F — 135
FOR MARCH 1960 Vol. 12 No. 3 (Including Provisional Data at Showa Base) Issued in May 1960 Prepared by THE RADIO RESEARCH LABORATORIES MINISTRY OF POSTS AND TELECOMMUNICATIONS KOKUBUNJI, TOKYO, JAPAN
FOR MARCH 1960 Vol. 12 No. 3 THE RADIO RESEARCH LABORATORIES KOKUBUNJI, TOKYO, JAPAN
CONTENTS

SITES OF THE RADIO WAVE  OBSERVATORIES
Ionospheric observation is carried out at the following four observatories in Japan.
Solar radio emission and radio propagation conditions are observed at Hiraiso Radio Wave Observatory. Latitude 36°22.0'N. Longitude Site 140°37.5'E. Hiraiso-machi, Nakaminato-shi, Ibaragi-ken Hiraiso
SYMBOLS AND TERMINOLOGY
A. IONOSPHERE
All symbols and terminology in the table of ionospheric data are used in accor- dance with the First Report of the Special Committee on World-Wide Ionospheric Soundings (URSI/AGI), Brussels, September 2, 1956, and the Second Report of the Committee, May, 1957, supplementary to the First Report.
h' E n h pF 2 ypF2 The lowest virtual height of the trace used to give the foEs. The virtual height of the F2 layer measured on the ordinary-wave branch at a frequency equal to 0.834 f nF2. The semi-thickness of the F2 layer deduced from a parabolic fit to the " nose " of the electron density distribution with height and based on the observed h'f trace. (The difference between hpF2 and the virtual height at 0.969 f o F 2). a. Descriptive Symbols Used following the numerical value on monthly tabulation sheets. A Measurement influenced by, or impossible because of, the presence
b. Qualifying  Symbols Used as a preceeding symbol on monthly tabulation sheets. D E I J T U Z greater than…… less than...... Missing value has been replaced by an interpolated value. Ordinary component characteristic deduced from the extraordinary component. Value determined by a sequence of observations, the actual observation being inconsistent or doubtful. Uncertain or doubtful numerical value. Measurement deduced from the third magnetoionic component.
c. Description of Standard Types of E,
The nine standard types of E, are identified by small (lower case) letters: I, c, h, q, r, a, s, f, n. These letters are suggestive of the names low, cusp, high, equatorial, retardation, auroral, slant, flat and unclassified, respectively ; it is strongly emphasized that these names are suggestive, not restrictive. The standard types are : flat Es trace at or below the normal E layer minimum virtual l A Use in daytime only. height. An E, trace showing a relatively symmetrical cusp at or below c This is usually continuous with the normal E trace though, f o E. when the deviative absorption is large, part or all of the cusp may be missing. Use in daytime only. An E, trace showing a discontinuity in height with the normal E h layer trace at or above f o E. The cusp is not symmetrical, the low frequency end of the E, trace lying clearly above the high frequency end of the normal E trace. Use in daytime only. An E, trace which is diffuse and non-blanketing over a wide q frequency range. The spread is most pronounced at the upper edge (This type is common in daytime in the vicinity of of the trace. the magnetic equator.) An E, trace which is non-blanketing over part or all of its fre- r quency range showing an increase in virtual height at the high fre¬ quency end similar to group retardation. This is distinguished at present from true group retardation (a blanketing thich layer in¬ cluded in the E layer tables: foE, h'E) by the lack of group retar- dation in the F traces at corresponding frequencies. An E, pattern having a well defined flat or gradually rising lower a edge with stratified and diffuse (spread) traces present above it. These sometimes exceed over several hundred kilometers of  virtual height. A diffuse E, trace which rises steadily with frequency. This S usually emerges from another E s trace which should be classified separately. At high latitudes the slant trace usually starts to rise from a horizontal E, trace, I, h or f, and frequencies which greatly exceed the E layer critical frequency (e.g. about 6 Mc/s) whereas at low latitudes it usually rises from equatorial type E n q, at fre- quencies near the E region critical frequency. An E g trace which shows no appreciable increase of height with f frequency. The trace is usually relatively solid at most latitudes. This classification may only be used at night; apparently flat Es traces observed in the daytime are classified according to their virtual height : h or l. An E trace which cannot be classified into one of the standard types. This must not be used for intermediate cases between any two classes. A choice should always be made whenever possible, even if it is doubtful.
d.  Multiple Reflections from Ex
When the ionogram shows the presence of multiple reflections from E s , the number of traces seen should be recorded after the letter indicating the type.
