From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Summary of Solar Geophysical Activity for 10 September
Apparently-To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
Organization: University of Lethbridge
Date: Fri, 11 Sep 1992 08:18:47 GMT

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                 DAILY SUMMARY OF SOLAR GEOPHYSICAL ACTIVITY

                              10 SEPTEMBER, 1992

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                  (Based In-Part On SESC Observational Data)


SOLAR AND GEOPHYSICAL ACTIVITY INDICES FOR 10 SEPTEMBER
-------------------------------------------------------

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 254, 09/10/92
10.7 FLUX=116.9  90-AVG=124        SSN=086      BKI=4866 6434  BAI=072
BGND-XRAY=B4.1     FLU1=4.2E+06  FLU10=1.2E+04  PKI=5787 5655  PAI=090
  BOU-DEV=062,345,154,166,125,054,025,040   DEV-AVG=121 NT     SWF=01:008
 XRAY-MAX= M3.2   @ 2257UT    XRAY-MIN= B3.3   @ 0520UT   XRAY-AVG= C1.0
NEUTN-MAX= +002%  @ 0705UT   NEUTN-MIN= -006%  @ 2025UT  NEUTN-AVG= -2.9%
  PCA-MAX= +0.2DB @ 1535UT     PCA-MIN= -0.1DB @ 2300UT    PCA-AVG= -0.0DB
BOUTF-MAX=55541NT @ 0333UT   BOUTF-MIN=55318NT @ 0803UT  BOUTF-AVG=55405NT
GOES7-MAX=E:+156NT@ 0648UT   GOES7-MIN=N:-027NT@ 0328UT  G7-AVG=+062,+074,+001
GOES6-MAX=P:+128NT@ 0758UT   GOES6-MIN=E:-020NT@ 0338UT  G6-AVG=+071,+006,+047
 FLUXFCST=STD:116,115,115;SESC:115,115,110 BAI/PAI-FCST=035,020,020/040,025,025
    KFCST=2334 3222 3345 5333  27DAY-AP=013,011   27DAY-KP=3223 4422 2241 2233
 WARNINGS=*MAJFLR;*SWF;*GSTRM;*AURMIDWRN
   ALERTS=**MINFLR:M3.2/2B@2257UTC;**SWEEP:II=3@2254UTC;**245STRM:0442-0615;
          **MAGSI:54NT@0330UTC;**MAJSTRM;**TENFLR:250SFU@2251,DUR=3MINUTES
!!END-DATA!!


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

     Solar activity became moderate today by virtue of a single class M3.2/2B
tenflare from Region 7276 (N15E40).  This flare was associated with a major
Type II sweep that coincided with the time of the maximum x-ray flux at 22:54
UT.  Region 7276 was also responsible for several C-class flares, the largest
of which was a C9.4/SF event at 02:33 UT.

     Region 7276 was fairly stable today in terms of growth and structure.
It continues to possess a beta-gamma magnetic configuration and has the
potential to produce additional minor M-class flares.  There is also a slight
chance the region may support a major M-class flare sometime during its
passage across the solar disk.

     New Region 7280 (S12E79) was numbered today.  Preliminary observations
show this group to be a fairly small and simple CRO type spot group.

     Solar activity will be moderate.  M-class flare activity is expected
from Region 7276.  None of the other four spotted groups are significant
enough to spawn anything more energetic than weak B and/or C-class subflares.

     The geomagnetic field remained at moderate to strong major storm levels
throughout the day.  A sudden magnetic impulse of 54 nT at Boulder marked the
arrival of a second interplanetary disturbance at 03:30 UT.  This disturbance
maintained major to severe geomagnetic storming throughout much of the UT
day.  Conditions are expected to begin stabilizing by 12:00 or 15:00 UT on 11
September with a return to quieter conditions on 12 and 13 September.  Over
the next 24 hours, minor to major storming will be evident until after 12:00
UT when the field should become mostly active.  The source of this activity
is the major solar flaring which occurred earlier this week.

     Auroral activity continued at moderate to strong levels over the last 24
hours.  Activity was observed as far south as Rochester, Minnesota (43 N
geographic latitude).  Conditions were favorable for observations of activity
further south, although no reports have yet been received.  Despite the
moderate to high level of lunar interference, auroral activity was easily
visible from the northern U.S. states and all of the Canadian provinces.
Auroral activity will diminish over the next 24 hours and become increasingly
dormant and isolated in visibility on 12 September.  The Middle Latitude
Auroral Activity Warning will be allowed to expire at 19:00 UT on 11
September unless conditions warrant an extension.

     HF propagation conditions remained well below normal over most regions.
High and polar latitude signal paths were most heavily affected, with very
poor propagation throughout the entire UT day.  MUFs were depressed by as
much as 30 to 45 percent below seasonal normals.  Strong levels of fading,
multipath activity, and signal absorption affected the polar, high, and
northerly middle latitude signal paths.  Similar conditions are expected for
the high and polar latitude regions for much of the UT day of 11 September.
Some improvements over these regions can be expected on 12 and particularly
13 September.  Middle latitude regions may begin to see some mild
improvements late in the UT day of 11 September, with more substantial gains
on 12 September.  It will require several days for the ionosphere to recover
after this major geomagnetic storm ends.


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

REGIONS WITH SUNSPOTS (LOCATIONS VALID AT 10/2400Z)
---------------------------------------------------
NMBR LOCATION  LO  AREA  Z   LL   NN MAG TYPE
7276  N15E40  261  0220 DAI  10  028 BETA-GAMMA
7277  S11E05  296  0010 BXO  06  002 BETA
7278  N10W01  302  0010 BXO  05  003 BETA
7279  S07E48  253  0000 AXX  01  001 ALPHA
7280  S12E79  222  0040 CRO  02  002 BETA
REGIONS DUE TO RETURN 11 SEPTEMBER TO 13 SEPTEMBER
NMBR LAT    LO
7268 N05   176


LISTING OF SOLAR ENERGETIC EVENTS FOR 10 SEPTEMBER
--------------------------------------------------
BEGIN  MAX  END  RGN   LOC   XRAY  OP 245MHZ 10CM   SWEEP SWF
 2230 2257 2307 7276  N12E41 M3.2  2B   1500 250    II


POSSIBLE CORONAL MASS EJECTION EVENTS FOR 10 SEPTEMBER
------------------------------------------------------
           UT TIME                 OPTICAL          XRAY    RADIO
 BEGIN        MAX      END     LOCATION   TYPE   SIZE  DUR  II IV
10/ 2254              2315       N12E41   RSP    M3.2   37  3


INFERRED CORONAL HOLES (LOCATIONS VALID AT 10/2400Z)
----------------------------------------------------
               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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