INTERNATIONALURSIGRAM

AND

WORLD

DAYS

SERVICE

IUWDS

Synoptic Codesfor

Solar and Geophysical Data

Third Revised Edition
1973

IUWDS
The International
Ursigram and World Days Service (IUWDS)
is a Permanent Service of the International
Union of Radio Sci‑
ence (URSI) in association with the International
Astronomical
Union (IAU) and the International
Union of Geodesy and Geophy‑
sics (IUGG). The
IUWDS, as now constituted, was formed in 1962
as a combinationof the former International
World Days Service,
which had been initiated in 1959 to continue many aspects of the
IGY World Days program, and the former URSI Central Committee on
Ursigrams which represented
rapid data interchange activities
first begun about 1930.
The IUWDS Steering Committee comprises representativesofthe interested
ICSU scientific unions, as well as some regional
representatives
and liaison with other interested organizations
like the World MeteorologicalOrganization(WMO). The
Committee
gives recognition
to certain national institutions
for playing
internationalroles ― Regional Warning Centers, Associate Re‑
gional Warning Centers, and the World Warning Agency. It also
maintains a list of National Warning Contacts (NWC), who help
coordinate activities at a national level. The
Steering Commit‑
tee meets almost every year, and minutes or summaries of thesemeetings appear in the URSI Information
Bulletin. The
officers
and other leading participants
are continuallyactive by corres‑
pondence and informal meetings. The
IUWDS program is explained
and coordinatedthrough the issuance of program documents, thecode booklet, notices in STP Notes and other information bulle‑
tins of ICSU groups, through items like the InternationalGeo‑physical Calendar printed in the technical literature and sepa‑
rately, and through mimeographed"RWC Circulars" issued direct‑
ly to RWCs and NWCs. Sincemuch of the work is done by scien‑tists who are supported from national sources or is done in co‑operation with other groups, the cost of the activity to inter‑national funds is quite small. The
IUWDS does receive a small
allotment through the Federation of Astronomicaland Geophysical
Services from UNESCO sources for printing, travel and office ex‑penses which cannot be covered otherwise.
The IUWDS works very closely with other ICSU organizations
involved in international
cooperationin astronomical,
geophy‑sical and space sciences. In fact there is no sharp line be‑ ,tween the IUWDS "program" and those arranged through other 'groups. The
IUWDS attempts to respond to the needs of the sci‑
entific community, whether these are expressed formally or in‑formally. ThusIUWDS leaders participate
in the work or meet‑ings of the URSI, IAU, IUGG (particularly
IAGA and IAMAP), IUPAP(Cosmic Ray Commission), COSPAR, SCOSTEP, CCIR, WMO, SPARMO, SCAR,
and formerly in the IGY, CIG and IQSY activities. Also
there isno sharp line between IUWDS work and the activitiesof the STPWorld Data Centers. The
data handled in the IUWDS‑sponsoredactivities also go to the World Data Centers; the institutions(continued

on back

cover)LISTRWC NUMBEROF

AMMENDMENTSDATEPOSTEDPAGES

CHANGED/ADDEDPAGEPART

E ‑ REPORTING

CODES

FOR

SATELLITEDATA 149

X‑ray (USOXO Code)
Solar Particles (UPART Code)
Solar Wind fTTSOT,W PnHpl
PART F ‑ REPORTING
t l Pritipal

II.1

SuddenTTT.lAhsorotionPART

G ‑ REPORTING

CODES

FOR IONOSPHERIC

Prpniipnr.ifis

Ionospheric(UFOFO/UFOFD/UMUFD
Codes) 158

DisturbanceObservations
CODES

FOR

DATA 157(UABSEOTHER(USIDSGEOPHYSICAL

1.1 Geomagnetic(UMAGE Code) 166
II.1 Aurora
1 (UAURE Code) 168
III.l Cosmic
Rays (UCOSE Code) lPART

H ‑ REGIONAL

AND/OR

SPECIALIZED

Moscow Codes 174
Paris Codes 176
111.1 Boulder
Codes 177
111.2 TENCM 178
SPATS 179
PIONR 180
111.5 DALAS 181
111.6 SPDSP 184
111.7 EVENT 185
111.8 USRAS 186
IV.1 Sydney
Codes 188
V.1 Tokvo
Codes 189
Other Snecialized/Resiona
VII.1 FORDA" 192
VTI.2 FORWE 194
VI 1.3 AD 196
VI 1.4 PROPO 197
VII.5 PQA
― 199

Code) 160

Code) 162
DATA 165

70
CODES 173

1 Codes 190

INTRODUCTION

Alan ShapleyThis booklet is a tangible document ona remarkable
activity in science, in international
cooperation,and ina kind of practical service
which is important now andwill be even more important in the future.
The
short‑timeexchange of current observationsof the solar‑terrestrial
environment, the "Ursigrams", is basicallyvoluntary on thepart of scientists
and scientificand technical groups
throughout the world. And
it has beenplanned and is coor‑dinated by an inconspicuous
but effective
arm of the non‑governmental scientific organizations,the International
Ursigram and World Days Service. This
Code Booklet
servesseveral purposes: itgives the key to the messages sent
daily or more often; it gives the basic informationon thecommunication arrangements;
and it contains short articles
on the reasons for the data interchange
and examples of
how the data are used. In
thevities and expenses have to be present era where all acti‑
justified both tooneself and to those who providecarefully
budgets, it is both con‑structive and necessary to consider in this way why we dowhat we do.
It is interesting
to old‑timers likemyself to con‑trast the present with the past. Perhaps
the present gen‑eration will be patient for a paragraph or two. The
first
Ursigram broadcast was from a long‑wave transmitteron theEiffel Tower on December 1, 1928, with data in plain lan‑
guage transmitted
in Morse
code ‑‑ "geophysique"and "astro‑
physique." Almost
all of us now are too young to have beeneven radio "hams" at that time, but I think we can imagine
the excitement of being able to tune in on the crackling
wireless set and find out today's
sunspot number today. I
first heard of Ursigram about 1943 and this from Watson
Davis, director of Science Service in Washington.
Until
World War II, he served as the focal point forcollecting
data from a few American institutions, by telephone oreven by mail, and for giving the information
to a nearby
radio station for broadcast in Morse code, I believe about
one day a week. The
data hardly looked likewhat we now
exchange, but as I recall they did include the sunspot num‑bers, some geomagnetic indices (the K‑index had not yet
come into use), and much dataon the height of the Kennelly‑
Heaviside layer at various probing frequencies
and times.
Davis also mimeographed
the messages in code form and sent
them by mail to a small list of cooperatorsin the U.S. andabroad, in case some of them missed the radio broadcast.
When this work
new era. Ionospheric

resumed in 1945, we were already in aor radio propagation
forecastingcen‑ters had sprung up in several countries and the observing
techniques had become much more advanced. However,we werefaced with a dilemma ‑‑ in many countries there was notenough time or man power to monitor regularly the short‑wave― but we didradio broadcasts which carried Ursigrams
telegrams. The
not haveenough
money
to
pay
for
overseas
U.S. did not resume broadcasts after the war but used themodern tool of "air mail" and began to seek the cooperationof the telecommunication
organizations
who in principle
ben‑efitted from the ionosphericforecasts to carry our short
Ursigrams
it was not until
as "service"messages. In
fact,
after the IGY
that telecommunications
arrangementsfor Ursi‑
gram types of messages began to be formalized either as "payarrangements
wit
as
you go" oras rather definite
reciprocalfor international
governmentorganizations.
Themechanism
coordinationof the data interchange
evolved painfully inthe late 1940's and early 1950Ts. One
problem was how toaccommodate the desires of research scientists and at thesame time those of the forecastingorganizations
whose prod‑
ucts,
both the re‑than andthe detailed
servedsearch rather
scientists
practical data,
telecommunications.
The
research scientists tended to want the codes and messages
to be in exhaustive
neededdetail while the forecasters
dependably
andonly
selected
datatransmitted
economically,
will notrapidly, with details to follow by air mail. I
dwell on this evolutionary
process ‑‑ it is covered in the
1963 URSI Jubilee Volume by Col. E. Herbays, who along with
Father P. Lejay were the most prominent bridges from theUrsigram service of the 1930Ts to that of the early 1950's.
I more nearly
represented
the approach of the forecastingfor "World
groups, and particularlyindesigning had
the planDays
to try to merge
andCommunications"
for
the
IGY,
the twoviewpoints.
We
still havethese same supplemented
viewpoints,
but I think
the present
schemeis compatible,
as it is by many data exchanges by air mail for those whoneed prompt but not quick or "real‑time"
information onthedisturbanceparameters, ofparameters, particularly
thethe Sun‑Earth environment.
The evolution since the IGY has also been dramatic.
The teletypes,
the "hot" telephone lines, the direct telexconnections are a far cry even from IGY, when I once madea trip to Japan for the main purpose of convincing
author‑ities to install (without charge to we poor scientists) a
teletype line from downtown Tokyo to the Ursigram center
operated by Takiguchi at outlying Kokubunji. The
major
centers
and some work around
are
now
open
seven
days
a
week
the
and thedata include interplanetary
sectors
radioclock. The
There
are data fromspectral spacecraft
type of solar
instrumented
postedbursts.
at key locations in the solar
system toto the earth. There
monitor disturbancessolar
en routeisflares in quick‑timefromnear observatories.
24‑hour coveragegroundIt ofhas been 15 years since I stood ashift as an alerter or a forecaster, and I doubt if I could
still cope, though I have noticed some of the methods intro‑
duced in the 1940fs and 1950's are still in use. In
fact, I
believe the modern warning center staffs have rediscovered
many of our old techniques, with a much sounder basis in thephysics of solar‑terrestria1
relationships.
Enough of contrasting
the past with the present. It
isthe future that matters, and the future is in good hands with
Dr. P. Simon and the modern interunion and interdisciplinary
IUWDS. I am still convincedthat still more huge steps are
before us. At
some time, whether
before the year 2000 orafter, there will be a ful1‑flowered"Weather Service for
the Space Environment"in several countries, tied together
by a world organizationof space environment
services. We
will not be struggling along on an ad hoc basis as now, we
will be recognized
as a needed, bona fide activity both forpractical space activities, manned and unmanned, and for in‑creasing complex scientific experiments
and explorations.
Whether the disturbanceson the sun and in the space environ‑ment will become recognizedas significant
factors influenc‑
ing or predicting conditionsat or near the surface of theearth is not yet settled, but recent studies are more andmore pointing in that direction.
Thus, I am confident that the rapid solar‑terrestrial
data interchangesponsored by IUWDS has much more room inwhich to evolve, and it will do so in partnershipwith theMONSEE program and the exchange of definitive and detailed
data through the World Data Centers. Fromthe present solid
foundation with the continued cooperationof observers, warn‑
ing centers, telecommunicators,
institutions
and authorities
in all countries, there is a future of increasing relevanceto man's affairs and increasing satisfactionof contributing
to a better and more exciting world for all of us.

A. H. Shapley
Former Chairman
IUWDS Steering
July

1973

Committ

PART

A.

I

GENERALINFORMATION

The purposeof this section
is to describe
the con‑tents of this booklet.
The
first portion(PARTA) con‑tains information
on Forecasting
Techniques,
Proceduresand Limitations,on acceptedrules of data interchange
between
RWC's
and within
an RWC area, andlists the coop‑erating
observatories,
the
RWC's, the ARWCTs,
and the NWCTThe following sections of the booklet (PARTS B
through H) contain current code forms used by the IUWDS
to interchange
data. There
are very few changes from thecode forms shown in the previous edition of the Code book‑let (1969 Edition); however, there has been an effort tosimplify and reduce the number of codes while at the sametime enlarging the print size.
The booklet
has been printed
on the assumptionthat
future changes
will come in the form of individual
pages
to replace
existing
pages, (orto be added)
therebyeli‑
minating
the issuanceof a new edition.
If
this assump‑tion is valid,
one may anticipate
that certain
sections
will have pages that will be numberedwith sub lettersaspage 46 C, 46 D, 46 E, as a particularsectionexpands
beyondthe spaceoriginally
allotedto it.

We recommend that one person be assigned the respon‑
sibility for maintenance of this booklet as special caremust be taken to insure it is correct. We
will issue allchanges of this booklet via an RWC letter and we will is‑sue annually (on 1 January) an RWC letter which will list
all changes issued during the previous 12 months. All
pages of this booklet are identified (upper right handcorner) with the date of the appropriate
RWC letter.
We sincerely
believe
this editionof the booklet
tobe an improvement
over previous
editions,
but we makenoclaim for perfection.
Infact, we are reasonably
certainthat despite
our best intentions,
there
are errors.
We
would appreciate
your comments,
criticisms,
andsugges‑tions for improvement.
Hopefully
these
can be introduced
and implemented
on a timely
basis.
R. B. Doeker
Secretaryfor

Ursigrams

PART

A.II

Some Commentson the Forecasting
P. Simon

The indicesof solar‑ IUWDSof Solar

Activity

Secretaryactivity

Several indices may be used in order to forecast the solar
activity: theWolf number, the 10 cm flux, the flare index
and so on... They
are given in the form of numbers easy touse for an estimate of a correlative
function or any othercomputation. They
appear like a very simple expressionofthe activity, something
like "high temperature
in case ofi 1 lness".
But after thorough observationof their physical content it
is obvious that they combine several elements together, which
are very different on the grounds of solar activity. In
theWolf number several tiny spots may possibly have the same
weight as one very complex group of spots whereas that one
group may possibly be the one to produce
an outstanding
ilare. (M.
J. MARTRES
et al. 1966). The
10 cm flux comesfrom several active centers with definite different spectrain the centimetricrange, but the slope of that spectrum isconnected with the outstanding
events in a specific sort ofway. (H. TANAKA et al. 1964). The
same kind of criticism
may be raised against any global index of solar activity:
none of ihese indices can be of significant
use for the fore‑
Distribution

of

the

flare

activity

amongst

the

solar

centers

For many years
now solar observers
have had the feelingthatsome active
centersare very eruptive
when others
are veryquiet. Thisis a point
easy tocheck:
tryingto summarize
the Quarterly
Bulletinon Solar
Activity,withthe help ofsome catalogues
such as the Meudon
catalogue
about active
centers,
it is easy to noticethat 20% of them give 80% of
the flares.
We
concludethat we have to identify
the erup‑
tive centersin orderto forecast
the solar
activity.
The eruptive

centers

It has been known for many years now that the Mt. Wilson
magnetic classificationof the spot groups is an index of
the flare activity, (R. G. GIOVANELLI,
1939): theGammaclass with both polarities
irregularly
distributed
amongstthe spots is the most active class. But,
besidesthe spots
there is a noticeable
surrounding
magnetic field, and it is
not possible to describe the complexity of a group only ac‑
cording to the polarity of its spots. (S. F. SMITH et al.

Another difficulty comes from the value of the data forthe groups situated near the solar limb at a meridian dis‑tance
more thethan solar
60‑70 radius°:the
angular slope of the line ofsight withmakes the results of the longi‑
tudinal component uncertain.
The last problem
written message.

consists

Radio and otherdata

in reportingthese features

in a

Other data happen to confirm these optical reports. The
first one is related to the size, brightness
and spectrumof the centimetric"spots". It has been
pointed out first(M. R. KUNDU, 1959) that a very narrow and bright spot isa good source for centimetricwith outstanding
flares. Later, outbursts
Japanese also associatedastronomers(H.
TANAKA et al., 1964) studied the centimetric
spectrum ofthese "spots": aflat spectrum in the range 7 cm to 3 cm
is a good index of this important flare activity. The
useof the brightness, spectrum
and flux obtained with a goodinterferometercan all together contributevery, valuably
to the solar activity forecast.
Another interesting report is the X‑ray data: inthe band40 to 60 A an increase of the flux is related to the erup‑tion of complex active centers on the surface of Jhe solar
disk, and the increase of the flux in the 1 to 8 A is re‑lated to the eruption of an outstanding
flare ere long.
(R. MICHARD et al. 1968). There
are practical problems
about that point, too. Mostof the flares are able to pro‑
duce a short enhancementof the X‑rays flux during theireruption. These
data are obtained by a satellite which
does not report the optical flaress
to now the X‑ray
data have only been registeredduringandtheup ten
minutes passof that satellite: one
must determine
the actual originof any reported enhancement.
According to the Pioneer experimentcarried out by the Chi‑cago group (R. Y. FAN et al. 1968) a continuous
proton fluxin the energy range 0.6‑13 MeV isreported from a few activ
centers. These
last centers produce flares with high energ
protons and fill an interplanetary
magnetic sector which ma
possibly have a 180 ° aperture. On
neutron monitors a small
decrease (J. P. LEGRAND, 1960) coincides with this flow of
low energy protons. The
report of low energy flux fromspace probe experiments and measurements
and from neutron
monitors may be used to identify theactivecenters thatmi rrIt+nr>nr1ii/‑>pnrntnn ‑FT o roc

the two spots of opposite polarity which constitute that
configuration, and it may be an index
of the next eruptionof a flare. The
other flares
related to radio events with‑out particles appear on a B configuration
with only one big
spot. The
importance of the magnetic field gradient has
been acknowledged
under the form of the ratio of the dis‑
tance between the spots to the spot's diameters. But
wemust notice that if on one hand most of the proton eventsand type IV bursts
occur on A, A' or B configurations,onanother hand many other flares which are reported on these
configurations
are not proton events nor type IV bursts.
These last events are related to the biggest flares.
At Boulder it has been noticed that a Delta configuration
plays an important part in the proton flare's appearance.
This configurationis the report of two spots of opposite
polarity in the same penumbra (C. S. WARWICK, 1966).
Another study has been carried out at Meudonwith the mate‑rial collected during the Cooperative
Studyof Solar Active
Regions (M. J. MARTRES
et al. 1968, a and b). It
is relatec
to the eruption of any flare during the life of several ac‑tive centers. In fact, most of these events are only sub‑flares. For
that work use has been made of the sunspot dat ￡with identificationof their magnetic polarities, in orderto specify the most important variationsof the magnetic
field. According
to that work any flare can occur when two
spots of opposite polarity are very near each other, andeach one evolves the opposite way, that is, the one increas‑ing, the other decreasing
in terms of total flux or field
intensity. This
relation between the eruption of a flareand this evolution has been checked in both ways: startingfrom the eruption of the flare or from the evolution of themagnetic features. Now
it has been confirmed from magnetic
measurements related to an active center (E. RIBES, 1968).
Philosophyof thisforecast

These last results allow one to accept two conclusions.
First, only a small number (one or two pairs) of the magnet‑
ic units or features of an active center (or of two active
centers close to each other) may be concerned with a flare.
The second point is that the conjunctionof two circumstancesis necessary for a flare to be observed. These
are that mag‑netic
featuresof opposite polarity exist close to each other,and thenthe flare
only occurs when they evolve the opposite
way. The
first conclusionemphasizes the need for detailed
reports of the complex magnetic features. Global
reports suchas the Zurich or the Mt. Wilsonclassifications
are useful but
not sufficient for this kind of task. In
order to forecast
the place of the flare and its importancethe reported mate‑rial must describe any active configuration
as well as its
size and distance to allow an estimate of the gradient value
and magnetic flux balance. In
thesame way the forecast
must try to include the birth and evolution of any of thesesmall areas which are, in fact, the most important places.

Happily the outstanding
eventsto large active configurations
The
secondconclusionof anyforecast:theThe evolution

are most of the timeeasy to report.

the most difficult
emphasizes
way
the evolution goes.

relatedpoint

forecast

The
first consists
Severaldata
may be taken into account.
in theflare
is connected
with
same
flare
activity.
Ifathefeatures,theeruptionof thatevolutionof the magnetic
flare is the best sign of the right evolutionof thesefea‑
as any in‑tures. The
radio bursts,
X‑ray
bursts,as welldirect reportconcerninga flare(such
as its ionosphericeffect)areto have the opticaluseful,but it is necessary
activecenters,data
at one'sknow difficult
the associatedand these
last disposal
data are toquite
to obtain
on a con‑tinuousbasis.
To
obtainthem implies
a networkof observa‑
toriesgood connections
andall cooperating
togetherwithgood observers.
Using
the occurrence
rate of the flares,
(V.
BUMBA
et
it is
possible
activityal. 1968).
But, to inforecast
fact, ittheis coming
necessary
to use othersigns
showing
the flare activity
at the same time because
the sur‑vey
after
the eruptionof sever‑
of
a
flare
can
only
be
used
al flares
forecastof those
firstand it is of no use for thefla res.

Another possible means consists in studying the evolution ofthehard problem. Thereareactive centers. Thisis a very the evolution of the ac‑plentyofstatistics
concerned
with
tive
but
centers according to the Zurich classification,
this does
has been taken at
not
help
much.
A
first
step
Meudonactive center be‑
related to the birth of a bipolar (M.
J. MARTRES,
sideorinsideaprevious
activecenter.
1968). Dependingon the stage of evolution of the firstcenterrules can be es‑
and the position of the new one sometablished,
forecast the evolu‑
which
give
an
opportunity
totion of both groups. The
aspect is that theremnant
magnetic structures fundamental
existing at a center's birth‑place
evolution ofor nearby are an important factor in theflares is relatedthenewcenter.
Thelargestproductionofto thecenters very near one
birthof several approach, but it looks
another.simultaneousThis
is onlya preliminary
full of promise. Still,there is a problem about the circu‑
lationthat might be suitable
of
the
solar
data
a form is a satisfactory
for that kind of forecast. in Therestart
and improvements
are expected before long.
Protonevents,All these

geomagnetic

geophysicalstorms,eventsetc.

are concerned

withsolar activ‑

ity, and as reported above, the flares and active centers
have been studied in connection with these geophysicalevents. In
some ways the forecast of a flare might be apreliminary warning of a geophysicalevent. The
report ofan A configuration
as well as the forecast of the right evo‑lution results in the forecast of proton events. It is the
only valuable forecast concerningthat event. SID
can beforecast in the same way.
About geomagnetic
storms there is still another possibility
related to the travel time of the shock wave between the sun
and the earth. According
to the reported radio emission of
the flare, and to the previous geomagnetic
activity, one canevaluate the speed of propagationand predict the time of
the arrival (C. CAROUBALOS,
1964 ‑ T. OBAYASHI, 1962).
There is also a delay between the occurrence of the proton
event on the sun and its arrival on the earth. It
may beshorter than 20 minutes, but it can last a few hours or
more. According
to the centimetricflux (M. PICK, 1961),
it is possible to forecast the arrival of the protons, but
it is hard because of the short delay and the problem of
the reception of the data on a real time basis.
Limitationsof the forecasts

The limitations
come from many different circumstances.
First of all the value of the available material may change
from day to day, and it unfortunately
happens that on somedays no material or reports are available. Anotherpoint
is related to the same solar activity. Manyof its aspects
escape any form of available forecast. For
instance we havenot been able to predict the birthplaceand date of appear‑
ance of any new center up to now. Some
events are unusual,
such as the proton events of January 28, 1967. They
also
escape being forecast. Howlong in advance could a forecast
be issued? One
point is the rotation of the sun. But
themost critical point is the speed of the evolution of the ac‑tive centers. The
quicker they grow, the more flares they
produce. As
a consequence
the longest reasonable
delay isabout two days. This
limitation
comes from the possible un‑
expected birth of new centers.
The new codes
It is impossible
to obtain the data which are required forthe forecast within the limits of one observatory only. Fromthe mere point of view of the group's evolution a lot of in‑formation is required, (such as flare appearances and so on...)from different observatories
situated at different longitudes.
At the present time some data can only be obtained by a sin‑gle observatory
in the whole world (radio location at differ‑ent frequencies).

Still, bad weather sometimes prevents one from making obser‑
vations. Thenan exchange of data through encoded messages
is required and sometimes difficult. But
all things consid‑
ered, it is the easiest way since it eliminates
the diffi‑
culty of the difference of languages, and is the most secure
as far as it states very clearly the nature of the data to
be given. Further,each group of observers only sends one
or two different classes of data, and the codes rapidly growfamiliar. On
the other hand, changes introducedin the codes
are always difficult, because it is hard to change habits.
However, as far as the codes are concerned the scientificprogress must be taken into account to make the data really
useful. These
are the reasons which induced us to discuss
the problem.
We
especially tried to constitute a biblio‑
graphy as complete as possible to allow the observers to
improve their documentation,and to justify the eventualchanges and introduction of new elements in the codes.
Conclusion
The first aim of the forecast of solar activity and geophy‑sical disturbances
was to improve the effectivenessof radiotelecommunications
by way of the ionosphere, and despite theintroductionof relay satellites
and the perfectingof alter‑native techniques of telecommunications
on the earth, theproblem has not much changed. Asa matter of fact the traf‑
fic grows more rapidly than the facilities, and the newtechniques allow wider and consequently
more difficult trans‑missions and connections. But
since the birth of the spaceresearchand thedisposal,
new technicalplacedat theexperimenter's
these possibilities
forecasts became
an essential
element for many of the very ticklish space experiments.
Finally, the manned satellites and space probes, as well as
the commercial
supersonic flights, raise the problem of thepreservationof the human life or health acutely. This
does
explain the increasing
interest taken in the study of solar
activity and in all the techniques which allow a prompt
reduction of the data in view of immediate use. Of
course,all this implies new hard problems for the observatories
where the systematic observations
and research programs exist,
competitively.
It also states the problem to those involvedin forecasting
and related work: mustthe forecast activity
be the job of technicians or must it be part of the work ofa research group? Fromthe scientific point of view the
problem concerningsolar activity is not yet on a level where
the definitive question consists in determining
a quantity ora temperature.
It
is a matter of evolutive phenomena, andthe rules governing such an evolution are still to be learned.
They are the key for the forecast.
To dedicate a few moments daily to participating
in somepart of the total forecasting
activity is tantamount tocollating the previous knowledge with the concrete reality.