B. SOLAR RADIO EMISSION
Solar radio emission is received on 200 Mc at Hiraiso Radio Wave Observatory using a 6x4 dipole broadside array and an ordinary superheterodyne receiver. The type of observation is of intensity recording of both steady flux and outstanding occurrences.
a.

Outstanding The mean value of recorded base level. occurrences are to be omitted except the phenomena with duration of hours or more. Variability is expressed in four grades as follows :
Number of bursts is determined relatively in comparison with the base level. If the number of bursts be fixed, the variability is greater, when bursts are widely distributed, than in the case of being concentrated in a short period.
When the start is not obvious, 20% rise time of smoothed flux is adopted and x is suffixed. (e.g. 0234x) When the instantaneous maximum can not be taken, the smoothed maximum is used and x is suffixed. (e.g. 0539x) When the phenomena have ended obscurely the time of 20% of maximum smoothed flux is written. Outstanding emissions are classified as follows: On another point of view, the classification in the URSI Interchange D : distinct from (i.e. apparently superposed upon) the general //
b.
activity M : multiple peaks separated by relatively long period of quietness F : multiple peaks separated by relatively short period of quietness E : sudden commencement or rise of activity Combined letters express one phenomenon (e.g. SD, ECD); letters joined by + express some phenomena occurring in parallel; the preceding term is more important (e.g. SD+F, SA+C). Maximum intensity Instantaneous : Smoothed : The highest value above the base level. By multiplying the duration, the approximate total power of the phenomenon con be estimated.
C.  RADIO PROPAGATION CONDITIONS
a.
Radio Propagation Quality Figures
Radio propagation quality figures are usually expressed on the scale that ranges from one to five as follows : 1 = good 2= normal 3=rather poor (unstable) 4=poor (disturbed) 5= very poor (very disturbed) The tabulated circuits contain WWV (frequencies 10, 15, 20 Mc broadcast from Washington, D.C.), San Francisco (commercial circuit) and WWVH (frequencies 10, 15 Mc broadcast from Hawaii), which are received at Hiraiso Radio Wave Observa- tory near Tokyo. Warnings of radio propagation broadcast from JJY station are expressed in three grades: N = normal U = unstable W = disturbed The letter W expresses disturbed condition expected to be during the following 12 hours after issue. The letter U and N means also unstable or normal conditions, respectively. Whole day radio quality indices are the weighted averages of the 6-hourly indices of WWV and S.F., with half weight given to quality grade 2 (normal). This procedure is taken to avoid the concentration of the whole day indices to grade 2. Start- and end-time of principal geomagnetic storms closely correlated to radio propagation conditions are tabulated from observations at Kakioka.
Sudden Ionospheric Disturbances (S. I. D.)
b.
The data of short wave fade out (SWF) are preparated from the field intensity records on following circuits received at Hiraiso. Characteristics of the phenomenon are classified as follows. 6 Circuits and Drop-out intensity W S .....WWV 20 Mc, 15 Mc and 10 Mc (Washington) S F ......WNA-27: 7.6550 Mc, WND-20: 10.4925 Mc, WNC-93: 13.7525 Mc, WMJ-30A2: 20.8173 Mc (San Francisco) H A ...... WWVH 15 Mc and 10 Mc (Hawaii) T O ......JJY 15 Mc and 10 Mc (Tokyo) M N .....DZM-28 : 14.5850 Mc (Manila) L N ......GIJ-34 : 14.6702 Mc (London) Start-time and Duration, Types and Importances are described from the data of a circuit whose Drop-out Intensity is underlined. Drop-out Intensities of 10 Mc, 15 Mc and 20 Mc for WWV, WWVH and JJY are marked; 10 Mc ( ' ), 15 Mc (none) and 20 Mc ( '' ). Start-times and Durations Types : sudden drop-out and gradual recoverly S slow drop out taking 5 to 15 minutes and gradual recoverly Slow : gradual disturbances; fade irregular in both drop out and recoverly ..یImportances Degrees of SWF are classified into 9 grades according to the amplitude of fade-out ;
The data of sudden enhancement of atmospheric (SEA) observed on 28 kc are tabulated on each Start-time, Duration and Importance. Besidcs, the time associated phenomena of SID's, that is, solar flare, solar radio , noise outburst and crochet (solar flare effect in magnetic record) are given in this table from interchange messages or measurements at Hiraiso.
