p.0. = 031.20 a
E.LONG, = 265.90

N.P.O. = 018.50 an
E.LONG. = 128.00
cn
|___ 10
||»
Pamir |r
OI ww it7
N.P.o. = 016.50 6
E.LONG. = 080.50 —-
ios
a)
a I ne |
[Munn 3
AI cw |»
N.P.O. = 021.70 P]
E,LONO. = 018-80 ao
{|_| 4 | | | | 4 oe | Jt [Lt 4 0
oO UAT. 16 20 24

4 8 12
SCALE IS 250 GAMMAS PER CM
16


LR

N.P.0.

E.LONG,

NAS

N.P.0.

E.LoNs.

co

NPD.

E.LONG,

BW

N.P.0.

E.Lono,

TI

N.P.D.

E.LoNe,

OI

N.P.D.

E.LONG.

Al

NPD.

E.LONG.

COMMON SCALE MAGNETOGRAMS
BY STATIGN DAY

29° APRIL

1976

i

TT T
Le

i

eas

ch

| 10

J :

|__| 8

7

6

ts

|| +

pm | rey

|_| 2

PEE

Pj} fp ppp ppp tp pp tp pp tpt °
ou. 4 @ 12 16 20 2

SCALE IS 250 GAMMAS PER CM

37


LR

N.P.D.

E.LONG,

NAS

NPD.

E.LONG,

co

N.P.0.

E.LoNG,

Al

N.P.D.

E,LONG.

=z

)

125 90
138.30

025.20
212.20

018.70
203.30

018.50
129.00

016.50
080.50

021.70
018.80

COMMON SCALE MAGNETOGRAMS
BY STATION DAY

25 APRIL

1976

{|_| t

|} | | | | t

out.

SCALE IS

4

8 12
250 GAMMAS PER CM
33


AURORAL ELECTROJET MAG INDICES AE(8) » AURORAL ELECTROJET MAG INDICES AE(8)

ww "
AU AU
m TM”
san _ | dart 1 hh Lada
4 " bot
soa AMET LIN a mai re!
au LY an LY
aL AL i
an “nm H
- am 76/04/13 bd a 76/04/14 ¥ i
|
oo ve t
AE AE |
vt vw |
‘ ‘ I
‘an Hic n on AM i
i MJ 4 * bh Lp LAA WF |
‘ ;
ho Th ho ery 7 | :
a d om | k
L_ELECTROJET MAG INDICES AE(8) iw AURORAL ELECTROJET MAG INDICES AE(8) |
ne . |
”
H 1 LL]
BBeRER LL : TRG i = Ra
Sau
AL
an
eyoasis | * id _ | 6/04/16 :
vn vw
AE AE
we vt
‘ .
.” m Al ph
tb 1 Aslan : Acnahs be |
Ao Ao
w © T 1 a ” v w a
wn AURORAL ELECTROJET MAG INDICES AE(8) ww AURORAL ELECTROJET MAG INDICES AE(8)
AU
”
‘
he " ‘ nu
San
AL
vw
I6/04/17 ’ bl resoasie | 4
1800 vse |
AE AE
ve ‘i
‘ ‘
Pc) _
i LAr toy Yale Laat) H Al
s! s!
Ao Ao
ha w a ” a
42



COMMON SCALE MAGNETOGRAMS
BY STATIGN DAY
2 APRIL 1976

rrry?rftseytttyttrytttyttt

LR ow [re
ver.o. = 26.30 unl mnm4

E,LONG.

NAS oH Ban a
23

E.LONG.

iG.

Pre toey py tp pp tp ppt yp py pt tt °

oO UT. 16 20 24

4 8 12
SCALE IS 250 GAMMAS PER CM

10



“AYyBLuplW ILQeUBeuosg [e907 JO OWL LA B42 SyYAeW MOsue Ue UOLIe7S
yoed uoj “9/61 Lludy 4uos uoLqeys Aq UOLSLAOUd HY ULW-T Jo AOUENbauy *Z aunBLy4

v2 12 ai st at 60 so 60 ve iz ai st at 60 90 e0 “1:0 00
|

CN Er

52


“Burssadoud 404 duly
UL S[qeLLeAe awodaq Spuoda4 Lay} Se pappe aq [LLM SUdL}ezs BuLULeUY “Zuoda. SLYy2 uO eJep BuLpLAoud satuozeAuasqo 7YBLda sy] x

s°tot oreo 2°ee 08 g°2e ee GNVISI NOXIG = IG x

grzez 2°TS T°0S 63T= 8°60 99 N3113M 3d¥9 = 3N Helms $*99 O° Ld= 0°9T SS °Y 3IVHM 1V3ND =UM9
netet 9°09 0°00 62t O°se Te AWG BIXIL = Il x G°9S2 9°89 2°05 LHT= 9°TS HO 3937709 09
aeze O°tL O°2T Sa- 0°90 T9 DVNSSUVSSYVN =SVN + °9OLT 2°99 O°4T HOT O°fh LZ NINSMAT3HO*D = 99
orts 2°02 Of2h T2= O°tt 49 UNSOAMTST = Y7 x T°tn2 S°69 694% GST= 2°ST TL MOUNVG = ME x
gezze 2°89 0°90 "S= O°8h ES TVHIHOSNHO*8 1S = O45 x 6°HTT 0°99) 4°64 BT a°te 89 OxSTey = IV +
9NO7 iva 9NO7 4vd 9N07 ava N07 iv7

OILSN9VNO39 OIHdvVs9039 NOITLVOISTLN3OL OTL3N9VNO39 OIHd¥a9039 NOTIVOISTAN3OT

uioIL If Io Iq Ig Ia M@ MG MG Ma 94 ME MG 94 4 SUN SUN SYN YT YT YI YI Iv oF
Iv Iv IO IL IL ma M&@ OD MG MB 94 D4 93 SVN SYN Iv IG IG IG SVN SYN SVN TIL TL 62
Iv Iv Iv IL 10 TO IL MB MB 93 94 D4 YI IV IV O94 SYN SYN IO SVN SYN B12 BT BT ee
Iv Iv IG IG IL Ma M@ IL 94 04 OF OF IV Iv IV IQ SVN SYN SVN YT YI BT 8d Iv 22
Id IG Ia 09 Iq Il MS MS MG ME 94 D4 BS D4 D4 SVN SVN SYN SYN 35 SYN SVN BT IL 92

IL Iv Iv IG IG MG MG MG MG MS 94 ME Iv 94 94 94 IG O94 SYN SYN SVN SVN IV IV se
Iv IG IG IG IG IL M@ ME ME 09 OF OF D4 OF OD SYN SYN SYN BT SWN Ii Id TL 09 ne
09 09 09 O89 O89 IG IL mG ME MG Iv MS 94 IV 94 SVN SVN SVN SVN YT SYN BT YI IV £2
Iv Iv Iv IG IG IG Id TQ IL IL IL O03 94 OF OF SYN SVN SVN SYN SYN SYN IL IL 09 22
09 09 09 IL 106 IG MS MG MG OF 94 D4 09 YI Tv IG IQ 10 IG IL IL IL SYN 09 teb

09 09 09 IL IG IQ IG SVN M8 MG M8 YT IV BI Iv Ia Id IG IG IO IL IL IL 09 o20
09 03 09 O89 Id IQ IG TL M& MAG MA€ 94 94 D4 Iv IQ IG IG IO SVN SVN SVN TL IL 6TD
09 09 09 09 OD IG IG Id m8 mG MG MG Iv Iv Iv Ig I0 IG IG Ii IL Ib Th Tb eto
09 09 0O Ta Iq M@ M@ MG ME SVN SVN Iv Iv 94 Iv Iv IG IG SYN SYN SYN SVN SUN 87 at
uloiv Ig Ia Ig 10 m@ me 93 M8 94 34 Iv Iv I¥ 94 IG 10 SYN SYN SVN SVN 81 U7 oT

u1o09 09 Id IG IG IG M@ M€ YY YI 93 BI Iv Iv IG IG 94 IO IL TL SYN SYN BT STO
ua Ig Ia 10 IG IO IL wa IL M8 MA OF D4 MA ME 94 OF SYN O94 SYN SVN SVN ST YT had
uloiIv Iv IG 30 IG IG IG IL 93 93 94 09 09 D4 Iv IG 94 SVN 94 SVN BT BT BT et
IL IL IG 1G 10 10 IQ IL Ik 94 94 D4 09 09 D4 D4 SYN SYN 34 D4 SYN SVN BT 87 et
Iv fo IO Iv IL IQ TIL IL IL IL 94 33 09 OF IV IO IO IG IG Id SYN YT at WI TT

Ia 09 10 IG IG IG IL IL f1 IL O09 OD OD OF OF SVN SYN SVN SVN 87 YT B81 Iv Iv
Iv Iv 10 IV IL IL IL IG O09 O09 OD SYN Iv IV I0 I0 I0 IG SYN SVN SYN SVN 4&7 87
Iv Iv Ig IG I0 1G IL Ti 09 09 09 OF 94 93 D4 SVN 94 SYN 93 94 BT BI BI BI
Iv Iv Ig Iv IG Ii IL IL IL 09 OF OF OF SYN SYN 94 SVN SVN SYN SYN 94 YT YT BT
uy. Id IV IG IG IL IL 09 09 09 OF OD D4 OF OD SYN SYN SVN SVN SYN YT YT a7 IV

Iv Iv IG Ii IL TIL IL I1 IL 09 09 OF OD 94 D4 SYN SYN SVN SVN YT BIT 81 Iv Iv
Iv Iv Iv IG Ii IL IL IL 09 09 09 OD OF D4 OF SVN SVN 94 SVN SYN 93 BT Iv IV
Ta Ii Ti IL IL [1 09 99 OF OF 93 IG IG IO SUN SVN SVN BT BI YT yt ytoiv iv
Iv Id Ig IL IL IL 09 Tid 934 O4 SYN SVN IV IV Iv IV SVN 94 SVN BT BT Iv Iv Iv
Iv IG IL IL IL IL IL T1 93 94 94 IG 10 94 D4 TL Id SVN BT Tv Iv IW Iv 41

HNMEH CNRODS
e000 0

42 £2 22 T2 02 6T BT LT OT GT HT ST 2T TT OF 60 90 240 90 SO 40 £0 20 TO an

H VL13G WOWINIW = 1¥ 926T TTudy
san,eA ueay uo paseg Ty AL4noH BuLdddng salsoqzeavasqg “9 aLqel

50




6£f- 2ee-
gfo- eto-
64T= 94T=
OTt- 620-
90Z- L62-
e80- 9TO-
ftt= gare
2s0- 20t~
£60- g00-
£lTe 49T-
220- 900-
ToT- 2es-
£60- 4T0-
2tQ= OTO-
490- 2T0-
£20- oT0-
TS0- 4TO-
9L0- T6T-
920- 240-
Set- fete
Ont= L2t-
eg0- 2TO-
22t- 640-
Tht £20-
69T- 8tz=
n9T= 19TH
Lne- S82-
48Z= n6E-
£08= Stz-
6k £gs-
2ef- seen
£2T= 66T-
6Sh= ZTT-
NVBH 42

SVWHYS NI

O6z=- £92-
Ot0- soo-
Tete 96TH
9T0- 9T0-
6TS= Ofh-
S6T= Tet
£ST= 4eTe
220° 6TO-
220° 692=
g02- 6ST=
Too- TOO

ang- L02-
g00- £00-
200- TO0=
600- 200-
at0- 900-
ST0- SO0-
n22- 99TH
2t0- sto-
28f= hhh
£6f- 4LT=
Oto- @20-
g9f- ohe=
600- StO-
S4T- 622-
OS2= 992
42S= B8L=
aTT> T90-
nBT= ShT=
ade 402-
Zda- 4ES~
26£= SZ29~
4n0Z= OLe-
e222

