From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Summary of Solar Geophysical Activity for 09 September
Apparently-To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
Organization: University of Lethbridge
Date: Thu, 10 Sep 1992 19:06:32 GMT

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                 DAILY SUMMARY OF SOLAR GEOPHYSICAL ACTIVITY

                              09 SEPTEMBER, 1992

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                  (Based In-Part On SESC Observational Data)


SOLAR AND GEOPHYSICAL ACTIVITY INDICES FOR 09 SEPTEMBER
-------------------------------------------------------

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 253, 09/09/92
10.7 FLUX=116.9  90-AVG=124        SSN=093      BKI=5756 6443  BAI=058
BGND-XRAY=B6.5     FLU1=3.0E+06  FLU10=1.8E+04  PKI=5768 7444  PAI=087
  BOU-DEV=093,214,105,192,121,046,042,025   DEV-AVG=104 NT     SWF=02:037
 XRAY-MAX= M3.1   @ 0213UT    XRAY-MIN= B4.5   @ 1745UT   XRAY-AVG= C2.0
NEUTN-MAX= +000%  @ 0445UT   NEUTN-MIN= -009%  @ 1950UT  NEUTN-AVG= -3.8%
  PCA-MAX= +0.3DB @ 1245UT     PCA-MIN= -0.1DB @ 2235UT    PCA-AVG= +0.0DB
BOUTF-MAX=55468NT @ 0322UT   BOUTF-MIN=55294NT @ 1326UT  BOUTF-AVG=55397NT
GOES7-MAX=E:+186NT@ 1128UT   GOES7-MIN=N:-071NT@ 1146UT  G7-AVG=+072,+084,+007
GOES6-MAX=N:+191NT@ 1332UT   GOES6-MIN=E:-038NT@ 0818UT  G6-AVG=+079,-004,+056
 FLUXFCST=STD:115,115,110;SESC:115,115,110 BAI/PAI-FCST=030,020,015/035,020,015
    KFCST=4345 5311 2233 3222  27DAY-AP=010,013   27DAY-KP=2122 3333 3223 4422
 WARNINGS=*MAJFLR;*SWF;*PROTON;*GSTRM;*AURMIDWRN;*FORBUSH
   ALERTS=**MINFLR:M3.1@0213UTC;**MINFLR:M1.9/SF@1803UTC;**245STRM:0459-0632;
          **MAGSI:52NT@0139UTC;**MAJSTRM;**FORBUSH
!!END-DATA!!


SYNOPSIS OF ACTIVITY
--------------------

     Solar activity was became moderate today.  Region 7270 (S10W83) spawned
a class M1.9/SF flare at 18:03 UT.  The only other M-class flare observed was
not optically correlated with anything on the visible disk.  This event
attained a class M3.1 x-ray level at 02:13 UT and was moderately long in
duration.  Aside from this M3 flare, there were four other optically
uncorrelated C-class flares that were reported.  A yet unseen east-limb
region is thought to be responsible for this activity.

     Solar Region 7270 will rotate off the west limb on 11 September in an
eruptive, yet stabilizing state.  M-class flares are still possible from this
region.

     Region 7276 (N16E53) was only responsible for several subfaint flares.
It has experienced some decay and simplification over the last 24 hours.

     New Region 7279 (S06E63) contributed a few subflares during the day. The
only other new region assigned was Region 7278 (N05E14).

     Solar activity is expected to be low to moderate.  The departure of
Region 7270 will decrease the probability of M-class flare activity. C-class
flares should dominate.

     The geomagnetic field became strongly disturbed during the day.  A
sudden storm commencement (SSC) was observed at 01:39 UT with an amplitude of
52 nanoteslas (nT).  By approximately 04:00 UT to 05:00 UT, minor to major
storming was being observed over most regions.  Severe storming was observed
several hours thereafter.  This storm is rated as a major geomagnetic storm
and is expected to continue throughout the next 24 hours before beginning to
subside.  Major to severe storm activity will be possible throughout much of
10 September.

     A fairly unstable Forbush decrease was observed a few hours after the
arrival of the interplanetary disturbance.  The Forbush decrease reached a
preliminary maximum of 9 percent near 09:50 UT, but fluctuated above and
below event levels throughout the day.

     Significant levels of auroral activity have been observed in conjunction
with this disturbance.  Activity has been observed throughout the northern
tier of the U.S. states, although lunar phase drowned out much of the
activity.  The most equatorward observation of activity appears to be
Rochester, Minnesota.  Conditions were favorable enough to be observed from
points south of this 43N geographic latitude, despite the luminosity of the
moon.  Activity is expected to continue throughout much of 10 September
before beginning to subside.  The Middle Latitude Auroral Activity Warning
will remain active until 19:00 UT on 11 September when it will either be
updated or allowed to expire.

     HF propagation conditions were strongly below normal over all regions.
Polar and high latitude signal paths experienced very poor to near radio
blackout conditions.  Middle latitude signal paths varied from fair to very
poor propagation, while low latitude paths experienced fair to good
propagation. Episodes of VHF backscatter on frequencies below 100 MHz have
been reported in conjunction with this major geomagnetic storm activity.
Conditions are expected to become unfavorable for VHF backscatter on 11
September, barring the arrival of further disturbances.  Improvements in
propagation should begin to be observed on 11 or 12 September.


COPIES OF JOINT USAF/NOAA SESC SOLAR GEOPHYSICAL REPORTS
========================================================

REGIONS WITH SUNSPOTS (LOCATIONS VALID AT 09/2400Z)
---------------------------------------------------
NMBR LOCATION  LO  AREA  Z   LL   NN MAG TYPE
7270  S10W83  037  0140 DAO  09  009 BETA
7276  N16E53  261  0240 DAI  09  023 BETA-GAMMA
7277  S11E18  296  0020 CRO  05  005 BETA
7278  N11E12  302  0020 CRO  04  004 BETA
7279  S06E63  251  0000 BXO  04  002 BETA
7274  N05W63  017                    PLAGE
REGIONS DUE TO RETURN 10 SEPTEMBER TO 12 SEPTEMBER
NMBR LAT    LO
NONE


LISTING OF SOLAR ENERGETIC EVENTS FOR 09 SEPTEMBER
--------------------------------------------------
BEGIN  MAX  END  RGN   LOC   XRAY  OP 245MHZ 10CM   SWEEP SWF
 0153 0213 0249              M3.1            22
 1351 1351 1352                          230
 1756 1803 1843 7270  S11W78 M1.9  SF


POSSIBLE CORONAL MASS EJECTION EVENTS FOR 09 SEPTEMBER
------------------------------------------------------
           UT TIME                 OPTICAL          XRAY    RADIO
 BEGIN        MAX      END     LOCATION   TYPE   SIZE  DUR  II IV
09/ 0153     0213     0249                LDE    M3.1   56
09/ 1756     1803     1843       S11W78   LDE    M1.9   47


INFERRED CORONAL HOLES (LOCATIONS VALID AT 09/2400Z)
----------------------------------------------------
               ISOLATED HOLES AND POLAR EXTENSIONS
      EAST   SOUTH  WEST   NORTH  CAR  TYPE  POL  AREA   OBSN
                 NO DATA AVAILABLE FOR ANALYSIS


**  End of Daily Report  **
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