From: oler@rho.uleth.ca (Cary Oler)
Newsgroups: sci.space.news
Subject: Daily Summary of Solar Geophysical Activity for 23 August
Date: 24 Aug 92 03:59:28 GMT
Followup-To: sci.space
Organization: University of Lethbridge
Apparently-To: sci-space-news@ames.arc.nasa.gov


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                 DAILY SUMMARY OF SOLAR GEOPHYSICAL ACTIVITY

                               23 AUGUST, 1992

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                  (Based In-Part On SESC Observational Data)


SOLAR AND GEOPHYSICAL ACTIVITY INDICES FOR 23 AUGUST
----------------------------------------------------

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 236, 08/23/92
10.7 FLUX=110.7  90-AVG=125        SSN=042      BKI=6663 4333  BAI=040
BGND-XRAY=B4.9     FLU1=5.7E+05  FLU10=1.0E+04  PKI=7873 3234  PAI=068
  BOU-DEV=127,186,188,022,042,029,021,021   DEV-AVG=079 NT     SWF=00:000
 XRAY-MAX= C5.1   @ 2045UT    XRAY-MIN= B3.9   @ 1730UT   XRAY-AVG= B7.7
NEUTN-MAX= +000%  @ 2355UT   NEUTN-MIN= -007%  @ 0905UT  NEUTN-AVG= -2.9%
  PCA-MAX= +0.4DB @ 1215UT     PCA-MIN= -0.1DB @ 0725UT    PCA-AVG= +0.1DB
BOUTF-MAX=55255NT @ 0002UT   BOUTF-MIN=55128NT @ 0523UT  BOUTF-AVG=55189NT
GOES7-MAX=E:+186NT@ 0609UT   GOES7-MIN=N:-044NT@ 0425UT  G7-AVG=+074,+077,+009
GOES6-MAX=N:+171NT@ 0625UT   GOES6-MIN=E:-035NT@ 0648UT  G6-AVG=+083,+012,+055
 FLUXFCST=STD:103,098,095;SESC:100,100,095 BAI/PAI-FCST=020,015,015/025,015,010
    KFCST=3343 4333 2333 3333  27DAY-AP=010,021   27DAY-KP=3122 2333 4542 3332
 WARNINGS=*SWF;*FORBUSH;*GSTRM;*PROTON
   ALERTS=**MINSTRM;**FORBUSH;**MAGPAUSE
!!END-DATA!!


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

     Solar activity continued low.  Fairly frequent but weak C-class
subflares were observed today from Region 7260 (N16W78).  The largest was a
class C5.1 event at 20:45 UT.

     Region 7260 continued to decay and simplify.  Additional minor C-class
flares are expected with a persisting chance for an isolated M-class flare
before it rotates out of view late on 24/25 August.

     No new regions were numbered today.

     Solar activity is expected to be mostly low to possibly moderate.
M-class flare activity is only possible in Region 7260.  All of the other
regions are insignificant and dormant.

     The geomagnetic field ranged from unsettled to severe storm levels over
the last 24 hours.  Severe geomagnetic storming was observed over the high
latitude regions early in the UT day between 00:00 UT and 09:00 UT.  Middle
latitudes observed minor to major storming during this same interval.  A
Forbush decrease began near 01:00 UT and ended near 17:00 UT.  The Forbush
decrease reached a maximum of approximately 7 percent near 09:05 UT.  Neutron
counts returned to near pre-storm levels by the end of the UT day.  The
geomagnetic field is expected to be mostly unsettled to active on 24 August
with periods of minor storming possible over the higher latitudes during the
local night sectors. Additional stabilization to mostly unsettled levels is
expected for 25 and 26 August.

     Moderate to high levels of auroral activity were observed from the
Canadian Arctic to areas as far south as Pennsylvania, Ohio, northern
Indiana, Iowa, and South Dakota.  Activity has since diminished and is
expected to be confined in visibility to the high and northerly middle
latitude regions well north of the U.S./Canada border.  No reports of auroral
activity were received from Australia/New Zealand.  The most intense phase of
the storm activity occurred over North America and had stabilized somewhat by
the time the Australian regions had favorable observing conditions.  For this
reason, most of the activity is thought to have remained confined to the
North American regions.  The Middle Latitude Auroral Activity Warning that
was issued early in the UT day of 23 August has been cancelled.

     HF propagation conditions became extremely degraded over the high and
polar latitude signal paths early in the UT day of 23 August.  Fair to poor
propagation was also noted over the middle latitude paths between 00:00 UT
and 09:00 UT.  MUFs were depressed by up to 50 percent over some regions with
occasional near radio blackout conditions over the high latitudes.  Weak VHF
auroral backscatter was observed on frequencies as high as approximately 100
MHz.  An Australian site also reported weak but consistent backscatter on
92.1 MHz between 04:50 UT and 05:05 UT.  Propagation is expected to improve
over the next 48 hours to near normal.  High and polar latitude paths will be
last to recover.  Middle latitudes should return to near-normal later on 24
August.


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

REGIONS WITH SUNSPOTS (LOCATIONS VALID AT 23/2400Z)
---------------------------------------------------
NMBR LOCATION  LO  AREA  Z   LL   NN MAG TYPE
7260  N16W78  257  1150 EKO  13  021 BETA-GAMMA
7265  S19E13  166  0040 HSX  02  001 ALPHA
7264  N13W37  216                    PLAGE
REGIONS DUE TO RETURN 24 AUGUST TO 26 AUGUST
NMBR LAT    LO
7257 S20   063
7245 S07   064


LISTING OF SOLAR ENERGETIC EVENTS FOR 23 AUGUST
-----------------------------------------------
BEGIN  MAX  END  RGN   LOC   XRAY  OP 245MHZ 10CM   SWEEP SWF
 0031 0107 0117              C1.8        130
 0902 0904 0905                          130
 0919 0923 0926 7260  N14W66 C4.5  SF    150


POSSIBLE CORONAL MASS EJECTION EVENTS FOR 23 AUGUST
---------------------------------------------------
           UT TIME                 OPTICAL          XRAY    RADIO
 BEGIN        MAX      END     LOCATION   TYPE   SIZE  DUR  II IV
NO EVENTS OBSERVED


INFERRED CORONAL HOLES (LOCATIONS VALID AT 23/2400Z)
----------------------------------------------------
               ISOLATED HOLES AND POLAR EXTENSIONS
      EAST   SOUTH  WEST   NORTH  CAR  TYPE  POL  AREA   OBSN
                 NO DATA AVAILABLE FOR ANALYSIS


**  End of Daily Report  **
Newsgroups: sci.space.news