G3SS38dxF

als=
ef0-

Tst-

gtt-
eta
ooz-
£0t-
Tho-

290-
S6f-
£0T-
8h0-
"00-

to0
gnt-
“00-
Tot
eo0-

THO-
68T=
Tet-
220-
£60-

gu0-
ezc-
22t-
agt-
968-

049-
o2t=
60e-
Tro-
90%

6T

Og2- sTE-
TO0- 4TO-
2gt~ A8Te
STO- 26T-
G2f= Tht=
$20- e22-
$22- 960-
2to- TtO-
SET- 960-
T90- Lez-
goo oto
Sh2- Seo-
goo TO0-
zoo S00
s00 sz0-
ooo #00
O%0- soz-
£0T- TrO-
2to- £S0-
T2te 990-
T9Z- Lse-
£T0- 240-
Sh0- 200-
2T0- 900-
622- 61T=
Qnf- Le0-
yO2- g2t~
650- 94f-
££2- sse-
60T- 080-
295- 99f-
4Tte thd}
Lgh- 98 he
tz 02

ayy Saniva

geZ-
2£90-

Late

aso-
gTo9-
ago-
s60-
620-

26T-
g6T-
z£90-
6TT-
920

400-
ge2-
SuGe
O20-
2802

S20-
ene
Zit
T20-
2tg-

400-
thee
260-
g2t-
62T-

6ez-
SST-
298-
2z0-
6TH

at

2zs-
£90-

g2t-

480~
668-
690-
eTt-
9to-

Th2-
290+
n20-
9gz-
22te

400-
6£T-
£T0-
220
200-

ef0-
Late
220
et0-
geo

too

£9T-
Te0-
690-
te2-

22t-
Lnz=
zo
6T0-
age

at

g9e-
£90-

gtt-

eso-
4ST
290-
2to-
eoo-

Té2-
ago-
2T09
6 0-
22t-

640-
9g0-
2002
gto.
200-

oso-
Sot
£h0-
200-
onde

200-
60T=
T90-
g20-
nB2-

O2T=
n2e-
TLe-
420-
622-

oT

294-
£40-

2oT-

O4t=
gat
640-
s00-
9s0-

9BT-
azg~
9Toe
£20-
9g0-

2g0-
990-
620
T20-
2t0-

220-
ehTt~
6T0-
900-
0z4-

9z0-
S04
zete
Zst~
Lane

602-
6zS-
S69-
Z80-
g6o~

st

6£4-
6s0-

TL

Sht-
462-
£s0-
£90-
ThO-

eto-
est=
6To-
g20-
2st=

zs0-
oso-
9£0~
nz0-
620-

oz0-
L82-
so0-
£20-
est-

£TT
86T-
29T-
429-
agh=

S2he
£T9-
eet-
gz0-
06s-

oT

2tg~
£0T-

TSt=

gfo-
L9h-
T£0-
s80-
tHO-

StO-
2ete
680-
ante
efee

£20-
sg0-
onde
Tz0-
s90-

2g0-
ege-
ato-
seo-
o02-

2g2-
ze0-
£202
Z6T-
TOT=

ahte
8She
620-
620-
TS9°

et

S201 pul W

S92=
s60-

gnte

s80-
9ef-
220~
920-
ago-

e20-
se0-
TS0-
git
TLT-

s20-
eet
£n0-
ogo-
s20-

6f0-
S0T=
290-
9T2-
2se-

agg
sz0-
L9T-
elz-
980-

oat
aol~
920-
£2£0-
sst=

2t

9iT- SSt~
830= 220=
OTT- ett-
QT- 29T=
990- L20-
£20~ S20-
420~ ez0-
f60- 290-
@ho- OnO-
a92- Sit=
200- 9TO~
O4Z- 692-
£20- TZ0-
S$20- 0f0-
dte~ 220-
4S0- 2£0-
T4o- ogo-
420- 420-
Tz0- Sz6-
S2t- f0-
LLT= 9%0-
L2t- s0T=
SETt- 920-
9ST- z90-
S$20- S20-
68T- OfT~
eet- sez~
B2T- athe
6ST- so2-
O80- 604-
2g0- 980-
280- 2n0-
28h- £99-
TT Ot
“py ager

962
9202

a2t=

6Tz-
6To-
gs0-
e20-
aso-

2a0-
afz~
s20-
£tz-
Tz0-

220-
6z0-
Se0-
sz0-
eeo-

T20-
2902
920-
2zz-
Sz0-

seo-
St0-
620-
9es-
2ne-

osz-
See~
Tez-
s£0-
£se-

ogs~
Te0-

L2te

090-
zz0-
eet-
220-
ec0-

£20-
£go-
zg0-
£t2-
4e0-

n20-
Te0-
s0-
9z0-
220-

ng 0-
Tate
£20-
68T=
$z0-

Teo-
920-
es0-
eze-
2ts-

902-
69%-
zS4~
geo~
£T2-

fng-
2e0-

SeTt-

z0t-
6to-
220
Tete
9so-

£60~
TSe-
ozt-
g0f-
640-

220~
szo-
40-
on0-
220-

4g0-
6hz-
La0=
96T-
$20-

sot-
200-
oTo-
ge0-
Z02-

oes-
est
624-
StT-
Onee

£8-
2z0-

olt-

6£z-
9to-
9t0-
eez-
Te0-

2et-
sag
2et-
gos
ez0-

2T0-
£20-
9zo-
Tet
2n0-

eto-
£0k-
Teo-
get
2z0-

60T-
es0-
Tate
220-
£68-

66h-
tor-
bho
480-
dade

S92-
6To-

62T-

SL2-
eeo-
ato-
L2t-
£e0-

t90-
2e0-
$L0-
zoz-
6T0-

900-
ogo-
£20-
o60-
602-

ato-
£gt-
s6T-
£9T=
eso-

SET-
62T-
622-
860-
ze2-

gos=
zzo-
z0z-
att-
60s-

Z6h~ £24-
asa- 2£0-
BET~ 99T-
S2t= TL0-
6LT= LEt~
aST= T2T=
OLT- 990-
§S0- 690-
£90- OnT=
TrO- 2t0-
So0- TLT=
6ST- of0-
2U0- 2t0-
2to- 2t0-
220- 020
£20- gto-
nST- 020-
6S2- 8TT-
6TO= 680-
e0T- 290-
anT- Info
ee0- f20-
690- 42T
60f- Soz-
aSe- £6f-
L£bT- 8hT=
T62- 2tT-
2Lf~- 06f-
209- She
20z- Tes-
£9T- 2£T=
£Lt- 9tz-
ez0T-89l—
4 £
9L6T

Shh
zz0-

LLt

gtte
oT 0-
6s0-
ast
Tet

nza-
To
ete-
2to-
oro-

2to-
£T0-
2t0-
9To-
e20-

ss0~
gat-
S8f-
980-
4Lte

Llz-
ate-
Shee
OTH
£15

g0E-
ogs-
60T=
62e-
s0l-

£22-
T20-

9ST-

eat
600-
n2Te
S22~
2200

9f0-
$00-
eof-
£T0-
TtO-

Oto-
800-
s00-
gToe
S60-

£20-
S6T-
TS0-
6TT-
LgT

ete
26T-
£ts-
L6£-
aTfe

92he
£2t-
£82
L8T=
laze

Nvan as
NVBH 0S

o
oy
cog o

fa
2 900

in

qVWadv

48


COMMON SCALE MAGNETGGRAMS
BY STATION DAY

12 APRIL 1976

TTT TTT TTT T
LR ow NS aaa ene {|
wir.o. = 08.90) \ YY
E,LONG. = 338.30
NAS cH pepe pe |
WP. = 020.90 DVO ee ee at
E.LOND. = 314.80
FC ox
N.P.O. = 031.20 faa rn
E.LONG. = 265.90

025.20
212.20

po
018.50
128.00

cn

|__‘o

ls

Ol wm Coane ION CONT ure ae i Is

N.P.O. = 016.50 once ie,
EsLONG, = 080.80

ts

os

Ht.

tos

ee a eS ee pV

2

1

|_| | 1 on | o

Oo U.T.

SCA

T 4 8 12
LE 1S 250 GAMMAS PER CM

20


NAS

NAP .D.

E.LONO,

FC

WP .D.
E.LoNe,

co

NAP sD.
E.LONG,

BW

NP .D.
E.LoNo,

N.P.D.
E,LONG,

=

wu

=

=

=

025.20
212.20

018.70
203.30

018.50
129.00

016.50
080.50

021.70
018.80

COMMGN SCALE MAGNETOGRAMS
BY STATIGN DAY

30 APRIL

1976

pw J

{jt | | 1

TTT
a aera ae aint

acre cena ies

Oo UT.

SCALE IS

4

8 12
250 GAMMAS PER CM

38


GEOMAGNETIC DATA FOR APRIL 1976
(AE(8) INDICES AND STACKED MAGNETOGRAMS)

by

J. H. Allen, C. C. Abston and L. D. Morris
NGSDC/EDS/NOAA
Boulder, Colorado 80303 USA

SECTION I. GENERAL DISCUSSION

1. Introduction

This is the fourth of a series of data reports in support of the International Magnetospheric
Study (IMS) and includes selected geomagnetic variation data for April 1976; the series began with
UAG-60, which presented data for January 1976 (see Section 1(5) below). Included herein are analog
records from eight auroral zone stations; preliminary AE indices based on these data; and various
related tables, graphs, and statistics. It is expected that this series will continue on an in-
creasingly timely schedule and will contain data from additional stations which may be processed
in time for publication.

2. Data Selection and Processin

The eight observatories supplying data for this report are shown in figure 1. These are
Leirvogur (LR), Narssarssuaq (NAS), Fort Churchill (FC), College (CO), Barrow (BW), Tixie Bay (TI),
Dixon Island (DI), and Abisko (AI). They were chosen from among the list of 12 observatories whose
records are now routinely used by WOC-A for Solar-Terrestrial Physics in the derivation of Auroral

— Ke Ni lL. a
i y) A

ye

Figure 1. Provisional AE(8) network.

1



LR

N.P.D.

E.LONG,

NAS

NPD.

E.LONG,

FC

N.P.0.

E.LONG,

co

NPD.

E,LONG,

=

un

&

=

=

=

=

=

025.90
338-30

028.90
314.80

031.20
265.90

028.20
212.20

018.70
203.30

018.50
129.00

018.50
080.50

021.70
018.80

COMMON SCALE
BY STAT
23° APRIL

MAGNE TOGRAMS
IGN DAY
1976

we
I
~~

re ee

own
aa

TT Ty] TTT

pF

{| jf ff tt

oO UT.

SCALE IS

4 8 12
250 GAMMAS PER CM

31



DI
NeP.0.
E.LONG.

N.P.D.
E.LONG,

21.70
18-80

es

COMMON SCALE MAGNETOGGRAMS

BY STATIGN DAY

9 APRIL

1976

{|_| 4

acd

|
ij

| Jj J fj t tt

TTT
ae

|

“WA

Oo UT.

SCALE IS

4 8 12
250 GAMMAS PER CM
7



COMMON SCALE MAGNETOGRAMS
BY STATION DAY
15 APRIL 1976

TTT TTT TTT TTT TTT TTT
LR ees
N.P.0. = 025.90
E-LONG, = 338.30

NAS cH [eer

N.P.O. = 028.90
23

E-LONG, = 314.80
re LL ——_~
po ———

N-P.0. = 031.20 a ane \ aaa

E.LONG. = 265.30

CO ww fe
N.P.D. = 025.20

E-LONG, = 212.20

BW a ens PY te Lh

Ppyt py piper et pepe typ yy te yyy o

out. 4

8 12
SCALE IS 250 GAMMAS PER CM

23


COMMGN SCALE MAGNETGGRAMS

BY STATION DAY

1976

=

er}

8 12
SCALE IS 250 GAMMAS PER CM



LR

N.P.D.

E.LoNG,

NAS

N.P.D.

E.LONG.

FC

N.P.D.

E.LONG.

co

NPD.

= 031.20
= 265.90

BW cw
NeP.D. = 018.70
E.LONG, = 203.30
TI ow
NeP.0. = 018.50
E.LONG, = 129.00
OI wm
N.P.D. = 016.50
E.LONO. = 080.50
AI om
N.P.D. = 021.70
E,LONO. = 018.80

COMMON SCALE MAGNETGGRAMS

BY STAT
24 APRIL

IGN DAY
1976

was
PN

TTT TTT To

| ee

» :

|

athena

cn

| 10

Ll AN --*

i} 68

SW yer

| 6

is

aa ie TT:

t——_-~— | s

ve

1

| | 4 | J 4 {| 1 1d °
OU. 4 8 12 16 20 24

SCALE IS 250 GAMMAS PER CM

32


LR oo
N.P.D. = 025.90
E.LONG. = 338.30
NAS cH
N.P.D. = 028.90
E.LONG, = 314.60

E.LONG,

COMMGN SCALE MAGNETGGRAMS

BY STATION DAY
6 APRIL 1976

5

eed

|

TTT TTT TTT

ara

3

"

ns nail

Se

et ate At epee

cH

_—— 10

9

6
|I_s5
ito
its

|| _2

jit

|_| 4 {| 4 {| | | 1
0 UT. 4 8 12 16 20 24
SCALE IS 250 GAMMAS PER CM

14



UAG-48A

UAG~49

UAG-50

UAG-51

UAG-52

UAG-53

UAG-54

UAG-55

UAG-56

UAG-57

UAG-58

UAG-59

UAG-60

UAG-61

UAG-62

UAG-63

UAG-64

"Synoptic Observations of the Solar Corona during Carrington Rotations 1580~1596 (11 October 1971 - 15 January 1973)";
[Reissue with quality images] by R. A. Howard, M. J. Koomen, D. J, Michels, R. Tousey, C, R. Detwiler, D. E,
Roberts, R. T. Seal and J. D. Whitney, E, 0. Hulbert Center for Space Research, NRL, Washington, D. C. 20375
and R. T. and S. F. Hansen, C. J. Garcia and E. Yasukawa, High Altitude Observatory, NCAR, Boulder, Colorado
80303, February 1976, 200 pages, price $4.27.

"Catalog of Standard Geomagnetic Variation Data", prepared by Environmental Data Service, NOAA, Boulder, Colorado,
August 1975, 125 pages, price $1.85.

“High-Latitude Supplement to the URSI Handbook on Ionogram Interpretation and Reduction", by W. R, Piggott, British
Antarctic Survey, c/o SRC, Appleton Laboratory, Ditton Park, Slough, England, October 1975, 292 pages, price $4.00.

"Synoptic Maps of Solar Coronal Hole Boundaries Derived from He II 304A Spectroheliograms from the Manned Skylab
Missions", by J. D. Bohlin and D. M. Rubenstein, E. 0. Hulbert Center for Space Research, Naval Research Lab-
oratory, Washington, D. C. 20375 U.S.A., November 1975, 30 pages, price 54 cents.

"Experimental Comprehensive Solar Flare Indices for Certain Flares, 1970-1974", compiled by Helen W. Dodson and
Ruth Hedeman, McMath-Hulbert Observatory, The University of Michigan, 895 Lake Angelus Road North, Pontiac,
Michigan 48055 U.S.A., November 1975, 27 pages, price 60 cents.