Clearly, this is a good stimulus forresearch on the basisof increasing
knowledge as well as obtainingof a few more
bits of data. On
another hand someexperimentersstatevery difficult questions to the forecasting
centers. They
are glad to submit them toscientists well informed onthese problems.
Finally, we must admit that the forecast
solar activity
more than any other activity must be the ofresult of inter‑national cooperation:
cooperationon the grounds of ob‑
taining the data, of thefor the best profit of theelaboration of the methods, andusers. Thisemphasizes
the part
which may be played inview of such a cooperation by theInternational
Ursigram and World Days Service, as far as
it is the necessary basis for thecooperationand makes it
possibleand makeeasy.its
The
1966 Proton Flare Project was anoccasion to
on a world‑wide
scale quite
apparent. Let
us hopeefficacy
that thisservice will confirm
these possibilities
on the groundsof the various projects
accepted by the Inter‑Union
Commission
on Solar‑Terrestrial
ics for the coming‑ vears

P. SIMON

Meudon, November

28, 1968

BIBLIOGRAPHY

AVIGNON, Y., MARTRES, M. J., and M. PICK, Identificationde classes d'eruptions chromospheriques
associees aux
emissions de rayons cosmiques et a l'activite
radio‑
electrique, Ann. Astro. 27̲, 23‑28, 1964.
BUMBA, V., KRIVSKY, L., MARTRES, M. J., and I. SORU‑ISCOVICI,
Flare activity and spot groups development, n ° 35 IAU
Symposium, 311‑317, 1968.
CAROUBALOS, C., Contribution
a 1'etude de l'activite' solaire
en relation avec ses effets geophysiques, Ann. Astro.
27, 333‑338, 1964.
FAN, C. Y., PICK, M., PYLE, R., SIMPSON, J. A., and D. R.
SMITH, Protons associatedwith centers of solar activity
and their propagation
in interplanetary
magnetic fieldregions co‑rotatingwith the sun, J.G.R. 73, 1555‑1582,
1968.
GIOVANELLI, R. G., The relations between
spots, Ap. J. 89, 555‑567, 1939.

eruptions

and

sun‑

GOPASIUK, S. I., OGIR, M. B., SEVERNY, A. B., and E. F.
SHAPOSHNIKOVA, The structure of magnetic fields andits variation in flare regions, Izv. Krym. Astrofiz.
Obs. 29, 15‑67, 1963.
HAURWITZ, M. W., Solar longitude distributionsof protonflares, meter bursts and sunspots, Ap. J. 151, 351‑
364, 1968.
KUNDU, M. R., Structureset proprietes
solaire sur ondes centimetriques,1959.

des sources d'activite
Ann. Astr. 2^2, 1‑100,

LEGRAND, J. P., Les prebaisses de rayons cosmiquesde maximum de l'activite solaire, Ann. Geoph.
1960.

en period^
Ij5, 140‑14^

MARTRES, M. J., MICHARD, R., and I. SORU‑ISCOVICI,
Etude
morphologiquede la structure magnetiquedes regions
actives en relation avec les phenomenes chromospheriques
et les eruptions solaires, Ann. Astr. 29>, 245‑253, 1966.
MARTRES, M. J., Origine des regions solaires actives
males", n ° 35 IAU Symposium 25‑32, 1968.

"anor‑MARTRES, M. J., MICHARD, R., SORU‑ISCOVICI,
I. and T. TSAP,
A study of the localizationof the flares in selectedactive regions,n ° 35 IAU Symposium

318‑325, 1968a.

MARTRES, M. J., RICHARD, R., SORU‑ISCOVICI,I., and T, TSAP,
Structure evolutive magnetique des regions actives
solaires, Solar Physics 5, 187‑206, 1968b.
MICHARD, R., and E. RIBES, La composantelentement variable
des rayons X solaires en relation avec la structure
des centres d'activite, n ° 35 IAU Symposium, 420‑430,
1968.
MORETON, G. E. and A. B. SEVERNY, Magnetic fields and flaresin the region CMP 20 September 1963, Solar Physics 3^,
282‑297, 1968.
OBAYASHI, T., Propagationof solar corpuscules
and inter‑
planetary magnetic fields, J.G.R. 657, 1717‑1729,
1962.
OGIR, M. B., Some peculiaritiesof the origin and motion of
the flares accompanied
by type IV bursts, Izv. Krim.
Astrofiz. Obs. 37, 94‑104, 1967.
PICK, M., Evolution
des emissions radioelectriques
solairesde type IV et leur relation avec d'autres phenomenes
solaires et geophysiques,Ann. Astr. 2̲4, 183‑210, 1961.
RIBES, E., Private

communication,

1968.

SMITH, S. F., and R. HOWARD, Magnetic classification
tive regions, n ° 35 IAU Symposium 33‑42, 1968.
SVESTKA, Z., Motions in chromosphericflares,Inst. Czechoslovakia
JL3, 190‑198, 1962.

Bull.

of ac‑Astr.

TANAKA, H. and T. KAKINUMA, The relation between the spec‑
trum of slowly component of solar radio emission andsolar proton event, Rep. Ion. Space Res. Japan ̲18, 32‑
41, 1964.
WARWICK, C. S., Sunspot configurations
J. 145. 215‑223. 1966.

and proton

flares,Ap

PART A.III. Radio

Propagation

Forecasting

The quality of radio
communication
between points on
the globe was the major factor
the initial developmentof the IUWDS data exchange and in
prediction service. Throug
the years, the need forof radio propagation
conditions has varied. Inpredictions
some nations, the need is great
er now than before,
while in other nations the need has de‑creased. Generalstatementsof CCIR regarding Ionosphericand Radio Propagation Prediction
are given in III.l; state‑ments of a few RWCfs are given in the remainder of the sec‑the occurrenceof a flare of importance3
or 4 (very great) regardlessof its posi‑tion on the Sun. The
probabilityof dis‑turbance is greater if the flare occurs in
the Sun's central zone. According
to Bell[l963] nearly half of the major flares fol‑
lowed by geomagnetic
disturbanceswere lo‑cated within 30 ° of the central meridian(CM). During
the past three sunspot cycles
in 80% of the very great storms flares wereobserved within 20 ° of CM and all but oneof the remainder between 20 ° and 39 °.Yo‑
sliida and Akasofu [l965] have shown that
this result applied especially to geomag‑
net storms corresponding
to flares accom‑
panied by emissions of oarticles. Again
according to Bell [l963] the very greatstorms correspondfor the most part toflares observed on the northern hemisphereof the Sun.
1.1.2

Radio

bursts

The radio burst associatedwith a so‑lar flare is another element for forecast‑ing geomagnetic
disturbances.
From
their
observations
made at frequencies
around200 MHz, Dodson and Hedeman [l958] were
the first to identify bursts followed bygeomagnetic storms. Sino
and Hakura[1958J have shown that the radio bursts
whose power spectra increase towards thelower frequencies(mainly in the VKF band)
tend to cause geomagnetic
storms, although
they have little relation to SIDs. When
studying type IV radio bursts, Pick [l96l]
recognized the importanceof the SHF bands
on which observations
are only very slight‑ly affected by the position of the flare on
the solar disc. Bell[l963] reported that,of 30 major flares accompanied
by full‑range(100 MHz to 2800 MHz) type IV bursts, 87%
were followed by magnetic storms within aninterval of 10 hours to 3 days. The
proba‑
bility falls off for type IV events of more
limited frequency range. Caroubalos[l9G4]
has shown that it was possible to forecast
the hour the geomagnetic
storm would startfrom the characteristics(duration, maximumflux) of the SHF burst.
Radio observations
to forecast solar proton

can also be used
events. Tanaka

and Kakinuma [l964] have shown that theratio of emission at 3 cm to emission at
10 cm is useful for predicting solar pro‑ton events. Castelli
and Aarons [l970]
have shown that radio bursts associatedwith proton‑producing
flares typicallyhave a characteristic
U‑shaped spectrum.
This spectral property along with somethreshold level (1000 flux units) forthe burst allows the short‑term forecast‑ing of solar proton events and the result‑ant polar cap absorption. SHF
radio burst
may also be used to identify solar proton
emissions. Croom[l971a, 1971b] has shownthat the time profiles of radio bursts ob‑
served on a fixed frequency, preferably
within the range 5 to 20 GHz, are related
to the intensity of the proton flux andmay be used to forecast the occurrence ofpolar cap absorption.
1.1.3

High

energyprotonemissions

(>20

MeV)

Polar cap absorption generally follows
an intense flare very rapidly (within 6hours); the phenomenon has been describedby Bailey [l964] who noted that, in 92% ofcases, geomagnetic
storms occurred in thethree days following the onset of the PCA
events.
It should be noted that the arrivalsof very high‑energy particles (GeV) on theneutron indicators are also generally fol‑
lowed by a sudden‑commencement
magneticstorm, and the same thing happens on thearrival of low‑energy
particles (of theorder of 1 MeV) observed by satellites
orspace probes [k. A. Anderson, 1969], but
the storm following these sudden disturb‑
ances of the magnetic field varies great‑ly from one event to another. Observa‑
tions by satellites, particularly
Explorer
34 and 41, have^ improved knowledge of pro‑ton emissions (start, evolution, spectrum).
It appears that only about half of them canbe associatedunambiguouslywith a solar
flare.
According to the energy of the parti‑
cles detected by the different techniques
one obtains lists of events which have on‑ly a few in common. In order to obtain co‑herence between these results, there has
been establisheda solar proton eventclassification
system [Smart and Shea, 197l].
This has been approved for international
adoption by the Inter‑Union
Commission
on
Solar‑Terrestrial
Physics and the Committeeon Space Research (COSPAR). The
system isbased on the solar proton flux in the vici‑
nity of the Earth at the time of maximum
intensity based upon (a) direct satellite
measurements; (b) riometer absorption meas‑
urements in the polar cap; and (c) the
counting‑rateof a high latitude cosmic‑ray
neutron monitor.
These arrivals of particles can be de‑tected by several techniques: scattering
on VHF circuits [Reid and Collins, 1959],
cosmic noise absorption, chiefly at highlatitudes [Reid and Leinbach, 1959], VLF
phase variation on circuits crossing thepolar cap [Lange‑Hesseand Rinnert, 1965],
measurement of the f‑min with conventionalsounders [Hakura et al., 1958], satellites
outside the magnetosphere,
etc. FromtheVLF measurements
Lange‑Hesseand Rinnert[1970] found a probabilityof 65% that astorm would occur with an average time de‑lay of 2 days after a PCA. They
predicted
recovery at a rate of about 4 dB per day
on frequencies
around 19 kHz. On
the otherhand, it is generally rather difficult to
identify the event rapidly for several rea‑sons:‑‑ there are many other causes of absorp‑
tion, particularlyin the neighborhoodof the auroral zone during the auroras(auroral X‑rays) or even in the polarcap during the arrival of relativistic
electrons;― PCA is a phenomenon
whosecoverage varies with time

geographical[Hakura, 1967];‑‑ there is a very marked night effect[Bailey, 1964] which makes observations
more difficult in a non‑lit zone.
It is a field where the rapid exchangeof data or even their automatic comparison
is essential for a rapid identificationofan event of medium or slight importance.

Satellites in geostationary
orbit, particu‑
larly ATS‑1, continuously
observe the arri‑vals of particles of solar origin and datafrom these satellites are readily accessi‑
ble. Furthermore,
every time they passabove the polar caps and auroral zones, thepolar satellites can provide direct infor‑
mation on the arrivals of particles (pro‑tons and electrons).
1.1.4

Solar

wind

[Wolfeet aj.. [1966] and Hundhausen1970] have found that monitoringof thesolar wind plasma properties(velocity,
density, temperature,and magnetic fieldmagnitude and direction) is required to de‑fine the state of the interplanetarymediumin which the Earth is immersed. Wilcox[1968] has indicated the importance of mag‑netic sector boundaries
to magnetic activi‑
ty, and Intriligator[l97l] has shown how
both solar wind temperature and stream‑
stream interactions‑with
sectors ‑ haveprofound influence on initiating
magnetic
activity. Impulsive
solar events (flares)
also produce shock waves (c.f. Dryer,[1968])which, in turn, cause sudden com‑mencements. Henceadvance warning of suchsolar wind disturbances by proper space‑
craft monitoring
will prove most useful inthe understanding
and prediction of magnetic
storms. The
passage of shock waves has been
observed by certain satellites [Van Allen
and Ness, 1967] but the possibilities
ofusing these observations
for forecasting
magnetic storms at present seem fairly li‑
mited as the correlation between the solar
wind speeds observed by several satellites
decreases very rapidly as they move awayfrom each other [Gosling, 197l]. The
solar
wind values are not associatedin a simple
way with either the Wolf number or the Kp
geomagnetic indices. A
certain relation
does seem to exist, however, between geo‑
magnetic activity and the fluctuationsofthe transverse component of the interplan‑etary magnetic field [Ballif et a^l.
, 1969].
The relationshipestablishedby Arnoldy[1971] between
the southward component of
the interplanetary
magnetic field and thestart (with an hour's delay) of a sub‑storm
in the auroral zone (according
to the AEIindexvalues)iswithout

real indicationthat
precursors
indicative

doubt

the

first

it is possibleof ionospheric

to finddis‑

Monitoring of the solar wind plasma ispresently being carried out at a low levelof tracking and data reduction by Pioneers
6, 7, 8 and 9 which are in heliocentricor‑
bit at approximately
1 AU. Other
Earth or‑biting spacecraft such as Vela, 0G0‑5, andATS are also monitoring
both the solar windplasma as well as the low energy solar cos‑
mic rays ejected by flares. Large
improve‑ments in real time reporting are still re‑quired before forecast centers can use suchinformationfor on‑the‑spot
predictions.
These data should then be published on ashort‑term basis (within 1‑6 month's delay)
for research purposes.
Forecastingof storms

associatedwithflaresThis is a fairly rare event (less than 20 per
year on the average between 1957 and 1963 accord‑
ing to data collected by Jonah and Dodson‑Prince￡l964‑1965]). Forecast
ing can be done at differ‑ent stages: withsolar activity forecasting
thecenters of activity liable to produce flares canbe determined
one or two days in advance; at the
moment this is a means of forecasting
PCAs and
SIDs. Aftera flare it is possible to tell whe‑ther a geomagnetic
storm is probable or not andforecast more or less accurately the moment of
its arrival ^Caroubalos, 1964]. Lastly,
it is
still possible to warn those concerned by the ion‑ospheric storm after the start of the geomagnetic
storm.
Solar activity forecastingis a complex opera‑tion which requires the rapid assembly of numerous
data and immediate distributionof forecasts andwarnings. It
is carried out in national centresof varying sizes working in collaboration
with eacother within the International
Ursigram and World
Days Service: mostof these centres are managed b;
local radio organizations(see Synoptic Codes for
Solar and Geophysical Data, 1973).
Forecasting methods have developed rapidly inthe last few years: thebasic data used are themagnetic fields of the solar activity centres, X‑
ray emissions, radio emissions mainly in the SHF

band, complete observationsof flares (Ha, bursts,
X‑rays, etc.), emissionsof particles of solar ori‑
gin, the level of cosmic radiation, and certain
ionosphericand geomagnetic
data. Some
recent ar‑
ticles [Simon ert aJL, 1969, Simon 1969, Fichtel and
McDonald, 1967, Severny and Steshenko, 1969] con‑tain a detailed descriptionof the scientific bases
and practical problems relating to this forecasting
and a fairly complete bibliography.
At present forecasts are issued daily, cover‑ing a period from one to three days. Solarphenom‑ena are classified
in several categories
dependingon their geophysical effects and an indicationisgiven of the probability of observing different
types of phenomenon
or even the points of the solar
disc on which these phenomena will be observed [Si‑mon, 1968]. Immediate
warnings are also issued
when an important solar event likely to cause a
geomagnetic storm has been observed.
This world organizationis also of interest to
research workers who need forecasts and warnings
for certain experiments or projects: thiscolla‑
boration has contributed
greatly to the forecast‑ing services by giving them quickly the benefit
of new scientificmethods and new measurements,
in particular
those obtained by satellites. The
Administration
concerned with radiocommunications
should encourage and develop this collaboration
to the extent where it will permit them to improve
the quality of their forecasts.
1.3 Ionosphericstormsoccurring

every 27 days

In the years approaching
sunspot mimimum 27‑
day recurrent storms predominate. These
are thegradual commencement
storms to which Bartels gave
the name M‑regions since positive visible solar
activity identification
had not been made, al‑though the 27‑day period of the solar rotation
cycle suggested a long‑lived
solar stream origi‑
nating from a hypotheticalsource on the Sun.
The discovery in 1963‑1964 of interplanetary
magnetic sectors gave new dimensions to the prob‑
lem: Wilcox[l968] made a review of the subject
which contains a study of the sectors and theirrelation to geomagnetic activity, the state ofresearch on their̲solar
origin and a copious bib‑
liography. There
has been an increasing
amountof circumstantial
evidence which links the orien‑
tation of the interplanetary
magnetic field vec‑

tor (with respect to the ecliptic plane) with sub‑storm initiationand ending. That
is when thefield turns such that a southward
component ispresent, connectionof the interplanetary
field(after passage into the magnetosheath)with thegeomagnetic field, via a still little understood"merging" process, takes place. Substorm
activi‑ty [Nishida, 1971J is then initiated; when thefield loses its southward component, the activity
ceases. An
additional
effect on magnetic activi‑
ty has been the observationof interplanetarypistons, seeded with a high alpha/protonabun‑
dance (about .20 compared with the usual solar
wind value of .04). These
pistons [Hirshberg
eta 1., 1970] appear to be associatedwith inter‑
planetary shock waves [Dryer, 197l] and may be
associated with the interplanetary
magnetic fieldchanges mentioned above regarding thesouthern‑
Hi ronfprl r> nm nnnont
On the average the geomagnetic
field ismoststrongly disturbed
two days
after
the
has
entered a sector whose magnetic field Earthis directed
towards the Earth; this also corresponds
to thehighest mean value of the interplanetary
magnetic
field, to a high velocity of the solar wind andto a minimum strength of cosmic radiation.
these relations are purely statisticaland ‑Allpre‑sent considerable
local divergencies,
but
theypermit the hope that a satisfactory
physical ex‑
planation based on theseobservations
will befound for these recurrent events.
The orientationof the Earth's axis of rota‑tion in relation to the Sun‑Earth line
plays animportant role in the distributionof geomagnet‑
ic activity between the Earth's
northern andsouthern hemispheres[Mayaud, 1967], activity
being greatest in the hemisphereturned towards
the Sun.
The origin of these sectors
still the subject of debate.

on theSun isPecker and Roberts [1955] using 1952‑1953
data suggested the "cone of avoidance"
theory.
They showed a maximum in the number of quiet
days about three days after the central meridianpassage of active solar
centres. This"cone ofavoidance" is formed by deflection of the cor‑puscles over an active region by the action of
the magnetic field of the regionc Saemundsson[1962] reconfirmed
this theory with data from
1919‑1954. He
found the prolonged M‑region emis‑sion to occur 30 °‑90° from the active regions,particularlyon the following side of the coneof avoidance.
Mustel [i960] on the other hand advocates that
M‑regions appear to be correlatedwith active cen‑tres on the Sun. These
are young calcium plage re‑gions above which long coronal rays extend up to
the distance of the EarthTs orbit.
Tanaka and Kakinuma [l966] suggest, after astudy made from August 1962 to December 1963, thatgeomagnetic disturbance preceded the CMP of a so‑lar radio active center at 4000 MHz by 1‑5 days.
Thus identificationof radio sources at 4000 MHz
perhaps could assist in the selection of recurrent
storms.
At present it seems that the origin of these
sectors is attributableto very extensive
regions
at low latitudes of the Sun that are characterized
by a weak magnetic field (a few gauss), the cen‑tres of activity with a very strong magnetic field
being local "accidents"
without much effect at long
distance on the interplanetary
field [Wilcox, 1968],
This study was recently extended over a period from1959 to 1967 [Bumba and Howard, 1969]0 It
can bededuced, from a practical point of view, that the
27‑day recurrences
are long‑term phenomena (which
may last for several years) whose use is fully jus‑tified during a great part of the solar cycle forforecasting
ionospheric disturbances.
1.4 Ionosphericforecasting

services

The principles
of predicting
ionosphericandmagnetic disturbancesand short‑range radio propa‑
gation prediction
services have been given by the
U.S.SoRo in a manual by R.A. Zevakina, Ye. V. Lav‑
rova and L.N. Liakhova fl967]. Their
predictions
are for the whole days for for 12 hours) and esti‑
mate AfoF2? the level of Es ionization, the degreeof absorption, and the presence of spread echoes.
This system necessitatesa rapid interchange of
ionosphericinformation from a network of stations,especially those in high latitudes. Equallyimpor‑
tant is the need for a considerable
increase in ab‑sorption‑measuring
stations, especiallyin highlatitudes, for providing up‑to‑date data on which
reliable short‑term
absorption forecasts can bebased.

In the United States of America at the Insti‑
tute for Telecommunication
Sciences of the Officeof Telecommunications,a programme has been devel‑
oped to produce, by computer techniques, for agiven instant, synoptic
maps of deviations of foF2
from the monthly median. Practicaluse of thetechnique requires that foF2 be digitized and trans‑mitted to the computer on a real‑timebasis. Spa‑tial and time‑lag dependenceof ionosphericcharac‑teristics [Gautier and Zacharisen, 1965] will help
determine the optimum feasible distributionof ion‑ospheric stations to provide coverage sufficiently
complete for the synoptic mapping of other programs.
Computer‑oriented
programmes using observed andpredicted solar and geophysicalparameters
are nowused by the United States to forecast for specificcircuits the time, location, probability
and magni‑
tude of ionospheric variations
caused by solar flaresand magnetic storms. The
outputs of the forecasts
can be expressed in dB of attenuationand in revised
MUF, or percentage change of MUF from the normal me‑
dian MUF. Developmentof the computer programmes
continues.
Radio propagation
quality figures continue to bepredicted in the U.S.A. on a 6‑hourly and a
weeklybasis. The
6‑hour forecast is based upon current
levels of solar and geophysicalparameters, i.e., theaverage level of solar activity as indicated by the2800 MHz flux (Algonquin Radio Observatory, Ottawa,
Canada); state of the geomagnetic
field observed atFredericksburg,
Virginia, and Boulder, Colorado
andseasonal influences. The
weekly forecast, in addi‑
tion to the high latitude radio quality figure, pre‑dicts the probability of occurrenceof sporadic ex‑
cess attenuation, ionosphericstorms and polar cap
absorption.
Usefulness

and reliabilityof short‑term

forecasts

Progress in the improvementof short‑term
iono‑spheric disturbanceforecasts depends to a consider‑able extent on the adoption, by various Administra‑tions, of uniform methods of evaluating
thesuccessof such forecasts. The
large number of factors in‑volved in radio propagation quality encourages
thediversity of evaluation techniquesthat now exist.
This Report is intended to draw the attention of thevarious Administrations
to this problem.
Severalto evaluate

methods have been used [C.C.I.R., 1963]
the forecasts issued by the various

Administrations.
2.1 M=(x‑ky)/S

(used

They

are as follows:by the United

Kingdom)

where
M is a measurecasts,of the usefulness

x is the number of storm
casts were issued,

daysof short‑termfor whichcorrect

y is the number of quiet days for which storm
casts were issued (i.e. false alarms),
S is the total

numberof storm

fore‑
fore‑
fore‑

days,

k is an arbitrary constant depending on how the traf‑
fic handling capacity of the system is affected bya storm and on the degree of traffic interruption
which results from unnecessary
action taken follow‑
ing the receipt of a false alarm (United Kingdom
experience suggests that k=0.5 is a reasonablevalue).
2.2 R= A2/SiS2(suggested

by Japan[Sinno,1958])

where
A is the number of storm days correctly forecast(identical to x as defined in para. 2.1),
is the number of storm days forecast
to x+y as defined in para. 2.1),
is the number of actual storm
S as defined in para. 2.1).

(identicaldays (identicalto

The index M is designed to measure the usefulnessof a set of short‑term
predictions
in a radiocommuni‑
cations organization.
Onthe other hand, the index
R is simply product of rate of correct alarms, A/S,
and predicted storms, A/S^, and is based on purely
statistical considerations;
i.e., is closely related
to the correlation
coefficient between forecast andactual conditions. Whenthe accuracy of a set ofpredictions is low, the index R gives an over‑opti‑
mistic estimate of the usefulnessof the predictions
from the point of view of the communications
engi‑
neer. Further
details of this comparison
between M
and R are given by Minnis [1962].

The general radio‑propagation
quality figure,both forecast and observed, is expressed ona scaleof 1 (unusable) to 9 (excellent). A
forecast is
considered to be a success when it differs from theobserved figure by not more than one unit. Thera‑tio of successes to total number of forecasts, interms of percentage, is computed. Periods
observed
to have been quiet and disturbed are
analyzed sepa‑
rately. It is desirable, in evaluating
any set of
forecasts,
to notethat the correct forecastingofa deteriorationin propagation
quality is of greater
inherent worth than the correct forecastingof acontinuance of an existing situation. This
techniqu<developed
in the has
daysbeenof covered
the Central
Radio Propaga‑tion
Laboratory
extensively
in theCRPL‑RWS descriptive literature.
Information
on present services is available, onrequest, at the Telecommunications
Services Centerof I.T.S. (see Reoort 248‑2
At the FTZ in the Federal Republic of Germany,a quality figure is in use
which takes into accountthe highest and lowest observablefrequency for agiven path as well as the received field strength,
and which relates the quality of a given day to theaverage conditionsof one solar rotation [Beckmann,
1954]. Thisquality figure brings to evidence var‑iations of propagation
conditions not only during
disturbed periods but also during quiet periods.
It is used also for comparison with short‑termforecasts and the study of their reliability[Beckmannand Ochs "*3. Diurnal

distribution

ospheric disturbances
disturbed conditionsof the times of onset of ion‑and stability of foF2 during

In the U.S.S.R., statisticalstudies of iono‑
spheric disturbances
have been made which show that
disturbancesusually commence during
night hours.
Thus, "forbidden"intervals for
storm
commencements
have been found for every ionosphericstation in the
U.S.S.R. These
results have enabled short‑term fore‑casts to be made more accurately[U.S.S.R., 1957].
Studies of the rapid changes of foF2 during the storm
showed that the F2 layer is sufficiently
stable topermit useful extrapolationof values of foF2 a few
hours in advance.
Liakhova [l96lj found that, induring disturbancewhen reflections

the auroral zone
from the F2 lay‑er do exist, foF2 does not undergo strong fluctua‑
tions over periods of 15 to 30 minutes. This
indi‑cates that relatively
stable communications
may bepossible in the high latitudes during the disturbed
periods.
REFERENCES

Anderson, K.A. [1969] Electronsand protons in long‑lived
streams of energetic solar particles. Solar
Phys., 6,
111‑132.
Arnoldy, R.L. [l97l] Signaturein the interplanetaryfor substorms. J. Geophys. Res., 76, 5189‑5201.

mediumBailey, D.K. [1957] Disturbancesin the lower ionosphere ob‑served at VHF following the solar flares of 23 February
1956, with particularreference to auroral‑zone
absorp‑tion. J. Geophys. Res., 62, 431.
Bailey, D.K. [1964] Polar‑cap
Sci., 12, 495‑541.

absorption.

