From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Summary of Solar Geophysical Activity for 23 July
Apparently-To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
Organization: University of Lethbridge
Date: Fri, 24 Jul 1992 06:58:38 GMT

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                  DAILY SUMMARY OF SOLAR GEOPHYSICAL ACTIVITY

                                23 JULY, 1992

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                  (Based In-Part On SESC Observational Data)


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

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 205, 07/23/92
10.7 FLUX=098.8  90-AVG=128        SSN=073      BKI=4533 2123  BAI=017
BGND-XRAY=B2.2     FLU1=9.3E+05  FLU10=1.1E+04  PKI=4433 2333  PAI=019
  BOU-DEV=068,097,028,025,016,006,014,030   DEV-AVG=036 NT     SWF=00:000
 XRAY-MAX= B4.1   @ 0637UT    XRAY-MIN= B1.8   @ 1914UT   XRAY-AVG= B2.4
NEUTN-MAX= +001%  @ 1735UT   NEUTN-MIN= -003%  @ 0620UT  NEUTN-AVG= -0.5%
  PCA-MAX= +0.1DB @ 1725UT     PCA-MIN= -0.1DB @ 2355UT    PCA-AVG= -0.0DB
BOUTF-MAX=55252NT @ 0307UT   BOUTF-MIN=55213NT @ 1739UT  BOUTF-AVG=55233NT
GOES7-MAX=P:+098NT@ 2110UT   GOES7-MIN=N:-012NT@ 0550UT  G7-AVG=+078,+051,+004
GOES6-MAX=P:+113NT@ 2115UT   GOES6-MIN=E:-002NT@ 1707UT  G6-AVG=+095,+014,+040
 FLUXFCST=STD:095,095,103;SESC:095,090,100 BAI/PAI-FCST=015,010,010/015,010,010
    KFCST=3334 4322 3334 4222  27DAY-AP=009,014   27DAY-KP=2233 3232 2124 3344
 WARNINGS=*AURMIDWCH
   ALERTS=
!!END-DATA!!


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

     Solar activity became very low.  Very little x-ray activity was observed
over the last 24 hours.  Only a single small subflare was observed from
Region 7234 (S17W81) at 01:50 UT.

     Region 7229 (N24W79) was stable as it approached the west limb.  It is
expected to remain quiet as it departs the west limb early on 25 July.  The
prominence which erupted yesterday remained eruptive throughout the day.
This is, perhaps, the most interesting activity that was observed from this
region.

     Region 7236 (N16W16) is now the strongest (although still quite simple)
spot group visible.  It has continued to slowly grow over the last 24 hours
and should be capable of producing small C-class subflares.  It never
produced any notable flare activity today.

     The eastern edge of a large Fe XIV coronal hole began crossing the
central meridian late in the UT day.  This stable hole, which has persisted
for the last four solar rotations, is confined to areas between approximately
30 and 50 degrees north solar latitude and spans 55 to 60 degrees in
longitude (to the east).  This hole is not well defined in 10830A imagery.

     No new regions were assigned.

     Solar activity is expected to continue mostly very low to low.
C-class flares are possible from Region 7236.  Old Region 7216 (N14) which
was responsible for numerous small C-class subflares on its last rotation, is
due to return early in the UT day of 26 July.  It may produce a moderate
enhancement in east-limb 10.7 cm emissions at that time and contribute
additional minor C-class flare activity.

     The geomagnetic field stabilized throughout the day.  The estimated
24-hour A-index for middle latitude regions briefly surpassed the minor storm
threshold of 30 at 06:00 UT on 23 July with an estimated A-index of 32.
Conditions continued to become increasingly dormant as the day progressed.
Generally unsettled to quiet levels were observed by the end of the UT day.
The coronal hole which was responsible for this disturbance is no longer well
placed and will continue to become less influential over time.  The field is
expected to be mostly quiet to unsettled over the next 72 hours.  The Fe XIV
coronal hole noted previously will not influence geomagnetic activity.

     Auroral activity stabilized substantially over the last 24 hours.  Most
of the activity remained confined to the higher latitude regions, where
fairly stable (or at least, slowly changing) curtains were visible overhead
near 52 to 55 degrees geographic latitude over North America.  This activity
was not energetic enough to be observed over the central middle latitude
regions.  Auroral activity will continue to diminish.

     HF propagation conditions were slightly degraded early in the UT day,
but improved to near-normal by the end of the UT day.  Low and middle
latitude signal paths should enjoy generally good propagation over the next
72 hours, while high and polar latitude regions should return to near normal
with mostly fair propagation by 25 July.


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
7229  N24W79  308  0050 HAX  01  001 ALPHA
7234  S17W81  310  0070 CAO  05  003 BETA
7235  S05W72  301  0040 HSX  01  001 ALPHA
7236  N18W16  245  0060 DAO  05  013 BETA
7237  N05W50  279  0030 CRO  04  005 BETA
7230  S14W59  288                    PLAGE
7232  N17W32  261                    PLAGE
REGIONS DUE TO RETURN 24 JULY TO 26 JULY
NMBR LAT    LO
7216 N14   115


LISTING OF SOLAR ENERGETIC EVENTS FOR 23 JULY
---------------------------------------------
BEGIN  MAX  END  RGN   LOC   XRAY  OP 245MHZ 10CM   SWEEP SWF
NO EVENTS OBSERVED


POSSIBLE CORONAL MASS EJECTION EVENTS FOR 23 JULY
-------------------------------------------------
           UT TIME                 OPTICAL          XRAY    RADIO
 BEGIN        MAX      END     LOCATION   TYPE   SIZE  DUR  II IV
23/B0551             A0938       N21W90   EPL    B4.1   45


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  **