"Description and Catalog of Ionospheric F-Region Data, Jicamarca Radar Observatory (November 1966 - April 1969)", by
WL. Clark and T. E. Van Zandt, Aeronomy Laboratory, NOAA, Boulder, Colorado 80302 and J. P. McClure, University
of Texas at Dallas, Dallas, Texas 75230, April 1976, 10 pages, price 33 cents.

“Catalog of Ionosphere Vertical Soundings Data", prepared by Environmental Data Service, NOAA, Boulder, Colorado
80302, April 1976, 130 pages, price $2.10.

“Equivalent Ionospheric Current Representations by a New Method, Illustrated for 8-9 November 1969 Magnetic Disturb-
ances", by Y. Kamide, Cooperative Institute for Research in Environmental Sciences, University of Colorado,
Boulder, Colorado 80302 and Geophysical Institute, University of Alaska, Fairbanks, Alaska 99701, H. W. Kroehl,
Data Studies Division, NOAA/EOS/NGSDC, Boulder, Colorado 80302, M. Kanamitsu, Advanced Study Program, National
Center for Atmospheric Research, Boulder, Colorado 80303, J. H. Allen, Data Studies Division, NOAA/EDS/NGSDC ,
Boulder, Colorado 80302, and S.-I. Akasofu, Geophysical Institute, University of Alaska, Fairbanks, Alaska
99701, April 1976, 91 pages, price $1.60.

"Iso-intensity Contours of Ground Magnetic H Perturbations for the December 16-18, 1971 Geomagnetic Storm", by
Y. Kamide, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder,
Colorado 80302 and Geophysical Institute, University of Alaska, Fairbanks, Alaska 99701 (currently Guest worker
at Data Studies Division, NOAA/EDS/NGSDC, Boulder, Colorado 80302), April 1976, 37 pages, price $1.39.

“Manual on Ionospheric Absorption Measurements", edited by K. Rawer, Institut fiir Physikalische Weltraumforschung,
Freiburg, G.F.R., June 1976, 202 pages, price $4.27.

"ATS6 Radio Beacon Electron Content Measurements at Boulder, July 1974 - May 1975", by R. B. Fritz, Space Environment
Laboratory (currently with Wave Propagation Laboratory), NOAA, Boulder, Colorado 80302 USA, September 1976,
61 pages, price $1.04.

“Auroral Electrojet Magnetic Activity Indices AE(11) for 1974", by Joe Haskell Allen, Carl C. Abston and Leslie D.
Morris, National Geophysical and Solar-Terrestrial Data Center, Environmental Data Service, December 1976,
144 pages, price $2.16.

“Geomagnetic Data for January 1976 (AE(7) Indices and Stacked Magnetograms)" by J. H. Allen, C. A. Abston and
L. R. Morris, NGSDC/EDS/NOAA, July 1977, 57 pages, price $1.07.

"Collected Data Reports for STIP Interval II 20 March - 5 May 1976", edited by Helen E. Coffey and John A.

McKinnon, National Geophysical and Solar-Terrestrial Data Center, Environmental Data Service, August 1977,
313 pages, price $2.95.

"Geomagnetic Data for February 1976 (AE(7) Indices and Stacked Magnetograms)" by J. H. Allen, C. A. Abston and
L. R. Morris, NGSDC/EDS/NOAA, September 1977, 55 pages, price $1.11.

"Geomagnetic Data for March 1976 (AE(7) Indices and Stacked Magnetograms)" by J. H. Allen, C. A. Abston and
L. R. Morris, NGSDC/EDS/NOAA, September 1977, 57 pages, price Stil

"Geomagnetic Data for April 1976 (AE(8) Indices and Stacked Magnetograms)" by J
L.-R. Morris, NGSDC/EDS/NOAA, February 1978. Snetograns)" by J. H Alen, C. A. Abston and

USCOMM-NOAA-ASHEVILLE ,NC-3/78/2500



WO Yad SUMHYD OOS SI 31NIS

Udy 9Z6T
wo an

oa-o10 = -ovor3
ozs = oan

oveto = oan
@ omg

ete = voran
@ 94

sas oe
att

05-520 = “oraW
ay


LR

N.P.D.
E,LONG,

FC

NPD.
E.LONG,

BW

N.P.D.
E.Lone,

TI
NP.
E.LONG.

Al
N.P.0.
E.LONG.

wn

018.50
129.00

COMMON SCALE MAGNETOGRAMS

BY STATION DAY

21° APRIL 1976
TTT TTT TT T TTT TTT
A a en es
ad ene ee
cn
—— 10
it»
. \—+—. 8
Pt fp | 7
it «
5
+
3
i—j— 2
1
{1 4 {| | 4 | | t | J 4 [1 J 1 °
oUt. 4 @ 12 16 20 2
SCALE IS 250 GAMMAS PER CM

29


COMMON SCALE MAGNETOGRAMS
BY STATIGN DAY
18 APRIL 1976

TTT TTT TT T TTT TT

LR om
N.p.0. = 025.80
E.LONG. = 338-30
NAS cw
N.p.0. = 028.90
E.LONG, = 314.80
FC tx LT
Nep.0. = 031-20
E.LONG, = 265.80
CO tw
N.P.O. = 025.20
E.LONG. = 212.20

BW cH [mnt $$

N.P.D. = 018.70
E.LONG, = 203.30
TIoaw

AI cw
N.P.D. = 021.70
E.LONG. = 018.80

pipet uppt tpt tp pt | tt

Oo UT.

T 4 8 12
SCALE IS 250 GAMMAS PER CM
26


this report is compiled. W. I. Paddock has carefully adopted the temporary baseline values and
checked each stage of the digitization. We hope that IMS participants who find this report useful
or who can suggest improvements will correspond with the authors.

5. The Series of IMS Data Publication Reports

The publication series listed below, and to which this issue belongs, presents analog records
of geomagnetic variations from selected auroral zone stations in support of the International Mag~
netospheric Study (IMS). The IMS period (January 1976 to December 1979) marks an interval during
which extensive simultaneous observations of the magnetosphere will be made from the ground to
satellite altitudes. Investigators will treat this region of near-earth space as a single system
of interacting plasmas, fields, waves, and energetic charged particles. A massive, internationally
coordinated, interdisciplinary program has been assembled -- one focusing on well-defined problems
of the magnetosphere and one designed to achieve a quantitative understanding of the cause-and-effect
relationships among its many dynamic processes.

IMS Data Publication Reports are for sale by World Data Center A for Solar-Terrestrial Physics,
NOAA, Boulder, Colorado 80303, U.S.A. Single copy prices vary; a check or money order should be
made payable to the Department of Commerce, NOAA.

IMS-1 "Geomagnetic Data for January 1976 (AE(7) Indices and Stacked Magnetograms)" by J. H. Allen,
C. C. Abston and L. R. Morris, NGSDC/EDS/NOAA, Report vAG-60, July 1977, 57 pages, price $1.07.

IMS-2 "Geomagnetic Data for February 1976 (AE(7) Indices and Stacked Magnetograms)" by J. H. Allen,
C.C. Abston and L. R. Morris, NGSDC/EDS/NOAA, Report UAG-62, September 1977, 55 pages,
price $1.11.

IMS-3 “Geomagnetic Data for March 1976 (AE(7) Indices and Stacked Magnetograms)" by J. H. Allen,
C. C. Abston and L. R. Morris, NGSDC/EDS/NOAA, Report UAG-63, September 1977, 57 pages,
price $1.11.

6. References

ALLEN, J. H. 1972 Auroral Electrojet Magnetic Activity Indices (AE) for 1970,
World Data Center A for Solar-Terrestrial Physics, Report UAG-22.

ALLEN, J. H., 1973 Auroral Electrojet Magnetic Activity Indices AE(11) for 1968,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-29.

L. D. MORRIS

ALLEN, J. H., 1974a Auroral Electrojet Magnetic Activity Indices AE(11) for 1969,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-31.

L. D. MORRIS

ALLEN, J. H., 1974b Auroral Electrojet Magnetic Activity Indices AE(10) for 1967,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-33.

L. D. MORRIS

ALLEN, J. H., 1974¢ Auroral Electrojet Magnetic Activity Indices AE(10) for 1966,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-37.

L. D. MORRIS

ALLEN, J. H., 1975a Auroral Electrojet Magnetic Activity Indices AE(11) for 1971,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-39.

L. D. MORRIS

ALLEN, J. H., 1975b Auroral Electrojet Magnetic Activity Indices AE(11) for 1972,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-45.

L. D. MORRIS

ALLEN, J. H., 1975¢ Auroral Electrojet Magnetic Activity Indices AE(11) for 1973,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-47.

L. D. MORRIS

ALLEN, J. H., 1976 Auroral Electrojet Magnetic Activity Indices AE(11) for 1974,

C. C. ABSTON, and World Data Center A for Solar-Terrestrial Physics, Report UAG-59.

L. D. MORRIS

ALLEN, J. H. and 1975 Spatial and Temporal Distributions of Magnetic Effects as

H.W. KROEHL Derived from AE Indices, J. Geophys. Res. 80, 3667-3677.

DAVIS, T. N. and 1966 Auroral Electrojet Activity Index AE and Its Universal Time

M. SUGIURA Variations, J. Geophys. Res. 71, 785-801.

3



Electrojet (AE) magnetic activity indices. Reasons for their selection were (1) records from these
sites are most promptly available, (2) the sites are about evenly spaced in longitude, and (3) each
location has demonstrated its importance in the prior derivation of AE indices [Allen and Kroehl,
1975]. We hope that as digital data processing from other observatories becomes more routine the
network can be expanded and we can include data from Great Whale River and Yellowknife to improve
the station distribution for these prompt indices.

Among the stations supplying data for this publication, only Fort Churchill and Barrow are
presently recording digital variations on-site. Both observatories use flux-gate instruments
supplemented by proton precession magnetometers and generate more or less routine absolute obser-
vations. Each component's amplitude is recorded every 10 s (20 s for BW) on magnetic tape, and
analog chart records are prepared as backup data. These high-time-resolution digital data are
processed at central facilities responsible for each observatory. Obvious errors (usually spikes)
are corrected and 1-min average values are computed. These preliminary data are sent on tape to
WDC-A for Solar-Terrestrial Physics where they are plotted and checked for stability of quiet-time
levels (baseline drift), presence of noise, and day-to-day continuity. As necessary, remaining
spikes are removed, and "temporary" baselines are adopted to compensate for data problems that would
affect derivation of AE indices.

All the other observatories record magnetic variations photographically. Their magnetograms
are copied on 35-mn microfilm for transfer to WDC-A for Solar-Terrestrial Physics together with
calibration information. Here they are reproduced as almost original size magnetograms and digitized
at 1-min intervals using semiautomatic scaling equipment. Resulting digital tapes of component ampli-
tudes relative to baselines are passed through the same plotting and other quality control processes
as the original digital data described above.

After completion of quality control checks, all digital records are merged and replotted to
common time and amplitude scales. These are the monthly H, Z, and D components and daily H (or X)
component stacked plots included in this report. For most observatories intervals of missing data
are apparent in one or more components. Gaps may arise from (1) loss of on-site digital data, (2)
noise in original digital data, (3) movement of traces off magnetograms during large excursions with
no secondary trace for that component, (4) lack of low-sensitivity storm magnetograms for disturbed
periods, and (5) loss of intermixing of analog traces during large, rapid field fluctuations. Every
reasonable effort is made at WDC-A for Solar-Terrestrial physics to curve-follow disturbed traces.
Effects of data gaps are seen in AE indices only when they occur at a critically located station and
in the H component. Often they are only apparent in the graphs of AU or AL.

3. Auroral Electrojet Magnetic Activity Indices

The AE index gives a global, quantitative measure of auroral zone magnetic activity resulting
from enhanced ionospheric currents associated with magnetospheric substorms. As defined by Davis
and Sugiura [1966], AE is the total range of H component deviations from quiet-time levels of the
field at a selected group of high-latitude magnetic observatories. Typically, a constant quiet-time
H value is determined for each observatory and subtracted from recorded H values. The resultant
deviations for all stations may be plotted to common time and amplitude scales and graphically super-
posed on a common reference or zero level. Then the amplitudes of the enclosing upper and lower
envelopes from moment-to-moment give the values of AU and AL, respectively. The range between them
is AE, i.e., AU-AL=AE. Their average is (AU+AL)/2=Ao (often indicated AO because many computers
lack the ability to produce lower case characters).

Complete discussions of AE and associated indices can be found in the two papers referenced
above and in the series of WDC-A for Solar-Terrestrial Physics Reports UAG-22, 29, 31, 33, 37, 39,
45, 47, and 59 which cover the years 1966-1974. Each of these contains precautionary notes about
the inherent limitations of AE indices, even when derived from a relatively complete station network.
Additional notes on AE are given before the daily index graphs (page 39). Also given in this report
are figures based upon minute-to-minute "frequency of index provision" by each station (pages 52 and
54) and graphs showing the cumulative amplitude of H deviation for times when each station was pro-
viding AU and AL indices (pages 53 and 55).