Planet.

Space

Ballif, J.R., Jones, D.E. and Coleman, Jr., P.J., [1969] Fur‑ther evidence on the correlation
between transverse
fluctuationsin the Interplanetary
Magnetic Field andKp., J. Geophys. Res., 74, 2289‑2301.
Beckmann, B. [1954] Betrachtungen
zur Giite des Funkwetters(Remarks on radio propagation
quality figures). Fern
meldetechn. Zeitschrift,
7, 285.
Beckmann, B. and Ochs, A. [1969] Die Vorhersage
der ion‑ospharischen
Kurzwellen‑Ausbreitung(Predictionforionosphericshort‑wave
propagation).
Jahrbuchdeselektrischen
Fernmeldewesens,
281‑365.
Bell, B. [1963] Type IV solar radio bursts, geomagnetic
storms, and polar‑cap absorption (PCA) events. Smith‑sonian Contributions
to Astrophysics, 8, 119‑131.
Bumba, V. and Howard, R. [1969] Solar activity and recurrencein magnetic field distribution.
Solar
Physics,
28‑38,
̲7,
Caroubalos, C. [1964] Contribution
a l'e'tude de l'activite'
solaire en relation avec ses effets geophysiques(Con‑
tribution to the study of solar activity in relation togeophysical effects). Ann.
Astrophys.,27, 333.
Castelli, J.P., and Aarons, J. [1970] Radio burst spectra
and the short‑term
predictionof solar proton events.
Ionospheric
Forecasting, V. Agy, Editor, AGARD Confer‑ence Proceedings[l963] Report
C.C.IoR.
Assembly, Geneva,

No. 49, January

1970.

247. Documents
251.

of the Xth Plenary

Croom, D.L., [l971a] , Solar microwave bursts as indicatorsof the occurrence of solar proton emission, Solar Phy‑sics, 19, 152‑170.
Croom, D.L., [l971bj , Forecasting
the intensity of solar pro‑ton events from the time characteristics
of solar micro‑
wave bursts, Solar Physics, 19, 171‑185.
Dodson, H.W. and Hedeman, E.R. [l958j Geomagnetic
disturb‑
ances associatedwith solar flares with major premaxi‑
mum in bursts at radio frequencies
200 Mc/s. J. Geo‑phys. Res., 63, 77.
Dryer, M. [l968j Dynamics
of the magnetosphericshock‑solar
blast wave interaction.
Space
Research VIII, p. 150,
North‑Holland
Publishing Company, Amsterdam
1968.
Dryer, M. [l97l] Interplanetaryshock waves generated
by so‑
lar flares. Review
paper presented at XV IUGG Gener‑
al Assembly, Moscow, U.S.S.R., 2‑14 August 1971.
Dryer, M., Merritt, D.L. and Aronson, P.M. [l967] Interactio:of a plasma cloud with the earthTs magnetosphere.
Jc
Geophys. Res., 72, 2955.
Fichtel, C.E. and McDonald, F.B. [1967J Energetic
particlesfrom the Sun. Annual
review of Astronomy and Astro‑
physics, 5, 351‑398.
Gautier, T.N. and Zacharisen, D.H. [l965j Use of space andtime correlationin short‑term
ionosphericpredictions.
Conference
Record,First
IEEE
AnnualCommunications
Convention, 671‑676, Boulder, Colorado.
Gosling, J.T. fl97l] Variation
the Earth^s orbit. Solarin the solar wind speed
Physics, 17, 499‑508.

along

Hakura, Y. [l967] Entry of solar cosmic rays into the polar
cap atmosphere.
J. Geophys. Res., 72, 1461‑1472.
Hakura, Y., Takenoshita,
Y. and Otsuki, T. [l958j Polar
black‑outs associatedwith severe geomagnetic
stormson September 13, 1957 and February 11, 1958. Reportof Ionosphereand Space Research in Japan, 12, 459‑468.
Jonah, F.C. and Dodson‑Prince,
M. [1964‑1965]
Solar acti‑
vity catalogue. NASA
Reports 000 503/538/650/654.

Lange‑Hesse, G. and Rinnert, K. [1965] Results of phase varia‑
through thetion measurements
on VLF signals
propagated Ubertragung,Arctic polar cap. Archiv
der elektrischen
20, 123‑129.
Liakhova, L.N.[l96l]
Latitude‑variationof the stability of
the F2‑layer critical frequencies
at times of disturb‑
ance. Trudy
IZMIRAN, 19 (29), 48‑51.
Mayaud, P.N. [1967] Preliminary
calculationof indices Km,
Kn and Ks or dm, dn and ds, measurementsof magnetic
activity on the world scale and in the northern andsouthern hemispheres.
Institutde Physique du Globe,
University of Paris, Note 23.
Minnis, C.M. [1962]Ionospheric
the assessment of theirlogy, 39, 172.

storm forecasts;
usefulness.

formulae forTechno‑Electronic

Mustel, B.R. [i960] Results of a statistical
study of geo‑
magnetic disturbancesfor 5 cycles of activity. Astron.
Zh., 38, 28‑44 (Soviet Astron. J. 5, 19‑30).
Pecker, J.C. and Roberts, W. 0. [1955] Solar corpuscles
res‑ponsible for geomagnetic
disturbances.
J. Geophys.
Res., 60, 33‑44.
Pick, M. [l96l] Evolution
des emissions radioe'lectriques ^o‑laires de type IV et leur relation avec d'autres pheno‑
menes solaires et geophysiques.
(Evolutionof solarradio emissions of Type‑IV and their relation to othersolar and geophysical phenomena). Ann.
Astrophys., 24,
183.
Reid, G.C. and Collins, C. [1959] Observationsof abnormal
VHF radio wave absorption at medium and high latitudes.
J. Atmos. Terr. Phys., 14, 63.
Reid, G.C. and Leinbach, H. [1959] Low energy cosmic‑ray
events associatedwith solar flares. J. Geophys. Res.,64, 1801.
Saemundsson, T.H. [1962] Statistics
of geomagnetic storms
and solar activity. Monthly
Notices Roy. Astron.
Soc.
Geophys. Suppl., 123, 299‑316.
Simon, P. [1968] IUWDS report
Bulletin, 167, 41‑45.

on activity

during1967. URSI

Simon, P. [1969] Some comments on the forecastingof solaractivity,, Synoptic
codes for solar and geophysicaldata. IUWDSSecretariat, Boulder, Colorado.
Simon, P., Martres,

M.J.

and

Legrand, J.P.

fl969]

Flare

fore‑

PART

A.Ill.2

REGIONALFORECASTS

Severalof the RWC's
have emphasized
the Radio Pro‑
pagation
Prediction
aspects
withintheir
region.
Inor‑der to satisfy
theirclientele,theyhave developed
andimplanted
specific
proceduresand products.
A
brief
des‑
pri nti nn rrf thpcp
f n 1 1 n we・PART

A III.2.1

Moscow

A BIBLIOGRAPHYOF RESEARCH PAPERS
CONCERNED WITH RADIO PREDICTION
1. R.A.
Zevakina, E.V. Lavrova, L.N. Lyakhova. "Manualonshort‑term
prediction of ionospheric‑geomagnetic
stormsandradio‑propagation
forecasting
Publishing House, "Nauka", Moscow,
1967. service."The
stormsand their main features of ionospheric‑geomagnetic
Disturbancesinprobablecausesarereviewed.
storms are dis‑
short‑wave radio propagation
duringsuch
cussed. The
principlesof short‑term
prediction of ion‑ospheric‑geomagnetic
storms are summarized
and all kinds
of IZMIRAN's forecasts are described. The
applicationof these forecasts and current ionospheric
data to thecalculation of usable radio propagation
frequencies
isexplained.
2. "Ionosphericdisturbances
and their effects on radio pro‑
Publishingpagation",ed. R.A. Zevakina, L.N. Lyakhova.
House, "Nauka", Moscow, 1971.
Papersionospheric
dis‑concerning morphology of during disturbances,turbances,changesof
N(h)‑profiles
statistical distributionof deviation of ionosphericparameters from their normal values are presented.
Short‑wave propagation, absorption
F‑layerand sporadic
during disturbances
are also considered.
The
possibili‑tyN(h)‑profilesof predicting
and calculation ofduringdisturbed criticalconditions frequencies
and also thefield strength using the current ionospheric
data areshown.
3. N.P.
Benkova, R.A. Zevakina. Ionosphericdisturbances
after the Proton flare of 7 July, 1966. Annalsof the
IQSY, 3, 448, 1969.
4. E.E.
Goncharova, R.A. Zevakina, E.V. Lavrova, L.A. Yudo‑
vich. Ionosphericeffect of low‑energy solar plasmaejected during proton flares. Geomagnetism
and Aerono‑
my, 10, N 1, 67, 1970.
5. E.E.
Goncharova, R.A. Zevakina, E.V. Lavrova, L.A. Yudo‑
vich. Changesof N(h)‑ during positive and negative
ionosphericdisturbances
at maximum and minimum of solar
activity. Geomagnetism
and Aeronomy, ̲I0, N 3, 547, 1970
Ionosphericeffects of proton and non‑proton flares
aredelay and larger acti‑
The
smaller timevity considered.
the proton flares isofdisturbances
following
shown. Thisis due to larger energy of solar plasmaejected during proton flares.
Thechangingof ionosphericparametersatdifferentlatitudes is proportional
to theactivity of flare andmagnetic disturbance.
Theion‑production
rate increas‑es during the positive phase of the disturbanceand de‑creases during the negative phase.
N.P. Benkova, R.A. Zevakina. Ionosphericdisturbances.
"IonosphericResearch", N 19, "Nauka", Moscow, 1970.
Planetary distributionof disturbances
duringnegative and positive phases is described.
N(h)changing
during disturbancesis shown using the ground and satel
lite observations.
I.S. Vsechswjatskaja,
N.P. Sergeenko, L.A. Yudovich.
On statistical
relationsof NmaxF2 fluctuations
at mid‑dle latitudes. Geomagnetism
and Aeronomy, 10, N 4, 606
1970.
Statistical distributionof deviations
foF2 frommedian values was described using the random process

PART A.III.2.2

Darmstadt
Scientific

Information

NeededforRadio

Propagation

B. Beckmann‑

Forecasting

RWC‑Darmstadt

The ionospherictransmission
frequency range is represented
by the variation of field strength as a function of time andfrequency. Its
limits are affected by the standard‑MUF,
op‑erational MUF, LUF, signal‑to‑noise
ratio (atmosphericandman‑made noise or interference)and the fading‑character,i.e., the distortionsof the signals caused by the lattervary as a function of the type of service. The
objectiveof the forecasting
activity should be the prediction of thetransmission
frequency range expressed in median values fora relatively
long time (e.g., monthly
median predictions)
together with additional
information
about short‑termvaria‑
tions exceeding the normal statisticaldeviations (disturb‑
ances, e.g., daily forecasts). For
the description of theseshort‑term variations use is made of current, if possible
real time critical frequency values of ionosphericsounding
stations (e.g., foF2 and f‑min) [see UFOFI, UFOFO, UFOFU].
If these data are not available to a sufficient extent,
current observationsof field strengths of azimuthally
dis‑tributed long distance transmission
areas are used as afunction of frequency and time [publishedby NOAA Environ‑mental Data Service in the series "Solar‑GeophysicalData"
as Transmission
Frequency Ranges‑North
Atlantic Path, ob‑
servations by Deutsche Bundespost]. Theseobservationalre‑sults can be combined in a so‑called "band character figure"(these are the product of the usable transmission
frequency
range times the mean logarithmic
field strength). Values
are normalizedwith respect to a running average and adapted
to a prediction
scale from G = 0.0 to 9.8 in steps of 0.2(normal value G = 6.0) [see PROPO]. These
character figures
show the times of quiet conditions(G>6, broad transmission
frequency ranges with high field strengths) and of disturb‑
ances (G<6, narrower frequency ranges with lower fieldstrengths), as well as their regional differences. ‑Assessed
quality figures as provided by radio operators from different
stations can also be used.
The above mentioned ionosphericparameters define the propa‑
gation conditions
as a basis for the forecast. Its
extrapo‑lation in time (if possible by autocorrelation)is also an
important basis for the forecast, especiallyin comparison
with the previous solar rotation period. The
extrapolationin time of operationalparameters
is studied in detail by
CCIR (CCIR Doc. VI/160, Boulder
1968).* Thesame applies to*These documents are usually available
trations for ITU; the IUWDS Secretary
supply copies upon request.

from national adminis‑
for World Days cang) incase that after emission of energetic protons fromtype IV centers a PCA occurs within about 6 hours ob‑
served by riometer as cosmic ray associated[UABSE,
type IIIJ or as phase ‑ and amplitude variations
ob‑
served on VLF circuits via the polar‑cap.
h) incase successive
type IV outbursts occur in "repe‑
tition centers", groupedin privileged
areas of the sun.
are detected over
i) in
case
energetic
protons(30‑100
MeV)
the polar region or a GLE (>1 GeV) is observed in cosmic
rays [UCOSB, UCOSE],j) incase the precipitationof electrons is indicatedbyaurora QlAURE] and the existence of soft X‑ray radiationby black‑outs^UABSE, type II].
k) in case pre‑decreasesof anisotropic
effects in the am‑
plitude and phase of the daily variation of the cosmic
rays are detected ^UCOSeJ in connection
with character‑istic variationsof worldwide positive phases (G>6) andlocal break‑downs
in the night‑criticalfrequencies
foF2 (see above).
1) incase these variations are about parallel with thosein the previous solar‑rotation
corresponding
to the sec‑
tor‑structureof the solar‑interplanetary
magnetic field
and a development
tendency of a disturbanceis indicatedby this comparison. Criticaltime intervals are local
break‑downs of critical frequencies
foF2, geomagnetic
disturbances, ionosphericpositive phases as well as thedisturbances in the previous solar rotation.
The above mentioned criteria are derived from the interpre‑
tation of a number of geomagnetic
or ionospheric events.
They are not always applicable and their importancechangeswithin the sunspot cycle. The
physical relations are only
known in part. Therefore,
forecasts
are still difficult.
The forecasters
are very grateful to get flare forecasts
from the solar observatories
in the GEOSOL, SDF, SFD‑Reports
tend‑
The same applies to solar and geomagnetic development
encies indicated therein. Successfulpropagation forecasts
require the latest information
to be passed on as soon as
possible. Some
radio propagation
forecasts are included in
the Ursigrams for scientificpurposesB. Beckmann
RWC‑Darmstadt
December,

1968

PART A III.2.3

Boulder

LONG TERM PREDICTIONS
The former
monthly publication "Ionospheric
has been replaced
Predictions"by a set of "permanent
sisting of acon‑
set of four volumes. Volume predictions"charts,1 contains thenomograms
andinstructions
maximum usable frequencies from the to be used inestimatingin Volumes 2,3,
set of maps
and 4. Volumes
2,3, reference
wide maps
and4containworld‑
of monthly median MUF (ZERO) F2, MUF (4000)
and MUF (2000)E
F2,
for
three
levels2 containsof solar activity. Volume
maps
for
a
typicalperiodvity ― the 12‑monthof minimum solar
moving average Zurich
acti‑(Rl2)=10. Volume
sunspot number
3
contains
an average
maps
for
the
maximum
solar cycle ― R]̲2=110. Volume
period offor the maximum
4 contains maps
period of a higher than
― Rl2=160. Interpolation
average solar cycleof solar activity other thanprocedures
can be used for levels
thoseworld maps.
of the three sets ofThese volumes
for sale by the Superintendent
U. S. Governmentare Printingof Document!
Office, Washington,
30 cents for Volume
D.C., 20402 at
1(StockNumber0300
for Volumes 2, 3,0318) and $3.00 eac.
and 4 (Stock Numbers 0300
0319, 0300 0320,
and 0300 0321 respectively).
Predictionsof the 12‑month moving
number for
Zurich sunspot
with this method may averagebeServices anduseRadioobtained from the EMC
Systems
Predictions
Telecommunication
Group, Institutefor
Sciences, Officeof Telecommunications,WEEKLY

PREDICTIONS

A weekly
forecastof radiopropagation
tained in
is con‑a report
known
as the "Weekly conditions
cation Forecast".
Radio
TelecommuniItis issuedeach Wednesday
UT by the Telecommunication
about
1900
Service
Centerreport consistsof ITS. Thisof two main parts: (A)apagation
forecastofpro
conditions
the next sevenof observed
nrooaeration
days and (B) asummary
conditions
the
Part

A is

further

dividedinto five
separate
forecasts.
1. General
radio
conditions
and maximum
quencies
usablefre‑
and a detailed
forecastoflity"
figureforthe "radio
qua‑
each
of
the
next
seven
days
on a 9 point scale,based
1 (useless)to 9 (excellent).
2. Theprobabilityof occurrenceouts (SWFs)
toof short‑wave
fadeoroducemoderate(ud to 20
decibelslasting up to about thirty minutes) or large atten‑
uation (over 20 decibels for events lasting from―the amount of at‑
thirtyminutes
to whichseveralwould
hours)
tenuationis thatoccur at the subsolar
point at a frequency of 5 MHz.
3. Ionosphericstorms associatedwith geomagnetic
turbance ―the importance, start time, duration
probability of occurrence are indicated.
4. Theprobabilityof occurrencetion events (PCAs).

of polardis‑andcap absorp‑

5. Semi‑monthly
revised ionosphericpredictionsin theform
pre‑offactorstobeappliedtomonthly
mediandictions for a given month at a specified
solar ac‑tivity index (twelve‑monthrunning sunspot number).
The
includes a generalreview portion of the weekly report(including
MUFs
evaluationof radio propagation conditions
and the6‑hourly radio qual‑
occurrenceof SWFs), daily
andity figures,
daily geomagnetic
activity
indices (Aj^ indicesat Fredericksburg,
Virginia)
and daily solar indices (10.7cm
noon at Ottawa, Ontario).
radio flux
observed
It should
be noted
that atalllocal
observations
contained in thissummary are provisional values.
ThisAn
abbreviatedversionreport is delivered by mail.
consisting
to expected propa‑ofasingleparagraphdevotedgationteletype, telegram, orconditions
available
telephone.
Delivery is isinitiatedby about 1900 UT.
Daily Predictions
Daily forecasts of radio propagation
conditions are issued
by the Telecommunication
Services Center (TSC) Monday
through Friday, national
holidays excluded. These
fore‑
casts
day. They
give an ad‑
cover
the
followingGreenwich
jective description of expected geomagnetic
and radio con‑
(Optimum Traffic
ditions,aforecastofusablefrequencies
Frequency, FOT, and Lowest Usable High Frequency, LUHF) re‑
lative to predicted medians, and the probabilityof theoccurrence of SWF in association
solar flares. Thesewith
daily forecasts are "canned" statements
in plain language(for teletype or telegram distribution)or coded for refer‑ence to
distribution).
Dis‑
mastersheet (fortelephone
tributiona isinitiated
at about
1900 UT0
Six‑hour forecasts are issued by the TSC also. These
fore‑
casts
HF circuits in the Northareapplicable
primarilytoAtlantic
at 0100,
four timesis daily,
0700, 1300area.
and They
1900 UTareandissued
each forecast
for propagation
conditions for the six‑hour period beginning one hour after

the time of issue. The
forecast statement is in the formof a letter (N, U or W) and a
letter portion is an estimation number (1 through 9). Theof existing propagationcon‑
ditions at the time theis issued where N = quiet(quality 6 through 9), U statement=
disturbed (quality 1 through unsettled4). The (quality 5), and W =portion repre‑
sents the expected radio quality duringnumber
six‑hour fore‑
cast period on a scale from 1 to 9. This theradio
propagation
quality figure has been
seasonally related to daily valuesof the 10cm solar
radio flux and the Fredericksberg,
Virgin‑ia(AFR). The
quality figures are definedas Geomagnetic
follows: 1‑Indexuseless, 2 ‑ very poor, 3 ‑ poor, 4 ‑ poor‑
to‑fair, 5 ‑ fair, 6 ‑ fair‑to‑good,
good, 8 ‑ very goodand 9 ‑ excellent. These"short term"7 ‑forecasts
are distri‑buted by teletype or telegram, and they are broadcast eachhour, at about 14^ minutes past the hour, by National Bureauof Standards radio station WWV.
In addition, the latest 6‑hour forecasts
be obtained at
any time by way of an answering device by may
telephoningarea
code 303, 499‑8129. Militaryusers may access the device
by using Autovon to Lowry Air Force Base and requesting theabove phone number.
The recording is updated every(seven days a week)at the regular time of issue forsixthehours
forecast. Included
in
the recording in addition to the
propagation
forecast are
the latest 3‑hour index of geomagnetic
activity at the timeof issue and the most recent valueof the 1700 UT ten centi‑
meter solar flux reported from Ottawa,
Ontario. Monday
through Friday, the daily forecast of propagation
conditions
is carried on the recording between 1900 UT and about 0100
UT.
These daily forecasts and/or the weekly reports may be ob‑tained on a continuingbasis bythe Telecommuni‑
cation Services Center, Institute contacting
for Telecommunication
Sciences, Office of Telecommunications,
Boulder, Colorado

PART A.IV

Data

DETAILS
Description

Interchange
OF PLANRules

FOR RAPID

of Arrangements

for

COMMUNICATIONS
RapidInterchange

The basic concept of the rapid interchange
is that observing stations transmit data reports arrangements
toa Region‑
al Warning Center (RWC), that the RWCs interchange
data
among
themselves, that each RWC serves the needs of institutionsin
its region for prompt data, and that in addition the RWCs pro‑vide any necessary forecasts and alerts based on the compre‑
hensive data and informationassembled through the whole datainterchange
activity. For
the worldwide alerts, all the RWCs
provide their opinions to the World Warning Agency (WWA) ‑ RWC
Boulder, Colorado‑ which issues the world‑wide GEOALERT.
For purposes of this interchange, the IUWDS has identi‑
fied five regions of the world, each with a Regional Warning
Center. The
regions and responsible
RWCs are:Western Europe ‑ RWC Paris (Alternate
RWC Darmstadti
Western Hemisphere‑ RWC Boulder
Western Pacific ‑ RWC Tokyo
Eurasia ‑ RWC Moscow
Australasia and Antarctica ‑ RWC Sydney
In addition, there are Associate RWCs in India, Sweden, Czech‑
oslovakia and USSR which perform part of the functions of an
RWC. The
regions are not strictly geographicalbut are deter‑
mined by the efficiency
or economy of communications.
Detailsof the RWCs and Associate RWCs are given in PART A.VI.
Participating
observing stations are listed in PART A.V.
Some send reports regularly but many others send reports only
when they have observed a most unusual event. The
stations
send their reports to one of the RWCs
or Associate RWCs andthus the data gets into the rapid interchange system.
Observing stations should dispatch their data reports assoon as practical after the observations
are made. The
IUWDS
codes should be used, with plain language used when required.
Speed is especially
important when very unusual events
are observed ― such as outstanding
flare or proton events;
in these cases the observing station should send the message
as PRESTO in plain language without taking time to prepare
the usual data code. The
full data report in the appropriate
code should always be sent afterwards.
The RWC receives data from the observing stations withwhich it is in direct contact. It
has
an habitual daily sched‑ule for the interchange with other RWCs as given in the sub‑sections of PART A.VI. There
are understandings
among theRWC so that essentially
duplicating
data reports are not in‑terchanged. Thus
each RWC has an equivalent amount of so‑lar and world‑wide geophysical data on which to base theforecasts, regional alerts and data distributions
which
are made in that region. The
RWC also uses this body ofdata as the basis for sending each day its advice on theworld‑wide GEOALERT to the IUWDS World Warning Agency.
When very unusual events are reported as PRESTOs (whether
from within its region or from outside), the RWC has the
responsibility
to relay by expedited communications
to theother RWCs (if reported from within its region) and in allcases to any scientificinstitutions
within its region
which have requested this expedited service. The
objective
is to distribute these PRESTOs to the relativelv
few re‑questing institutions
within one hour.
The world‑wide alert (GEOALERT, see PART B.II) identi‑
fies or forecasts major solar or geophysicalactivity. Manyobservational
programs are influenced
by the informationinthe GEOALERT message, which tends thus to coordinate theworld‑wide observational
effort. Thismessage is issued
each day at 0400 UT by the IUWDS World Warning Agency. It
is distributed
very widely, through RWCs, by radio broad‑casts and over the WMO meteorologicaltelecommunications
network. The
content of the GEOALERT is decided from theadvice sent each day by the RWCs to the World Warning Agency.
The success of the plans for all of these rapid inter‑change services depends on there being effective arrange‑ments for communications.
Since
many different communica‑tion channels are involved, the overall scheme has to be
the sum of many individual
arrangements
for communications
between observing
stations and RWC and between RWC and theusers of the services. In
practice all forms are used ―telephone, telex, special or commercial or government tele‑
type, radio links, meteorologicalnetworks. To
help solvethese practical communication
problems, it has been foundconvenient, beginningwith IGY, to have in each country
participatingin the program, an individual who is desig‑
nated as the "National Warning Contact" for that country(see PART A.VII for detailed list). This
individual has
knowledge of the practical communication
possibilitiesinhis country and is requested to work with the RWC in making
suitable and effective arrangements
for communications
toor from stations or institutions
in his country. It
ishoped, moreover, that he can solve any problems of inciden‑tal cost which may arise. The
requirements
for communica‑
tions are both dependability
and speed, and the general ob‑
jective is a maximum of two hours for the delivery of a mes‑sage over any single link, with the possibilityof expedited
communications
in a few tens of minutes to or from selected
stations or institutions
involved in the Advance Alert(PRESTO) phase of the program.

