From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Summary of Solar Geophysical Activity for 20 August
Apparently-To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
Organization: University of Lethbridge
Date: Fri, 21 Aug 1992 04:40:36 GMT

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                 DAILY SUMMARY OF SOLAR GEOPHYSICAL ACTIVITY

                               20 AUGUST, 1992

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                  (Based In-Part On SESC Observational Data)


SOLAR AND GEOPHYSICAL ACTIVITY INDICES FOR 20 AUGUST
----------------------------------------------------

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 233, 08/20/92
10.7 FLUX=155.5  90-AVG=126        SSN=103      BKI=2533 2212  BAI=013
BGND-XRAY=B8.9     FLU1=5.1E+05  FLU10=1.1E+04  PKI=3645 3222  PAI=024
  BOU-DEV=018,112,038,039,017,014,008,010   DEV-AVG=032 NT     SWF=04:151
 XRAY-MAX= M4.0   @ 1437UT    XRAY-MIN= B7.2   @ 0048UT   XRAY-AVG= C4.5
NEUTN-MAX= +004%  @ 1415UT   NEUTN-MIN= -002%  @ 2150UT  NEUTN-AVG= +0.4%
  PCA-MAX= +0.6DB @ 1450UT     PCA-MIN= -2.1DB @ 1800UT    PCA-AVG= -0.1DB
BOUTF-MAX=55266NT @ 0524UT   BOUTF-MIN=55215NT @ 1731UT  BOUTF-AVG=55246NT
GOES7-MAX=E:+141NT@ 0944UT   GOES7-MIN=N:-012NT@ 0516UT  G7-AVG=+080,+058,+011
GOES6-MAX=P:+127NT@ 0019UT   GOES6-MIN=E:-015NT@ 1131UT  G6-AVG=+088,+006,+043
 FLUXFCST=STD:150,150,145;SESC:150,145,130 BAI/PAI-FCST=015,010,010/015,015,015
    KFCST=3334 5322 2224 5222  27DAY-AP=011,012   27DAY-KP=3223 3333 3222 3432
 WARNINGS=*MAJFLR;*SWF;*PROTON;*PCA
   ALERTS=**MINFLR:M2.9/1B@0921;**MINFLR:M4.0/1B@1437;**MINFLR:M1.9/1B@1730;
          **TENFLR:240SFU@1748,DUR=7MIN;**MINFLR:M3.0/1B@2046;
          **SWEEP:IV=1@0445UTC
!!END-DATA!!


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

     Solar activity became significantly moderate today.  Four M-class flares
erupted out of the trailer spot complex of Region 7260 (N16W38).  The largest
of these was an M4.0/1B flare at 14:37 UT.  Two of the M-class flares were
long in duration; an M2.9/1B flare at 09:21 UT and an M1.9/1B event at 17:30
UT.  This latter flare was associated with a 240 sfu tenflare at 17:48 UT
that lasted 7 minutes.  Also of interest today was a weak Type IV sweep at
04:45 UT that was not well correlated with any of the visible activity.  A
class C4.5 x-ray event at 03:54 UT appears to correlate the best in time with
the observed sweep, although uncertainty remains.

     Region 7260 continued to grow and develop over the last 24 hours,
particularly in the trailer spot complex.  A delta configuration persists in
the trailer spot complex with a predominantly east-west oriented neutral
line.  The flare activity that was observed today does not appear to have
significantly affected the potential volatility of the group.  Minor M-class
flare activity is expected to continue, with a developing risk for major
flaring should growth persist.  Most of the flares observed thus far have
been moderately radio-quiet and none of them have been clearly associated
with any sweep frequency events.  However, they were all associated with
low to moderate intensity high-frequency short wave fadeouts.  Region 7260 is
presently 1,440 millionths in area in an EKC, beta-gamma-delta configuration.
Further growth is possible over the next 24 hours.

     Todays large increase in the 10.7 cm solar radio flux (to 156 from 135)
was accompanied by a similar enhancement in the background x-ray flux.  This
is all attributed to the growth of Region 7260 and is representative of the
potential volatility of the group.

     All of the other regions are small and insignificant.  No new regions
were assigned.

     Solar activity is expected to continue moderate.  There is a chance
Region 7260 may support a major flare over the next 72 hours.  The potential
for an associated proton enhancement cannot be ignored should a major flare
develop.

     The geomagnetic field was mostly unsettled today, although periods of
active to minor storm level activity was observed during the local night
hours over the middle latitudes.  High latitudes reported episodes of minor
to major storming during local night hours, but were otherwise mostly
unsettled.

     HF propagation conditions were near-normal over all regions.  Short wave
fadeout activity was confirmed over daylit paths with most of the M-class
flares that were observed today.  Frequencies in excess of 15 MHz were
affected by some of these events, particularly the M1.9/1B tenflare at 17:30
UT that affected frequencies near 20 MHz to a minor extent, and frequencies
below 15 MHz to a stronger extent.  Additional SWF activity is expected over
the next 24 to 48 hours as Region 7260 continues to pump out occasional minor
M-class flares and a possible isolated major flare.  A relatively unsettled
level of geomagnetic activity should keep night-sector propagation
near-normal over all regions, with fading and minor signal absorption
occasionally evident over the higher latitude paths.


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

REGIONS WITH SUNSPOTS (LOCATIONS VALID AT 20/2400Z)
---------------------------------------------------
NMBR LOCATION  LO  AREA  Z   LL   NN MAG TYPE
7260  N16W38  257  1440 EKC  15  065 BETA-GAMMA-DELTA
7264  N17E08  211  0010 BXO  07  007 BETA
7265  S19E53  166  0030 HSX  01  001 ALPHA
7263  N15W85  304                    PLAGE
REGIONS DUE TO RETURN 21 AUGUST TO 23 AUGUST
NMBR LAT    LO
7252 S16   129
7241 N14   120
7242 N16   103


LISTING OF SOLAR ENERGETIC EVENTS FOR 20 AUGUST
-----------------------------------------------
BEGIN  MAX  END  RGN   LOC   XRAY  OP 245MHZ 10CM   SWEEP SWF
 0445                                                 IV
 0901 0921 1031 7260  N16W27 M2.9  1B        28
 1425 1437 1458 7260  N15W29 M4.0  1B        63
 1654 1730 1806 7260  N17W34 M1.9  1B    500 240
 2030 2046 2120 7260  N16W33 M3.0  1B


POSSIBLE CORONAL MASS EJECTION EVENTS FOR 20 AUGUST
---------------------------------------------------
           UT TIME                 OPTICAL          XRAY    RADIO
 BEGIN        MAX      END     LOCATION   TYPE   SIZE  DUR  II IV
20/ 0445                                  SWP                   1
20/ 0901     0921     1031       N16W27   LDE    M2.9   89
20/ 1654     1730     1806       N17W34   LDE    M1.9   72
20/ 2030     2046     2120       N16W33   LDE    M3.0   49


INFERRED CORONAL HOLES (LOCATIONS VALID AT 20/2400Z)
----------------------------------------------------
               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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