4. Acknowledgments

The authors of this IMS data report are on the staff of the National Geophysical and Solar-
Terrestrial Data Center (NGSDC) of the Environmental Data Service, National Oceanic and Atmospheric
Administration. WDC-A for Solar-Terrestrial Physics is collocated with NGSDC and shares the same
staff. The agencies kindly providing magnetogram records are the University of Iceland, Reykjavik
(Leirvogur); the Danish Meteorological Institute, Copenhagen (Narssarssuaq); the Department of Energy,
Mines and Resources, Ottawa, Ontario, Canada (Fort Churchill); the U.S. Geological Survey, Denver,
Colorado, U.S.A. (College and Barrow); IZMIRAN, Moscow Region, U.S.S.R. (Tixie Bay and Dixon Island);
and the Geological Survey of Sweden, Stockholm (Abisko). We wish to recognize the efforts of those
Persons who operate the high-latitude magnetic observatories and process the data from them. Recog-
nition is also due the operators who patiently curve-follow, check, and correct the data from which


COMMON SCALE MAGNETGGRAMS
BY STATIGN DAY
7 APRIL 1976

3
|
é |

LR ow
N-P.0. = 025.90
E,LONG. = 338.30

TI om ey I Oe
EJLONG. = 129-00
cn
10
8
Jp
OL om [ior na Pye 8
N.p.0. = 016.50 1
EsLONG. = 080-80
6
5
4
Ile
oo
Pittippr tp p ry pepe |p ppt py °
ovat. r 3 12 16 20 2
[SCALE IS 500 GAMMAS PER CM]

15



Ud 9Z6T

oe sz
TT TTT

20 = od
«) SUN



COMMON SCALE MAGNETGGRAMS
BY STATION DAY
13° APRIL 1976

TTT]? TTT y ttt y tr ry tit

Lae Annee a ee eee

NPD.

|
|
a,

FC oo

E.LOND. |
|
CO ww Re prrnnera pw |
N.p.o. = 026.20
E.LOND. = 212.20
TI ow + | |
N.P.D. = 018.50 (nena
E,LONG, = 129.00
ch
10 |
_—+— 9 i
DI ow ee ele etn, }
E.LONG. = 080.50 7 |
16 I
its |
ft, k
AI cw fama nr | 3
N.P.O. = 021-70
tos
Jott} tt tt tt |} tpt pt tt tt tt °
ou. ry 16 20 24

8 12
SCALE IS 250 GAMMAS PER CM

21



WORLD DATA CENTER A

for
Solar-Terrestrial Physics

REPORT UAG - 64

GEOMAGNETIC DATA FOR APRIL 1976
(AE (8) INDICES AND STACKED MAGNETOGRAMS)

February 1978

IMS DATA PUBLICATION No. 4



wy AURORAL ELECTROJET MAG_INDICES AE(8) wm AURORAL ELECTROJET MAG INDICES AE(8)

AU AU
aa
ty heed NM Ltt | | eh * kde! | LI
a! | " Part
a | jen} A : + aia ry
Sam 500
AL AL
. aml 76/04/25 mn ma 76/04/26 | id 2
oo ven
AE AE
ve we
‘ ‘
” Pre Ll
Lv [he ‘, Meh Attuleesl} A |

° Ao

oy ttt a :

mn AURORAL ELECTROJET MAG INDICES AE(8) ww» AURORAL ELECTROJET MAG INDICES (8)
AU Ty | AU
” Pld
AAS etnicaan pRSNAEE Na L LLL
1 PORN a ay 1 4 aan
1 PEEING My ba
AL AL
a aren al oH searee } 1
mo am

oH - a
Ac AE
” . IN am
» ANY ait Le A 1 Naw Lae LLU LM

‘ s
ho i Ao

| + m

tw AURORAL ELECTROJET MAG INDICES AE(8) wn AURORAL ELECTROJET MAG INDICES AE(8)
au 1 au
: aneeainaaee 1 Mey ade a
A a ea 1 hl a
“an an Yan I ha eT MMM y|
AL AL
mr | teroares 4 wer] 76704730 t

‘eH ve
ar ! ar
‘ ‘
. Po
tka | U ‘ Rael Mey wey ve AN I

te ee aTed i LA Th
oy pit iit 0 ip

44


2. Stacked Common Scale Magnetograms by Station Day (H Variations)

The following stacked plots of H (or X) common scale magnetograms are reproduced from the digital
magnetic variations data obtained as described on page 2. Each station is identified by the abbrevia-
tion from figure 1 and two coordinates: North Polar Distance (N.P.D.) and East Longitude (E. Long.).
The amplitude scale is given at lower left of each figure and corresponds to the centimeter scale at
lower right. The amplitude scale is the same for each day except when the range of deviation would
cause a trace to exceed the space reserved for it. For such days (see, for example, 1 April 1976)
the scale is increased in uniform steps to assure nonoverlapping traces. To call attention to the
scale change (similar to switching to storm magnetograms), the new value is enclosed in a box.

The label "NGSDC (BOULDER) yy/mm/dd" at the bottom of the first day plot identifies the source of
the published data and the day on which the plots were prepared. The difference between data record-
ing date and its preparation date provides an indication of the time required to collect the records,
initiate program development, and process the data.



WO Y3d SINNIW OZI SI 319s

:
|
2

i
En

|
Li
|

°
a

TT

Lt
9461 Ted

,
| :

zig) = “aan
woo

o6-ez0 = “oan
(0) SUN


UAG Series of Reports
Prepared by World Data Center A for Solar-Terrestrial Physics, NOAA, Boulder, Colorado, U.S.A.

These reports are for sale through the National Climatic Center, Federal Building, Asheville, NC 28801, Attn: Publications.
Subscription price: $25.20 a year; $12.00 additional for foreign mailing; single copy price varies. These reports are issued
on an irregular basis with 6 to 12 reports being issued each year. Therefore, in some years the single copy rate will be less
than the subscription price, and in some years the single copy rate will be more than the subscription price. Make check or
money order payable to: Department of Commerce, NOAA.

Some issues are now out of print and are available only on microfiche as indicated. Requests for microfiche should be sent
to World Data Center A for Solar-Terrestrial Physics, NOAA, Boulder, CO 80302, with check or money order made payable to
Department of Commerce, NOAA.

UAG-1 “IQSY Night Airglow Data", price $1.75.

UAG-2 "A Reevaluation of Solar Flares, 1964-1966", price 30 cents.

UAG-3 "Observations of Jupiter's Sporadic Radio Emission in the Range 7.6-41 MHz, 6 July 1966 through 8 September 1968",
microfiche only, price 45 cents.

UAG-4 “Abbreviated Calendar Record 1966-1967", price $1.25.

UAG-5 “Data on Solar Event of May 23, 1967 and its Geophysical Effects”, price 65 cents.

UAG-6 "International Geophysical Calendars 1957-1969", price 30 cents.

UAG-7 “Observations of the Solar Electron Corona: February 1964-January 1968", price 15 cents.
UAG-8 "Data on Solar-Geophysical Activity October 24-November 6, 1968", price (includes Parts i & 2) $1.75.
VAG-9 “Data on Cosmic Ray Event of November 18, 1968 and Associated Phenomena", price 55 cents.

UAG-10 “Atlas of Ionograms", price $1.50.

UAG-11 "Catalogue of Data on Solar-Terrestrial Physics" (now obsolete).
UAG~12 "solan-Geophysical Activity Associated with the Major Geomagnetic Storm of March 8, 1970", price (includes Parts
1-3) $3.00.
UAG-13 "Data on the Solar Proton Event of November 2, 1969 through the Geomagnetic Storm of November 8-10, 1969, price 50 cents.
UAG-14 "An Experimental, Comprehensive Flare Index and Its Derivation for 'Major' Flares, 1955-1969", price 30 cents.
UAG-15 "Catalogue of Data on Solar-Terrestrial Physics" (now obsolete).

UAG-16 "Temporal Development of the Geographical Distribution of Auroral Absorption for 30 Substorm Events in each of IQSY
(1964-65) and IASY (1969)", price 70 cents.

UAG-17 "Tonospheric Drift Velocity Measurements at Jicamarca, Peru (July 1967-March 1970)", microfiche only, price 45 cents.

UAG-18 "A Study of Polar Cap and Auroral Zone Magnetic Variations", price 20 cents.

UAG-19 "Reevaluation of Solar Flares 1967", price 15 cents.

UAG-20 "Catalogue of Data on Solar-Terrestrial. Physics" (now obsolete).

UAG-21 "Preliminary Compilation of Data for Retrospective World Interval July 26 - August 14, 1972", price 70 cents.

UAG-22 "Auroral Electrojet Magnetic Activity Indices (AE) for 1970", price 75 cents.

UAG-23 “U.R.S.1. Handbook of Ionogram Interpretation and Reduction", price $1.75.

UAG-24 "Data on Solar-Geophysical Activity Associated with the Major Ground Level Cosmic Ray Events of 24 January and
1 September 1971", price (includes Parts 1 and 2) $2.00.

UAG-25 "Observations of Jupiter's Sporadic Radio Emission in the Range 7.6-41 Miz, 9 Septenber 1968 through 9 Decenber 1971", |
price 35 cents.

UAG-26 "Data Compilation for the Magnetospherically Quiet Periods February 19-23 and November 29 - December 3, 1970",
price 70 cents,

UAG-27 "High Speed Streams in the Solar Wind", price 15 cents.

UAG-28 “Collected Data Reports on August 1972 Solar-Terrestrial Events", price (includes Parts 1-3) $4.50.

UAG-29 “Auroral Electrojet Magnetic Activity Indices AE (11) for 1968", price 75 cents.

UAG-30 “Catalogue of Data on Solar-Terrestrial Physics", price $1.75.
UAG-31 urgral Electrojet Magnetic Activity Indices AE (11) for 1969", price 75 cents.
UAG-32 “Synoptic Radio Maps of the Sun at 3.3 mm for the Years 1967-1969", price 35 cents.

UAG-33 “Auroral Electrojet Magnetic Activity Indices AE (10) for 1967", price 75 cents.
UAG-34 “Absorption Data for the IGY/IGC and IQSY", price $2.00.
UAG-35 ‘atalogue of Digital Geomagnetic Variation Data at World Data Center A for Solar-Terrestrial Physics", price 20 cents.

UAG-36 "An Atlas of Extreme Ultraviolet Flashes of Solar Flares Observed Via Sudden Frequency Deviations During the ATM-SKYLAB
Missions", price 55 cents.

UAG-37 “Auroral Electrojet Magnetic Activity Indices AE (10) for 1966", price 75 cents.

UAG-38 "Master Station List for Solar-Terrestrial Physics Data at WOC-A for Solar-Terrestrial Physics", price $1.60.

UAG-39 “Auroral Electrojet Magnetic Activity Indices AE (11) for 1971", by Joe Haskell Allen, Carl C, Abston and Leslie D.
Morris, National Geophysical and Solar-Terrestrial Data Center, Environmental Data Service, February 1975,
144 pages, price $2.05.

UAG-40 "H-Alpha Synoptic Charts of Solar Activity For the Period of Skylab Observations, May, 1973-March, 1974", by Patrick
S. McIntosh, NOAA Environmental Research Laboratories, February 1975, 32 pages, price 56 cents.

UAG-41 "H-Alpha Synoptic Charts of Solar Activity During the First Year of Solar Cycle 20, October, 1964 - August, 1965",
by Patrick S. McIntosh, NOAA Environmental Research Laboratories, and Jerome T. Nolte, American Science and
Engineering, Cambridge, Massachusetts, March 1975, 25 pages, price 48 cents.

UAG-42 “Observations of Jupiter's Sporadic Radio Emission in the Range 7.6-80 “Hz 19 December 1971 through 21 March 1975",
by James W. Warwick, George A. Dulk, and Anthony C. Riddle, Department of Astro-Geophysics, University of
Colorado, Boulder, Colorado 80302, April 1975, 49 pages, price $1.15.

UAG-43 "Catalog of Observation Times of Ground-Based Skylab-Coordinated Solar Observing Programs", compiled by Helen E.
Coffey, World Data Center A for Solar-Terrestrial Physics, Nay 1975, 159 pages, price $3.00.

UAG-44 "Synoptic Maps of Solar 9.1 cm Microwave Emission from June 1962 to.August 1973", by Werner Graf and Ronald Ny
Bracewell, Radio Astronomy Institute, Stanford University, Stanford, California 94305, May 1975, 183 pages,
price $2.55.

UAG-45 “Auroral Electrojet Magnetic Activity Indices AE (11) for 1972", by Joe Haskell Allen, Carl C. Abston and Leslie
D. Morris, National Geophysical and Solar-Terrestrial Data Center, Environmental Data Service, May 1975,
144 pages, price $2.10,

UAG-46 "Interplanetary Magnetic Field Data 1963-1974", by Joseph H. King, National Space Science Data Center, NASA Goddard
Space Flight Center, Greenbelt, Maryland 20771, June 1975, 382 pages, price $2.95.