PART .A .V Station

Lists

Station lists follow in two sections; the first by station
number and the second alphabetically.
Stationnumber (IIIII)
is assigned by the IUWDS Secretariat
using the following
guidelines:
The indicator

group

a =

of

octant"IIIII"is assigned

as follows

in orderworld

northernnorthernnorthernnorthernsouthernsouthernsouthernsouthernb = tens position

hemispherehemispherehemispherehemispherehemispherehemispherehemispherehemisphereof longitude

if a = 1, 3, 5, or 7

if a = 2, 4, 6, orc = tens

position

8of latitude

dd = station number within(arbitrarily
assigned
Boulder, Colo.
Boulder, Colo.

position "abc"by IUWDS)NOAA
N40 W105 becomes 20401
Universityof Colo. N40
W105
becomes 20402

PART

A.V.I

STATIONS
Indicator

AND INDICATORS

Geographical

IN NUMERICAL

Location

10101 Ouagadougou
10401 Bordeaux France N4510402 Mres/Adour
10501 Abinger UK N54
10502 Herstmonceux

Upper

ORDER

Coordinates

Volta N12France N44
UK N5110503 JodrellBank UK N53
10504 Slough UK N51
10505 Lannion France N48
12101 Dakar
Senegal
N15
12301 Canary
Is. Spain
N28

W02 URAN
W01 UFOF
W03 UFOF
W17 UCOS,
W16 UFLA,

12601 Reykjavik
14601 Narssarsuak
15101 Paramaribo

Iceland N64
Greenland N61
Surinam N06

W21 UCOS
W45 UFOF
W55 URAN,

15501 St.

Canada N47

W52

John'sNf Id

16101 Trinidad West
17201 Ramey

AFB

Indies N10
Rico N18

Puerto17202U‑Klxtt

Arecibo Puerto17401 Sagamore Mass.

17402 Wallops
17403 Prospect Mass.

W67 URAN
W70 URAN,

USA N37
USA N42

W68 UABS,
IndiesUFOF
UPAT
URAN, USID

UFOF

UPLA.

,

UPAT,
USSP

W75 UFOF
W71 URAL

17801 Thule Greenland N76
1820Ulvlrl
1 Jamaica West18401 Washington

USSP

W61 USID
W67 UFLA,

Rico N18
USA N42

Is. Va.

Codes

W02 UFOF
W01 URANWOO UCOS
W02 UMAGWOO UFLA

N18

W76 UFOF'
W77 USID

USA N38

UCOS,
UMAG.Li.UFOF

NASA D.C.
18402 Washington

USA

NRL

N38

18403 Fredericks‑
Va. USA N38
burg
18404 McMath‑Hul‑
Pontiac,Mich.
bert USA UPLA!
1840uoiu
5 Ottawanion

18406 Ottawa
18407 Ottawa
18408 Penn

18501 Deep
18502 GreatW77 USOX

D.C.

Domi‑
Obs. tjmag

W77 UMAG
N42

Canada N45

W76 UFKANRC Canada N45
CRC Canada N45
State Pa.
University
nv TTt‑i‑ifrDov≫ lr

W76 URAN
W76 UFOF

USA N41

River Ontario
CanadaWhale Canada N55

W83 UFL.A,

W78 URAN

N46

W77 UCOS
W77 UABS

UP.AT
USSP
USID
UPAT

Indicator

Geographical

Location Coordinates19501 Aberdeen S.
19502 Winnipeg/

Dakota N46
Canada N50

W98 USOX
W94 UFOF

Canada N58
Bav Canada N74
Davis Texas
USA N31W94 UABS
W94 UABS,
W104 URAN

Kenora19601 Churchill
19701 Resolute
20301 Ft.

203 02 Houston Texas

USA N320401 NOAA, Colo.
Boulder UR.AN,
20402 U.

21301 Sacramento
pPak USSP.

21302 Tucson Ariz.
21303 White
21401 Climax

Colo.

Mex.

W105 UFLA,N40

USA N32

W105 URAN

USID

W105 UFLA,

UPAI
UCOE

USA N32
Mex. USA N32
USA N39

Sands N.
Colo.

WHO UMAG'
W107 USID,
W106 UFLA.

Canada N52
USA N34
Calif.

Anereles

UP^

URM
IM
USSf

US ID, UFOJ
USOX

N.

21501 Saskatoon
223 01 Corona Calif.
22302 Lockheed Burbank,

UFOP

0 W105 UFLA,USA N40of Colo. Boulder,USA

223 03 Los

Codes

USA

Calif.

UFOJ
UPAI
UCOR, UCOS

W106 UAUR
W118 USID,
W118 UFLAN34

USA N33

UM

W118 UFLA,

UPM

USSP, URAL
22304

Calif
Mt

Palo

22501

Penticton

W118

N37

W122

N49

W120

N57

W13

N61

W150

USSP

,

Calif
22401

N31
USA

Wilson
.

URAL

USA

Alto
.

URAN
B

C
Canada
.

.

UMAG
23601

Sitka

AlaskaUSA

9Sfim

Anrhfira

AlaskaUSA

5

mi
UMAG, UPM
W147 UABS,
UFOF
UMAG, UM
USID,

25602 College Alaska

USA N6426201 Honolulu Hawaii
9fi9.n9 ManiHal

USA N21
USA N20

W158 USID
W157 UFLA,TISA N20

W157 UABS.

TISTD

pa‑ Hawaii

USSP
9 ≪9.m Mdiii

NRS Hawaii

26204 Oahu Hawaii
USA N2l W158 UFLA,
26701 Barrow Alaska
USA N71 W157 UMAG
28701 Cape
Schmidt USSR N69 W179 UFOF
30201 Tamanrasset Algeria N22 E05 USID.
30401 Pic‑du‑Midi
3 0402 Tortosa Soain N4130501 Baemeux France N49

France N43

E00 UCOR,EOO UFLA,
E02 USID

US

UFOF
UPA'

UMAi
UFOF
UCO:
UPA

USSP, UFO
UMAG

Indicator

Geographical

Location Coordinates

Codes

30502 Bretigny France USOX
v/iic*mu v.
30503 Chambon‑la‑France N48

E02 UMAG

Foret

30504 DeBilt Netherlands N52 E05 UFOF
30505 Dourbes Belgium N50 E05 UMAG
30506 Garchy France N47 E03 UMAG
30507 Kootwijk Netherlands N52 E06 UFOF
30508 Meudon France N49 E02 UFLA,
30509 Nancay France N47
30510 Nera Netherlands N52

E02 URAN,
E05 UFLA,

30511
Poit

iers

France
N46

E00

N50

E04

UPAT,
UPLA
URAL
VMAG,
UPAT, URAN,
USSP, URAL,
USID, UCOS,
ADV
USID

UFOF
,
30512
Uccle
Belgium

UFLA

UPAT
,

31401
Anacapri‑G
Italy

N40

E14

Italy

N40

E14

UFLA

UPAT
,

31402
Anacapri‑S
UFLA

UPAT
,

31403
Arcetri

Italy
N43

Ell

UFLA
UPAT
,
,

USSP

uoor,

31404 Bologna Italy N44
31405 Catania Italy N37

Ell UCOS,
E15 UFLA,

33.406 Rome Italy N42

E12 UFLA,

31501 Arosa

Switzerland N46

31502 Berlin‑Ad‑
lershof31503 Breisach GFR N48
31504 Darmstadt
31506 Juliusruh/
Rueeren

31507 Kanzelhohe
31508 Kiel GFR N54
Q 1 ^ no n

E09 UFLA,GDR N53

E14 URANGFR N50
GDR
N54

E07 UFOF,
E09 USID
E13 UFOF

GFR N46/‑>VI

m^R

E14 USSP
E10 URAN,
ftE1 1 UCOS

T*I431510 Kuhlungsborn
GDR N5431511 Lindau GFR N51
31512 Ljubljana
Yugoslavia N46
31513 Locarno Switzerland N46

E12 USID
E10 UFOF
E15 USSP
E09 UFLA,

31514 Luchow GFR N53
31515 Neustrelitz
GDR N53
31516 Ondrejov Czechoslovakia

Ell PROP
E13 USID
E15 UFLA,

31517 Panska
31518 Predigtstuhl
31519 Pruhonice
31520 Tremsdorf
31522 Wendelstein

31523 Wingst GFR N54

Ves

Czechoslovakia
GFR N47
Czechoslovakia
GDR N52
GFR
N47

USOX

u o^/rs.
URAN
XJPAT,
USSP
uoor
UPAT,
USID
UPAT
USSP,
UCOR
.

N50
N51
N50

E15 USID
E12 UCOS
E14 UMAG
E13 URAN
E12 UFLA,

E09 UMAG

UCOS

UPAT,
USSP

un/UN .

USSP

Indicator

Geographical

Location

Coordinates31524 Witteveen
Netherlands N53
31525 Zurich Switzerland N47
31801 Spitzbergen
32001 Bangui Central

Norway N78
AfricanCodes

E07 UMAG
E08 UFLA,UPAT.
TIS5S5P

E15 UABS
N04 E19 UMAG

Republic
32401 Athens Greece N38

E23 UFLA,

32402 Belgrade Yugoslavia N45
32403
Greece32501 Thessalonika
Budapest Hungary
N47 N41

E20 USSP
E23
E19 UFLA,
UFOF

UPAT

32502 Lomnicki Czechoslovakia N49

E20 UCOS,

UAUR

Sti t

32503 Skalnate Czechoslovakia
Pleso
32504

N49

USSR

UPAT,
ussp, usid￨
uran

E20 USSP

N50

E24

N60

E17

UFL

A

Lvov

32601
Emmaboda

SwedenEnkoping

SwedenLycksele

Sweden

UFOF

32602

N60

E17

N65

E19

USID

UAUR
,

32603
UFOF

UMUF
,

32604
Nurmijarvi

Finland

Stockholm

Sweden

N61

E25

N59

E18

UFOF

UMAG
,

32605

UFLA

UPAT
.

.

USID

32606 Andenes
Uppsala Norway
Sweden N69
N60
32701
32702 Kiruna Sweden N68

E18 UCOSUFOF,
E16
E20 UABS,

32703 Tromso Norway N70
333 01 Helwan Egypt N3
o o a ＼if
Di Pnm

UMUF
UFOF,
UMUF

E19 UMAG
0 E31 UMAG
4 E2 6 UFLA

cini n N4

,UP
USSP

33402 Simferopol USSR

N44

E34

UFLA,

33501 Kiev USSR

N50

E30

UFLA

33601 Leningrad USSR

N60

E31

URAL

33701 Ivalo Finland

N69

E27

UCOS

33702 Murmansk USSR

N68

E33

UABS

33703 Sodankvla

Finland N67

34101 Djibouti Fr.
34401 Abastumani USSR N41
34402 Kislovodsk USSR N43
iruovL‑ , TTSST? N50
34502 Moscow USSR N55

E27 UFOF.

Somaliland N12

AT

USSP

UMA ≪

E43 UFOF
E43 USSP
E42 USSP
E36 UFLA
E37 UFLA,

URAN,
UMAG

34503 Gorky

USSR N56 E44

URAN34601 Arkhangelsk

USSR N65 E40

35401 Tehran

Iran N3

36401 Ashkhabad

USSR N37 E58

UFOF37201 Ahmedabad

India N23 E73

UFOF37401 Tashkent

USSR N41 E70

UFLA,37701 Salekhard

USSR N66 E66

UFOF

UMAG

6 E52

UFLA,

UP

USSP

AT

Indicator

Geographical

Location

38101 Kodaikana1

Coordinates

India N10

E77 UFLA,

38102 Thumba India N09

38201 Hyderabad
38301 New
38401 Alma

Codes

E77 TIFOF

India N17

E78 UFLA,

Delhi India N28
Ata USSR N43

N74

E81 UFOF

40501 Irkutsk USSR N52
42101 Manila Philippines N14
42102 Quezon
City Philippines N14

Rep.
of China USSPUPAT

E77 USID
E77

3 8 7 0 1 D i x o n USSR

42201 Baguio Philippines N16
42202 Taipei Taiwan,

UPAT,
USSP, USID,
UFOF, UMAG

E104 UFLA,
E121 USSP
E121 UFLA,
E120 USSP'
E121 UFOF,

N25

URAN
UPAT,
USSP, USID,
URAN, UFOF
UMAG,

42301 Nanking China

N29

El16 UFLA,

UPAT

43301 Okinawa R.I.

N26

E128 USID,

UFOF

N43

E132 UFLA,

43401 Voroshilov

USSR

USSP,
URAN

43402 Seoul Korea N38
43501 Khabarovsk

43601 Yakutsk USSR N62

43701 Tiksi
Bay
44301 Toyokawa Japan N35

E127 UFOF
E135 UFOF

USSR N48

E130 UMAG,

USSR N71

UFOF

E129 UCOS
E137 URAN

4 4 4 0 1 H i r a i soJapan N3

El41

URAN, USID

4 4 4 0 2 K a k i o ka

Japan N36

6

E140

UMAG

4 4 4 0 3 K o k u b unji

Japan N36

E139

UFOF, ADV

44404 Mitaka

Japan N36

E140

UFLA, UPAT,

Japan N36

E138

USSP, URAN
44405 Mt.

Norikur;

UCOR, UCOS

TAO

44406 Tokyo Japan N36
44407 Mt.
Norikura
Japan N36
IPCR
45601 Magadan USSR N60
56301 Buenos
Aires
Argentina S35
56302 San
MiguelArgentina S34

E140 UCOS
E138 UCOR

56303 Tucuman Argentina S26
56501 Port
Stanley57101 Huaneayo Peru S12

W65 UFOF
W58 UFOF
W75 UFLA,

F.I. S52

E151 UFOF
W58 URAN,W58 UFLA,

62801
Station
65201 Byrd
Tahiti Polynesia
S18 Antarctica S79
66201 Rarotonga
Cook
Islands S21
70901 South
Pole Antarctica S90
72301 Capetown South
Africa S34

W120
W150 UAUR,
UFOF
W159 UFOF
E00 UABS
E18 UFLA,

72701 Roi
Baudouin
73001 Lwiro Congo S02

E24 UABS
E28 URAN,

Antarctica S70

UCOS
UPAT,
USSP
UPAT,
USID, UMAG,
UFOF

UABS

UPAT,
UFOF
UFOF

Tnriir.at.or

GeoeraDhinal

73301 Potchefstrom
73302 Johannesburg
74701 Syowa
75201 Tananarive

Location

Base

Coordinates

South Africa S27
South Africa S26
Antarctica S69
Malagasy
Rep. S20

Codes

E27 UCOS
E28 UFOF
E40 UABS
E48 UFOF

76701 Mawson Antarctica S68
77501 Kereuelen
Island S49

E63 UFOF
E70 UCOS,

79101 Cocos
81201 Carnarvon

E97 UFOF
E114 UFLA,

Island S12Australia S25

usid
UFOF, UMAG

URAN, USID
81702 Casey Antarctica S66
81801 Vostok Antarctica S78
82301 Gnangara Australia S32
82302 Mundaring Australia S32
84001 Vaniu Australia S03
84301 Woomera Australia S31
84701 Terre
Adelie Antarctica S66

E110 UFOF
E105 UMAG
E116 UMAG
E116 UFOF
E141 UFOF
E136 UFOF
E141 USID,

85101 Port
MoresbyAustralia S09
85201 Townsvilie
Australia S19
85301 Brisbane Australia S27
85302 flanhfirra Anstra
1 i a S3

E147 UFOF
E147 UFOF
E153 UFOF
5 "El 4Q TTFOF

R53 03 Hiile‑oora Australia S3

0 E149 UFLA,

85304 Sydney Australia S34(Fleurs) USID,

E151 URAN,

85401 Hobart Australia S43
87301 Norfolk
Island S29
87401 Wellington

N.Z.

UMA(

UFOF

UMAG
UPA'
URAN, USI1
USSP

URA
UMA

E147 UFOF
E168 UFOF
S41

E175 UFLA,

UPi

USSP
87402 Christchurch
N.Z. S43
87501 Campbell
Island S52
87801 McMurdo Antarctica S77
87802 Scott
Base Antarctica S77
88301 Rami!
Tel anH V o r>mo H o T QOQ

E172 UFOF
E169 UFOF
E166 UABS
E166 UFOF
n
7C

PART

A.V.2

STATIONS

StationAND

INDICATORS

Indicator

Abastumani 34401
Aberdeen 19501
Abinger 10501
Ahmedabad 37201
Aires/Adour 10402
Alma Ata 38401
Anacapri‑G 31401
Anacapri‑S 31402
Anchorage 25601
Andenes 32701
Arcetri 31403
Arecibo 17202
Arkhangelsk 34601
Arosa 31501
Ashkhabad 36401
Athens 32401
Bagneux 30501
Baguio 42201
Bangui 32001
Barrow 26701
Belgrade 32402
Berlin H. Hertz 31502
Bologna 31404
Bordeaux 10401
Boulder NOAA 20401
Boulder U. of 20402
Colo.
Breisach 31503
Bretigny 30502
Brisbane 85301
Bucharest 33401
Budapest 32501
Buenos Aires 56301
Burbank (Lock‑ 22301
Heed)
Byrd Station 62801
Campbell Island 87501
Canary Islands 12301
Canberra 85302
Cape Schmidt 28701
Capetown 72301
Carnarvon 81201
Casey 81702
Catania 31405
Chambon‑la‑Foret
30503
Christchurch 87402
Churchill 19601

IN

ALPHABETICAL

Station

ORDER

Indicator

Climax 21401
College 25602
Cocos Island 79101
Corona 22301
Culgoora 853
03
Dakar 12101
Darmstadt 31504
DeBilt 30504
Deep River 18501
Dixon 38701
Djibouti 34101
Dourbes 30505
Emmaboda 32601
Enkoping 32602
Fredericksburg
18403
Ft. Davis 20301
Freiburg 31504
Garchy 30506
Gnangara 82301
Gorky 34503
Great Whale 18502
Helwan 33301
Herstmonceux 10502
Hiraiso 44401
Hobart 85401
Honolulu 26201
Houston 203
02
Huancayo 57101
Hyderabad 38201
Irkutsk 40501
Ivalo 33701
Jamaica 18201
Jodrell Bank 10503
Johannesburg 73302
Juliusruh/Ruegen
31506
Kakioka 44402
Kanzelhohe 31507
Kerguelen 77501
Khabarovsk 43501
Kharkov 34501
Kiel 31508
Kiev 33501
Kiruna 32702
Kislovodsk 34402
Kodaikanal 38101
Kokubunji 44403
Kootwijk 30507

Station

Indi c a t o r

Kranzbach 31509
Kuhlungsborn 31510
Lannion 10505
Leningrad 33601
Lindau 31511
Ljubljana 31512
Locarno 31513
Lockheed (Bur 22302
bank)Lomnicki Stit 32502
Los Angeles 22303
Luchow 31514
Lulea 32602
Lvov 32504
Lwiro 73001
Lycksele 32603
McMurdo 87801
McMath 18404
Magadan 45601
Manila 42101
Maui (Haleakala)
26202
Maui (NBS) 26203
Mawson 76701
Meudon 30508
Mitaka 44404
Mt. Norikura 44407
IPCR
Mt. Norikura 44405
TAO
Mt. Wilson 22304
Moscow 34502
Mundaring 82302
Murmansk 33702
Nancay 30509
Nanking 42301
Narssarsuak 14601
Nera 30510
Neustrelitz 31515
New Delhi 38301
Norfolk Island 87301
Nurmijarvi 32604
Oahu 26204
Okinawa 43301
Ondrejov 31516
Ottawa Domin. 18405
Obs.
Ottawa NRC 18406
Ottawa CRC 18407
Ouagadougou 10101
Palo Alto 22401
Panska Ves 31517

StationIndicator

Paramaribo 15101
Penn State U. 18408
Penticton 22501
Pic‑du‑Midi 30401
Poitiers 30511
Port Moresby 85101
Port Stanley 56501
Potchefstrom 73301
Potsdam 31513
Predigtstuhl 31518
Prospect Hill 17403
Pruhonice 31519
Quezon City 42102
Ramey AFB 17201
Raoul Island 88301
Rarotonga 66201
Reykjavik 12601
Resolute Bay 19701
Roi Baudouin 72701
Rome 31406
Sacramento Peak 21301
Sagamore Hill 17401
Salekhard 37701
San Miguel 56302
Saskatoon 21501
Scott Base 87802
Seoul 43402
Simferopol 33402
Sitka 23601
Skalnate Pleso 32503
Slough 10504
Sodankyla 33703
South Pole 70901
Spitzbergen 31801
St. John's 15501
Stockholm 32605
Sydney (Fleurs) 85304
Syowa Base 74701
Tahiti 65201
Taipei 42202
Tamanrasset 30201
Tananarive 75201
Tashkent 37401
Tehran 35401
Terre Adelie 84701
Thessalonika 32403
Thule 17801
Thumba 38102
Tiksi Bay 43701
Tokyo 44406
Tortosa 30402

Station

Indicator

Townsvilie

85201

Toyokawa

44301

Tremsdorf

31520

Trinidad

16101

Tromso32703

Tucson213

02

Tucuman

563

03

Uccle

30512

Univ.

Park

18409

Uppsala32606

Vanimo

84001

Voroshilov(Ussurisk)

43401

StationIndicator

Vostok 81801
Wallops Island 17402
Washington NASA 18401
Washington
USNRL 18402
Wellington 87401
Wendelstein 31522
White Sands 21303
Wingst 21523
Winnipeg/Kenora 19502
Witteveen 31524
Woomera 84301
Yakutsk 43601
Zurich 31525

PART

A VI.

RWC

This section
concerns
and the ARWC's.
An
attempt&

ARWC

the major
has beenthe "real time"
data available
H p c p r i thpi
v m n i nr nvnHnpfc

at65

specificsof the RWC
made to include
alleach RWC as well as toPART A VI.1

Western

Hemisphere

RegionWarningWORLD WARNING

AGENCY(WWA)

andCenterRWC BOULDERSupervisory
Immediate Charge
cast Center)

Dr. D.J.
(Fore‑

Immediate
Charge(Com‑munication
Center)Williams,

R.B.

Doeker

D.M. Baker
J.D. Schroeder

Mail Address

Space Environment
Services Center(NOAA)
325 Broadway, Radio Bldg., Rm. 2010
Boulder, Colorado
80302
US A

Telephone

303‑499‑1000,

Telex

45897

TWX

303‑443‑3653

U.S. Military

Teletype

3171

SOLTERWARNRUWTGPASOLTERWARN,

Cable

Extension

Boulder,

Colorado

Operating

Organization

National Oceanic
Administration,of Commerceand Atmospheric
U.S. Department

Operating

Hours

Communication Center 24 Hours/day,
7 days/week
Forecast Center 24 Hours/day, 7
days/week

Outgoing

Messages(Data)

Solar and geophysical data for
IUWDS interchange
issued daily
nominally at 0400, 1600, 2100 UT(Alert)PRESTOGEOALERT(Forecast)as appropriate
at 0230

UT

Regular solar and geophysicalactivity summary and forecast
issued daily at 2200 UT

Data collected

at RWC(WWA) ‑ Observatories

Solar (optical)

Boulder, McMyth, Canary Islands, Ci
narvon, Hawaii, Manila, Ramey AFB,
Athens. Tehran. Mt. Wilson

Solar (radio)

Ottawa, Sagamore Hill, Prospect Hill,
Boulder, Stanford, La Posta, CanaryIslands, Athens, Manila, Carnarvon

Solar Cosmic

Ray

Anchorage, Thule, NASA Ames, Boulder(ATS‑1 satellite), (Pioneer), Suit‑
land (ITOS)

X‑ray

Washington
Greenbelt,

Ionospheric(SID)

Boulder,(NRL, SOLRAD)
Md. (GSFC, OSO‑7)

McMath,Anchorage,

CanaryManila,Tehran,Islands,
La Posta,
Athens. Rampv
AFR

Ionospheric(UPOF)

Geomagnetic
Exchanges

Boulder,
Vandenberg
AFB, Wallops
Is‑
lands, St. John, Newfoundland,
Ft.
Phnrrhi＼. Hawa i i . Ma ni 1 a

Fredericksburg,
Boulderwith

RWC

Anchorage,

Tucson& Others

Telegrams
Time Frequency From/To
0200 UT Daily fromSYDNEY.

mnn
1,ulGEOSOL
1UK.KUOJOO tr'
Daily

WWA

1330‑ rnni
1400‑1‑

Daily

ex.
j.
Daily from1500 Daily?aily to

from
irom

to
to

MOSCOW

PARIS.F.flKlS
MOSCOW

ex. Sat.,ex. Sat.,Sun. from

9inn °n Daily to
Z10

Broadcasts

Sun.
ouii.

Sun ≪ from1500 Daily
i?

TOKYO

everyoneeveryone
PARIS, o, DARMSTADT,
NERA.

rTtr'
Paily <hwa
to

‑i *

(for

details,

DARMSTADT

NERA
irum is.UK.fl
U.S. Agencies°* "Sencies
SYDNEY,TOKYO

see

RWC letter

12m

wwv

Voice message
hour. Message

every hour
at 18 minutes past thenormally changed at 0400 UT.

WWVH

Voice message
hour. Message

every hour at 45 minutes past thenormally changed at 0400 UT.

PART A VI.2

WesternEuropeRegional

Warning

CenterRWC PARIS
Supervisory and
Immediate Charge
Mail

Simon
Ursigrammes Observatoire
92190 Meudon, France

Address

Telephone

027 11 39

TWX

20590

Cable

TX 20590

CNETOBS

CNET
96
Issy' Les' Moulineauxand (Pillet)
OBSERVATOIRE
92 Meudon

CNETOBSX MEUDOMEUDONFRANCE

Operating

Organization

Jointlv:

ODeratine

Hours

0730 UT ‑ 1600 UT
Saturday 0900 ‑ 1400 UT(Closed on Sunday and holidays

Messages(Data)‑ Abbreviatedsolar and ge
physical data issued dai
close to 1400 UT (Sunday
exceoted)

URSIGRAM‑ Solar and Geophysicaldata issued daily (Sun‑day excepted) close to1000 UT and 1400 UT.
(Saturday the 1400 UT
onlv."

Solar activity and geophysicalcjturbances in the GEOSOL and the .
UT URSIGRAM.

(Forecast)Data

GEOSOLcollected

in its

Solar

data

Solar

cosmic

X‑ray

data

Ionosphericarea

Catania, Meudon, Nancay,
MiHi. Roma. Tortosa
ray

data

data

Pic‑du‑lies Kerguelen,

Pic‑du‑Midi

SOLRAD

CNES

BRETIGNEY‑ lies

Kerguelen,through

Daily reports
Poitiers

Weekly reports
Geomagnetic
Exchanges with

data
RWC

‑ Dakar, Djibouti,
Tahiti, Tananarive

Chambon‑la‑Foret,lies

Kerguelen

and WWA

0700 UT From
Boulder and Moscow (occasionallyfrom
Sydney)1000 FromPraha and Tokyo to Darmstadt, Nera, Praha
1200 From
Darmstadt and Nera
1400 To
Boulder,Darmstadt,
Moscow, Nera, Praha
1500 ToTokyo(occasionallyto Sydney)
Country Call
Transmitting
Sta t inn

Frequency
Sign (kHz) Emission

Class

Times

of Remarks
UTFranceSTE ASSISE

FTA91 91.15 A1 i3o￨(l)2008(2)2108(2)

PONTOISE FTK77 10775

A1 1208(1)2008(2)FTN87 13873 A1 1308(1)1000 UT Ursigram
1400 UT Ursigram

at times
at times

2108(2)
denoted (1)denoted (2)PART A.VI.3

Eurasian

Regional
RWC

Warning

CenterMOSCOW

Supervisory and
Immediate Charge

Mme
Mme

R.A.
L.N.

