:Product: Weekly Highlights and Forecasts
:Issued: 2001 Oct 09 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
01 - 07 OCTOBER 2001

SOLAR ACTIVITY REACHED HIGH LEVELS FOR THE FIFTH CONSECUTIVE WEEK.
THE PERIOD BEGAN WITH ACTIVITY AT HIGH LEVELS DUE TO AN M9 X-RAY
FLARE AT 01/0515 UTC. THE FLARE SITE WAS NEAR THE SOUTHWEST LIMB IN
THE VICINITY OF REGION 9628 (S18, L = 292, CLASS/AREA FKC/880 ON 24
SEPTEMBER), WHICH WAS CROSSING THE WEST LIMB AT THE TIME OF THE
FLARE. THIS REGION WAS LARGE AND MAGNETICALLY COMPLEX THROUGHOUT ITS
PASSAGE. THE SAME WAS TRUE OF REGION 9632 (S19, L = 272, CLASS/AREA
DKI/790 ON 24 SEPTEMBER), WHICH ROTATED OUT OF VIEW ON 02 OCTOBER.
BOTH REGIONS HAD A HISTORY OF ISOLATED MAJOR FLARE PRODUCTION. WITH
THE DEPARTURE OF THESE REGIONS, ACTIVITY DROPPED TO MOSTLY LOW
LEVELS. HOWEVER, ISOLATED LOW-LEVEL, OPTICALLY UNCORRELATED M-CLASS
FLARES OCCURRED ON 02 AND 06 OCTOBER (FOR FLARE TIMES AND
MAGNITUDES, PLEASE REFER TO THE ENERGETIC EVENTS AND OPTICAL FLARES
LISTS). BY THE CLOSE OF THE PERIOD, THE DISK WAS POPULATED BY MOSTLY
SMALL, SIMPLY-STRUCTURED SUNSPOT REGIONS.

SOLAR WIND DATA WERE AVAILABLE FROM THE NASA ADVANCED COMPOSITION
EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD. SWEPAM DATA
(SPEED, DENSITY, AND TEMPERATURE) WERE UNRELIABLE DURING 02/0130 -
1300 UTC DUE TO PROTON CONTAMINATION. MULTIPLE CME PASSAGES OCCURRED
DURING 01 - 04 OCTOBER. THE MOST SIGNIFICANT EFFECTS OCCURRED ON 03
OCTOBER WITH VELOCITIES AS HIGH AS 600 KM/SEC ALONG WITH A SUSTAINED
PERIOD OF SOUTHWARD IMF BZ WITH MAXIMUM DEFLECTIONS TO MINUS 23 NT
(GSM). CME EFFECTS SUBSIDED DURING THE LATTER HALF OF 04 OCTOBER.

A GREATER THAN 10 MEV PROTON EVENT WAS ASSOCIATED WITH THE M9 X-RAY
FLARE OF 01 OCTOBER. THE GREATER THAN 10 MEV FLUX BEGAN TO INCREASE
AT AROUND 01/1145 UTC, THEN REACHED A PEAK OF 2360 PFU AT 02/0810
UTC. THE EVENT ENDED AT 05/0330 UTC, BUT FLUXES REMAINED ENHANCED
FOR THE REST OF THE PERIOD.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT RANGED
FROM NORMAL TO MODERATE LEVELS.

THE GEOMAGNETIC FIELD WAS DISTURBED DURING 01 - 04 OCTOBER DUE TO
MULTIPLE CME PASSAGES. UNSETTLED TO MAJOR STORM LEVELS OCCURRED
DURING THIS PERIOD WITH BRIEF SEVERE STORM CONDITIONS DETECTED AT
HIGH LATITUDES. FIELD ACTIVITY DECLINED TO MOSTLY QUIET TO UNSETTLED
LEVELS AFTER 04/1800 UTC.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
10 OCTOBER - 05 NOVEMBER 2001

SOLAR ACTIVITY IS EXPECTED TO RANGE FROM LOW TO MODERATE LEVELS.
ISOLATED M-CLASS FLARES ARE EXPECTED. THERE WILL BE AN INCREASED
CHANCE FOR ISOLATED MAJOR FLARE ACTIVITY DURING 15 - 30 OCTOBER WITH
THE RETURN OF OLD REGIONS 9628 AND 9632.

THERE WILL BE A SLIGHT CHANCE FOR A PROTON EVENT DURING 15 - 30
OCTOBER WITH THE RETURN OF OLD REGIONS 9628 AND 9632.

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 WILL BE POSSIBLE AROUND 28
OCTOBER.

THE GEOMAGNETIC FIELD IS EXPECTED TO BE AT ACTIVE TO MINOR STORM
LEVELS DURING 11 - 13 OCTOBER DUE TO AN EXPECTED CME PASSAGE (A HALO
CME WAS OBSERVED ON 09 OCTOBER). ACTIVE CONDITIONS WILL BE POSSIBLE
DURING 26 - 27 OCTOBER DUE TO CORONAL HOLE EFFECTS. QUIET TO
UNSETTLED CONDITIONS ARE EXPECTED DURING THE REMAINDER OF THE
PERIOD.


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