:Product: Weekly Highlights and Forecasts
:Issued: 2000 Feb 16 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
07 - 13 FEBRUARY 2000

SOLAR ACTIVITY RANGED FROM LOW TO MODERATE LEVELS. REGION 8858 (N26,
L = 200, CLASS/AREA EAI/170 ON 05 FEBRUARY), A SMALL MIXED-POLARITY
GROUP, GRADUALLY DECAYED THROUGHOUT THE PERIOD, BUT MANAGED TO
PRODUCE TWO M-CLASS FLARES. THE FIRST WAS AN M1/1B PARALLEL-RIBBON
FLARE AT 09/0900UT WITH AN ASSOCIATED TYPE II RADIO SWEEP AND A
FULL-HALO CORONAL MASS EJECTION (CME). THE SECOND WAS AN M1/1N AT
12/0410UT ASSOCIATED WITH TYPES II AND IV RADIO SWEEPS, AND A 200
SFU TENFLARE. REGION 8858 ALSO PRODUCED A LONG-DURATION C7/1N FLARE
AT 10/0208UT ACCOMPANIED BY A 240 SFU TENFLARE, TYPE II RADIO SWEEP,
AND A FULL-HALO CME. REGION 8853 (S13, L = 241, CLASS/AREA BXO/020
ON 06 FEBRUARY) PRODUCED A LONG-DURATION C7/2F FLARE AT 09/2006UT
WHICH WAS FOLLOWED BY A FULL-HALO CME. REGION 8853 WAS A DECAYING
PLAGE AREA AT THE TIME OF THIS FLARE. A PARTIAL-HALO CME WAS
OBSERVED ON 11 FEBRUARY FOLLOWING A C2 AT 11/1234UT FROM REGION 8856
(S14, L = 207, CLASS/AREA ESO/190 ON 05 FEBRUARY).

REAL-TIME SOLAR WIND DATA WERE AVAILABLE FROM THE NASA ADVANCED
COMPOSITION EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD. A
CORONAL HOLE SIGNATURE WAS EVIDENT ON 07 - 08 FEBRUARY WITH ELEVATED
VELOCITIES (PEAK 700 KM/SEC ON 07 FEBRUARY) AND LOW PROTON
DENSITIES. NOMINAL SOLAR WIND CHARACTERISTICS WERE OBSERVED DURING
09 - 10 FEBRUARY. TWO CME-RELATED SHOCK FRONTS PASSED THE ACE
SPACECRAFT ON 11 FEBRUARY. THE FIRST SHOCK OCCURRED AT 11/0214UT
ACCOMPANIED BY ABRUPT INCREASES IN SOLAR WIND VELOCITIES AND
DENSITIES (PEAKS TO 580 KM/SEC AND 14 P/CC, RESPECTIVELY), AND A
BRIEF SOUTHWARD TURNING OF IMF BZ WITH MAXIMUM DEFLECTIONS TO MINUS
07 NT (GSM). THE SECOND SHOCK FRONT PASSED THE SPACECRAFT AT
11/2319UT ACCOMPANIED BY SUDDEN INCREASES IN VELOCITY (PEAK 640
KM/SEC) AND DENSITY (30 P/CC), AND PERIODS OF SOUTHWARD IMF BZ WITH
A MAXIMUM DEFLECTION TO MINUS 18 NT (GSM).

THERE WAS A GREATER THAN 10 MEV PROTON ENHANCEMENT AT GEOSYNCHRONOUS
ORBIT ON 12 FEBRUARY. PROTON FLUXES WERE AT BACKGROUND LEVELS DURING
THE REST OF THE PERIOD.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS AT
MODERATE TO HIGH LEVELS DURING 07 - 11 FEBRUARY, THEN DROPPED TO
MOSTLY NORMAL LEVELS FOR THE REMAINDER OF THE PERIOD.

THE GEOMAGNETIC FIELD WAS DISTURBED DURING 07 FEBRUARY DUE TO
RECURRENT CORONAL HOLE EFFECTS WITH UNSETTLED TO ACTIVE LEVELS AT
MIDDLE LATITUDES AND UNSETTLED TO MAJOR STORM LEVELS AT HIGH
LATITUDES. FIELD ACTIVITY DECLINED TO MOSTLY QUIET TO UNSETTLED
LEVELS DURING 08 - 10 FEBRUARY. ACTIVITY INCREASED TO UNSETTLED TO
ACTIVE LEVELS ON 11 FEBRUARY FOLLOWING A 23 NT SUDDEN IMPULSE (SI)
AT 11/0301UT (AS MEASURED BY THE BOULDER USGS MAGNETOMETER). A MAJOR
GEOMAGNETIC STORM OCCURRED ON 12 FEBRUARY FOLLOWING A SUDDEN STORM
COMMENCEMENT (SSC) AT 11/2353UT (19 NT) WITH ACTIVE TO SEVERE STORM
LEVELS DETECTED GLOBALLY.  ACTIVITY DECREASED TO QUIET TO MINOR
STORM LEVELS ON 13 FEBRUARY AS THE STORM ENDED. THE 11 - 12 FEBRUARY
DISTURBANCES WERE DUE TO CME PASSAGES AT EARTH.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
16 FEBRUARY - 13 MARCH 2000

SOLAR ACTIVITY IS EXPECTED TO RANGE FROM LOW TO MODERATE LEVELS
DURING THE PERIOD. OCCASIONAL C-CLASS FLARES ARE LIKELY THROUGHOUT
THE PERIOD.  ISOLATED M-CLASS FLARES WILL BE POSSIBLE BEGINNING 01
MARCH WITH THE RETURN OF PREVIOUSLY ACTIVE LONGITUDES.

NO PROTON EVENTS ARE EXPECTED AT GEOSYNCHRONOUS ORBIT.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS
EXPECTED TO BE AT NORMAL TO MODERATE LEVELS DURING MOST OF THE
PERIOD. HOWEVER, HIGH FLUX LEVELS ARE EXPECTED DURING 25 - 28
FEBRUARY AND 05 - 08 MARCH.

GEOMAGNETIC FIELD ACTIVITY IS EXPECTED TO BE AT MOSTLY QUIET TO
UNSETTLED LEVELS DURING MOST OF THE PERIOD. HOWEVER, ACTIVE TO MINOR
STORM LEVELS ARE EXPECTED DURING 24 - 25 FEBRUARY AND 04 - 05 MARCH
DUE TO RECURRENT CORONAL HOLE EFFECTS.

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