Zevakina
Ljakhova

Mail Address

P/0 Akademicheskii
Gorodok
Moscow District, USSR

Telex

Solter MSK 523

Cable

Moscow

7523 SOLTER

MSK

Operating

Organization

Institute of Terrestrial Magnetism
Ionosphere and Radiowave Propagatii
Academy of Sciences, USSR(IZMIRAN)

OperatingHours

24 hours/day

Messages(Data)

Ursigram:
Solar and Geophysical data issued
daily close to 1600 UT(Forecast)

Solar activity
and geophysicaldisturbances
in GEOSOLat 1600
ionosphericdisturbancesin
URSIGRAMfor National
Centers

Data

collected
its area
Solar

in

Kislovodsk, Simferopol,
Voroshilov
Irkutsk, Tashkent, Moscow, Kharkov
Lvov, Gorky, Abastumani,
Berlin H,
Hertz, Tremsdorf

data

Ionospheric

UT;

data

Daily reports ‑Juliusruh, Budapest,

PruhoniceHourly ‑Druzjnaja, Murmansk, Dixon, Cape
Schmidt, Leningrad, Salekhard,
Yakutsk, Magadan, Khabarovsk,
Mos‑cow. Kiev. Alma‑Ata. Ashkhabad
SID ‑Kuhlunesborn,

Geomagnetic

data

Irkutsk,
Moscow

PanskaKhabarovsk,

Ves,

South

NeustreSachaliExchanges

with

RWC

and

Telegrams
Before 0900
Before

1500

WWA

UT
UT

1600 UT

From Boulder
From Tokyo, Darmstadt, Praha,
Meudon, Sydney, NERA, (occa‑
sionally from India'
To Boulder,Tokyo,
Sydney, Darmstadt,
National
Irkutsk

Ursigram

broadcasts― transmission,
― cx
Time
of
・
M
oscow

legal

0740 ‑ 0810

time cies,

Call

Meudon,India,

Centers,toand Prague

Subcenters

Moscow ‑ three times a day,current data summaries andforecasts
letters o rrequeii‑
Frequen‑RYeM‑4kHz

Remarks

10275 From
3937.5

1/3 to30/9
From 1/10
to 28/2

1330 ‑ 1400

RYeM‑40130 ‑ 0200

RYeM‑44565 All
5780 All
6980 All
5380 All
7450 All
9145 All
13360 All
3937.5 All
4395 All
5780 All
6980 All

year
year
year
year
year
year
year
year
year
year
year

PART

A.VI.4

Western

Pacific

Regional

Warning

CenterRWC TOKYO
Supervisory and
Immediate Charge

I. Kasuya
T. Takiguchi

Mail AddressRadio Research Laboratories'
Ministry of Post and Telecommu‑
nications
2‑1, Nukui‑Kitamachi
4‑chome
Koganei‑shi, Tokyo, 184 Japan

Telephone0423‑21‑1211

Telex

2832611

Telegraph

TLX 2832611(DEMPAKKB)DEMPA TOKYO

Cable
Operating

Organization

Radio

Research

OperatingHours

24 hours/day

Laboratories

Messages:(Forecast)Datacollected
its area

Solar

Radio propagation
advance
forecast issued on Monday
Thursdayweeklyandin

Hiraiso.

data

Mitaka.

Mt.

Norikura,

Toyokawa
Solar cosmic

ray data

Mt. Norikura,

Ionospheric

data

Hiraiso,Geomagnetic

data

KakiokaTokyo

X‑ray data

Exchanges

with RWC

0100 UT To
0230 From

Kokubunji(dailyand WWA
Boulder
Sydney033 0 From
0430 From

Boulder
Boulder

0730 To
1400 From

Boulder,
Paris

1500 From

Moscow2000 From

Boulder

2100 From

Sydney(advice(Geoalert)Parismessageonly)

report)Ursigrambroadcasts:

Means of transmission
The message begins with theword "URSIGRAM" and the text of
message is repeated twice. Broadcastingtakes the following
1)

The following are sent repeatedly
the time of the above schedule:2)

Immediately
after the end of theabovenals and information
below are sent:

VVV WVVW

DE JJD/JJD2

five

JJD/JJD2

times beginning
JJD/JJD2
signals,CQ CQ CQ DE JJD/JJD2

JJD/JJD2

JJD/JJD2AR VA DE JJD/JJD2

JJD/JJD2

JJD/JJD2URSIGRAM= text‑ textofofmessagemessage

AR

at

RPT

the

sig‑

PART A.VI.5

Australasia

and Antarctica

Regional

Warning

CenterRWC SYDNEY
Supervisory and
Immediate Charge

C.G. McCue
F.E. Cook

Mail

IUWDS Regional Warning Center,
Ionospheric Prediction
Service
Division
P.O. Box 702
Darlinghurst, N.S.W. 2010
Australia

Address

Location

162‑166 Goulburn Street,
Darlinehurst (Sydney)

Telephone

2698615

TWX
Telex

IPSO

20663

Telegrams

IPSO

SydneyCable

IPSO Sydney

Operating

Organization

IonosphericDivision
BureauOperating

Hours

of

Prediction

Service

Meteorology

2230‑ 0630UT (and closed
later asquired)(sometimes
fromre‑0300 UT on Saturdays, Sundays,
and holidays)

Messages

Ursigrams:( Data )Solar

and GeophysicalData
issued daily
at 0100
UT, fol‑
occasionallyat 0600
UT, andlowing major events(Forecast)

Daily in TAdviceT message to WWA
and occasionally as required toorganizations
mostly in Australia,
New Zealand and Antarctica

Data collected

in region

Solar(optical)data

Solar data (radio
noise)

Culgoora,

Carnarvon

Sydney, Culgoora,

Carnarvon

Solarcosmic

X‑ray

data

ray

cosmicIonospheric

data

(SID)

Ionospheric

data

(SID)

Sydney,(UFOF)

Canberra,

Weeklyreports

lands,

Brisbane,

Canberra,

Geomagnetic
Exchanges

data
RWC

and

2230

UT

From

Is‑

Hobart,Island,MawsonPort

Moresby,

Casey,

Sydney,Cocos

Gnangara

WWA

Boulder,
ing

0100 To

the
Boulder,To

Moscow
Boulder,Darmstadt
0800 From

Norfolk
Townsville,

Mundaring,

sionally

0600 To‑

Vanimo,Canberra,with

Culgoora

Tokyo

Tokyo,

Paris

Moscow,(messages

andreceivednight)
Tokyo(Events)
Tokyo,

Moscow,(Events)(JJD

Broadcast)Paris,

occa‑
dur‑PART A,VI.6

West

Germany
RWC

Regional

Warning

CenterDARMSTADTSupervisory and
Immediate Charge

Dr. Eyfrig
Mr. S. Elm

Mail Address

FTZ

D

33

Am Kavalleriesand
61 Darmstadt
Federal Republik
Darmstadt

Telephone3of Germany(06151)

83‑25 30 (Eyfrig)
25 33 (Elm)

TWX
Telex

0419291

IONO

Telegraph

IONOSPHERE

D

Darmstadt

Operating

Organization

Fernmeldetechnisches
61 Darmstadt

OperatingHours

063 0 ‑ 153 0 UT
(Closed Saturdays,
Holi days)

Zentralamt

Sundays,

Messages
Solar and Geophysical Data issued
daily at 1200 UT (Saturdays, Sun‑days and Holidays excepted)(Data ‑ Ursigram)

Datacollected
its area

Solar data
(optical)Kanzelhohe,

Solar data(radionoise)

Kiel

Solar cosmic
ray data

Lindau, Kiel

Wendelstein

Ionospheric

data

Breisach, Lindau, Darmstadt,
Kiruna,Slough, Nurmijarvi, Sodankyla,
Lvcksele. Uoosala

Geomagnetic

data

Wiriest, Sodankyla,

Ionosphericpropaga‑tions conditions

Liichow

Nurmijarvi,

EnkopinExchanges

with

ARWC, RWC

and WWA

before0600 UT From Boulder
0700 UT To Stockholm,
0830 UT From Slough
1030 UT From Praha(irregular)

Telex
Praha

(Boulder1200 UT To Boulder,
Meudon, Moscow,holm, Praha
1330 UT NERA and Tokyo via Meudon
1430 UT From Meudon
irregular From
Stockholm
1530 UT From Moscow
after 1630 UT From Austria
Mail 1530

Message)

Stock‑UT To Athens,
Stockholm, Meudon,
Bruxelles, Praha, Vienna, Tokyo,
Ent.‑Colo., Sydney

PART A.VI.7

Scandinavian
ARWC

Associate

Regional

Warning

CenterSTOCKHOLM

Supervisory and
Immediate Charge

L. Hultman

Mail Address

Central Administrationof
Swedish Telecommunications
Development Department
S‑12386 Farsta. Sweden

Telephone

Sweden 87132105
orStockholm
7132105TWX
Telex

053 19208 Radgen S (after053 19734 Tgfstkra S)

Cable

RADIOGEN

hours

Stockholm

Operating

Organization

Central Administrationof
Swedish Telecommunications

OperatingHours

0700‑1540 UT
0700‑1500 UT May‑August(closed Saturdays, Sundays
holidays)

Messages(Data)

Alerts, solar and geophysicaldata issued temporarily(Forecast)not

Data collectedits

issued

in

area

Solar

Stockholm

data

Solar cosmic

ray data

X‑ray data
Ionosphericdata

Enkoping, Uppsala,Kiruna, Sodankyla,

Geomagnetic

data

Enkoping, Sodankyla,

Exchanges
0700

with
UT

From

0900 From
0900 To

1300 From
1500 From

RWC

and WWA
Boulder,via

WMO

Darmstadt
Darmstadt.

NERA

Paris

NERA

Lycksele,
Nurmijarvi
Nurmijarvi

PART A. VI.8 Czechoslovakia

Associate

Regional

Warning

Center■ARWC PRAGUESupervisory and
Immediate Charge

P. TriskaAsst. M. Jiskra

Mail Address

Geophysical InstituteBocni II
Praha 4 ‑ Sporilov
Czechoslovakia

Telephone762548Telex

11 346 XONPC

Operating

Organization

Geophysical Institute of the
Czechoslovak
Academy of Sciences

OperatingHours

0530 ‑ 1330 UT(closed Saturdays,
and holidays)

Sundays

Messages(Data ‑ Ursigram)Solar and Geophysical Data
issueddailydays)
at 1000 UT(Operating

Data collected
its area
Solar data

(optical)Ondrejov, Skalnate

Solar data(radio)Berlin, Neustrelitz,

Ionosphericdata

Pruhonice, Panska Ves, Juliusruh,
Kuhlungsborn, Neustrelitz

Geomagnetic

data

PruhoniceExchanges

with

Pleso
Ondreiov

RWC

TelexA
0700

UT

0700
1000

From
From

From

1000 To
1200 From
1400 From

Darmstadt

MnsrnwParis.

NTCPA

Darmstadt,
Darmstadt
Paris

Moscow,

NERA,

Paris

PART A.VI.9

India

Associate

Regional

Warning

Center

ARWC NEW DELHI
Supervisory
andImmediate
ChargeA.P. Mitra
Associates:

Mail

c/o National PhysicalDelhi‑12, INDIA

AddressDr.
B.M.
Mr. P.L.

Telephone585298, 582045
584213 (Dr. MitraTs

Telex

ND 522

Telegraph

NATPHYLAB

Reddy
MalhotraLaboratory

residence)

CSIR

Operating

Organization

National PhysicalDelhi‑12, India

Laboratory

OperatingHours

10.15 A.M. to 5.15 P.M. I.S.T.
Closed 2nd Saturday, Sunday andother closed holidays.

Messages

Ursieramand Geoalerts(Data)

Geoalert Messages are being re‑ceived from RWC Tokyo. Thesemessages are received by R.T.T.
MULTIPLEX Systems from Tokyo toDelhi via Bombay (Teleprinterline from Bombay to Delhi) at
about 1100 hrs I.S.T. To
thisDelhi Data of foF2 and SID isadded and a consolidated
messagegoes out daily via the following
channels:(1) Transmitted
through NPL Standard
Service (ATA) on 10 MHz daily at 1500

Time
hrs.

& Frequency(2) Transmitted
by AIR as a plain message daily at
2240 hrs. I.S.T. (2310 hrs on Saturdays).
Thefre‑quencies used are 3,4,6,7,9 and 10 MHz. These
fre‑quencies are periodicallyalerted.
(3) Themessage is also put on R.T.T. broadcast
IMD) at 1805 hrs G.M.T. R.T.T.
frequencies
used19, 12, 7 and 3 MHz.

(bj
are

PART

A.VI.10Siberian

Associate

ARWC

Regional

Warning

CenterIRKUTSK

Supervisory
andImmediate
ChargeDr. E.S. Kazimirovsky
Ms G.V. Belikova

Mail Address

Siberian Institute ofTerrestrial Magnetism
Ionosphere and Radio Propagation(Sib IZMIR) 664033
Irkutsk 33, Box 4, USSR

Telephone

4‑55‑66;

4‑37‑34

Irkutsk

Ionosphernaya

Telegraph
Cable
OperatingOperating

Organization

Sib IZMIR
Siberian Department Academy
Sciences of the USSR
24 hours

Hours

a day,

all

of

days

Messages

(Data

State
field

)

Supply some organizations
monthly
forecastsof theradio frequency
intervals;
and 12‑hour
forecastsofdisturbances.

(Forecasts)

Dataof ionosphere,
magnetic
and radio communications
with
useful5‑dayionosphericcollected
its area

in

Solar

(optical)Irkutsk,

Moscow,

Ussurisk

Solar data (radio)

Moscow,

Irkutsk,

Ussurisk

Solar cosmic

ray data

Irkutskdata

Irkutsk, Yakutsk, Norilsk, Novo‑
sibirsk, Sverdlovsk, Khabarovsk,
Moscow, Salekhard,
Magadan, Tomsk,
Cape Schmidt

X‑ray

data

data

IonosphericGeomagnetic

dataInterregional
tacts

Irkutsk, Khabarovsk,
Sachalinsk, Moscow

South‑

Con‑
1 Receivingof Japan Ursigram
Broadcasts JJD.
2 Receivingfrom NCXAA of "Preli‑minary Reports and forecasts
of solar‑geophysicaldata".
3 Receiving
through Moscow RWC
some geophysicaland solar
data from foreign observatories.
4 PRESTOS
to Moscow, Boulder
and Jakutsk, InstituteofSpace Physics and Aeronomy.

Exchanges

with

RWC:

Telegrams

PRESTOS to SOLTERWARN,
and Yakutsk, InstitutePhysics and Aeronomy

Broadcastsa) Monitor Japanese
broadcasts, JJD,
2200 UTb) See following
missions fromTransmission time,
Moscow legal time
0540‑0600
1740‑1800

Frequency
kHz

10344
5860
7545
5860
3740
4490

Moscow,of Space

Ursigram
1100 andtable for trans‑
Irkutsk.

PART A.VI.11

Netherlands

Regional

Warning

CenterRWC NERA(Not Operating

At Present)

Supervisory and
Immediate Charge

G. Brussaard
A. PelMail Address

Section Propagation
RCL
Dr. Neher Laboratory
St. Paulusstraat
4
Leidschendam, Netherlands

Telephone

The Hague (070) ‑ 755696
Nera (02945)‑ 1441(Brus;
(Pel)

TWX

Telex

12 308 propa

Cable

TONRAST

nl

LEIDSCHENDAM

Operating

Organization

Netherland Postal andcation Services
Dr. Neher Laboratory

OperatingHours

0730 ‑ 1600 UT(Closed Saturdays,
holidays)

Telecommuni‑

Sundays,andMessages(Data)

Alerts, Solar and Geophysicaldata
1300 UT daily(Saturdays, Sundays
and holidays
excepted)(Forecast)

Solar and Geomagnetic

activity

NERA, Capri

Stockholm)

Data collected
its areainSolar data (optical)(through

Solar datanoise)(radioIonospheric

data

De Bilt (K.N.M.I.).

Geomagnetic

data

Witteveen, NERA

Kootwvk(P.&T.)

Exchanges

Telex

with

RWC

and

0700

UT

From

BoulderPraha,

1300

From
To

1500

To

Boulder

1000

No

radio

broadcast

WWA

Meudon,MeudonoftheUrsie'rams.

(including

Tokyo)

PART

A.VII

NATIONAL WARNING CONTACTS(as of May 1972)
Although only a few
nations maintain RWC's and ARWC's,
almost all nations have designateda National Warning Con‑tact (NWC). NWC'sserve as the interface between scientistsof their nation and the IUWDS. Alphabeticallybynation,Argentina,

RepublicofServicio Meteorologico
Nacional
25 de Mayo 658
Buenos Aires

Brasi 1
Dr. Fernando
de Mendonca
General
Director
I N P E CX Postal 515
12200‑S Jose' dos Campos

lustralia
Mr. F. E. Cook
Ionospheric Pred. Servic
P.O. Box 702
Darlinghurst NSW 2010

Bulgaria

Cables: IPSD
A 20663
Telephone: 616791,
ext.

Telegraph: SOFIA,
MGSS
Telex: SOFIA,H METEOR SS 542
Telephone: Sofia,
1‑22‑71,
7‑24‑50
Immediate Charge: Sasho
Mulushev

AustriaProf. Dr. Ferdinand
Stein‑
hauser, Director
ZentralanstaIt fur Meteoro‑
logie und Geodynamik,
Hohe
ViennaWarte
1190 38,

Mr. U. Ba Kyi
Assistant Director
Burma Meteorological

Department

Building

CanadaNicolet,InstitutdfAeronomie
tiale
AvenueCirculaire3
R‑1180RriiRSf^ 1 R

ServiceBurma

New Secretariat
Merchant Street
RangoonBelgium
Prof. Marcel
Director

Hydro‑Meteorologicalboul. Lenin 146,
Sofia

Spa‑

Dr. T. R. Hartz
Communications
ResearchCenter

Department
1241 Clyde of
Ave.Communications
Ottawa, Ontario
K2C
1Y3

Bolivia

CeylonDr. Luis Fernandes,
Director
Laboratorio de Fisica
Co'smica
Universidad Mayor de San
La Andre's
Paz

Mr. R. Mahadeva, Secretary
Ceylon National Committee for IQSY
Department of Meteorology
Bullers Road
Colombo 7

NWC

China, Republic

EthiopiaofProf. K.H. Pai
Department of ElectricalEngineering
National Taiwan University
Taipei, Taiwan

Dr. Pierre Gouin
Director of the GeophysicalObservatory
Haile Sellassie I University
Addis Ababa

Colombia

FinlandJefatura de Estudios
Escuela Naval de Colombia
Cartagena

Mr. Terho Haikonen
Radio Division
The Finnish P T T
Box 511SF‑00101 Helsinki 10

Cuba
Director
Observatorio
Casa Blanca
La HabanaFranceNacional

Cables: CLIMATO‑HABANA
Telephone: 60‑1231
Czechoslovakia
P. Triska
Geofyzikalni
Ustav
Bocni II
Praha 4, Sporilov

CSAVTELEX: Oil
346 ‑ ION PRU‑
HONICE
Telephone: 727
788 or792 204
Denmark
Mr. Jorgen Taagholt
Det Danske Meteorologiske
Institut
Ionosfaerelaboratoriet
Dansmarks Tekniske
Hojskole
2800 Lyngby
Kobenhavn
East Africa
Department of Physi
University College
Dar es Salaam

Dr. Yvette Avignon
Observatoirede Paris‑Meudon
92190 Meudon
German Democratic

Republic

Dr. W. Lippert
German Academy of Sciences
Central Institute of Solar‑Terres‑trial Physics, Observatory
Neustrelitz
DDR‑208‑Neustrelitz
5
Ka lkhorstweg
Cables: OBSERVATORIUM
NEUSTRELITZ
Telex: 033
727 (Key word: hhi
nsdd)Telephone: 3279,
3203
German Federal

Republic

Dr. B. Beckmann
Deutsche Bundespost
Fernmeldetechnisches
Zentral61 Darmstadt Postfach 800
Ghana
The Director
Meteorological
Services
Department Headquarters
P.O. Box 87
Legon

NWC

GreeceIndonesia

IonosphericInstitute
National
Observatory
AthensThision306‑Athensof(Cont.)

Director,
MeteorologicalGeophysicalInstitute
Djalan Geredja
InggrisDiakarata

and3

Ireland

GuatemalaEngr. Haroldo Duarte Villela
Chief of Geophysics
SectionDireccion General de Carto‑
graflaAvenida "Las ‑Americas" 5‑76
Zona 13, Guatemala
City,
C.A.
Telephone:Hong63281‑2‑3

Kong

Mr. G.J. Bell
Director,Royal
Nathan Road
KowloonObservatory

Dr. Aharon Eviatar
National Committee
Research
1740 Ramat‑Aviv

Dr. Thorsteinn
SaemunScience
InstituteDunhaga
Reykjavik
India
Dr. B.M. Reddy
Radio Science
Division
National
PhysicalLabora‑tory
New Delhi 12

Professor M. Giorgi
Consiglio Nazionale
Delle Ricerche
Piazzale Delle Scineze
Rome 00100

Jamaica

7

W.I.

Dr. G.S. Kent
Department of Physics
University of the West
Kingston 7

Mangoensoemarto

IndiesJapan
Dr. Isao Kasuya
Radio Research Laboratories
Ministryof Posts and Tele‑
communications
2‑1, Nukui‑Kitamachi
Koganei‑shi
Tokvo. 184
Korea, Democratic
Republic ofIndonesia
Sorrotofor Spaceone: 4993
Observatory

IcelandDr. Ir.

IsraelItaly

HungaryProf. L. Deszo
Director
Heliophysical
Debrecen

Di rector
Meteorological
Service44 Upper
0TConnell
StreetDublinLie Rak Bok
Astronomical
Pyongyang

4‑chome,People'sObservatory

NWC
Korea, RepublicofPhilippines

Mr. Shin‑YongKang
IonosphericPrediction
Section, RRL
Ministry of Communications
Seoul (An Yang)
171 Korea

The
Director
Weather
BureauDept. of Commerce
P.O. Box 2277
Manilaand Ind

Portugal
Netherlands
Mr. G. Brussard
Section Propagation
Dr. Neher Lab.
St. Paulusstraat
4
Leidschendam

RCL

The Director
Serv Meteorologico
Nacional
Rua Saraiva de Carvalho 2
Lisboa 3
Rhodesia

New Zealand

Mr. A.C.

The Director
N Z Meteorological
P.O. Box 722
Wellington

Federal Departmentof Trigonome‑
trical and Topographical
Sur‑
veys
P.O. Box 8181
Causeway, Salisbury

Service

Nigeria
The Director
Meteorological
Headquarters
Lagos

Iauld

Senega 1
Services

Prof. H. Masson
University of Dakar
Dakar
South Africa

Pakistan
Mr. A.W. Kahn
Deputy Director
Pakistan Meteorological
Service
Secretariat Blocks 1‑3
Frere Road, Karachi 3

The Head
Science Cooperation
CSIR
P.O. Box 395
Pretoria
Telegrams:
Telephone:

Division

NAVORS
74‑6011

Cables: METEOR
Spain
Peru
Ing. A. Giesecke
Instituto Geofisico delPeru
Ministerio de Fomento
Apartado 3747
Lima
Cables: AGI

LIMA

Rev. Father J.O. Cardus,
Observatoriodel Ebro
Roquetas (Tarrogona)

S.I.

NWC

SwedenMr. Rune Lindquist
Chief, Section for Ionospher‑
ic Research
Forsvarets ForskningsanstaIt
The Research Institute of theSwedish National Defense
S‑104 50 Stockholm 80
United Arab

Republic

Mr. M.F. Taha
Chairman, Board of Directors
Egyptian Meteorological
Authority
Koubry El‑Quobba
Cairo (A.R.E.)
UnitedKingdom

Director
Science Research Council
Radio and Space Research
StationDitton Park
SloughSL3 9JX
Bucks, EnglandUnited Statesof America

Mr. R.B. Doeker
Space Environment
Laboratory
ERL/NQAA
Boulder, CO 80302

Union of Soviet
Republics

Socialist

Mme. R.A. Zevakina
P/0 Akademicheskii
Moscow District

Gorodok

Viet‑Nam, Democratic
lic ofRepub‑

Nguyen Xien, M6teorologiste
Service Meteorologique
Hanoi
West Africa
W.A.L. Scott
Acting Director
MeteorologicalDept.
F18 Charlotte St., Freetown
Sierra Leone
Zaire Republic
Monsieurle Directeur
Service Meteorologique
Kinshasa II

PART

B

ALERT, ANALYSIS,FORECAST

CODESThis section
defines
the
codes
which
RWCTs are expected
to use in their
daily data interchange.
The
interchangeofalerts, summarydataand forecast
shouldenablethe RWC's toconcentrateon data from theirregions,andgreatly
reducethe quantityof "raw
data" routinely
interchanged
among RWC's.
This
but rather
basic

does not meanthat RWC's

observations

that

raw

data

shouldcarefully
from outsidetheir

Code B.I ‑ PRESTO
Code B.II ‑ GEOALERT/GEOSOL

will not be interchanged,
consider
their
needs
for
own
region.

PART B.I

HUb

PRESTO
1. Content.
Report of major eventsor regional customers.
2. General

to the other

RWC and to the loca!

form.