UAG-47 “Auroral Electrojet Magnetic Activity Indices AE (11) for 1973", by Joe Haskell Allen, Carl C, Abston and Leslie
D. Morris, National Geophysical and Solar-Terrestrial Data Center, Environmental Data Service, dune 1975,
144 pages, price $2.10.



wy AURORAL ELECTROJET MAG INDICES AE(8) am AURORAL, ELECTROJET MAG INDICES AE(8)

; 0
AU AU
_ m han tT HNL La ale! + Label fa nae
on (Wh INL lt ololal abe mrad
AL AL \
76/04/01 i : TM rT 76/04/02
| an
AE AE
‘wn peel ‘en nN
“Oth sommes ace ran
inp hey} \ We
AO AO
oa : 1 TM a M1)
wm AURORAL ELECTROJET MAG INDICES AE(8) wm AURORAL ELECTROJET MAG INDICES AE(8)
AU AU |
Wyn wh 1 Mdle Lll  ARIMAR LL Lab LN
ml 1 bape fry
F, IM tw LL f Al te
f acrTW i j
6/04/03 ¥ : rersossoa |
AE AE
ty wm 4 h
‘ ‘
‘en V Ay ‘in i
© hepa WITT a) Pl ane
5 ha $ balm] AI
Ao Mv La ao| Vj rv}
3 LTT] : Meee PT)
vm AURORAL ELECTROJET MAG INDICES AE(8) va AURORAL ELECTROJET MAG INDICES AE(8)
AU AU
‘m Po
+ ULV M an ANld lt etal 8 dnt baat PY ave, [Lan
: : 4
‘UNA, AAA AY Ny rt Tie sas ML ped Pac '
, ‘ "
AL AL (]
_ — revoaros | TM mT reroaros | *
m o
AE AE
aL UTA : f
rT 4 om pay
: : Hl
i i ft nu Ma H jae MI
so LAL a to NENT
of PAs *2)M Anta

40


LR ow
N.P.0. = 025.90
E.LONG, = 398.30
NAS cH
N.P.D. = 028-90
E.LONG, = 314.80
FC
Nep.o. = 031.20
E.LONG. = 265.90
co ow
N.P.O. = 025.20
E.LONG. = 212.20
BW ow
N.P.0. = 018.70
E.LONG, = 203.30
TI ow
N-P.D. = 018.50
E.LONG, = 129.00
016.50
060.50
AI um
N.P.D. = 021-70
E.LONG., = 018.80

COMMON SCALE MAGNETOGRAMS

BY STATI
20 APRIL

GN DAY
1976

TT T TTT TTT

TTT

11 1 | 1 { |

OUT. 4 8 12
SCALE IS 250 GAMMAS PER CM
28



Sy 6LE
890 640
22 422
ost seo
2ze 084
sst teo
TtZ 19%
HOT 682
Tst 220
ete ote
est seo
eof 26g
e60 290
6eo oso
got zo
40 080
ee0 TsO
n2t £22
T90 260
tZ2  66T
98t he
e2t so
T@Tt SOT
TAT LOT
ge2 gee
Tez £92
2s ene
Tom e2g
62h Ate
6£4 89%
Teh son
99t Fez
2Z5 99T
NVBN 42
SVWHYS NI

628 hHEe
seo 280
$92 922
990 © 6s90
865 4TS
262 «t22
962 e922
960 «190
neo 9ge
6sf 262
220 920
S2h 28
Tao 220
920 610
420 620
$20 420
zgo0 20
ete 0sz
oso 4s0
96h 295
42h 492
THO OTT
Sh fy
9so 490
STZ 9th
ele 698
2459 se6
202 Sat
Toe 882
£29 6S¢
86% S6h
ses 9g2
69z sth
£2 22
G3SS3udXx2

£98 SEH ShS Thh 405 965 2n9 995 eee ere 962 40S
Of0 sO 220 sot 660 e609 £e0 460 TSt Get fot £90

otz £12 282 282 402 set ef2 92 9t2 tz ezt 96T

290 "SZ T2t 260 AST GOT 4et soz 290 tz2t coz stz
2S S2f SOF 2H $89 OTE 9HZ Hy 422 TOS Ost suo
20t ze sof ZTE 9Ot £60 Zot HTT $90 260 so Te0
62f H9T Set TLE 94F 950 Sco TIT Sst sso s90 920
On0 280 090 G60 940 £60 960 4G S90 460 fat get

Ts2 fT OFT £42 Gee HOF 4H2 HHO 220 eo zz0 Teo
2ST £0f T6S 21S OLT OT 8Sh SES 462 Bh2 89% G24
20 £20 Sht Ght O80 £60 Seo 940 GOT 6TT 990 990
4ng Toh LOT Get STE 4H2T O20 HET 422 BHE Thy 42g
ve0 Tho £60 090 St SzZt GET Sz Tee 222 920 S20

O20 eT5 tO 20 £20 O20 4S0 20 250 0g0 950 sso
6£0 soo Tre Tee 622 Eft HTT sso 20 “tz sz 420
gta T20 #20 290 Ted 920 60 £40 990 £20 620 950
£00 ss2 4st Oot O50 fSf0 eo O40 6F0 260 S90 sz0
29t sh0 zeo 650 620 £0 20 2420 660 S50 850 060

THO €20 860 SHO 950 990 190 240 820 6¢0 6n0 sso
S92 2@ht 422 tS 662 Te2 Ot2 Lz2e OTS 99T Sst 220
oth 99% Tez n9F £80 @20 290 620 420 ZIT szz 200
Oso 080 s90 ago eso 220 T20 Sho Tet soz 69T EST
HT 420 Tht G90 080 40T 955 952 642 Soh 96t TsS0

6%0 £0 20 2420 e260 240 190 46T 22h tz2g BH2 sot
ong Tie 26h 244 Le2 99T 86h £82 eso “eo eco TS50
9% O4F £8T 99T 990 o2t 2oz zzz ozt 922 S22 get
eee et2 otf 222 T2t Teo ghz Le LHe UTE HTS Con
StF 29% 209 282 @hh Lhy 909 £26 6HT Let 4T2 029

Sig ess Cf Ohh LET One STE 926 29% he TE2 onh
Oet Zht s6T s92 see 6% 869 S62 465 908 “eT eT9
w£9 £25 Sly 65S 406 GST 016 622 980 280 sso 90T
602 9TF 90 a90 zea zeo os0 eto 6tO Of0 He0 960
OTS 06h 919 969 409 8G 289 BS2 Tre Lee zZ6 ezZ
v2 02 6 ef 2b SF st 4t st 2t tr oF
Buy SanqvA

S@OLPUT BY “LT Alger

e24
450

ooz

962
sso
28t
z90
22t

860
6TH
ett
eg
sso

260
T90
690
£20
960

940
Ont
20
os2
6s0

T60
£40
92T
£99
sos

To
£68
z25
Sho
O24

Slo
90

go2

22t
t30
aos
gee
ant

090
T09
zet
29h
T90

640
£90
eso
680
£90

190
202
eso
ze2
450

2st
eno
900
2th
£Th

224
TLS
089
4h0
982

OLh
6s0

“tz

est
640
86T
tse
Sat

62t
eso
ate
ets
420

740
4S0
Tso
so
T20

120
2te
990
ase
$40

6LT
$s0
090
ozo
gos

S6h
0g%
£09
SHt
$94

729 £6 sig 90% 2s 24f NaN OS
Teo 620 460 460 240 2”B NVBh DS
"SZ HOT £82 Stz H£2 LT2 NYBW
nt& Th Sh2 TIE 922 see ag
Oso se0 222 geet 190 640 62
680 660 £6T get TOT Oaz a2
£f% 22 998 eet soz g2e 22
6st 2€% SOT ZTt tet sso 92
£2 Sot 460 Tet 960 460 $2
£2n ett £40 6£0 240 2e0 ne
Tse 02 £TF 9T2 69f 42h £2
"S$ O0f 4T2 920 oho 4nO 22
nO 880 Seo Oso ono 620 20
ono Te0 20 420 se0 220 oz 0
4n0 460 TTT got zho 620 6T 0
240 £90 TSO 6f0 20 ¢z0 ae)
£22 Sht zt sot 250 e50 yas
$80 222 #28 96t B2t Sat oT
620 Teo O09 e240 980 gett sto
TOh S@2 49% L2t 9T2 sez at
S60 802 49T 9Sf 8th SOT eT
602 2487 sot S60 eet set 2
£90 840 980 Ost Tre tre 1
St 6ST 904 292 The vo6E Ot
$60 Ont S6£ 224 222 922 60
26T 942 TOT 622 S2h LES 20
Oso 242% 42f TOT Z2t 294 20
9f5 T2f OSS Osh 699 TEE a0 0
029 82% TTL 89S H4e egh so a
96£ S2t TLE 99h £69 eg2 400
eto 262 OT2 sot sZt sez so a
Ott 22 962 60f see O82 20
998 499 2e0T 2e2 22 60F to 0
9 s 4 £ 2 tT in
926T Tradv
SOOLpUT TW pue “Ay “Oy “ay JO Saiqel ‘¢


COMMON SCALE MAGNETOGRAMS
BY STATIGN DAY
19 APRIL 1976

NAS cH)
NeP.O. =o
E.LONG. = 314.80

E.LONG.

FC tx tp. ~~ —_| an Ce
N.P.O. = 031.20 a
= 2

BW oH p—__~_—__f —____| Lae
N-P.0. = 018-70
E.LONG. = 203.30

ch
| 10
i»
OI ww Jnl —— 6
N.P.O. = 016.50

E.LONG. = 080.50 i—j— 7
6
|I—_}+—. 5
f+
3

Al om a eee
N-P.0. = 021-70 or Itz
E.LONG, = 018.80 1
Ppoj} ppp te pe tp pp pp ty o

7 UT. 16 20 24

UT ‘ 8 12
SCALE IS 250 GAMMAS PER CM
27



SECTION II. COMMON SCALE MAGNETOGRAMS

1. Stacked Common Scale Magnetograms for Whole Month (H, Z, and D Variations)

The following three graphs display condensed stacked plots of the H, Z, and D variations,
respectively, for eight stations minute-by-minute over the entire month. Component intensities are
to the nearest 1 gamma, and declination changes are to the nearest 0.1 minute of'arc. Positive H,
Z, and D changes are north, down, and east, respectively. Amplitude scales given at the bottom of
each figure correspond to the original centimeter scale reproduced at lower right. For each station
the North Polar Distance (N.P.D.) and East Longitude (E. Long.) are given in degrees.



COMMON SCALE MAGNETOGRAMS
BY STATION DAY
10 APRIL

=

xe

Te 4 8 12
LE IS 250 GAMMAS PER CM

18



“TYBLUpLW LZeuBewosg [e907 40 SWLI IN eY2 SyAeW MOAUe UP UOLIEIS
yoes 4oj “9/61 LLddy 40g SuOLzeLUeA H BALZeBaU sow Jo apnqLidwe [eJo, *g aunBLy

ar st at 60 92 st cay 60

hed payed , aoe 8

oavatz
02°820

a
3
&
5
“2

£
&
2
3
£
z
2
<

os-ase
os-s20

oe v4 ww [REE EE
a yreN |

55


COMMON SCALE MAGNETOGRAMS
BY STATION DAY
27° APRIL 1976

TTT
. Maa a bee

CO ¢

N.P.D.
E.Lons,

025.20
212.20

|
|
|
:

eaten

BW ww

wero. “ o18.70 Lf hecneen iV Ainetn eee been
E.LONO, =

N.P.0.
E.LONG,

I 5,

al CT --°

E,LONG. = 018.80

i+

a es a eG GD °

OUT. 4 8 12
SCALE IS 250 GAMMAS PER CM

35


COMMGN SCALE MAGNETGGRAMS
BY STATION DAY
28 APRIL 1976 }

ee ee
LR aw wry ava

N.P.0. = 025.90
E.LONG. = 338.30

NAS 12 ees.0 ne aie a

E,louc, = 314.80

FC x

nep.o. = 031.20 | ~~“ __ | Je pn
E.LON, = 265.80 WhO ane

CO om ae ae Va tn SO |

N.P.D.
E,LoNG,

018.80

[jot ft pep fp pp pt fp pt 0

oO UT. 4

8 12
SCALE IS 250 GAMMAS PER CM
36



Sesit Iv
£609 Id
Lv6L IL
2086 Ma
TeOeT 02
Geel od
OS6IT SYN
seumeb yeeZT ca
9261 Lbady UOL3BIS
“san|eA aouasayoy H UL L-72LND ALYQUOW *g aLqeL
[s2z ]t»9 s2% ata 06 6 OF 4 Z 92 29 let 22€ Shh 909 see £2 Hf 8 S$ Sh 925 zoe 186
0 0 9 o 42 e2t gz ose zn2 ose [O68 66 2 Te 2h 4t 6 2 so 68 ue oo Qo 0
sez nen ezz nee [abOt}oz od o92 09 22 ~2n, 44 $$ SE Q8F ELE £29 91S BSh Z49T OT 42 LT OF
42y TIT 62 @ ey ft 9 eet oes sze fez} 069 s6n 282 96t 26 60T Z20T 9S ZT ZIT soz 9TT set
TéT 661 hz ee% Gey s6s 205 [ZOE] oes out om ay $ 8 9t 86t LZ e6T £82 2H SoH 2n2
0 a 0 Q 0 6 2 06 st2 699 [HEZ} £9 245 945 Lee 26 STT oy 27 0 0 a
oz ez 22 8 62 22t Sah ess zse oz "oor o2t o8 ne 2t 2 a 1 0 0 os
ce 42 Sh o22 sez 2et 62 ht 62 89 28% n2e 6% 295 099 289 60L 226 282 96 ff
ssf ath 22£ G2 22t se SZ 42t ene ney [69S] 02S OHF then mez ef 45 £ 0 oo os = g2z
a 1 st FT T ze 24 «= GhT «STE «16 «(GET 20 Ht 262 sue 6fs Hon 82s 224 [28S] sos s9f 002
a__o6 0 0 2h 4h 59 Git €22 Lse £05 sz9 [289] 926 eee 4Oh 992 Bee TOf 96T sot Be 0 a
fegut] 2e2t sztt 9eh 99T To 4 Z st 48 09 48 GL 68 28 Of Ost Btz2 Ste Zee OFS O58 4Ht2t esst
¢
sz 2t 0 oz 4t  st on 82 4S OOF 96 £6 $ g2t 422 TSS 622 Bes [PZB] 219 GTR HS ezz 09
oft 962 s9% tze [STH tte 9e9 see set of oF 9 ws 28 6 4 4 AT F 2 3 0 9 4g
zz 9L 2F Ot 0 2 $s 0. 6 On @2T GET STT GTT eS tT 22 62 OST HE HOH TEL
Tr a2 29 "tz ase "19 Tee [98Z} s29 62 Te 28 sh TS of fF Le 68 TE TT wz 8B
se £2 22 2 G2 6 @F Zt OF St Tt St 2t TE OF 60 go 2O 90 So 0 so 2 To
eet Tad
‘uolyng14qu0g Ty pue ny Jo Aouanbeuy uolqeis “7 elqeL

