:Product: Weekly Highlights and Forecasts
:Issued: 1999 Oct 06 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
27 SEPTEMBER - 03 OCTOBER 1999

SOLAR ACTIVITY WAS LOW. THE VISIBLE DISK WAS POPULATED BY A NUMBER OF
SMALL, SIMPLY-STRUCTURED SUNSPOT GROUPS WHICH PRODUCED B- AND
C-CLASS SUBFLARES. ONE EVENT OF NOTE WAS AN OPTICALLY UNCORRELATED,
LONG-DURATION C3 X-RAY FLARE AT 01/0813UT WITH A TYPE II RADIO SWEEP
(EST. VELOCITY 600 KM/SEC).

REAL-TIME SOLAR WIND DATA WERE AVAILABLE FROM THE ADVANCED
COMPOSITION EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD.
CORONAL HOLE EFFECTS WERE EVIDENT DURING 27 - 30 SEPTEMBER. DURING
THIS PERIOD VELOCITIES WERE ELEVATED WITH A PEAK OF 680 KM/SEC
DETECTED ON 27 SEPTEMBER, DENSITIES WERE IN THE 02 - 04 P/CC RANGE,
AND IMF BZ WAS MOSTLY SOUTH WITH MAXIMUM DEFLECTIONS TO MINUS 11 NT
(GSM). PHI DATA INDICATED AN AWAY (POSITIVE POLARITY) SOLAR SECTOR
DURING THIS PERIOD AS WELL.

NO PROTON EVENTS WERE DETECTED AT GEO-SYNCHRONOUS ORBIT DURING THE
PERIOD.

THE GREATER THAN 2 MEV ELECTRON FLUX WAS AT MODERATE TO HIGH LEVELS
DURING 28 SEPTEMBER - 03 OCTOBER.

THE GEOMAGNETIC FIELD WAS DISTURBED DURING 27 - 30 SEPTEMBER DUE TO
CORONAL HOLE EFFECTS WITH ACTIVE TO MINOR STORM LEVELS DETECTED
GLOBALLY. THERE WERE ALSO MAJOR TO (ISOLATED) SEVERE STORM PERIODS
DETECTED AT HIGH LATITUDES. ACTIVITY DECREASED TO QUIET TO UNSETTLED
LEVELS ON 01 OCTOBER, THEN INCREASED TO UNSETTLED TO ACTIVE LEVELS
ON 02 OCTOBER. ACTIVITY DECREASED TO QUIET TO UNSETTLED LEVELS ON
THE FINAL DAY OF THE SUMMARY PERIOD.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
06 OCTOBER - 01 NOVEMBER 1999

SOLAR ACTIVITY IS EXPECTED TO BE PREDOMINATELY LOW. ISOLATED M-CLASS
FLARE ACTIVITY IS POSSIBLE DURING THE FIRST HALF OF THE PERIOD.

NO SIGNIFICANT PROTON EVENTS ARE EXPECTED AT GEO-SYNCHRONOUS ORBIT.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEO-SYNCHRONOUS ALTITUDE IS
EXPECTED TO BE AT MODERATE TO HIGH LEVELS DURING 06 - 13 AND 25 - 30
OCTOBER. OTHERWISE, FLUXES ARE EXPECTED TO BE IN THE NORMAL TO
MODERATE RANGE.

THE GEOMAGNETIC FIELD IS EXPECTED TO BE DISTURBED DURING 06 - 11 AND
24 - 27 OCTOBER DUE TO RECURRENT CORONAL HOLE EFFECTS.


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