PRESTO observatory JJHHmm report
3. Definition
PRESTOof symbols.
= key word

observatory

for RAPID= name of reporting

JJHHmmreportingof major

eventsobservatory

in cleartext= Greenwich date and time of issue
in hours and minutes UTreport = one or more of statements
For GEOMAGNETICMAGSTORM
STRONGof message

as below

ACTIVITY

BEGINS JJHHmm
MAGSTORM

WEAK MAGSTORMIN PROGRESS JJHHmm
IN PROGRESS JJHHmm(A>50)(3

0<A<50)Note: One
may add plain language comments related
to auroral reports or Forbush effect expect(
For MAJOR

FLARES

SOFLARE(date‑ importanceclass ‑ coordinates(i.e. N20 E78)
‑ JJHHmmand time) ‑ "duration in minutes given" or state‑ment "in progress"
Note: One
may add plain language comments like"Y‑shaped" or "covering spots" or "sus‑pected proton flare"

For TENFLARETENFLARE(solar radio emission outburst at 10 cm>100%
over background)‑ XX units ‑ JJHHmm for onset ‑ duration inminutes, or statement "in progress" at thetime of PRESTO,
or statement "observed
until hours and minutes UT"

Note: Units
give the increase of the flux
density over the pre‑burst l^evel inconventional
units (10 22Wm Hz ^)by significant
digits and words suchas "1700 units over backgound"
For PROTON

EVENTCOSMIC RAY INCREASE ‑ JJHHmm ‑ percent
normal based on neutron monitor

increase

above

POLCAP ABSORPTION ‑ JJHHmm ‑ dB of absorption by rio‑
meter or ionosphericforward scatter technique
PROTON EVENT ‑ JJHHmm
spacecraft report
Notes: 1.

‑ specify

energy

range

from

a

PRESTO
should be circulated
as soonas the event has been recognized.

2. ThePRESTO will only
eventsand no forecasts. Any reportchange of aforecast would be sent to the in‑terested customers as
a GEOSOL,GEOALERT or in plain language.
3. Ifscheme,
the observatories
follow
it is not necessary
report the

kind

this
to

of experiment

SOFLARE signifies a chromosphericreportTENFLARE signifies a centimetricoutburs
COSMIC RAY INCREASE signifies a neutron
monitor count increase
POLCAP ABSORPTION signifies a groundbased polar cap report
PROTON EVENT signifies spacecraft
report1 ＼T

PA RT B. 11

GEOSOLor
GEOALERT
1. Content.
For sending combined
and for general data
For sending

ADVICEdata andusers

forecasts

to otherinformation

to other

RWCs

RWCs

3. Definitionof symbols.

GEOSOL =key word for sending combined
GEOALERT = key word for sending combined
including
ADVICE information

data anddata and

forecasts
forecasts

III = warning center of origin
MEU ‑ Meudon TOK‑ Tokyo
WWA ‑ Boulder (SOLTERWARN) SYD‑ Sydney
MOS ‑ Moscow DAR‑ Darmstadt
NN = originating
center's serial number
DDHHmm = date (DD) hour (HH) and minutes (mm) in UT of
issue of message
9 = key number to indicate indices follow
HHJJ = the middle of the 24‑hour period for which theindices apply in UT; HH ‑ hour; JJ ‑ date1 = key number to indicate sunspot data follows
aaa = relative sunspot number (Wolf number)b = number of new sunspot groups that have appeared(by rotation or birth) during this period
2 = key number to indicate 10 cm solar flux data follows
ccc = value of 10 cm solar flux in lO^^Wm^Hz""!
units
d = number of known IMPORTANT 10 cm bursts during thisperiod3 = key number to indicate
eee = Ak index for Greenwich

magnetic
dateactivity

follows

f = important
0 =
1 =
2 =
6 =
7 =
8 =

event, if any, where

no event
end of magnetic storm
storm in progress
gradual storm commencement
sudden storm commencement (sc)very pronounced
sudden storm commencement

4 = key number
by neutronggg= medianlevel

to indicate cosmic
monitor follows

level

h ‑ importantinthousandthsofradiationandataarbitraryobserved
normalevent, if any, where

0 = no event
1 = pre‑decrease

2 = beginning of a Forbush decrease
3 = Forbush decrease in progress
4 = end of Forbush decrease
5 = arrival

of

solar

particles

Q ‑ quadrant (heliographic
region whereof the active

3 = SW (south‑west)
4 = NW (north‑west)NE
SE (north‑east)(south‑east)

Note: Definitions(GLE)

coordinates)of classC, M

or X flares

follow:

CLASS

C: A

solar flare which is not associatec
with significant
X‑ray production.

CLASS

M: Solarflares which are accompaniedbysignificant X‑ray production, greaterthan 10 ^ergs cm"^sec"^ in 0‑8A band,or 10"^ergs cm'^sec"^ in 0.5‑5A band,
comparable SID (SWF or SPA).
Solar flares which are accompaniedbygreat X‑ray production, greater than
10 lergs cm‑^sec l in 0‑8A band, or
10‑2ergs cm 2Sec l in 0.5‑5A band,
comparably great SID, or by a 10 cmradio noise outburst of more than
1000 flux units over backgroundandduration greater than 10 minutes.

This classification
is designed
to give an
indicationof the geophysicaleffectwhich
is likely
to be associatedwith a solar
event. ClassC events
will usually
be ac‑
companiedby only minor
suddenionosphericdisturbances(SID), class
M by significant
SID, andclass X by major
SID.
OUTSTANDING.FLAREEVENTS= key word to indicate
OUTSTANDING
event data
follows,
where
PROTONFLARE‑ protons
from this flare
have been
observedin the earth's
vicinity
MAGFLARE‑ a geomagnetic
and/or
has been associated

MAJORFLARE‑ this flareis the basis
forecastof geomagnetic
mic storm
and/orprotons

JJHHmm = UT of beginningof OUTSTANDING

Q ‑ quadrant of the OUTSTANDING
1 = NE (north‑east)
2 = SE (south‑east)

MAGSTORM = key to indicate
JJHHmm = UT of beginning
Notes:

cosmic‑storm
with this flare
for thestorm,
cos‑in theflare

flare location,

where

SW
NW (south‑west)(north‑west)

magnetic storm data follows
of magnetic storm

Omit these groups if no events to be re‑ported.
Use clear text if event does not corres‑
pond to conventionalclassification.
Include data from earlier PRESTO messages
for this period.
DETAILEDFORECASTS

8 = key number to indicate 24‑hour forecast information
follows
HHJJ ‑ the UT hour (HH) and date (JJ) of the beginning of
the 24‑hour forecast period
7777 ‑ key numbers to indicate available local observatories
follow

C = definitionsofavailable

local

0 = none
1 = solar radio observations
2 = partial solar opticalobservations
Q = quadrant of PREDICTED
1 = NE (north‑east)
2 = SE (south‑east)

ZZZ ≪≪≪ZZZ = key

word

ACTIVEto describe

theobservatories,

3 = all (opticalradio)

whereand

4 = all including
solar
magnetic field meas‑
urements
REGION, where
3 = SW (south‑west)
4 = NW (north‑west)

PREDICTED

ACTIVEREGION,

where

QUIET = less than one chromospheric
event per day
ERUPTIVE = at least one radio event (10cm) and several
chromospheric
events per day (Class C Flare)
ACTIVE = at least one geophysicalevent or several
larger radio events (10cm) per day (Class M
Flare)PROTON = at least one high energy event (Class X Flare
Notes: 1.

Eventsare classified

as below:

Chromospheric
Events: someflares are just
Chromospheric
Events without Centimetric
Bursts or IonosphericEffects. (SID). (Class
C flare)Radioflareswith Centimetric
Burstsand/or Event:definite
Ionospheric
Event. (SID).

^
Geophysicalflare Outbursts(Importance(maximum
two or 1
larger)with Event:Centimetricof the flux higher than the Quiet Sun flux, v
duration longer than 10 minutes) and/or strong
SID. Sometimes
these flares are followed byGeomagnetic Storms or small PGA. (Class
M flanHigh Energy Event: flare(class two or more)with outstanding
Centimetric Bursts and SID.
High Energy Protons are reported at the Earthin case of most of these events occurringon
the western part of the solar disk. (ClassX
flare)
2. Somequiet groups being of very little importance,these can be reported only by their number.

If the word CAUTION
is inserted
between
QXXYY
group and the description
word, it signifies
one cannot
forecast
real evolutionof the groupat timeof the message.
If the word
DOUBTFUL
is inserted
between
QXXYY
group and description
word, it signifies
itis
impossible
to determine
definitely
the trueclass of activity
expected.
ADVTCES

ALERT

AND

AT/F1RTS

key word(s) to describe one or more of the fol‑lowing situations during the next 24 hours or
longer:SOLNIL ＼ EndMAGNIL > ‑ or
PROTONNILJ Beginning
SOLQUIETMAGQUIET

of active

periodof periodof very‑ No active regions on the solar‑ Only sporadic weak geomagnetic

low activity
disk
activity

SOLALERT JJ/KK ‑ increased solar activity expected
between days JJ and KK
MAG.ALERT JJ/KK ‑ increased geomagnetic
activity
expected between days JJ and KK
MAJOR

FLARE

PROTONFLAREPRESTOPROTONSTRATWARM
STRATWARM
STRATWARM
Notes:

ALERT JJ/KK
QXXYY(ClassX) expected
W J.
i ii
n J.
rpcri
1U1.
C5XUUnnI OYYVV
ALERT
JJ/KK
QXXYY
in earth's
vicinity
ton flare
predicted
davs JJandKK in‑ large
betweenbrightdays

flare
JJ and‑protons
expected
as a resultofpro‑
to occurbetweenregionQXXYYARRIVAL ALERT KK/JJHHmm‑ forecastof arrival of protons in earth's vi‑
cinity on day KK from flare which
occurred on day JJ at HHmm (UT)

STARTS f
EXISTS f
F.NTIS

The Alert
section
ALERT code format
DWPn J?TWW A

includesdayof week
geographical
area

and

is always
includedin theas it is used
as ADVICEby2) Morethan one type of Alert may be included in a
message3) Previoustransmissionof ALERT (SOL, MAG, MAJOR
FLARE, PROTON FLARE, PRESTOPROTON ARRIVAL) re‑quires the eventual transmissionof appropriate
NIL (SOL, MAG, PROTON)
Transmissionof STRATWARM STARTS or EXISTS re‑quires the eventual transmissionof STRATWARMENDSGEOALERTS are converted by WWA to plain language
and broadcast on WWV and WWVH as describedinCircular letter RWC‑123.

102

PART

C

ReportingCodes for Optical

Data

These codes are used by observatories
to report solar
optical data; generally
sunspots, plages, and flares.
CODE FORMS
Code
Code
Code
Code
Code
Code

C. 1.1C. 1.2
C. II.1
C. II.2
C.III.l
C. IV.1

Code C. V.l‑ USSPS/USSPT‑ USSPI/USSPY‑ UPATP/UPATV‑ USOLA‑‑ UPLAKUCORE‑ UFLAE

PART

C

I.1

SUNSPOTS

USSPS

or

USSPT

1. Content.
Description of sunspot groups, if key word is USSPS.
Description of sunspot groups and their associatedHa
structure, if key word is USSPT.

Definitionofsymbols.

USSPS
or
USSPT

= key

word,

SunSPot

S

= key

word,

SunSPot

and

He* , Together

IIIII= station

indicator

(See

lists

in

Part

date of observation
tenthsof hours
UTofobservation

JJ = Greenwich
HHH = hours
and

A.V)

aaa = relative
sunspot
numberb = seeing
quality
1 = very poor
2 = poor
3 = fair
4 = good
5 = exceptionalc = solar
disk sizeused for measurement
1 = diameterof the solar
disk less than 15 cm
2 = diameterof the solar
disk between
15 and 30 cm
3 = diameterof the solar
disk more than 30 cm
4 = individual
sunspotgroupsat very high resolution
dd = serial
numberof sunspot
group
eee = area of sunspot
group
in tensofsolar hemispheremillionths

Q = quadrant(heliographic
coordinates)in which
metric centerof sunspot
groupislocated
1 = NE (north‑east) 3= SW (south‑west)
2 = SE (south‑east) 4= NW (north‑west)
XX = distanceto central
meridianin degrees
YY = heliographic
latitudein degrees

of

the

geo‑

f =

type of penumbrain the largest
spot in group(see
diagram)
0 = no penumbra(Ziirich class
A or B)
1 = rudimentary(r)
2 = small symmetric(s) (diameter
less than 2.5 °)3 = small
asymmetric(a) (diameter
less than 2.5 °)4 = large
symmetric(h) (diameter
greaterthan 2.5 °)5 = large asymmetric(k) (diameter
greaterthan 2.5 °)g = relative
importanceof the leading
spot and den‑sity of the sunspot
population(see diagram)
1 = leading
spot largest
and sunspot
population
densityopen
2 = following
spot largest
and sunspot
population
densityopen
3 = leading
and following
spots nearlysame sizeand sunspot
population
densityopen
4 = leading
spot largest
and sunspot
population
densityintermediate
5 = following
spot largest
densityintermediateandsunspot

population

mi

6 = leading and following spot nearly same sizeand sunspot population
density intermediate
7 = leading spot largest and sunspot population
density compact
8 = following spot largest and sunspot popula‑tion density compact
9 = leading and following spot nearly same sizeand sunspot population
density compact
Note: g
= Zurich
12 == AB 45
3 = C 6

= / (slant line) for unipolarof Zurich class A, H or J
sunspot class (see illustration)== DE 78
= F 9

spots

== GH
= J

Note: Normally
G will be encoded as an open
E or F and J will be encoded as asmall H.
ii = numberof spots in the group

Q = quadrant (heliographic
coordinates)in which thegeometric center of Ha plage associatedwith thepreceding spot is located
1 = NE (north‑east) 3= SW (south‑west)
2 = SE (south‑east) 4= NW (north‑west)
XX = distance to central meridian in degrees
YY = heliographic
latitude in degrees
jj = longitudinal
extent of the Ho plagek = Ha brightness on a scale of 5 steps
1 = faint to 5 = very near to flare brightness
1 = description of the bright H‑alpha structure(seeillustration)
1 = sc; scatteredbright points
2 = sp; separated
areas of bright plage; interiorof the region not bright3 = cn; connectedareas of bright plage fillingthe interior of the region, but with corridor
among them
4 = cm; compact plage with little or no spaceamong emitting areas
5 = cx; complex structure embedded in large, com‑pact plagem = dark filament in relation to the photosphericspots (see illustration)
1 = no associatedfilament
2 = filament between the two main spots andbasically parallel to a solar meridian
3 = filament between the two main spots andbasically parallel to the solar equator
4 = filament surrounds a large spot, as an eye‑brow at a distance of less than half thediameter of the spot

filament
pointsbetweenvery near to each other
Note:

If

two

spots

that

are

more
than one filament
associatedwith the spot region,
describe
theone whichencodesby thehighestcode
numberthus implying
themost impor‑tant ‑Fi lampnt fpnturp

14 JUNE 1968 BOULDER
BRIGHT H‑ct STRUCTURE

PART C.1.2
USSPI or USSPY
Introduction

to the code

USSPI/USSPY

The gradient of the active centers magnetic
really an important point as far as the forecast
flare activity is concerned: unfortunately
servatories can make an estimate of the valueonlyoffield isof thefew ob‑
a
this
gra‑

dient. The
purpose of this new code is to circulate amagnetic descriptionof the spotted active centers witha qualitative
estimate of this gradient.
1. Classificationof the spotted

activecenters

The classification
which is used follows the philoso‑
phy of the Mt. Wilson classification,
but it contains someslight improvements.
The a groupis simply

named"unipolar

spots'1.

The Beta group has been divided into two classes: the"open bipolar spots'' and the "closed bipolar spots". Some
gradients of the latter class are higher than the gradientsof the former class.
The following two classes do not coincide exactly with
the Mt. Wilson classification:some
regions have the common
feature of having more than two main spots of opposite polari
ties
Some
of them canand are named the multipolar regions.
several uni‑
be reported
as made up by the juxtaposition descriptionofpolar and bipolar
follows
thisexactly the historygroups:of thissometimes
region, sometimes
it can be apurely arbitrary arrangement, but in any case the possibility
exists for a description of the main spots. This
point isimportant. The
last class is related to the complex regions(bipolar or multipolar)
which escape any reasonable
analysisbe reportedof the main spots, but the configurations
candaily.
2. Estimateof the higher

gradients

These places have been reported as active configurations
to eachtwomoredistanceof opposite
polarities
very close
otherspots(i.e.or the
betweenthe interioredges of themain spots is less than or equal to the diameter of the big‑gest spot). The
most general situation consists of two
spots
includes twoofunequalareas: theA configuration
limit situation withspots of equal area,
and
the
B
one
is
a
to
a large spot surroundedby several tiny spots very close
its
opposite polarity (this
edge,
these
tiny
spots
being
of
configuration has been first recognizedon chromosphericdateas a large round spot surrounded
by a dark filament like aneyebrow and often the spot companions
do not exist). The
Delta configuration
appears when both spots are in the same
penumbra and in this case the interest is mostly related to
the feature of the umbra.
The existence and place of these configurations
must bereported in order to specify and to achieve the magnetic des‑cription of the spotted active centers.
Conclusion
It is known that the sunspot data are not sufficientinorder to describe exactly the magnetic features of an active
center or of a region but two comments can be given: thehighest gradients
always exist between spots and the drawingof inversion lines between just sunspots is a useful approachto the real inversion line features.
The observers using code must point out that this classi‑
fication is mainly a practical one. Sometimes
one solar fea‑
ture can be reported through several classes or descriptions:
it does not matter since the only purpose is to issue a des‑cription which can help a solar astronomer to follow the evo‑lution of that region.
Please note that only spots with real measurement of thelongitudinalcomponent will be reported (i.e. with a longitudeless than 60 ° or 70 ° or with a sufficient area).

USSPI or USSPY
1. Content.
Sunspots classified
word is USSPI
Sunspots classified
word is USSPY

by magnetic

characteristics,

if

key

by magnetic

field

if

key

gradient,3. Definitionof symbols.

USSPI = key word, SunSPots,or
USSPY = key word, SunSPots,
11111 ‑ station

indicator

code

̲I

code

Y

(See

lists in Part

A,V)

JJ = Greenwich
date of observation
HH = hour UT of observation
G = Qualityof the seeing
1 = very poor
4 = good
2 = poor
5 = exceptional
3 = fairIf basically

UNIPOLAR:

Q ‑ quadrant (heliographic
coordinates)in which
metric center of sunspot group is locatedNE (north‑east)SW (south‑west)
SE (south‑east)
NW (north‑west)geo^XX = distance to central meridian in degrees
YY = heliographic
latitude in degrees

K = key number
5 = isolated
unipolarspot orlarge
spot surroundedby smallcompanionsof opposite
polarity(B coikfiguration) I
Zurich sunspot
1 = A
8 = H
9 = J
diameterof the main spot umbra
in degrees
magneticpolarityof the main spot
1 = north2 = south
3 = doubtful(related
to its heliographic
longitude)d = configuration
0 = not any configuration,i.e. single spot or all
tiny spots
1 = several tiny spots of opposite polarity at a
distance (configurationB)
2 = configuration
B suspected according to chro‑mospheric data (dark filament surroundingth*■
spot like an eyebrow)
If BIPOLAR:

Q = quadrant (heliographic
coordinates)of geometriccenter of bipolar groupSW (south‑west)
1 ‑ NE (north‑east)
NW (north‑west)
2 = SE (south‑east)
XX = distance to central meridian in degrees
YY = helioaraphic
latitude in degrees
K = keynumber

6 = open bipolar

7 = closed

a = Zurichbb =bipolarsunspot

2 = B
3 = C
4 = n
longitudeeds‑es ofthat is the shortest distance
between the edges of the main
spots is equal to or greaterthan the diameter of the lar‑gest spot
simple classicalbipolg/r
group and the shortest
dis‑
tance between
the closest
main spots
is less than the
diameterof the largest
spot
in the

class

5 = E
6 = F
7 = G
differenceinthe main soots

degrees

betweenexteriorc = number of five digit blocks used to describe
configuration,
if any configuration
exists, orX when this bipolar group is a part of a multi‑
polar region (see K = 8)
shortest distance in degrees between the interioredges of the closest spots of opposite polaritiese = diameter in degrees of the largest spot umbra
f = orientationof the inversion (neutral) line:
1 = the inversion line is roughly parallel (±30°)
to a solar meridian and the two main spots areequivalent (Beta) or the leading spot is thelarger (Beta P)
2 = the inversion line is roughly parallel (±30°)
to a solar meridian but the following main
spot is the larger (Beta F)
3 = the inversion line is tilted between 30 ° and
60 ° to the solar equator and the two main spots
are equivalent, or the leading spot is the lar‑ger (Beta and Beta P)
4 = the inversion line is tilted between 30 ° and
60 ° to the solar equator but the following
main spot is the larger (Beta F)
5 = the inversion line is roughly parallel (±30°)
to the solar equator and the two main spots
are equivalent or the leading spot is thelarger (Beta and Beta P)
6 = the inversion line is roughly parallel (±30°)
to the solar equator but the following mainis the larger (Betadescription of the polarities
1 = the polarities are normal in relation to thehemisphere and solar cycle
2 = the polarities are normal but with many tiny spot
3 = the polarities are reversed in relation to thehemisphere and solar cycle
4 = the polarities are reversed but with many tiny
spots
5 = the two polarities
are nearly at the same longi‑
If CONFIGURATION(two spots (or many more) of opposite polari‑ties very near together (i.e. the distance between the interioredges of the main spots is less than or equal to the diameterof the biggest spot) ― the best known is the Delta configura‑tion where two umbra of opposite polarities are in the same
penumbra (these are used to estimate the position of the high‑est gradients of the longitudinalmagnetic component)) exists:
Q = quadrant (heliographic
coordinates)of the geometriccenter of an active configurationwhere
1 = NE (north‑east)
3 = SW (south‑west)
2 = SE (south‑east)
4 = NW (north‑west)
XX = distance to central meridian in degrees

YY = heliographic

latitudein degrees

K = key number
0 = descriptionof active configurationh = type of configurationand orientationof the inver‑sion line ,1 = a spotted configurationand the inversion line I
is roughly parallel (±30°) to a solar meridian.
2 = a spotted configurationand the inversion line
is tilted between 30 ° and 60 ° to the solar
equator.
3 = a spotted configurationand the inversion line
is roughly parallel ( ±30°)to the solar equator,
4 = a Delta configurationand the inversion line isroughly parallel (±30 ) to a solar meridian.
5 = a Delta configurationand the inversion line istilted between 30 ° and 60 ° to the solar equator.
6 = a Delta configurationand the inversion line isroughly (±30°) parallel to the solar equator,i = diameter in degrees of the west spot (the west umbra
in a Delta configuration)j = diameter in degrees of the east spot (the east umbra
in a Delta configuration)k = distance in degrees between the interior edgesof the two polarities(the two umbrae in a Delta
configuration)[Note: For
two polarities
nearlyat the same longitude there is no special orderto report the spot or umbra diameters.]
11 = intensity of north polarity field (gauss divided
by 100)mm = intensity of south polarity field (gauss divided
by 100)n = evaluation of the strength of the magnetic field
gradient according to the following:
1 = weak, (less than 0.1 gauss/kilometer)
2 = large, (between 0.1 and 0.5 gauss/kilometer)
3 = very large, (greater than 0.5 gauss/kilometer)
If MULTIPOLAR
or COMPLEXBIPOLAR GROUPS:

region madeup of SEVERALUNIPOLAR

Q = quadrant (heliographic
coordinates)of geometriccenter of the region
1 = NE (north‑east) 3= SW (south‑west)
2 = SE (south‑east) 4= NW (north‑west)
XX = distance to central meridian in degrees
YY = heliographic
latitude in degrees
K = key number
8 = multipolar region which can be reported ascomprising a set of unipolar and/or bipolargroups and active configurations
aa = longitude difference
in degrees between exteriors of the main spotsor /bb = latitudeedges of
QXXYY
QXXYY
OXXYY

Kabcd
Kabbc
Khiik

difference
in degrees
the main spots= as defined
above
ddefg
= as definedllmmn = as defined

under
above
above

betweenexterior

UNIPOLAR
under BIPOLAR
under
CONFIGURATIONSAMPLE OF REPORTS
July 7, 1967
10720 58220

OF GROUPS,

Isolated

October 20, 1958 Typical
30405 58321 eyebrow
May 29, 1966 Classical40924 64120 07211
April
43118

REGIONS

Unipolar24, 1967

Spot

B Configuration
Open

Bipolar26, 1966 Closed
Bipolar74062 02231 guration

February

AND CONFIGURATIONS

with

Group

with

one active

Complex
Multipolar
Regionfour active configurations

11322 74032

ClosedBipolarfiguration
00255 11322 03220

￨

Group

with

It is difficult to report the configurations
inthe biggest spot is a bipolar one and according
version line only part of this spot contributes
tive configurationor the same place contributes
ously to two configurations
13624 91758 13823 03571 (a part of the biggest
14224 04311 (a Delta configuration)
14522 02111 (a part of the biggest
13124 02421
June 12, 1966

a spotted

Group, being

Confi‑

at leastthese data:
to the in‑to some ac‑
simultane‑
spot)
spot)

by itself

a con‑March 30, 1960
11512 81010
11714 02330

Multipolar
Region made up of two bipolargroups, being by themselves
two configurations
11714 7406X 00331 11411 7408X 03411
11411 01423

July 29, 1966
14724

ClosedBipolar Group, being
configuration !
74032 00211 14724 01210

September

17, 1966

13107 58421

by itself

an active,a

B configuration
which can alternately
be reported as a closed bipolaror 13107 73052 00431 13106 12410

March 6, 1967 Complex
Region24218 90952 24218 05217

witha Deltaconfiguration

July 6, 1966 Complex
Region44235 91062 44335 06221

witha Deltaconfiguration

September
34321

10, 1966

81208

34721

a

Multipolar
Region made up of two bipolargroups with one configuration
6407X 06111 34121 6405X 04111 34321 OHIOPART

C.II.l

UPATP
or
UPATV

1. Content.
Solar flare survey intervals for Hq patrols,
graphic only (P) or visual only (V)3. Definitionof symbols.

UPATP = key word, flareor
UPATV = key word, flare
IIIII= station

indicator

PATrolhours, Photographic

PATrolhours,

(See

check

sum

of

all

Visuallists in Part

JJ = Greenwich date of observation
U = overall Quality of observations
2 = poor0 = no data
3 = fair
1 = very pooraa =cinemato‑

following

A.V)

4 ‑‑ good
5 = exceptional

digitsbbb = UT of beginning of patrol period in hours and tenthsof hours
cc = UT of end of patrol period, in hours and tenths ofhours, with tens digit suppressed
Notes:

1. Repeat"UPATP (or UPATV) IIIII JJUaa"
whenever observing period covers two(universal time) dates. If
ambiguity
possible upon decoding insert an ex‑
tra group "bbbcc".
2. UPATPor UPATV sent only if the flareobservations
have been reduced and arebeing reported in the same message.
3. Themessage is sent, of course,
if no flares have been observed
ing: the patrol period.

even
dur‑

PART C.II.2
USOLA
1. Content.
Qualityof the opticalsurveys!
Coordinates of each active center together with numberof flares, flares of importance >1, and number of class
M and X events observed in the center during last 24 hours,

3. Definitionof symbols.

USOLA = key word, SOLar
IIIII= station

JJ =
a =
b =
c =

indicator

Activity(Seesummary
lists in PART

A.V)

Greenwich date of observation iquality of optical survey 00‑08UT f
quality of optical survey 08‑16UT
quality of optical survey 16‑24UT
Note: On
scale 0‑8 based on number
survey during periodof hoursof goodQ = quadrant (heliographic
coordinates)in which the flare
is observed
1 = NE (north‑east) 3= SW (south‑west)
2 = SE (south‑east) 4= NW (north‑west)
XX = distance to central meridian in degrees
YY = heliographic
latitude in degrees

dd = total number of flares in QXXYY region during
past 24 hours
ee = number of importanceone or greater flares in
QXXYY region during past 24 hours
f = number of reported M events in QXXYY region
during past 24 hours
g = number of reported X events in QXXYY region
during past 24 hours
Notes: dd‑(f+g)
dd‑ e= numberregion=numberDefinitions
CLASS C: A

of class

C flaresof subflaresof class

C, M

inin regionor X events

follow:

solar event which is not asso‑
ciated with significant X‑ray
production.