Wakkana Long, 141°41.1'B Lat.    45°213,6'1 foF2 135° E   Mean   Time     ( G.M.T.+ 9h.)
Mar.1960 Sveep _Lo__ Nc to _20-Z. Mc in __/_ foF2 g NOSPHERIC DATA Vakkana Lat.

ONOSPHERIC DATA
Wakkanai Lat.     4 5° 2 3, 6' N Long. 141°41.1'E foE 135° E   Mean   Time     ( G.M.T.+ 9h.)
Mar.1960 NOSPHERIC fakkana at.    45°2 3.6' ong. 141° 41.1
foEs ONOSPHERIC , DATA Wakkanai Lat.     45°23.6' N Long, 141°41,1'E
s 13
Time GMT+ 9h. 35° E   Mean 45° 2 3.6' ong. 141°41.1'
-min Mar.1960 Sveep _
Wakkana Lat.      4 5° 2 3.6° N Long. 141°41.1'E Mar.1960 13000F2 135° E   Mean   Time     ( G.M.T.+ 9h.)
W NOSPHERIC   DATA I GMT.+ 9h. Vakkana Long. 141° 41.1'E M3000F1 35° E   Mean   Time   -
Mar.1960 DNOSPHERIC DATA Wakkanai 135° E   Mean   Time     ( G.M.T.+ 9h.) h’F2 Mar.1960
Lat. Long. 141°41.1'B 17 long。 141° 41.1' Lat. 3.3.5°2 3.6'
h'F
NOSPHERIC
Time 35° E   Mean i GMT+ 9h
akkana
Mar.1960 h'F in automatic operat min ep _t o _ Mc to 2e.7_ Mc in _ /__ NOSPHERIC DATA 35° E   Mean   Time     ( G.M.T.+ 9h. Nakkanai Lat.     45°2 3.6°N Long. 141°41.1' B k'Es Mar.1960
NOSPHERIC   DATA Wakkana Lat.
DNOSPHERIC DATA
DNOSPHERIC DATA A k i t a Lat. foFl Mar.1960 135° E   Mean   Time
ONOSPHERIC DATA
IOSPHERIC sist L&O_No to 200_No in_20 foEs in automatic opera 39° 43.5' 140° 08.2 E k i t : V
NOSPHERIC DATA
Akita Lat. Long, 140° 08.2 E 135° E   Mean   Time     ( G.M.T.+ 9h.) fbEs Mar.1960
OSPHERIC
ONOSPHERIC
A k i t a Lat. 39° 43.5' N Long。 140° 08.2'E 35° E   Mean   Time     ( G.M.T.+ 9h.)
Mar.1960 M3000F2 43000F2
DNOSPHERIC DATA ONOSPHERIC DATA
29 NOSPHERIC k i t ong. 39° 43.5° 140° 08.2'
IOSPHERIC k i t a 39° 43.5°
ONOSPHERIC DATA 135° E   Mean   Time     ( GM.T.+ 9h. Akita Lat.       39° 43.5° N
Long.     140° 03.2° N

ypes of Es Mar.1960 INOSPHERIC DATA 135° E   Mean   Time     ( G.M.T.+ 9h.) okubunji Tokyo Lat. 35°42,4' Long, 1 3 9 29, 3 1 foF2 Mar.1960
NOSPHERIC DATA 135° E   Mean   Time     ( GM.T.+ 9h.) okubunji Tokyo Lat.     3 5° 4 2.4' N
Long.  1 3 9° 29.3' E
foF1 Mar.1960 INOSPHERIC 35° E   Mean   Time ( GMT.+ 9h. okubunji Tokyo Long, 139° 29,3' Lat. 35°42.4'
foE Vlar.1960
Long. 139° 29.3 kubunji Toky IOSPHERIC DNOSPHERIC DATA lokubunji Tokyo Long. 1 3 9° 29.3' E Lat. 35°42.4' N fbEs 135° E   Mean   Time     ( G.M.T.+ 9h.) Mar.1960
at.ス19 F 2, 2012, 3012, kubunji Tok 18 16 15 [ 21] 2.2.0 2.1.0 14 G.M.T.+ 9h. 2.50し8.0 13 z:15 _z 40 Z ZO 3.103 2.403 2.503 2.103 2.403 2.703 2.703 2.003 2.153 2.00 12 1777