Iv
Iv

Ig
Ig

IL
IL

cr)
Me

03
03

RE}
a4

SUN
SYN

1
a

vis

Wo} zeuMoJUT Le>19S13IS

-W
=n

“Ww
“nv

Ww
“nv

-W
ny

“Ww
“nv

-W
“ny

Ww
“nv

Ww
“ny

g

51


COMMGN SCALE MAGNETOGRAMS
BY STATION DAY

16 APRIL 1976
TTTTFTry?rtry?t rT ryp rt tty Tt Ti
LR ow r
woro. = oes.c0 WN
E.LONG, = 338.30
NAS cH
NeP.O. =
E,LONG. =

031.20
265-90

CO cw ee ee

N.P.O. = 025-20

E-LONG, = 212.20

BW cH \Sarrn lll hen meets AMIS ek Gee eam oe ecm eacenet ie

N.P.D. = 018.70

E.LONG. = 203.30

TI ww |

NeP.0. = 018.50

E.LONG. = 129.00

cn

-—— 10
|| s

DI cw Lig rn 8

N.P.O. 16.50

= 0
E.LONG. = 060.50

Al cw ee 3
NeP.o. = 021.70
E-LONG, = 018.80 || 2
jo 1
|_| 4 } | | | 1 4 } jt | jt {Jj °
0 U.T. 16 20 2

T 4 8 12
SCALE IS 250 GAMMAS PER CM
24


st

st

st

“ZUBLUPLW OLzeuUBeuIosy [e907 JO SW LN ay} SyueW Mouue Ue UOLIe7S

yora

4o4

“OL6T [tudy 4oy uolzeyZs Aq UOLSLAOUd JY ULW-T Jo Aouanbau4

“py aunBly

€0 “19 00

11

a |

é

}

ne

,
c
a

3

osrogo = -ovovs3.
oss = “oan

54


SECTION

SECTION

1.
2.

SECTION

TABLE OF CONTENTS

I, GENERAL DISCUSSION

Introduction. 2... ee ee
Data Selection and Processing .
Auroral Electrojet Magnetic Activity Indices ............0.
Acknowledgments 2... ee ee eee
The Series of IMS Data Publication Reports ...............
References 2... ee

II. COMMON SCALE MAGNETOGRAMS

Stacked Common Scale Magnetograms for Whole Month (H, Z, and D Variations)
Stacked Common Scale Magnetograms by Station Day (H Variations)... ..

III. PRELIMINARY AE(8) INDICES, APRIL 1976

Discussion of Graphs, Tables, and Statistical Information ........
Graphs of AU, AL, AE, and AO for Each Day of the Month. .........
Tables of AE, AO, AU, and AL Indices . 2... 2... ee ee ee
Tables of Observatories Supplying Hourly AUand AL ..........4
Statistical Information... 2... . ee ee eee

Page

wwnnee



 AURORAL ELECTROJET MAG INDICES AE(8) w AURORAL ELECTROJET MAG INDICES AE(8)

on
Au au

a a LL
m) ft ",

: Wj may t

Sow Sau

AL AL

om su | |
sm Ly a

wm 176704719 = mo 76/04/20

wm wm

AE

‘om ww

‘ ‘

a0 am

H | M LUNA " ,

so i= 5

AO AO

$l I ! $}L a !
vo» AURORAL ELECT w AURORAL ELECTROJET MAG INDICES AE(8)
AU AU

om | Po

Y Lb SORA aeducee LA
8 4 " iy

a ni ian DV wn
AL AL

ue a

“ ml revoarer | i 2 76/04/22 ¥ =
a
‘mo ‘e

a
ww» AURORAL ELECTROJET MAG INDICES AE(8) wm AURORAL ELECTROJET MAG INDICES AE(8)
au| AU
TM 1 os
1 batt | | 7 (HAL | emt LA!
: al : Walt me)
Sasy }_| San
AL AL
vw | ‘0 H
oe al 76/04/23 : 76/04/24
Ty TI
TM 1908
AE AE
v0 08
‘ 6
: : n H
Poo no fad
‘, LL Tp | an 7 ) iT et CN
:
ian do my as
“ v w a v 1 2

43



, AURORAL ELECTROJET MAG INDICES AE(8) » AURORAL_ELECTROJET MAG INDICES AE(8)

AU AU
ea oo
ny feted ease! tbl ty Abehes pele a te
ETON Wd a Pree MO ici MinacanvcaniaNe
aL Vv AL
‘i “m
76/04/07 an 76/04/08 ¥ 7d
mm a
AE AE
‘ ww
tw N, L ‘a Nb Lt
1 LW hh LOraal 7 LLINA Lay | Ld
A yj ‘a no We ia !
‘s (MUTT a) ST :
we AURORAL ELECTROJET MAG INDICES AE(8) im AURORAL ELECTROJET MAG INDICES AE(8)
au Au
tn TM
“8 ales A-VrAlnefen| oan tA mae a
«NARA Al) ed aa 1 err Ty ivf
AL aL
a a
- mal 76/04/09 | an Tevoavio | id
ve ‘on _|
AE AE
we i
H A ta
tow Woot ‘
manana Wey Teall? Ey WU
: A chain $ inidataed
‘ * 1 “2 fTF PHL
we AURORAL ELECTROJET MAG INDICES AE(8) vw AURORAL ELECTROJET MAG INDICES AE(8)
AU AU
” Pad
ao nate in en
WA pet W/ 1 MTNA
Sau 1 | San
AL \y AL
vw an
_ mi Tesoasiy | _ 7 76/04/12 *
oo 0
AE AE
wn vn
‘ ‘
“ne L “an
1 WAN Yev WW e : thy a MUM Nd rs
aol Tt Vi 4 Ao 7
rh J TM vr

41


COMMON SCALE MAGNETOGRAMS
BY STATION DAY
3. APRIL 1976

NAS cw

lnm Lahey
N.P.O. = 026.90 ~~
E.LONG, = 314.80

FC tx)
0 Nt
nr. 2 21-0 yey er
CO ww
E,LONO, = 212.20

TI op pm
N.P.O. = 018.50 | PO pel
E.LONG. = 128.00

|—— 10

i—j— 9
DI en on hi log
E.LONG. = 080.50

neaed een een ee

Loft pop pp tp pt tt te tg 0

oO u.T.

1. 4 8 12
[SCALE IS 500 GAMMAS PER CM]

11



“2YBLUpLW OL2eUBewosH [e907 JO SUL? IN ay2 SyveW MOuue UR UOLIeIS

yore 4oj “Q/6T [tady 40J suoLqeLaeA H BALZLSOd ysom Jo apnzL{dwe [eyo “¢ eunBbiy
ve 12 er st ar 60 30 60 ve TZ er st ar 60 30 €o “i'n OO

“0 oe ea I Tt TL I TI II TI TT Tt IT
ml Mu, i
soon +}
+0051 4

- Ma Ma

ml pvr

cost +}

“0 x ¥

aH oa ia ae Vr

“| ar ww

“o ¥ {| +

003}

‘e001 ved vind
2031]

“6 ea +

0001]

20st]

“0 ke +

ml A pA
+0001 |
“0st And And|

. + +
+03}
+0001 |
-oost H]
tr ir

7)
ooo 7]
003114]

Anooorer ol ct coor corr se

oa-aiz
o2rsz0

oerne
e620

osrase
oerszo

senor
ran

Id

53


COMMON SCALE MAGNETOGRAMS
BY STATIGN DAY
5S APRIL 1976

| anacmirtA prin ve WNT
ERO ow a lal
woP.0. = 026.90
EiLoNG. = 990/30

Lateran”
NAS ap any \w\ \ pane
P.O. = 028.90
EuLOnG. = 91480
rr ny La AN
N-P.0. = 031.20
E,LONG. = 265.90 yh
cO wm Lop t [hn /

me
bs
Zo
é
ao
BR
88

Tl ww rt Bi

N.P.D.

E.LONG. = 129.00
DI ow Owed
N-P.D. = 016.50

SLONG. = 080.50

sateen ns GG DG

oO UAT. 4

8 12
SCALE IS 250 GAMMAS PER CM
13


WORLD DATA CENTER A

for
Solar-Terrestrial Physics

REPORT UAG - 64

GEOMAGNETIC DATA FOR APRIL 1976
(AE (8) INDICES AND STACKED MAGNETOGRAMS)

by

J. H. Allen, C. C. Abston, and L. D. Morris
National Geophysical and Solar-Terrestrial Data Center

Boulder, Colorado 80303 USA

February 1978

Published by World Data Center A for WW
Solar-Terrestrial Physics, NOAA, Boulder, Colorado
and printed by Aa

U.S. DEPARTMENT OF COMMERCE

ZyB :
gins
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION Nw .

ENVIRONMENTAL DATA SERVICE
Asheville, North Carolina, USA 28801

SUBSCRIPTION PRICE: $25.20 a year; $17.30 additional for foreign mailing; single copy price varies.*
Checks and money orders should be made payable to the Department of Commerce, NOAA/NGSDC.

Remittance and correspondence regarding subscriptions should be sent to the National Geophysical and
Solar—Terrestrial Data Center, NOAA, Boulder, CO 80302.

PRICE THIS ISSUE $1.00



COMMON SCALE MAGNETOGRAMS
BY STATION DAY
26 APRIL 1976

a a a a a
LR oa fp |
N-P.O0. = 025.90 P\ner
E,LONG. = 336.30
NAS cH —_—srerr soo
wp.o. = 028.90 | Vee
E.LONG. = 914.80
FC «x |_| Won, vl
Woto. = 691.20 NV nana
E.LONG. = 265-90
CO wm Jp rrr a
N-P.O. = 028.20
E,LONO. = 212.20

BH ow P| J
we, = amo | | PY nr EN

E.LONG,

I—— 10

AI ww 3
NeP.D. = 021.70 to.
E.LONG, = 018.80
1
i { | 4 oo { 1 4 {| 4 {| | 4 °
out. 16 20 24

4 8 12
SCALE IS 250 GAMMAS PER CM
34


=

018-50
080.50

021.70
018-80

COMMON SCALE MAGNETOGRAMS

BY STATION DAY
14 APRIL 1976

Law|

|

TTT PTT ot

ne

aaa

|_| 4

|

aaa ed

|
|
f

oUt.

SCALE IS

4

8 12
250 GAMMAS PER CM

22


WORLD DATA CENTER A
National Academy of Sciences
2101 Constitution Avenue, N.W.
Washington, D.C., U.S.A., 20418

World Data Center A consists of the Coordination Office -
and seven Subcenters:

World Data Center A
Coordination Office
National Academy of Sciences
2101 Constitution Avenue, N.W.
Washington, D.C., U.S.A., 20418
[Telephone: (202) 389-6478]

Glaetology: Rotation of the Earth:
World Data Center A: Glaciology World Data Center A: Rotation
[Snow and Ice] of the Earth
Inst. of Arctic & Alpine Research U.S. Naval Observatory
University of Colorado Washington, D.C., U.S.A. 20390
Boulder, Colorado, U.S.A. 80309 [Telephone: (202) 254-4023]

[Telephone: (303) 492-5171]
Solar-Terrestrial Physics (Solar and

Meteorology (and Nuclear Radiation): Interplanetary Phenomena, TIonospheric
Phenomena, Flare-Associated Events,
World Data Center A: Meteorology Geomagnetic Variations, Magnetospheric
National Climatic Center and Interplanetary Magnetic Phenomena,
Federal Building Aurora, Cosmic Rays, Airglow):
Asheville, North Carolina, U.S.A. 28801
[Telephone: (704) 258-2850] World Data Center A
for Solar-Terrestrial Physics
Oceanography: Environmental Data Service, NOAA
Boulder, Colorado, U.S.A. 80303
World Data Center A: Oceanography [Telephone: (303) 499-1000, Ext. 6467]
National Oceanic and Atmospheric
Administration Solid-Earth Geophysics (Seismology,
Washington, D.C., U.S.A. 20235 Tsunamis, Gravimetry, Earth Tides,
[Telephone: (202) 634-7249] Recent Movements of the Earth's
Crust, Magnetic Measurements,
Rockets and Satellites: Paleomagnetism and Archeomagnetism,

Volcanology, Geothermics):
World Data Center A: Rockets and

Satellites World Data Center A
Goddard Space Flight Center for Solid-Earth Geophysics
Code 601 Environmental Data Service, NOAA
Greenbelt, Maryland, U.S.A. 20771 Boulder, Colorado, U.S.A. 80303
[Telephone: (301) 982-6695] [Telephone: (303) 499-1000, Ext. 6521]
NOTES:

1. World Data Centers conduct international exchange of geophysical observations
in accordance with the principles set forth by the International Council of Scientific
Unions. WDC-A is established in the United States under the auspices of the National
Academy of Sciences.

2. Communications regarding data interchange matters in general and World Data
Center A as a whole should be addressed to: World Data Center A, Coordination Office
(see address above).

3. Inquiries and communications concerning data in specific disciplines should
be addressed to the appropriate subcenter listed above.