CLASS M: Solarevents which are accom‑
panied by significant X‑ray pro‑duction, greater than 10 2ergs
cm"^sec"J in 0‑8A band, or 10‑^ergs cm ^sec̲1 in 0.5‑5A band,
comparable SID (SWF or SPA).
CLASS X: Solarevents which are accom‑
panied by great X‑ray produc‑tion, greater than lCT^‑ergs
cm'^sec" in 0‑8A band, or
lCT^ergs cm ^sec""^ in 0.5‑5Aband, comparably
great SID, orby a 10 cm radio noise outburst
or more than 1000 flux units
over backgroundand duration
greater than 10 minutes.
This classification
is designed to givean indicationof the geophysicaleffectwhich is likely to be associatedwith asolar event. ClassC events will usually
be accompanied
by only minor sudden iono‑
spheric disturbances(SID), class M bysignificant SID, and class X by major SID.

PART

C.III.l

UPLAK
Content.
Area, importance3. Definition

andintensityof calciumof symbols.

UPLAK= key word, PLAges,

code

K

IIIII

= station

(See

lists

indicator

JJ = Greenwich day of observation
HHH = time of observation in hours
q = quality

plagesin Part A.V)
andtenthsof hours

UTof observation
on a scale from 1 to 5;
1 ‑ very poor 4= good2 = poor 5= exceptional
3 = faird = number of days since last message from this stationx = always x (or slant bar in teletype messages)
nn = number of plages (three five‑digit groups each) for
which information
will follow
eee = serial number, assigned
by observatoryf = importancebined withof plage region on a scale of 1 to 3 com‑
information on the stage of evolution

1 =importance

1,

2 =

importance

2,

3 =

importance4 =increasing

stage

increasing

stage

3,

increasing

stage

importance1,

stable5 =importance2,

stable6 =importance3,

stable7 =importance1,

decreasing

stage

8 =

importance2,

decreasing

stage

importance3,

decreasing

stage

9 =
X

=

no

evalua t i o nsiven

g = age of the region
1 = born on disk
2 = born on invisible hemisphere,
3 = second disk transit
4 = thirdetc.
9 = eighth disk transit
X = no evaluation
given
Q quadrant
plage(heliographic

coordinates)

thecentrallatitudearea in millionths
by 100j = intensity
1 = (faint)
2 = 1.5
3=2

check, units

disk(containing

transittheSW (south‑west)
NW vnwj.
(north‑west)
tu‑wcaNE(north‑east)
SE (south‑east)v"
distancetoheliographic

first

in

meridiandegreesof the solar
4 = 2.5
5=3
6=3.5

digit of sum

indegreeshemisphere,

divided

7 = 4
8 = 4.5
9=5(very bright)of preceding 14 digits

PART

C

IV.

1

UCORE
1. Content.
Intensity of coronalgraphic latitude

3. Definition

line

emissionas a functionof helio‑of symbols.

UCORE= key word, CORona,

code

E

IIIII

= station

(See

lists

indicator

in Part A.V)

JJ = Greenwich date of observation
HHH = time of observation in hours andtenthsof hours

UT

a = line observed (See key word COLOR below)
1 = green ( ＼5303A) 3= red (
＼6702A)2 = red (>v6374A)
0= yellow (X5694A)

b = scattered light intensity (measure of observation
qualit
1 = strong (>60 millionths)
or observation
low qualit
2 = moderate (30‑60 millionths)
or observation
moderaquality
3 = weak (<30 millionths) or observationhigh quality
qqq = quadrants of limb for which values are given in message
1 = NE (north‑east) 3= SW (south‑west)
2 = SE (south‑east) 4= NW (north‑west)‑ if all four quadrants insert 999; if fewer than
three quadrants, complete group with O's.

c = latitude(dividedby 10) of intensity
reported
in dd
dd = intensity
measuredat latitude
indicatedby c (mil‑lionths
dividedby ten)ee = intensity
measuredat next succeeding
5 ° position
angle ‑ proceeding
N‑E‑S‑W‑(millionths
dividedbyten) (SeeNote 1)COLOR= more than oneof linebeing
Notes:

1.

line reported,
reported

word

signifieschangeAlwaysgive observations
in orderofincreasing
positionangle,
i.e. N‑E‑
S‑W. Agroup
givingintensities
atequatorand poles is usuallyneces‑
sary to avoid
ambiguity.
2. Usually
enoughmeasurements
will begiven to outline
the intensity
peaks
and usually
only for East limb, green
and yellow
line.

3.

Intensity
is measured
as millionthsofan angstromof the continuumof thecenter of the solar
disk (at same wave‑

PART C.V.I
UFLAE

1. Content.
Position, importance, time and duration of solar flaresas reported by a single optical observatory. (Importancein conformancewith the recommendationsof IAU Commission
10 as of 1 January 1966)

3. Definition
UFLAE

of symbols.

= key word, solar

FLArEs

IIIII = station indicator (See lists in Part A.V)
Y = last digit of year
MM = month of year, 01 = January, 02 = February,
JJ = day of month (UT)etc.

Q = quadrant (heliographic
coordinates)of the active
region where
1 = NE (north‑east) 3= SW (south‑west)
2 = SE (south‑east) 4= NW (north‑west)
XX = distance to central meridian in degrees
YY = heliographic
latitude in degrees
d = flare importancebased upon corrected area in square
degrees
0 = subflare (s); area<2.0
square degrees
1 = importance 1; 2.1 square degrees < area < 5.1 sq. degre
2 = importance 2; 5.2 square degrees < area <12.4 sq. de‑gree3 = importance

e =

AAA =
a =
HHmm =

3; 12.5squaredegrees<area< 24.7
square degrees
4 = importance 4; 24.8 square degrees <areaflare intensity based upon relative evaluation
7 = faint
8 = normal
9 = brightuncorrected
flare area in millionths of solar disk
start time qualifier
6 = start of flare
7 = first observation of flare in progress
UT of start or first notice of flareb = observing quality indicator
1 = very poor 3= fair 5= exceptional
2 = poor 4= good
HHmm = UT of flare maximum (//// if unknown)￨^Note: groupbHHmm

repeatedfor secondary

maximumsj

c = end time qualifier
8 = end of flare
9 = last observationof flare in progress
HHmm = UT of end or last observationof flareNote: groups

QXXYY

deAAA

aHHmm

bHHmm

cHHmm

repeatedasPART

D

AU
Reporting

Codes

for

Radio

Data

These codes
are used by observatories
lar radio
data; generallyradioburstsin
sweep frequencies
and quiet sun levelsinfrequencies.
Code
Code
Code
Code

D. 1.1
D. II.1
D.III.l
D. IV.1‑‑‑‑

to reportso‑discreteanddiscrete
radio

URANO
URANX
URALE
URALR

!

PART D.I.I
URANO

1. Content.
Solar radio flux and outstanding
eventsif desired) at any fixed frequency

3. Definition(andmedianflux,

of symbols.

URANO= key word, RAdio

Noise, code

IIIII

= station

indicator

JJ = Greenwich

date(See lists

of beginning0
in Partof period

A.V)
of observation

FF = radio frequency of observation
to two significant
figures in units and tenths of units
G = power of ten to convert FF to MHz
i.e., 283 = 2800 MHz
281 = 28MHz
aa = UT hour nearest beginningof period of observation
reported
bb = UT hour nearest end of period of observations
reportedc = 0 to 9 for number of outstanding
events reported
ddd = backgroundflux (adjusted for burst) for period
servation in 10 2^Wm Hz"1ee = nearest UT hour of background flux measurement
f = 9 to signify beginning of an event report
HHmm = UT hour and minutes of beginning of outstandingof ob‑

event

key to
0 =
1 =
2 =
3 =
4 =
5 =
6 =
7 =

type of outstanding event
minor burst (meter wave)
simple (microwave burst)
post burst increase (microwave
burst)
complex (microwave burst)
group or fluctuation (microwave)
major burst (meter wave)
major plus (meter wave)
onset of noise storm (or noise storm in progress)(meter wave)
8 = rise in base level
UT hour and minutes of end of eventh = key to measurement of maximum flux of event in
10 Wm
Hz"1
5 = actual measurement
6 = saturated record
iii = peak flux (above pre‑burst level) of the event to threesignificant figures relative to preceding backgroundlevel (expressedin hundredths of units) (if noise storm,
use median flux) 22
2
1
j = power of ten to express iii in 10" Wm"
Hzi.e. 3343 = 3340 units
3342 = 334 units
3341 = 33.4
units
3340 = 3.34
units
/ = always slant line
HHmm = UT hour and minutesof timeof maximum

Note: Secondary
maxima may be reported"hiiij /HHmm"
groups.
Groups "hiiij /HHmm"
following two groups.

may be replaced

without

by additional

ambiguitybykey to measurementof maximum flux in terms of percent
increase
7 = actual measurement
8 = saturated record
peak flux reported as percent of pre‑burst leveli.e., 0240 = 240% of pre‑burst level (pre‑burst level= 100%)
1280 = 1280% of pre‑burst level
always slant line
UT hour and minutesof timeof maximum

Note: Secondary
maxima may be reported"kllll /HHmm"
groups.

by additional

PART D.II.l
URA NX
1. Content.
Event observed

3. Definition
URANX

on sweeprecordsof symbols.

= key word, solar

IIIII =
Y =
MM =
JJ =
aa =
bbb =

frequency

RAdio Noise, codeXstation indicator (See lists in Part A.V)
last digit of year
month of year, 01 = January, 02 = February, etc.
day of month (UT)
lowest frequency in MHz ... .4.
highest frequency in MHz of observing equipmente = type of spectral activity J
1 = noise storm = type I storm f
2 = slow drift burst = type II burst
3 = fast drift burst = decimeter fast drift burst =type III burst
4 = broad band continuum = type IV burst
5 = brief period of continuum associatedwith fast
drift burst = type V burst
6 = dekameter continuum associatedwith type III bursts
7 = many fast drift bursts = many type III bursts
8 = microwave burst = short (minutes) microwave
con‑tinuum usually of impulsive start
9 = slow drift feature = decimeter slow drift burst= type I chain = gradual change in type III start‑
ing: freauencies

cc = lowest

frequency

dd = highest

frequencyv = importance and
1 = importance
2 = importance3 = importance
4 = importance
5 = importance
6 = importance
7 = importance
8 = importance
9 = importancein MHzinMHzof observed

time qualifier
1
2 times accurate
3
1
2 times accurate
3
1+
2+
3+

event

within2 minutes

within

5 minutes

times
and frequency
accurately
determined range

HHmm = UT of start of eventp = polarization

HHmm

of

burst

X = not available or undetermined
1 = left hand polarized burst
2 = predominantly
left hand polarized burst
3 ‑ none
4 = predominantly
right hand polarized burst
5 = right hand polarized burst= UT

of endof event

Note: groups
eccdd yHHmm
pHHmm
describe events detected.

repeatedas required

to

PART

D.III.l

URALE
Content.
Position, maximum

3. Definition
URALE

= key

IIIII

=

JJ
HHH

of
word,

intensity

solar
indicator= Greenwich

date

of

flux of solar

radio

source.

symbols.

stationr= time

and

RAdio
(See

noise

Location,

Code

lists

in

A.V)

Part

E

of observation

observation

in

hours

and

tenthsof hours

UT *FF = radio
frequencyof observation
to two significant
figuresin units
and tenthsof units
G = powerof 10 to express
FF in MHza = type of observation
reported
1 = single
group for description(defff),which
may
be repeated
2 = two groups
for description(QXXYYbbbcc),
which
may be repeated
K = last digitof checksum of following
groups(or slant
Q = quadrant(heliographic
noise source

coordinates)

containing

the

1]

1 = NE (north‑east)(south‑east)
―x V

aa

2 = SE‑̲ distanceYY― heliographictoSW (south‑west)
NW (north‑west)
nux‑ Uii‑wesi

thecentrallatitude,inmeridian,degreesinJ

degreesbbb =maximum
intensity
in tensof thousandsof degrees
Kelvin (Note:Toreportthepositionof active
solar
radio sourcesat mmwavelengths
the group "bbb"formaximum
intensity
will be in units of tens of degrees
Kelvinratherthan tensof thousandsof degrees
Kel‑vin, i.e.
6310 °K will encode
as 631.)‑ f 1 n v t.o(ti^nin 1 fT"2 2 w ‑ 2 tt‑ 1

ord ‑ importanceon scaleimportance s

e ‑ angularlocation
ian transit

fff=

1 = North, east
2 = South, east
3 = South, west
4 = North,to7west,̲v,
distance
N‑S
cent
125

of
=

the
125%

solar
of
the

with

0, 1, 2, 3 where
respect

diameter
opticalradius).

toN‑S

3 has the greatest
diameteratmerid‑

5 = Central, east
6 = Central, west
7 = ‑ ‑ ‑, east≪west
8 ‑= ‑‑ ‑‑ ‑,‑, westat
meridian
radius(e.g.

transit,
075

=

in
75%,

per‑

PART D.IV.l
URALR
1. Content.

Position, 3‑cm
noise source.

3 . Definition

flux, flux

ratio 3‑cm

to 8‑cmof solarradioof symbols.

URALR = key word, solar

RAdio noise

Location,

spectrumand Ratio

URGNT

for special

attention(Optional

group) (seeIIIII

= Urgent calling
symbol i)=

station

JJ=

Greenwich

FFF

=

total

(see

indicator

flux

date

of

of

the

lists

in

Part

A.V)

observation
sun

on

8

cm

in

10"22Wm"2Hz"1a = angular location at meridian transit
5 = central‑east
1 = north‑east
6 = central‑west
2 = south‑east
7 = ‑‑‑east
3 = south‑west
8 =― ‑west4 = north‑west
bb = distance to the north‑south
diameter at meridian transit inpercent of radius
cc = distance to the east‑west diameter at meridian transit inpercent of radius
dd = 3‑cm flux of the region in 10 ^^Wm ^Hz ‑1‑

PART E
ReportingCodes for Satellite

Data

These codes are used by telemetry
stations, forecast
centers and others to encode solar geophysicaldata ob‑tained from satellite based sensors.
Code E 1.1
Code E II.1

‑ USOXO‑ UPART

PART

E.I.I

usoxo

1. Content.
Background(orby satellites.

3. Definition

event)

of

solar

x‑ray

radiationmeasuredof symbols.

USOXO= key word, SlOlar X‑ray events,

IIIII= station

indicator

(See

code

O

lists in Part

A.V)

JJ = Greenwich date of observationa = satellite
0 = new satellite identified
by plain language at
end of message together with number to specify
satellite thereafter
4 = 1967‑73A (NRL data from 0G0‑4)
5 = 1967‑100A (data from 0S0‑4)
6 = 1968‑17A (SOLRAD 9)
7 = 1971‑058A (SOLRAD 10)
b = type of satellite readout
0 = real‑time
1 = from stored datac = last digit of check sum of all the following digits

d = general aspect of the record
0 = no detectable radiation
1* = stable
2 = fluctuation: "hhi"gives mean level
3 = beginning of an increase: "hhi"gives level
before increase
4 = definitive increase in progress: "hhi"givesmean level
5 = definitive decrease in progress: "hhi"givesmean level
6 = maximum: "hhi"gives maximum level
HHmm = UT hours and minutes of beginning of period reported
by "d" (usually this will be beginning of satellite
readout)e = number of groups to follow
HHmm = UT hours and minutes of endof period

reported

f = band of adjusted (or actual) flux measurements
0 = 0.5‑3 Angstroms (sensor actually 0.5‑3 Angstroms)
1 = 1‑8 Angstroms (sensor actually 1‑8 Angstroms)
2 = 1‑20 Angstroms (sensor actually 1‑20 Angstroms)
3 = 8‑20 Angstroms (sensor actually 8‑16 Angstroms)
4 = 44‑60 Angstroms (sensor actually 44‑60 Angstroms)
6 = 1‑5 Angstroms (sensor actually 1‑5 Angstroms)
Note: The
above bands are for theandplanned SOLRAD sensors. For existingother sat‑
ellites in the future additional
bands
will be specified and the adjusted flux
may equal the actual flux.
g = qualifier to "hh"0 = value on scale as given in "hh"8 = less than value given in "hh"9 = greater than value given in "hh"hh = flux in ergs cm ^sec""lxl0units
i = exponent of 10 group "hh"12=2= 1
etc.

i in units

andtenthsofNote: Thefghhi group may be repeated as many times
as necessary without repeating the dHHmm andeHHmm groups.

PART

E.II.lUPART
1. Content.
Solarparticleevent

3. Definition

ofUP.ART = key

word,

IIIII

=

stationsymbols.
solar

PARTicles

indicator

(See

lists

in

Part

A.V)

JJ = Greenwich
date of observation
HH = hour UT of message
a = type of apparatus
on which event
observed
1 = neutron
monitor2 = detector
carriedby balloon
3 = riometerin auroralzone
4 = VHF ionosphericforwardscatterin auroral
5 = earthsatellite(i.e. 0G0, etc.)
6 = spaceprobe (i.e.
Pioneer,etc.)
b = indicator
describing
time which follows
1 = beginningof event (the enhancement
flux of particles)

of

the

2 =

HHmm

event
in progress
at time of beginning
periodof readout
4 = following
data sent during
pre‑maximum
time corresponds
to highest
levelsas
6 = time of maximumof the event
9 = time of end of the event= UT time in hours
and minutes

If "a" was 3 orobservations)

4 (riometer

of

VHF

ionospheric

zone

of

the

of event,
yet recordec

forwardscatter

ccc = absorptionin tenthsof dB (the greatest
value
ofavailable
reports)
d = kind of solar
particles
1 = protons
2 = relativistic
electrons
3 = type of particles
unknowne = extent
of the event or
numberof reports
involved
1 = local or just one reportavailable
2 = smallextentor a few reports
available
3 = definite
event or several
reports
available
If "a" was 1 (neutron
monitor)
5 = always a five as key number
cccc = percent
of increaseof flux

themaximum

If "a" was 2 or 5 (balloon
or satellite)
5 = always
a five as key number
cccc = percent
of increaseof flux
at themaximumd = band of energy
7 = abovethe
8 = about the
9 = belowthenergyenergy

"eee"
"eee"

at

the

eee = energy/ = alwaysof referencea slant line

expressed

If "a" was 6 (space probe)
5 = always a five as key number
cccc = percent of increase of flux
d = band of energy
7 = above the energy "eee"
8 = about the energy "eee"
9 = below the energy "eee"eee = energy of reference expressed/ = always a slant line

in Mev

at maximumin Mev

4 = always a four as key number
fff = corotation delay in tenths of days
g = sign of corotation delay
0 = + (westward around sun)
1 = ‑ (eastward around sun)Note: Message
may repeat at "bHHmm..."to give details ofdevelopment of the event. If
b = 1, 2 or 9, only
group "bHHmm" given; if b = 4 or 6, groups following"bHHmm" depend upon encoding of "a".

PART

E III.l

USOLW
1. Content.
Solar
delay

wind

3. Definition
USOLW

velocity,

density,temperature,

corotationof symbols.

‑ key word, SOLarWind

JJ = Greenwich
date of observation
III = Space probe
006 =
007 =

HHmm/

= timePioneer
Pioneerof readout,

6
7

008 =
009 =

hours

1 ‑ identifies
solar windaaaa = velocity in km/sec
2 =
bbb =
c =

Pioneer
Pioneerand minutes
velocity

exponentof

UT(km/sec)

identifies
density(cm ^)
densityin 3 significant
figures,bv
10‑c ^
uy IU
negative89

tobe multiplied

10

3 = identifies
temperature(10^
ddd = temperaturein 3 significant
by 10 eo = norro + ‑iiro nvnnri nni r>‑F1 O°K)figures,

4 = identifies
corotation
delay('days)fff = numberof days in tenths
g = sign of corotationdelay
0 = + (westward
aroundsun)
1 = ‑ (eastward
around
sun)

to

be

multiplied

PART F
ReportingCodes

for Ionospheric

Data

Codes in this part are used to describe the state
the ionospherethrough direct and indirect sensors.
Code F. 1.1
Code F. II.1

‑ UFOFO/UFOFD/UMUFD‑ USIDS

PART

F.I.I

UFOFO

or

UFOFD

or UMUFD

Content.
Criticalfrequencies

of F2 region(foF2)

as a function

Maximum

and minimum

valuesandhour of occurrence

f‑min frequencies
first foF2 group)

3. Definitionof foF2for every six hours (firsthours

of timesame

as forof symbols.

UFOFO= key word, foF2, code0 (everysix hours, Universal

UFOFD= key word, foF2, code

D (every hour, Universal

time)

time)

PART

F.II.lUSIDS
1. Content.
Type of ionosphericappropriate times

3. Definition
USIDS

phenomena

observed,

importancewithof symbols.

= key word, Sudden

IIIII = station

indicator

Ionospheric(See

Y = last digit of year
MM = month digits, where
JJ = day of month (UT)Disturbance,

lists in Part

January

code

S

A.V)

= 01, February=

02, etc.

a = type of phenomena
0 = sudden frequency deviation (SFD)
1 = short wave fade‑out with sudden drop out (typica
S‑SWF)
2 = short wave fade‑out with slow drop out ‑ 5 to 15
minutes with gradual recovery (slow S‑SWF)
3 = short wave fade‑out with fade irregular in dropout and recovery (G‑SWF)
4 = sudden enhancement of atmospherics(SEA)
5 = sudden phase anomaly‑phaseadvance (SPA)
6 = sudden cosmic noise absorption(SCNA)
7 = sudden enhancement of signal .15 to 200 Khz (SES)
8 = sudden phase anomaly‑phaseretardation(SPA)
Note: to
HHmm

report

SPA by degrees= UT of beginninguse codeof phenomena

UABSE

c =

importanceofphenomena

0 = importance 1‑
7 = importance
8 = importance
1 = importance 1
9 = importance
2 = importance 2
3 = importance 3
HHmm = UT of maximum of phenomena

1+
2+
3+

d = recording definitivenessand time qualifier
0 = definite,
1 = reasonable,
times accurate within 2 minutes
2 = fair,
3 = questionable
5 =
6 =
7 =
8 =

definite,reasonable,
fair,aupstinnahlp.

HHmm = UT of end

time accuracy

not within

2 minutes

of phenomena

Note: groups
aHHmm cHHmm
dHHmm
may be repeatedadditional phenomena observed

to report‑

PART

F

III.l

UABSE

1. Content.
Ionosphericabsorption measurement
by riometer technique
or by ionosphericforward scatter or by VLF recordings

3. Definition
UABSE

of symbols.

= key word, ionospheric

IIIII = station

indicator(See

ABSorption,
lists

code

in PartE.

A.V)

JJ = Greenwich date of observation
T = type of measurement Mjt
1 = riometer f
2 = forward scatter
3 = VLF phase advance (rarely retardation)requires use. of group "dddHH" instead
HH = hour of message UT‑‑of group "ccXH

a = type of phenomenon
1 = SCNA (sudden cosmic noise absorption ‑ solar
flare associated normally reported by code USIDO)
2 = SPA (sudden phase anomaly ‑ solar flare asso‑
ciated may be reported by code USIDO)
3 = Aurora ‑ associatedabsorption
4 = PCA (polar cap absorption event) due to protons
5 = PCA (polar cap absorption event) due to relati‑
vistic electrons
6 = noise storm of solar radio emission superposedon absorption
7 = slowly varying ionospheric absorption ‑ defines
onset time of magnetosphericsub‑storm at auroralzone stations near the midnight meridian. (Eather
and Jacka, Australian
J. Physics jL9, 215, 1966).
HHmm = hours and minutes UT of beginning of phenomenonb = key number
9 = time of maximum to follow
HHmm = hours and minutes UT of maximum
Note: Group"bHHmm"time known.

usedof event
only whenmaximum

cc = number of decibels of maximum absorption before hour
indicated by next HH (use this group if T = 1 or 2)
X = always an X (or slant line in teletype message)
HH = UT hour of the ending time of the event. If
event
still in progress at time of message replace byslant lines.
ddd = phase advance (rarely retardation)
in degrees (usethis group if T =3)
HH = UT hour of the ending time of the event. If
event
still in progress at time of message replace byslant lines.

PART G
ReportingCodes for Other Geophysical

Data

Codes in this part are used to request geomagneti
auroral, cosmic ray data derived fromground based sen
Code G I.
1 ‑ UMAGE
Code G II. 1 ‑ ILAURE
Pndfi G TTT. 1 ‑ TTPOSF

PART

G

1.1

UMAGE

Content.
Geomagnetic Ak index
Geomagnetic K‑indices for the period reported
Geomagnetic disturbanceswith time of occurrenceTime and value of minimum H‑component(optional)

3. Definition

of

UMAGE

=

key

IIIII

=

station

JJ =
TT =
a =
bb

kkkkkkkk

word,

symbols.
MAGnetic

indicator

activity,
(See

lists

code
in

E
Part

A.V)

Greenwich
date
of beginningof 24‑hour
periodUT hourof beginningof 24‑hour
periodreported
last
digit
of checksum
of following
10 digits

reported= Ak‑index
forGreenwichdate
JJ(hundreds
digit
omitted(Note:
thisis notthe
24‑hourperiodreported,un
less
T is O. If
Aknotavailableat observatory,
put XXor slant
bar
in teletypemessage.)= K indicesforthe
24‑hourperiodreportedc = indicator telling the time reported in HHmm is
1 = storm end 6= gradual storm beginning
2 = bay (psc) 7= sudden storm commencement
3 = typical crochet (ssc)4 = provisional
figures 8 = very marked sudden storm
commencement(ssc)
HHmm = UT hour and minute of phenomenon
indicated by c. (Ifc = 4, HHmm used for reporting up to four additional
3‑hour periods following the 24‑hour interval reportedby the "k's".)
Optional

Groupsd = 5 signifies time to follow refers to absoluteof minimum reached on horizontal component
HHmm = time of minimum in hours and minutes UTeeeee = intensityof minimum

expressedvalue

in gammas

Note: Usegroups "dHHmm" and "eeeee" only for stations
where such a measurement is a good approximationof Dst, i.e. Fredericksburg.

