:Product: Weekly Highlights and Forecasts
:Issued: 2000 Jun 13 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
05 - 11 JUNE 2000

SOLAR ACTIVITY RANGED FROM LOW TO HIGH LEVELS. THE PERIOD BEGAN WITH
ACTIVITY AT MODERATE LEVELS DUE TO AN M1/1F FLARE FROM REGION 9031
(S32, L = 150, CLASS/AREA CSO/110 ON 06 JUNE). ACTIVITY INCREASED TO
HIGH LEVELS DURING 06 - 07 JUNE DUE TO MAJOR FLARE ACTIVITY FROM
REGION 9026 (N21, L = 074, CLASS/AREA EKO/910 ON 03 JUNE). MAJOR
FLARE ACTIVITY DURING THIS PERIOD INCLUDED AN X1/2N AT 06/1339UT
WITH AN ASSOCIATED 560 SFU TENFLARE, AN M7 AT 06/1401UT; AN X2/3B AT
06/1525UT WITH ASSOCIATED TYPE II AND IV RADIO SWEEPS, A 2300 SFU
TENFLARE, 11-DEGREE DSF, LOOP-PROMINENCE SYSTEM, FULL-HALO CME, AND
A SOLAR PROTON EVENT (SEE THE DESCRIPTION BELOW); AND A X1/3B AT
07/1553UT WITH ASSOCIATED TYPE II AND IV RADIO SWEEPS, A 200 SFU
TENFLARE, AND A FAINT FULL-HALO CME. REGION 9026 SHOWED MINOR
CHANGES PRIOR TO AND DURING THE MAJOR ACTIVITY AND WAS A LARGE,
MAGNETICALLY COMPLEX WITH A STRONG MAGNETIC DELTA STRUCTURE REPORTED
WITHIN ITS LEADER SPOT. REGION 9026 BEGAN A DECAY PHASE ON 08 JUNE,
WHICH CONTINUED THROUGH THE REST OF THE PERIOD. REGION 9031 PRODUCED
AN M2/1B FLARE AT 07/0444UT. ACTIVITY DECREASED TO LOW LEVELS DURING
08 - 09 JUNE WITH OCCASIONAL C-CLASS SUBFLARES FROM REGION 9026,
WHICH SHOWED SIGNIFICANT DECAY. REGION 9033 (N22, L = 016,
CLASS/AREA FKC/560 ON 10 JUNE) SHOWED SIGNIFICANT GROWTH DURING THIS
PERIOD, BUT PRODUCED NO FLARES. ACTIVITY INCREASED TO HIGH LEVELS ON
10 JUNE DUE TO AN M5/3B FLARE AT 10/1702UT FROM REGION 9026 WITH AN
ASSOCIATED TYPE II RADIO SWEEP, 550 SFU TENFLARE, LOOP-PROMINENCE
SYSTEM, FULL-HALO CME, AND A SOLAR PROTON EVENT. ACTIVITY DECREASED
TO MODERATE LEVELS ON THE FINAL DAY OF THE PERIOD AS REGION 9033
PRODUCED AN M1/1F FLARE AT 11/1049UT.

REAL-TIME SOLAR WIND DATA WERE AVAILABLE FROM THE NASA ADVANCED
COMPOSITION EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD. A CME
PASSAGE OCCURRED DURING 08 JUNE. THE SHOCK FRONT PRECEEDING THE CME
PASSED THE SPACECRAFT AT 08/0841UT FOLLOWED SHORTLY THEREAFTER BY AN
ABRUPT VELOCITY INCREASE (510 TO 830 KM/SEC), A BRIEF DENSITY
INCREASE, WITH PEAKS TO 27 P/CC; AND STRONG SOUTHWARD IMF BZ WITH
DEFLECTIONS TO MINUS 24 NT (GSM). BZ TURNED MOSTLY NORTHWARD LATE ON
08 JUNE AND REMAINED SO UNTIL ABOUT 09/2100UT, AT WHICH TIME IT
AGAIN TURNED SOUTHWARD UNTIL 11/1600UT WITH A RANGE OF MINUS 1 TO
MINUS 12 NT.