2tt- z60-
soo- 900
eso- ¥e0-
azo- 2t0
Thd- 9s0~
900- 20
g00- 40-
ooo +t0
gTo- 600
T2z0- 900-
£00- oFO
2g0- £e2-
400- £T0
00 $00
gto- 700
Too 00
200- 00
ST0- %S0-
00- 900
oso- sf0-
2n0- $S0~
2420- 040
Teo- 200
$z0- o£0
Oso- FS0-
Bh0- 4Z0-
O20- 6S0-
neO- SeT-
eg0- £S0-
660- 6TT-
Qt zet-
6f0- 250-
ELT- 6TO-
NVBN 42
SVHWYS NI

O0T- T60-
400 600
gS0- 650-
gta sz0
6t2~ eiT~
640- O20-
£20- 6t0-
2to OTO
to 060-
S20- £T0-
ato 4T0
g0T= TH0-
sto 2t0
soo 600
400 2T0
too soo
goo ato
490° £h0-
goo 0T0
6£T= 09T=
Ont- ThO-
600 eTO-
Set= LOT=
gto 9T0
280- T20-
T90- TZ0-
ehz- 02f=
2to- TT0
gs0- ToO0-
Z9t- SZ0-
22z- 992—
nZbe 9S2-
690- 4ST-
2 22
G3SS3udXx3

869- 660-
gto 900
420- ez0-
sto 990-
6S0- 120
920 $90-
o90- £20
20g 900
Oto- 210
2t0  Sh0=
ozo t20
T20° 4TT-
eto 670
2to 2t0
zz0 200
goo 4T0
Too 220-
T2o- oT0
200 4TO-
Too #00
4L0- 22T=
oto TOO-
9z0 620
20g OT0
9S0- 420-
@Tt= 200-
2£0- Lt0-
FOG- 2tt=
‘am0- 820-
6TO- 600-
Sh2- 90T=
600- to
Zet- 06T=
te 02
Buy S3NIVA

TOT=
£00-

2f0-

4z0-
ato
eh0-
g00-
200

2to-
660-
ogo-
soo
T20

goo
2£0-
200
2zo-
200

2to-
eg0-
Tho
ooo

2z0-

900

660-
Te0-
T20-
s60-

o2z-
220-
TZ0-
900

960-

et

290-
STo-

teo-

00
hte
400
g00-
azo

o90-
240-
210+
sz0-
400

200

690-
4TO-
azo~
200-

g00-
£60-
asa-
so
ozo

600

S0T-
g00-
zt0-
4g0-

g90-
z20-
20T~
200

Te60-

et

690~
Atos

420-

gto-
9c0-
9T0-
oso
900

220-
200
soo
90T-
e50-

900
420-
200
200
900

oto.
2t0-
#00
00
£00

sto
BHoe
baz)
ga0-
900+

ez0-
gs0-
ooz-
zo0-
9s0-

av

980-
ato-

z20-

£00-
ooo
stO-
sto
T20-

g0T-
200-
200

gf0-
ne0-

aT O°
6TO-
900
ooo
200

200+
62z0-
400+
200
900

azo
920-
000
goo
oga-

ooo
nl0-
Tage
s00-
ono

Qt

Ont
To0-

£n0-

Tho~
420-
700
220
g00-

£90-
T60-
ooo
oto
Tro

e00-
e00-
400-
z00-
oto

£00
2n0-
tt0
700
Tht-

700

9ST=
9z0-
£e0-
nlte

Ts0-
6LT=
6f2-
ThO-
2s0-

st

SST-
ato-

ah0-

2n0-
T20-
£00
e00-
g00

200
a60-
£00
oto-
6z0-

£t0-
200-
600-
£00-
600

roo
£20-
800
t00-
620-

sto-
960
ee0-
T8T=
e9T-

6ST
stz-
£20-
sto-
Tee

aT

22t-
2202

£n0-

100°
s0T-
ooo

2to-
e006

ooo
ng0-
sto
of0=
860-

z00
sto
eto.
ooo
4t0-

2t0-
zet-
ooo

6T0-
090~

TL0-
£00-
£t0-
6TO-
9z0-

Lite
ogt-
TrO-
6To-
S62-

st

‘S@OLpul OV

sot
$20

ono-

$z0-
so0-
£00
ooo
2to-

900°
920
eco
ooo
2g0-

ooo
6L0-
200-
400+
too

e00-
T20-
620-
£e0-
net=

660-
g00-
4g0-
ozo
z20-

2g0-
262-
600-
eto-
T9T-

at

8n0- 40T-
2T0- 4900
n20- 0z0-
yhO- 4S0-
2to Oto
£00 40
200 oto
Tzo- 400
600- 00
g20- “£0
ozo 920
6to- 200-
ato Sto
goo 200-
6go- 600
4to- 200-
ooo soo
200 «6T0
zoo to0
640- "00-
"90- 200-
Za0- 9f0-
2so- 000
2g0- 600-
g00- ooo
2L0- SE0-
eto 6TS0-
Oz0- 40T-
ego- z2£0-
“TO 00T=
4O0- 910
6TO- 4TO-
96T= 662
Tr OF
"2 Sigel

ze0-
200

azo-

220-
200
920
200
£70

too
6z0-
220
zs0
900

£00
Too
to0-
oto
sto

too
$00
200-
180-
400

400
soo
gto.
note
620-

620-
e80-
690-
2to-
fhe

£60-
200-

£20-

To0
800
280-
ono
2t0

900
zs0-
geo
sto
s00-

000
000
£00-
eto
900

£00-
6to-
700°
£20-
roo

STo-
ooo

st0-
Tete
SOT

"00

2et-
2tt=
£To-
690

L0T-
200-

220+

eo0-
400
ato
so0-
970

azo-
zg0-
s20

Ts0-
Tro-

o00
200
eo0-
zo0-
200

2t0-
o6o-
4T0-
TL0-
z00-

sta-
eto
6T0
ooo
eno

2oT=
2tt-
Late
zn0-
eot=

9lte
To0+

6n0-

280-
900
9z0
T20-
tro.

oto
990-
go0-
Te0-
s00-

goo

Tooe
400-
6to-
n00-

e00-
zot-
2e0-
eeo-
TOO.

geo-
OTO-
220-
200-
S2t-

n9T~
20T-
nOTe
ezo-
£0k-

9e0- soz-
too £00-
z220- 990~
$S0- £00-
£00 890-
ato £S0-
ata tro
4T0- S$O0-
9T0 Sto-
9z0 OT
20 TT0
2g0- 250-
ooo ooo
400 00
200- t20-
too 200
2to- £90-
£20- 960-
ooo ooo
TtO- 420-
e80- 990-
690- 9£0-
600- Sz0-
$40- 40T=
6S0- eST-
o60- 9s0-
420- 62T=
TL0- 20T-
n60- 942-
600- TOT}
940- 290-
yoo) SH0-
6LT- 2tS-
s a

ogt-
400

6S0-

sto-
£n0-
220-
920

Oto-

640-
200
£90-
200
200

400
9to-
too
2to-
6f0-

zt0-
eto-
L9T-
s20-
6n0-

£20-
Lgt-
920°
aso-
49T-

T9T-
gate
aso-
290-
gate

a8T=
too

ago-

n00-
40
ozo
T20-
aso-

£20
600
e2T~
900
400

£00
200
£00
TT0
nT O0-

ato
2e0-
9lt-
ozo-
290-

g0T-
9Z0-
get
oto
ese

6TT-
£02=
Tz0-
2ht-
Thee

20T-
Too

Shoe

STO
ato
700
T90-
00

oto
600
ost~
goo
200

goo
900
900
oto
£20-

£To-
£50-
too

220°
ze0-

£2t~
6TO-
6tz-
99T-
8tt-

Lot
soo

60T-
TLo-
te0-

NVBH aS
NV3H 0S

NVaW

oz

coo o

at
at
ot

st 0
aT
et
at
W

oT

eo
20
30 0

40
“0
£0
zo
to 0

eco

in

qd

46


COMMON SCALE MAGNETOGRAMS
BY STATION DAY
22 APRIL 1976

TTT TTT TTT TTT TTT TTT

LR ow L——_—~
SCA 2-1 I O00 ei yew)
NAS cH) Ler

Lara stern
titona. 2 Staceo Ayn [ey

FC «x | pete etter
Nep.b. = 081-20 | Cn
E.LON, = 265.90

;

|
|

|
[
S
\

W \ nn,

o1a.s0 — Nw A

\

|_9
DI ow eth han |»

|_|

NeP.0. = 016.50 7
E.LONG. 060-50 ——
6

| os

AI aw Pat ee — --*
NP.D. = 021-70 3
E.LONG. = 018.80 He

{|_| 1 | | 4 1 jot {| 14 {| | 4 | 1 1 °

12 16 20 24

o UT. 4 8
SCALE IS 250 GAMMAS PER CM
30



SECTION III. PRELIMINARY AE(8) INDICES, APRIL 1976

1. Discussion of Graphs, Tables, and Statistical Information

The following figures display the familiar AU, AL, AE, and AO graphs for each day of the month
and are based upon 1-min data samples. As indicated at the top of each frame, these indices are
derived from data from only eight auroral zone observatories and, as such, are considered "provisional."
WDC-A for Solar-Terrestrial Physics intends to update these indices during and after the IMS and to
publish "final" graphs and summary tables in the usual UAG Report format for each year.

Following the pages of AE graphs are tables 1-4 (pages 45-48) containing the index (AE, AO, AU,
AL) amplitudes for each hour of each UT day of the month, the monthly averages for each hour and for
the hours of the designated 5Q and 5D days, and the average amplitudes for each day and for the whole
month. Tables 5-6 (pages 49-50) give the station having the largest hourly average positive and
negative deviations (hourly AU and AL) for each hour of each day in the month. These provide a key
to the graphs of AU and AL by usually indicating which station's magnetogram provided the extreme
deviations giving AU or AL for that hour. Sometimes the most extreme deviation during an hour will
have occurred at another station. The general patterns, however, of UT time of AU and AL provision
by each station are the same whether based on hourly averages or on minute-by-minute extremes.

Table 7 (page 51) gives the number of times (1-min intervals) during the month when the indicated
station provided the AU and AL index in each hour of the UT day. For the relatively sparse station
distribution used in this AE(8) derivation, it is not surprising that each station could produce at
least one extreme positive and negative deviation in almost every hour of the day. The overall pat-
tern, however, is for the most frequent observation of the maximum positive H deviation to occur
around 6 hours before Local Geomagnetic Midnight (LGM) and the most negative H deviation to occur
around 3 hours after LGM [Allen and Kroehl, 1975]. Individual station deviations from this pattern
may be due to the dominant influence of a few isolated large substorms during a relatively quiet month.
This should become apparent as more months of data are similarly analyzed.

Table 8 (page 51) gives the monthly average of quiet-time H for each observatory. This is com-
puted from the 1-min H scalings on the 5 quiet days of the month, using known or assumed H baselines.

Figures 2-5 (pages 52-55) graphically display the details suggested by the tabulation of hourly
station frequency of AU and AL contribution. The "frequency of 1-min AU provision by station”
(figure 2) for the month is a smoothed curve showing the number of times that each station contributed
the extreme positive deviation from minute-to-minute, N(AU). An 11-point running mean was used on the
raw numbers of contributions for the 1440 1-min intervals of the UT day. Data for the UT day are
duplicated (0000-2400 UT shown twice) so that the end of the day will not interrupt the regular pat-
tern of progressive index contribution as each station rotates into the critical region around 1800
Local Geomagnetic Time (LGT). Arrows mark UT times of LGM for each station. Figure 3, on the oppo-
site page, shows the "total amplitude of most positive H variations." This is a smoothed graph for
each station's cumulative amplitude of deviation for each minute when it was providing the AU index.
Each scale division on the right side represents +500 gammas. Comparison of these curves with the
N(AU) graphs of figure 2 shows that the largest magnitude positive excursions generally occur at the
same time when the stations most often provide AU indices. Occasional postmidnight minor peaks result
from disturbances for which the H component at one site is first a negative extreme (giving AL) for
several minutes and then swings briefly to a positive extreme before recovery. Such events are in-
frequently observed in. AE indices derived from 10 to 12 stations because usually another station is
in position to monitor the true eastward electrojet effect rather than having oscillatory variations
near LGM providing AU.

The graph "frequency of 1-min AL Provision by station" (figure 4) shows the smoothed curve for
the number of times in the month that each station provided AL during each minute of the UT day,
N(AL). Evidently the pattern is for a station to rotate into the most probable region for encounter-
ing extreme negative H deviations some hours after LGM. Unusual, asymmetric peaks in frequency of
AL provision by any station may be attributed to disturbances on only a few days of the month. Such
unevenness due to a few isolated events should average out over the course of a year. Figure 5
shows the corresponding "total amplitude of most negative H variations." This is the cumulative
amplitude of negative H observed by each station during those minutes when they were providing AL.
Each scale division on the right side is -1000 gammas. Again, the comparison of cumulative amplitudes
and N(AL) curves can indicate the most probable time of occurrence of larger amplitude events.

For figures 2-5 slightly elevated levels of the curve for any station during normally quiet hours

indicate possible difficulty with the quiet-time level for some days of the month. This information
will be used as a quality control check for the final derivations of AE(12) indices at a later date.

39



NAS
WP.
E.LoNe.

FC

N.P.D.
E,LONG,

NPD.
E.LONG,

COMMON SCALE MAGNETOGRAMS
BY STATION DAY
17 APRIL 1976

028.20
212.20

018.70
203.30

Da

cn
i—— 10
is
a) pL is
= 016.50

2 nan i
|_ 6
| 5
jt 4
|| 3

a _—— fe
= 021.70 ——#
= 018.80 1
| jf { {it {_ Jf | | 1 | | l °

OUT. 4 16 20 24

SCALE IS

8 12
250 GAMMAS PER CM
25


COMMON SCALE MAGNETOGRAMS
BY STATION DAY
1 APRIL 1976

CO ww ORneen Deanne Aanene
a
N-P.D. = 025.20
= 2

E,LONG,

cH
| 10

is

Dwr ermnbaal ame 8

1

| 6

5

eee

its

I 2

| | | | | tt 0
16 20 24

T ry 3 12
[SCALE 1S 500 GAMMAS PER cM] NGSDC (BOULDER) 77/12/02

out.