PART

G

II.

1

ILAURE

1. Content.
Occurrence, principal
forms, activity, brightness
andcolor of aurora as functions of time and place of ob‑
servations
Quality of observations
and cloudiness3. Definitionof symbols.

UAURE = key word, AURora1

observations,

IIIII

(See

= station

indicator

lists

JJ = Greenwich date of message
a = type of message
1 = warning a
2 = survey I
HH = hour of end of observationcode

in Part

E
A V)

in UT

bb = Greenwich date of warning or beginning of observations
HH = UT hour of warning or of beginningof observations
d = tens of minutes after HH for warning or number offive digit groups "efghi" to follow if survey message

type

of aurora
during
the
first
hour
0 = no observation
1 = no aurora
2 = veil
3 = pulsating
patches
4 = homogeneous
bands
in thenorth
5 = homogeneous
bands
near
zenith
6 = homogeneous
bands
in thesouth
7 = forms
withtypicalray
structure
8 = combinationof bands
andrays
without
pro‑nouncedmotion9 =combinationof bands
and
rays
with
rapid

motionover
a greatpartof theskybrightness
and
color
of aurora
during
the
first
hour
0 = no observation
1 = color
uncertain(becauseof otherlights,moonlight,
dawn,
etc.)
2 = faint
yellowishgreen
3 = moderate
yellowishgreen
4 = brightyellowishgreen
5 = faint
yellowish
green
with
red
6 = moderate
yellowish
green
with
red
7 = brightyellowish
green
with
red
8 = faint
red
only
9 = brightred
only
qualityofobservations
andcloudinessduringthetwo hours
coveredby "ef"and"hi"
0 = cloudy
1 = occasional
observati
on andsemi‑cloudy
2 = occasional
observati
on andalmostclear
3 = occasional
observati
on and
clear
4 =
5 =
6 =
7 =
8 =
type
hour

periodical
periodical
periodical
continuous
continuous

9 = continuousof auroraor "0"
ifbrightness
during
the
es:

1.

In

2.

observation
observation
observati
observati
observati

on
on
on

observation
as in "e"above,
warningandcolor
of aurora
secondhour
or "0"

andsemi‑cloudy
andalmost
clear
and
clear
and
semi‑cloudy
andalmost
clear
and
clear
duringthesecondas in "f"if warning

above

the
first
"efghi"group"ef"refersto timeinterval
HH to HH+1
and"hi"
referstp thetimeinterval
HH+1
to HH+2.
Inthesecond"efghi"group,"ef"
refersto thetimeinterval
HH+2
to HH+3
abd"hi"
to thetimeinterval
HH+3
to HH+4
and so on to thelast"efghi"group.
The observer
shouldbemationis mostimportant

able
for

to judge
which
each
one
hour

infor‑
interva

PART

G

III.1

UCOSE

1. Content.
bi‑hourly flux
special events

3. Definition

values(basedof cosmic rays, dailyon code RAYCO)

variations,of symbols.

UCOSE= key word, COSmicrays, code

IIIII

= station(See

indicator

lists

E
in Part A.V)

JJ = Greenwich date of first period for which flux values
are given
T = type of apparatus
0 = neutron monitor (IGY‑Simpson
type)
1 = high counting rate neutron monitor (IQSY‑type)
2 = meson monitor (IGY‑type)
3 = meson monitor (IQSY‑type)
4 = telescope, no shielding
5 = ionizationchamber
HH = UT hour of message (normally in Greenwich day follow‑
ing the date of "JJ")a = typeofvariation

during

the

day

0 =
1 =
2 =
3 =
4 =

normaldaily variation
beginningof a pre‑decreasepre‑decrease(pre‑baisse)commencementof a Forbush
Forbushdecrease

5 =
6 =
7 =
8 =
9 =

recurrent
activity
increase
after‑effectof increase
daily variationof large
amplitude
dailv
variationof anomalous
anomalous
Dhasev^≪xx.y vrtxiaLiuu
ox
pnase

sign
of daily
7 = negative
8 = zero
9 = positive

variation(belowaverage deviation expressedof an arbitrary mean level
Notes:(pre‑baisse)decrease

or

above

in steps

arbitrarylevel)of thousandths

1. Thearbitrary level is selected sothat the deviations can be specified
by three digits. The
arbitrary levelis always chosen higher than theactual level

2. Groundlevel increases
should bereported by Code C.I.6. UPART.
HH = hour indicator; deviationof flux from the normal
value following with "ddd" refers to
the interval
HH‑1 to HH+1 hours; if the deviation ispositive
30 "is added to the hour to obtain HH.
ddd = deviation of cosmic ray flux from level expressedby steps of thousandths of an arbitrary mean countPART

H

Regional

and/orSpecialized

Codes

Codes in this part of the booklet
aremoreassociatedwith an RWC thanwith a type of solar
si r.a1 i rifnrmat i nn

Code H I. ‑ " ‑iinv

Moscow

Code

H

II.

Code
Code
Code
Code

H
H
H
H

III. ‑IV. ‑V. Tokyo
VI. ‑
‑

FORDA

Code H
Code H
Code H
Code H

VII.2 ‑
VII! 3 ‑VII.4 ‑
VII.5 ‑

FORWE
AD
PROPO
PQA

Code

H VII.1

‑

Paris

RWC
RWC

Boulder RWC
Sydney RWC
RWC
Other RWC

Codes

V^UUCO
Codes

Codes
Codes
Codes
Codes

nearlygeophy‑

PART

H

I.1

Moscow

FORECAST

1. Content.
5‑days forecast of ionosphericand geomagnetic
expressed by quality figures for Moscow

3. Definition
FORECAST
IIIII

conditionsof symbols.

= key word=

stationindicator

dd = Greenwich date of the beginning of 5‑days period
to which the forecast refers
DD = Greenwich date of the end of 5‑days period towhich the forecast refersm = month
ION = key word, IQNospheric(axxxx) = expected ionosphericconditions
expressedby quality figures for corresponding
date. The
6th quality figure refers to 31st dav of a month.
a =quality

figurequiet, IA foF2I < ±20%minor negative
disturbance
20% < I AfoFsl < 25%

2 = moderate negative disturbance:
25%< I AfoF2￨ <35%
3 = major negative disturbance:lAfoF2￨ >35%
4 = minor positive disturbance:
20%< I Af oF2 I<25%
5 = moderate positive disturbance:
25% < I Af oF2 I<35%
6 = major positive disturbance:
AfoF2 >35%
MAG = key word, MAGnetic
bbbbb(bxxxx) = expected geomagnetic
conditions
quality figures for correspondingdateb = quality figure0 = quiet (A <15). A‑ index

1 = minor disturbance 15
2 = moderate disturbance3 = maior disturbance A

25

for Moscow< A < 25
< A < 80>

expressed

PART

H.II.1

Paris

(TO

BE

ADDED

LATER)

PART

H.III.1

AFRED

Boulder‑ Geomagnetic

forecasts

1. Content.
Predicted value of A‑index, Fredericksburg,of next three days, by SOLTERWARN

3 .Definition
AFRED

of symbols.

= key word, A‑index

FREDericksburg

aaa = predicted
Apr‑index
JJ = date for predicted "aaa"

Va.,

for

each

PART

H.

TENCM

III.2

‑ Solar

radio

flux

forecasts

1. Content.
Predicted Ottawa 10‑cm
days, by SOLTERWARN

3. Definition
TENCM

flux

for eachof symbols.

= key word, 10‑cm

flux

aaa = predicted daily Ottawa 10‑cm
JJ = date for predicted "aaa"

fluxof the next three

PART H.III.3
SPATS
1. Content.
Instantaneous
solar proton
ary ATS‑1 satellite

3. Definition
SPATS ‑ keymeasurements

fromgeo‑station‑of symbols.
word, Solar

Protonsfrom

ATS‑1 satellite

Greenwich date of observation
UT hour and tenths of observation
denotes 5‑21 MeV recordercounting rate in XXXY protons/cm/seconddenotes 21‑70
counting rate/secondNote: 1.

MeV recorderin XXXY protons/cm

Readings
normally taken at 3‑hour intervals,
more often during events
2. Rates
exceeding 1000 protons/cm^/second
will be reported as 999.9

PART

H.III.4

PIONR

1. Content.
Measurementsof the interplanetaryof Pioneer satellites

3. Definition
PIONR
0000T
JJ
WWW

=
=
=
=

by the seriesof symbols.

key word, PIONeeR
satellite data
satellite (6, 7, 8, or 9)
Greenwich date of observation
solar wind speed in kilometers/second

HHMM = UT time of observation
F = status of interplanetary
0 = missing
1 = steady
2 = fluctuating
XXXYY

medium= particle

counting

ratemagnetic

in XXXYY

field, wherecountsper second

Note: XXXYY
groups will be reported as necessaryfor each satellite in ascending energy ranges
Pioneer
Pioneer
Pioneer

6, 7
8 ‑
9 ‑

‑ .6‑1313.9
13.9

MeV, 13‑70 MeV, 70‑175
MeV, >64.0 MeV
MeV, >40.0 MeV

MeV, >175

MeV

PART

H.III.5

DA LAS

1. Content.
Description
2. Generalof solar

DA LAS
Iliii YrMMYY

3. Definition

Iliii

and limb activity

3//nn

11111 qS JJJ EEIaRR

DALA

disk

form.

S

GGggL GGggL

BRAAA

7NNNN

QXXYY

QXXYY

99999

of symbols.
Data identifier. Alphabetic
solar disk and limb activity

II WMOiii WMOcharacter^ummary.

forblock number.
station number.
Last digit of the year.
Number of the month.
Dav of the month.

3//nn 3 Numerical// Filler.
nn Number
11111 DataqS JJJ q Quality

filter.
of data lines
line

in thismessage.

coded

accordingindicator.

of observation
Very Poor
Poor

to:

Fair
Good
Excellent
Status of the report

codedaccordinguiu
1. Preliminary A au^ui
estimate,visual
2. Final
report,visual
3. Final
report,photographic
4. Correction
5. Deletion

Last three digits of the event serial number
assigned independently
by each observatory.
EEIaRREE Typeof activity coded according to:
01 ASR
Activesurge region (less02 APR
Activeprominence
region03 MDP
Mound
prominence

than

0.15

04

BSL

Bright

surge

on

limb

(0.15

R

or

greater)05

EPL

Eruptive

06

LPS

Loop

prominenceonprominence

system

limb
(limb

or

disk)
07

SPY

Spray .

08

AFS

Arch

09

ADF

Active10

DSF

Disappearing

11

DSD

Dark

12

BSD

Bright

surge

13

SSB

Solar

sectorfilamentdarksystem (filament
filament

surge

on

disk
on

disk

boundary

(see

note

at

end)
CRN

la

Index
level

of
of

Coronalactivity.
activitv

rain

A
subjectivecoded
according:estimate
to:ofClear indicationof activity. Prominence
fluctuates in brightness. Filamentvarie
in absorption
range.
Active. Prominencechanges shape, moves.
Filament changes shape.
Very active. Prominence
disappears, butdoes not erupt. Filament
disappears, but
has no Doppler shift.
Not applicable.
Do
not assign a code forquiescent features.
RR

GGggLs GGgg
Ls

GGggLe GGggLe

BRA AA B

For limb events, radial extent above the limb
expressed in hundredthsof the solar radius vec‑
tor, R. For
disk events, enter heliographic
extent in whole degrees.
Start timeof event, (hours

andminutes, UT)Time qualifier coded according to:
1. Exact
start time
2. Approximate
start time (within two
minutes of actual)
3. Eventin progress at GGgg (start timeobserved or cannot be reasonably esti‑
mated within two minutes)
End time of event (hours and minutes, UT)Time qualifier coded according to:
Exact end time
Approximate end rime (within two minutesof actual)
Event ended aft or GGgg (end time not ob‑
served, still in progress at GGgg)
Event still in progress at report timeof GGgg. Morecomplete information
later
Observed amount of Doppler
tenths of angstroms.

shift in bluewin

R Observed

amountintenths

Note:

of

of

/

Doppler

angst

shift

in

red

wing

■oms.

indicatesnotmeasuredornotappli‑

toor

greatercable0

indicatesno9

indicates

shifts

than

shift

0.9

equal
oms

AAA Associatedremarks. Use
any combinationofthe following:No other effects
Flare associatedBright emission for at least 1/3 of thetimeNormal emission for at least 1/3 of thetime
Filler or not annlir.ahlp
7NNNN

Numerical

NNNN AESC
QXXYY

fillerregionnumber.

Quadrant
locationluuauur
1. Northeast
2. Southeast
3. Southwest
4. Northwest
XX

Centra1 meridian

Latitude(seventh

of

Use
event

distancegroup)/ if not applicable.
coded

in

according

whole

to:

degrees.

of the event in whole degrees.

Note: Active
features of less than ten degrees
extent are reported bygroup
located by the centroid. oneForQXXYY
featuresgreater than ten degrees,
up to three
QXXYY groups may be used to indicate
the two end points and one intermediate
99999

End of data indicator to be included
end of the last data line.

at theFor reporting solar sector boundaries,
be used for Ia, RR, Ls, GGggle, BRAAA, slashes (/) must
will indicate quadrant and CMD of the and NNNN. QXX//
neutral‑line/solar‑
equator intersection. The
first GGgg is used for thetime of analysis. Up to three QXX// may be used to re‑port up to three sector boundaries. Morethan threemust be reported by using another "11111" data linewith all int.prmpdiatp data rpnpatpd.

PART

H.III.6

SPDSP
1. Content.
Instantaneous
2. General

solar

protonmeasurements

from

form.

SPDSP DDHHT 1FFFX 2FFFX
3. Definition
SPDSP =
DD =
HH =
T =
1 =
2 =
FFFX =

of symbols.

key word, Solar Protons DSP
da t ehour
tenths of hour
10‑30 MeV
50‑100 MeV
FFF.X = flux in particles cm

^sec

^

DSP

satellite

PART

H.III.7

EVENT

Content.
Position, time, importanceof solarhvdroeen‑aloha
other than flares.
2. General
EVENT

eventsobserved

form.

IIIII

JJabK

3. Definition

ccdde

fHHmm

gHHmm

QXXYY

of symbols.

EVENT= key word, solar

IIIII

=

stationevent

indicator

JJ ― Greenwich date of observationa = quality of observation
1 = very poor
4 = good
2 = poor
5 = exceptional
3 =

fair

b = number of events reported
K = last digit of check sum of all the
cc = type of event

following

BSL ‑ brightsurge on limb
= BSD ‑ brightsurge on disk
= DSD ‑ dark surge on disk
= AFS ‑ arch filament
system= SPR ‑ spray= EPL ‑ eruptive
prominenceon limb= DB ‑
disparition
brusque= LPS ‑ loop prominence
system= APR ‑ active
prominence
region= ADF ‑ artive
dark filament
dd ‑ event importance,classifications
as yete = comment

digits01 =HHmm =g =HHmm ‑
Q =undetermined

0 = no other effects
1 = flare associated
3 = associated with SID or radio burst
indicator that time which follows is
1 = exact start time
2 = event first observed in oroeresstime in hours and minutes UT
indicator that time which follows is:end time
event still in progress at terminationof obser‑vationtime in hours and minutes UTquadrant (heliographic
coordinates) in which the event
was observed
1 =
2 =

NE
SE

3 =
4 =

SW
NW

XX ‑ distance to central meridian in degrees
YY = heliographic
latitude in degrees

PART

H.Ill.8

USRAS
1. Content.
Solar activity

3. Definition
USRAS

summary

Boulder

RegionNumbersof symbols.

= key word, Solar

IIIII = station

with

Regionidentifierand Activity(always

Summary

20401, WWA

Boulder)

DD = day of month
HH = hour (UT)S = sixths of hour
RRR = SESC region number
M = number of class M events
X = number of class X eventson UT dayon UT dayQ = quadrant of sun (NE=1, SE=2, SW=3, NW=4)
XX = degrees longitude from central meridian
YY = degrees latitude from solar equator
Z = modified Zurich classification(A=l, B=2, C=3, D=4, E=5, F=6, H=7)
AAA = area of sunspot in millionths/10
M = magnetic classificationof region(A=1, B=2, BG=3, G=4, D=5)

SS =
1 =
2 =
3 =
LLL =
R =

number of subflares on UT day
number of importance one flares on UT day
number of importance two flares on UT day
number of importance three flares on UT day
Carrington longitude of region (000‑359, neverremark0 = none
1 = first detection at east limb passage
2 = born on disk
3 = merger of two regions
4 = breakup of a region
5 = reappearance of an old region

PART

H.IV.lSydneyCodes(TO

BE ADDED

LATER)

PART

H.V.I

Tokyo

Codes

(TO

BE

ADDED

LATER)

PART

H.VI.lOther

Specialized/Regional

(TO

BE

ADDED

LATER)

Codes

PART

H

VII.1

FORDA

Content.
Daily
cuits

radio
propagation
betweenGermany

3. Definition

forecast
and certainfor different
areas of the

radio
world

of symbols.

FORDA = key word, FORecast

Daily,

code

IIIII = station‑ (SeePart A.V)

indicatorA

JJ = Greenwich date of issue of forecast
T = time of issue in tenths of day
FF = Greenwich date of beginning of the 24 hour period
which the forecast referstoa = circuit

1 = North America
2 = South America
3 = East Asiab = expected quality figure for beginning of next
periodc = MUF for correspondingnight period
1 = normal
2 = higher than normal and increasing
3 = higher than normal and decreasing
4 = lower than normal and increasing
5 = lower than normal and decreasingd = LUFfor uuicorrespondingnight ^cnuu
periodJr iuii eapuuuiug
uxgui,
1 =
2 =
3 =
4 =
5 =

normalhigherthan normal
higherthan normallowerthan normal
lower than normale = expected

quality

figurenight

and increasing
and decreasing
and increasing
and decreasingfor end of night

periodf ‑ expected quality figure for beginning of next
periodg = MUF for corresponding
day period
norma 1higher than normal and increasing
higher than normal and decreasing
lower than normal and increasing
lower than normal and decreasing
h =

LUF

for

corresponding

day

day

periodnormalhigher than normal and increasing
higher than normal and decreasing
lower than normal and increasing
lower than normal and decreasingi ‑ expected quality figure for end of day periodj = always a slant line in teletype message
Notes:

1. Thescale of quality
1 to 9, where
1 =
2 =
3 =
4 =

useless
very poor
poor
poor‑to‑fair

figures

is from

5 = fair
6 = good (normal)
7 = very good
8 = superior
9 = excellent

2. Thequality figures give deviations
from normal conditions, which are
predicted in the monthly forecasts.
3. As
day period is considered the period
in which usually the day frequencies
can be used; as night period is consid‑
ered the period in whichusuallythenight frequencies
are to be used.
4. Forevery forecast period two quality
are given in order to indicate theexpected development of conditions
during the forecast period.

PART

H

VII.2

FORWE

1. Content.
Weekly radio propagation forecast for different radio
circuits between Germany and certain areas of the world
for the following ten days

3. Definitionof symbols.

FORWE= key word, FORecast

Weekly,

IIIII

=

(See

stationindicator

Part

code

E

A.V)

JJ = Greenwich date of issue of forecast
T = time of issue in tenths of day
FF = Greenwich date of beginning of the first 24 hour
period to which the forecast refers
CC = circuit (or group of circuits) to which the following
5 digit groups refer
EA = East Asia
NA = North America
EU = Europe
SA = South America/// = always slant lines in teletype messagea = expected quality figure for the day periodwith date FF
corresponding
day period MUF
1 = normal
2 = higher than normal
3 = lower than normalc = corresponding
1 = normal
2 = higher
3 = lower

day

LUF

than normal
than normal

starting

expected quality figure for the night
ing with date FF+1
corresponding night period MUF
1 = normal
2 = higher than normal
3 = lower than normal

periodSimilar "abede" groups repeated for eachlowing nine days, ten groups in all.
Notes: 1.

start‑of thefol‑

Thequality figures give deviations
from normal conditions, which are
predicted in the monthly forecasts.
(See FORDA)

2. As
day period is considered
the period
in which usually the day frequencies
can be used; as night period is con‑sidered the period in which usually
the night frequencies are to be used.
3. Eachnight‑time period is reckoned
to follow the respective day‑time
period. For
circuits to the Westfrom Germany, it may therefore starton next Greenwich date.

PART

H

VII.3

AD
1. Content.
Radio

Propagation

3. Definition

Forecastforcoming7‑day

periodof symbols.

AD = ‑ADvance forecast
a = circuit, or combination of circuits
H = high northern latitude
J = combinationof circuits
JJ = date of beginning of seven‑day period
cast applies

to whichfore‑

bb = date of ending of seven‑day period to which forecast
applies
ccccccc = forecast quality figures for each of the seven daysof the periodd = check, units

digitof sumof preceding

11 digits

ee = date of beginning of disturbed
periodff = date of end of disturbed periodg = check, units digit of sum of preceding

4 digits

"normal" (index = 6.0) if theycorrespond to the average of thepreceding 27 days (1 solar rota‑tion) .
Ref. A. Ochs and B. Beckmann: On
the 27 days' recurrence
tendencyof radio propagation disturbancesin the period of high solar acti‑
vity in: The
Effect of Distur‑bances of Solar Origin on Commu‑
nications (ed. G. J. Gassmann), pp.
235‑244, AGARDograph
59, Pergamon
Press 1963.

PART

H.VII.5

PQA‑‑
1. Content.
Preliminary

3. Definition

daily

propagation

quality

figures

Quality

figureof symbols.

PQ ‑ key for PreliminaryaP≫== r≫‑i
circuitT≫ r>n‑i+daily

A = Atlantic circuits
B = North Pacific circuits
C = Antarctic circuits
D = Arctic circuits
JJ ‑ Greenwich date of beginning of 24‑hourbcde‑ preliminaryday, where"

periodfor each of the periods

J Jbrefers to1800‑ 2400c

refers to0000‑ 0600d

refers to

0600‑ 1200―refers
V4.to V
check,
units

1200

e

f =

qualityreport‑ 1800―V A" VV‑L VKJVJ
digit
of preceding

6

digitsof theinvolved
are usually
the same, andthe flow of preliminary
anddefinitive
data is thereby
coordinated.
Finally
it should
benoted that there
is no real distinction
betweena large
partof the IUWDS
programand the SCOSTEPProgram"MonitoringtheSun‑EarthEnvironment(MONSEE)";in this case also the leader‑
ship and many of the participants
are common
to the two under‑
takings.
Insummary,
the IUWDS
attempts
to provide
a central
serviceto the scientificand technicalcommunityin many as‑
pects of what might
be calledthe "active"
coordinationof pro‑grams involving
international
cooperationin astronomical,
geo‑
physicaland space science.
DirectingBoard
for IUWDS.
In
accordancewith FAGS Statutes,
the Unions
have establisheda Directory
Board,
which
will re‑port directly
to the Union,
andwhich will provide
generalpolicy and independent
adviceconcerning
IUWDS.
Membersare:Director
IUWDS

IAU
IUGG
URSI
IUWDS

Steering

Dr.
Dr.
Dr.
Dr.

G. D. R. Jager
D. J. Williams
A. P. Mitra
P. SimonCommittee:

Inaccordance

with

URSI

Information

Bulletin
No.186,
1963, theIUWDSSteering
Committee
is respon‑sible for the managementof the IUWDSServiceand for the con‑dition of the activitiesof the Regional
Centers.
Membersare:
Dr. P. Simon(Chairman)
European
RWC
Ms. J. V.
Lincoln,(Secretary
World
Days)
Mr. R. B.
Doeker,(Secretary
Ursigrams)
Dr. D. J.
Williams,(IUGG)
Western
Hemisphere
Mme. R. A. Zevakina,
Eurasian
RWC
Mr. C. McCue,
Australasia
and Antarctica
RWC
Dr. I. Kasuya,Western
Pacific
RWC
Dr. A. P.
Mitra,(URSI)
Dr. R. Michard,(IAU)
Dr. J. Vette,(WWA
for Satellites)
Dr. C. M.
Minnis,(Secretary
GeneralDr. G. W. Kronebach‑ (Liaison
WMO)
Dr. J. S. Sawyer‑ (Liaison
WMO)
Dr. Fournierd'Albe‑ (Liaison
UNESCO)
Mr. J. P. Leerand‑ (Liaison
SPARMO)‑ URSI)

RWC

The International
Ursigramand World Days Service(IUWDS). is a permanentscientifi
serviceof the International
Union of Radio Science(URSI),
withthe participationofthe International
Astronomical
Union and the International
Union
Geodesyand Geophysic
IUWDS adheresto the Federationof Astronomicaland Geophysical
Servicesof the Inter‑national
Councilof ScientificUnions.
The
IUWDS coordinates
the international
aspectof the world days program
and rapid data ・ interchange, and also publishes
subsequently
Condensed
CalendarRecords
of solar and geophysicalindicesand events, publishedin
STP Notes.
This Calendar
for 1974 has been drawn up by J. V. Lincoln,of the IUWDS Steering
Committee,
in close association
with A. H. Shapley,
Chairmanof MONSEEof SCOSTEP, andspokesmen
for the various
scientificdisciplines
in SCOSTEPand COSPAR. SimilarCalendars have been issued
annually
beginningwith the IGY, 1957‑58,
and have been publishe
in various
widelyavailablescientificpublications. ,Published
for the International
Councilof ScientificUnionswith the financial
assistanceof UNESCO.
(UNESCO
Subvention
1973 DG/2.1/414/36)
Additional
copies are available
upon request
to IUWDS Chairman,
Dr. P. Simon, Ursi
grammes Observatoire,
92190
Meudon, France,
or IUWDS Secretary
for World Days, Miss
V. Lincoln,
WDC‑A
for Solar‑Terrestrial
Physics, NOAA, Boulder,
Colorado,
80302,
U.SrA