THERE WERE TWO SOLAR PROTON EVENTS AT GEOSYNCHRONOUS ORBIT, BOTH
ASSOCIATED WITH MAJOR FLARES FROM REGION 9026. THE FIRST, A GREATER
THAN 10 MEV PROTON EVENT (WHICH FOLLOWED THE X2/3B FLARE OF
06/1525UT), BEGAN AT 07/1335UT, REACHED A MAXIMUM OF 84 PFU AT
08/0940UT, AND ENDED AT 09/0325UT (THERE WAS ALSO A SLIGHT
ENHANCEMENT AT GREATER THAN 100 MEV). THE SECOND EVENT FOLLOWED THE
M5/3B OF 10/1702UT AND SAW EVENT THRESHOLDS EXCEEDED AT BOTH THE
GREATER THAN 100 MEV AND GREATER THAN 10 MEV FLUXES. THE GREATER
THAN 100 MEV EVENT BEGAN AT 10/1750UT, REACHED A MAXIMUM OF 1.6 PFU
AT 10/1755UT, THEN ENDED AT 10/1830UT; WHILE THE GREATER THAN 10 MEV
EVENT BEGAN AT 10/1805UT, REACHED A MAXIMUM OF 46 PFU AT 10/2045UT,
AND ENDED AT 11/1130UT.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS AT
NORMAL TO MODERATE LEVELS DURING 05 - 09 JUNE, THEN INCREASED TO
MODERATE TO HIGH LEVELS DURING 10 - 11 JUNE.

A MAJOR GEOMAGNETIC STORM OCCURRED ON 08 JUNE DUE TO A CME PASSAGE AT
EARTH (THE CME FOLLOWED THE X2/3B FLARE OF 06/1525UT). THE STORM
BEGAN WITH A SUDDEN STORM COMMENCEMENT (SSC) OF 77 NT AT 08/0909UT,
AS MEASURED BY THE BOULDER USGS MAGNETOMETER. MAJOR TO SEVERE STORM
LEVELS OCCURRED DURING THE STORM WITH THE MOST INTENSE ACTIVITY
DURING 08/0900 - 1500UT. A MAGNETOPAUSE CROSSING WAS DETECTED BY THE
NOAA GOES-8 SPACECRAFT DURING 08/1510 - 1615UT. A FORBUSH DECREASE
COMMENCED AT 08/1100UT. FIELD ACTIVITY DECLINED TO QUIET TO
UNSETTLED LEVELS DURING 09 JUNE. UNSETTLED TO MINOR STORM LEVELS
OCCURRED DURING THE REST OF THE PERIOD WITH BRIEF MAJOR STORM
INTERVALS AT HIGH LATITUDES.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
14 JUNE - 10 JULY 2000

SOLAR ACTIVITY IS EXPECTED TO VARY BETWEEN LOW AND MODERATE LEVELS
DURING MOST OF THE PERIOD, WITH OCCASIONAL C-CLASS AND ISOLATED
M-CLASS FLARES EXPECTED. REGION 9026 DEPARTS THE VISIBLE DISK LATE
ON 14 JUNE. IT HAS BEEN DECAYING SINCE 08 JUNE AND IS NOT EXPECTED
TO BE A MAJOR-FLARE PRODUCER UPON ITS RETURN TO THE VISIBLE DISK ON
28 JUNE. REGION 9033 MAY PRODUCE ISOLATED M-CLASS FLARES BEFORE
DEPARTING THE WEST LIMB ON 19 JUNE.

THERE WILL BE A SLIGHT CHANCE FOR A PROTON EVENT AT GEOSYNCHRONOUS
ORBIT THROUGH 19 JUNE. NO PROTON EVENTS ARE EXPECTED FOR THE
REMAINDER OF THE PERIOD.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS
EXPECTED TO BE AT  NORMAL TO MODERATE LEVELS THROUGH MOST OF THE
PERIOD. HOWEVER, THERE WILL BE A CHANCE FOR HIGH FLUX LEVELS DURING
26 - 27 JUNE.

THE GEOMAGNETIC FIELD IS EXPECTED TO BE AT QUIET TO UNSETTLED LEVELS
DURING MOST OF THE PERIOD, BARRING AN EARTH-DIRECTED CME. HOWEVER,
THERE WILL BE A CHANCE FOR ACTIVE LEVELS DURING 25 - 26 JUNE.


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