9


nTT 260
oso Feo
220 @20
azo sso
22t set
tz0 $90
860 8ST
zoo TST
450 820
9st EST
490 2420
att 490
S40 240
zzo ozo
geo 020
tz0 azo
ogo 2t0
20 290
420 430
se0 $90
$70 990
neo £0
6s0 sso
oso 90
690 4TT
230 9TT
SOt HTT
TT g2t
92T 660
6TT ATT
860 O20
ano seo
2tt #20
NVBH 92
SVWHV9 NI

680
so

220

oso
620
960
sot
T90

90
gst
Teo
ost
geo

eto
sz0
TO
210
760

ze0
got
T20
oso
£60

2n0
690
82t
620
680

ZIT
oat
$20
2nt
$90

£2

t80
920

e20

990
£90
680
460
Tho

290
get
220
net
6z0

eto
220
8T0
220
Teo

geo
£2t
060
o%0
62t

6n0
ost
gt
ont
980

fat
4ST
6£0-
TIT
290

22

ego
620

e20

ono
902
220
OT
ez0

STT
960
eso
Zot
"20

2z0
290
gto
£0
6s0

azo
42t
eet
9e0
260

20
chai
60T
ost
960

Sot
ozo
T20
760
220

tz

Q3SS3udx3 3uv

STE Tt
oso sso
640 980
290 «9s0
AgT 902
960 40T
got 260
$20 940
290 240
Ont 96T
“20 240
sot 650
ono 840
Tz0 sto
ono 290
$20 020
oso sso
eso £20
4z0  9TO
S20 480
TIT 660
eso £80
290 840
ez0 6T0
Tt 82T
ee0 090
680 9ST
T2t soz
86T e6T
T9390 $20
SST 99T
T2020
"gO 602
02 6T
S3N WA

Sst
280

seo

Tao
see
Tso
220
690

$20
£tt
260
690
480

t20
$60
9to
620
t20

eta
t9F
Tso
920
£60

2z0
Tet
420
960
got

Tst
60t
tat
eso
ase

ot

a8
seo

e20

aso
ge2
220
4s0
620

960
290
$40
£60
seo

eto
060
2t0
220
t20

20
2tT
ono
$20
£90

620
ozo
40
TS0
2t2

490
Ont
Ts2
£0
Ln2

at

26T
seo

ozo

ts0
SST
oso
£50
$20

£20
250
so
220
£50

ozo
240
ozo
oto
$20

$20
680
seo
ozo
eso

440
9s0
6s0
eno
2or

o2t
Las
28T
2t0
ete

or

oet
ono

920

450
260
250
oso
ono

eso
28t
eto
90
ogo

2t0
eno
ozo
oto
neo

neo
z90
£40
sto
set

seo
260
S20
060
e2T

sot
69T
st2
£T0
£ez

st

22t 220 ss6 080 Z24T
ze0 240 THO sea seo

n2o0 790 290 e960 820

6s0 920 seo 990 260
Tst 962 AT2 Teo eho
090 220 of0 of0 sso
2n0 0S0 620 Tho 840
220 420 “£0 090 tz0

920 9T0 TO 620 On0
2t TTT s9t 202 anz
420 040 890 640 690
gs0 190 47 Toz saz
960 Tht sot esa Tso

S20 820 20 ze0 sz0
sz0 20 620 ef0 940
2t0 6F0 620 $z0 920
9t0 TO t20 250 2h0
en0 £0 620 Teo 90

220 920 o20 420 620
060 z22t T9390 420 #0
£20 2£t0 620 840 Le0
eto $0 640 240 aso
860 620 Zot o90 szo0

Teo 6£T TST Teo eno
seo 920 tT0 2to szo
490 940 990 480 250
292 4ST e882 94t bLT
260 eh0 tho 990 soz

£0T 80T 480 260 06T
2et GET SOT 60T 602
060 200 900 20 690
600- 600- £00- 200- et0
2st @S0 Teo 680 490

at et 2b TF OF

SsoLpul AY “€ SLgeL

zest
asa

620

420
seo
92T
ooo
920

aso
ost
260
ore
"20

620
ze0
eso
240
£90

920
#20
azo
250
920

2s0
220
sho
2et
z2t

Tat
got
Tat
ora
990

ant
220

190

290
6so
att
6st
780

220
Lnz
ost
ane
220

420
Tso
S20
£90
ono

220
£90
4T0
240
620

ago
920
220
790
ToT

Stz
20T
222
e00
920

2et
220

Teo

seo
620
STt
Olt
980

980
992
T6T
soz
$20

220
620
200
20
on0

6T0
290
eto
£60
ozo

410
240
640
920
n0T

sot
22t
elt
oso
net

net
eto

e240

420
920
£20
S6T
990

OTT
OLt
69T
one
9t0

620
ozo
9to
260
eso

oro
260
ato
ozo
azo

oso
9s0
S20
£20
2nt

OLT
S60
£2t
920
6ST

T60
oz

$90

sot
ono
no
64T
£50

760
seo
92T
260
eto

220
420
6To
750
£90

9T0
tet
sto
"20
40

£20
oro
240
620
980

6TT
£60
640
OTT
eat

290
420

sso

Zit
£40
e20
£6T
2n0

T£0
zeo
990
4S0
ato

ozo
£0
920
220
$90

t20
eso
sto
STO
2t0

660
£90
£40
zo
zat

60t
#90
£0
290
£00

z90
420

eno

eso
oso
990
o2t
eno

ono
220
440
S40
eto

t2o
20
t20
s£0
eso

£20
$40
ato
Teo
$20

20
azo
ago
ono
090

z2t
480
ze0
260
ATO

926T

20
$20

9s0

60t
sno
ToT
20T
6s0

t20
T20
ss0
220
420

020
620
6to
ono
6n0

t£0
ozo
220
ong
920

£90
6s0
220
220
S60

290
22t
390
S40
220

690
$20

£90

eat
eso
STT
TOT
zeo

20
920
90T
T£0
2t0

tz0
tz0
eto
eso
oT)

$40
690
4S0
soo
£20

t20
ett
£20
790
220

te0
Set
eso
£40
290

NVBK OS
NVaH OS

NW3W

og
62
92
22
92

o
a
gaa a

$0
40
£0
20
To a

e090 0

in
Trudy

47


“Burssaooud yoy amy
UL BLqeL LEAR aUlOdaq Sp4ods4 41842 Se pappe eq LLIM SuOLzeIS BuLuLeueY “Z4oder SLY 40g BIeP BULPLAOUd SaLuoqRAUasqo 3YBLe ay] »

S*T9t o°e9 Zee Of  G*2f EL  GNYISI NOXIO = 10%

Orzez2 2°T9 40S 63T- 8°60 99 N3773M 3dv9 = 3n HtLnE $999 O%L4 Li- O°9T SS *% 3IWHM LvaND =UMd
n*TeT 4°09 0°00 62T arse TZ AV@ 3IXIL = The $9952 9°h9 2°05 LhT~ 9°Ts 49 3937709 = 09%
Q°2£ O°td Of2T Sh= 6°90 TS OVNSSYYSSYYN =SYN ¥ weodb 2°99 Of2T HOT O°fh 22 NINSNAT3HO*D = 99
Orts 2°02 02h T2- TTT Ho UNIOAYTET = YT T*The S989 68Hh BST- Z°RT TL MOwdve = Me x
e°2ze 4°99 0°90 46- 0°94 GS WITHOWNHO*LS = D4 ye 6tHTT 0°99 46h BT  s*tz 29 OMSI6V = Iv x
9NO7 ivi 9NO7 iva 9N07 ava 9N07 av

OTL3N9VHO39 OTHd 89039 NOTIVOI4TAN30I OILAN9YNO39 OIHdv49039 NOIAVOI4IINSOT

943 SVN 94 SVN ¥7 YT SYN SYN YT Iv Ig IG IL IG IL IL M@ ME NG ME ME IG 94 94 OF
O4 945 93 95 SYN YT YT Iv Iv IG IG I0 IO IL M9 MB HG OF D4 NG ME ME 93 93 62
SYN 94 94 SYN SVN SYN SYN SYN IL IQ IG IL IL IL 09 09 09 M@ MG ME MG ME 94 93 82
93 (94 SVN SVN B81 41 SYN BT YT Id IG IL It IL IL MG MG MG MB ME MG MG 94 94 22
94 SYN 94 O04 SVN SVN SVN SUN SYN IQ Ii IL IL IL IL IL MG ME MS ME MB O35 94 D4 G2

IQ SYN O94 SVN SVN Y1 YT B81 47 IG IG Ii M@ M@ MG ME MG ME MB ME IO IO 94 94 G2
94 93 94 SYN SYN SYN YT 7 47 BI Iv IL IL IG IL Ti 09 09 09 ME 95 94 95 94 he
SVN SVN IG M8 SVN 47 Iv &17 47 94 94 IL IL IL 09 MG MG ME MG ME ME OF ME 93. £2
93° 93 94 SYN SVN SYN SUN 87 47 YT Iv IG IL IL IL IL IL 09 09 ME MG 93 95 95 22
O53 93 03 ME ME MG Iv Iv IG IO IG IG IG M@ Ma Ma MG M@ 94 94 OF D4 D4 D4 TAD

94 945 94 94 MB MB MG CO IO IG IG Me Il MG Me ME ME Ma MG OF 94 94 OF 94 OD
Id 10 IG ME M@ SVN YT Iv Iv Ig IG IL IL Ti M@ MG MG MG MB MB 95 94 95 95 GTO
94 93 94 ME MG SYN SVN IL IG IL IL IL IL 09 ME ME ME MB 09 94 943 D4 ME D4 BT
94 93 94 SVN SVN ¥7 37 47 IG 09 03 IL 09 MS MO MO M@ HG ME ME MG O35 94 IQ LT
O4 94 SVN SVN YT 41 471 OD Id Id IG Id IL M@ ME MO MG M@ MG MG MG 94 94 D4 OT

O43 94 94 SVN SVN SVN 47 YT Iv IO 132 IG Id IL TL 09 IL 09 MG ME MA D4 94 DS HT
O4 94 SVN SVN SYN SYN SYN Iv Iv Id Iv 09 IL IL IL IL 09 41 09 09 09 09 94 94 ST
94 94 SVN SVN SVN SYN SYN 87 Id IG IG IO IO IQ Th IL Ik 09 09 09 09 IQ 94 93 2T
94 93 94 SVN SVN SYN SYN 09 4817 Iv Id Id IG IG 09 09 09 943 94 09 94 94 D4 D4 TT

94 94 93 94 94 05 09 SYN 09 Id IG IG Id IG IL 09 09 09 09 09 09 09 09 94 OF
94 94 93 94 SVN 37 YT Iv Bt Iv Id TL IL IL 039 09 09 94 BI 029 09 09 94 94 6
94 94 04 SVN SVN SYN SUN BT IG IQ Iv IO IL IG IL IL 09 YT 09 09 09 94 94 09 8
94 94 93 043 SVN SVN YT SVN 47 YT Iv IG Id IL IL IG 09 09 94 IQ 09 09 93 949 2
94 93 94 94 SVN YT SYN BT YT YI Iv TL IL IL IG Ik IL IL 09 IG 09 09 09 09 9G
94 93 94 94 SYN SVN SVN 47 IG Iv Iv IG SYN IL Id IL 09 IL 09 69 09 09 09 09 GG
93 93 93 94 81 81 SYN BT Iv Iv Iv Iv IG I0 IG IL Id 09 09 I0 09 09 09 53 40
09 09 SVN 87 SUN SVN 47 BT Iv Iv Iv 87 417 47 OF IL IL IL 09 09 IG 09 IQ 09 € 0
93 94 94 SVN SVN SYN SUN SWN IG Ig Id IL 94 94 Q4 IL 09 09 09 09 09 09 09 09 2
93 93 SVN SVN 87 47 YT YT YI Iv yt yt Iv Iv Iv 09 09 IG IL IG 09 09 09 93 TO
"2 £2 22 t2 02 6t St LT GF ST Ht St 2t TE OF 60 oO 240 90 So 40 So 20 TO in
H Vi730 WOWIXYH = Ay 926T qredy

sone ueey uo paseg ny ALunoy BULA dng saluozenasqo “g aLqeL

TW pue ny ALINOH BULATdang SapAOTERISSGO JO SOLqeL

49


COMMGN SCALE MAGNETGGRAMS
BY STATION DAY
4 APRIL 1976

TTT] TTT TTT t yt? yt

N.P.0.

LR ow
= 025.90
E.LONG, = 338.30

NAS cH)

NAP «De

Pf

Or oaeac 4 Dn SY Dan Weel
yard
tr

TI ow ne ne en

N.P.D. = 016.50 PW
E.LONG. = 129.00

Ol mm ta eel a n/a

N-P.0. = 016.50 hava

EsLONG, = 080-50

AL cm fen po gerry nrc dS on |
N.P.D. = 021-70 vad

E.LONG, = 016.80

Ppp} ppp pt pp tt pt | td

Lami mnean] Wr Sn

ovate 4 3 12
[SCALE IS 500 GAMMAS PER CM]
12