 1977 Time 2.25 2.41 11 Mean NOSPHERIC z o o  E z  8 0 E z  9 0 ] z-LI Z. LO 1 0 35° E 1, 30 2.15 7. 301 09 2.10 5 , 9 0 7. 20. 08 07 -min 06 l. 20. 05 50° 9 o 1. 2.0 04 03 02 s of 15.5.70 1.30 90", 3051,900 , 300
,100 , 30 Mar.1960 0 1 00 B Day l 2 5 1.91 1.0.0.1 ]. [ 0] [ ]. [ 0] [ ]. [ 0] 9
-min g
ONOSPHERIC DATA
( G.M.T.+ 9h.) 135° E  Mean  Time M3000F2 Mar.1960 Long. 139° 29.3' E Lat
3 5° 4 2, 4' 1
Sweep L f__ Mo to_Zf_ Mo in_Zf_ (M30C0)F2 DNOSPHERIC DATA okubunji Tokyo
Long. 1 3 9° 29.3' E ONOSPHERIC DATA okubunji Tokyo Lat.     3 5 ° 4 2 , 4 ′  N Long. 139° 29.3' E k’F2 135° E   Mean   Time     ( G.M.T.+ 9h.) Mar.1960
41
ong. 139° 29.3' lat.     3 5° 4 2.4' GMT+ 9h. Time Mean 35° Eية
skubunji Toky h'F Mar.1960 NOSPHERIC Lat. = 35° 42.4° 1 skubunji Tokyo Long, 139° 29,3' E 35° E   Mean   Time LES Mar.1960
INOSPHERIC DATA okubunji Tokyo Lat.     3 5° 4 2.4° 1.
okubunji Tokyo Lat. 35°42.4' Long. 139° 29.3' E ( GMT.+ 9h.) 135° E  Mean  Time hpF2 Mar.1960
KL hpF2
ypF2 NOSPHERIC okubunji Toky Long, 139° 29,3 Late 3.5°4.2,4' ypF2
135° E   Mean   Time   - ( G.M.T.+ 9h.) K a m a g a w : Lat. 3 1° 12, 5' 1 Long. 130° 37.7' E foF2 Mar.1960
NOSPHERIC DATA Yamagawa Lat.     3 1° 1 2. 6° N
Long.    1 3 0° 37.7° B
.
NOSPHERIC - DATA
amagawa Lat. 31° 12.5' b Long. 130°37.7'B
NOSPHERIC a m a g a w 31° 12.5' Cong. 1730° 37.7'

NOSPHERIC DATA
Yamagawa Lat.     31° 12. 6' N Long. 130°37.7' B fbEs 135° E   Mean   Time     ( G.M.T.+ 9h.) Mar.1960
-min 35° E
Mean Time ( GMT,+ 9H 3 1° 1 2. 8° ong. 1 3 0 ° 37. 7 '
Mar.1960 min
t a m a g a w Lat. 31° 12, 5' N Long, 130°37,7'B 23 Mar.1960 Day M3000F2 135° E   Mean   Time      ( G.M.T.+ 9h.)
M3000F2 ONOSPHERIC   DATA .
ONOSPHERIC DATA
ة
NOSPHERIC
( GMT.+ 9H
a m a g a w
31° 12. ong. 130°37. Var.1960 Time Mean
abou ap 1.0   No to 20.3  Ho in 30. in automatic operat s  INOSPHERIC DATA t a m a g a w a Lat.   81°12,5'N Long. 130° S7.7' B h'Es 135° E   Mean   Time     ( G.M.T.+ 9h.) Mar.1960
h'Es DAT ONOSPHERIC I GMT.+ 9h. amagaw Lat.
Types of Es Mar.1960
Flux in 1C-22 v.m.-2 (c/s)-1, 2 polarizations
RADIO PROPAGATION QUALITY FIGURES = day of Special World Interval X ( ) = inaccurate = continuing magnetic storm DDEN IONOSPHERIC DISTURBAN (S.I.D.)
HIRAISO lime in U.T. 7 1994 Long, 39° 35.4' E
63 OVISIONAL IONOSPHERIC