:Product: Weekly Highlights and Forecasts

:Issued: 2001 Aug 15 2112 UT

HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY

06 - 12 AUGUST 2001



SOLAR ACTIVITY WAS LOW MOST OF THE PERIOD, BUT REACHED MODERATE

LEVELS ON 07 AUGUST. REGION 9557 (S20, L = 288, CLASS/AREA DKI/600

ON 07 AUGUST) PRODUCED THE SOLE M-CLASS FLARE OF THE PERIOD: AN

M1/SF AT 07/0737 UTC. REGION 9557 WAS CROSSING THE WEST LIMB AND IN

A GRADUAL GROWTH PHASE AT THE TIME OF THE FLARE. ISOLATED C-CLASS

FLARES OCCURRED DURING THE REST OF THE PERIOD FROM A FEW REGIONS OF

MODERATE SIZE AND MAGNETIC COMPLEXITY INCLUDING REGIONS 9563 (N24, L

= 241, CLASS/AREA EKI/470 ON 07 AUGUST), 9566 (N17, L = 225,

CLASS/AREA ON 09 AUGUST), AND 9570 (S11, L = 160, CKO/220 ON 09

AUGUST). PERHAPS THE MOST SIGNIFICANT EVENT OF THE PERIOD WAS A

LONG-DURATION C3 X-RAY EVENT DURING 09/1057 - 1215 UTC ASSOCIATED

WITH A FILAMENT CHANNEL ERUPTION JUST WEST OF CENTRAL MERIDIAN AND A

PARTIAL-HALO CORONAL MASS EJECTION (CME). NOTE: A FULL-HALO CME

OCCURRED ON 14 AUGUST FOLLOWING A FILAMENT DISAPPEARANCE NEAR THE

NORTH CENTRAL PORTION OF THE DISK. THIS CME IS EXPECTED TO IMPACT

EARTH DURING 17 - 18 AUGUST.



SOLAR WIND DATA WERE AVAILABLE FROM THE ADVANCED COMPOSITION EXPLORER

(ACE) SPACECRAFT FOR MOST OF THE PERIOD. A CME PASSAGE OCCURRED ON

12 AUGUST ASSOCIATED WITH THE FILAMENT CHANNEL ERUPTION OF 09

AUGUST. THE CME FRONT PASSED THE ACE SPACECRAFT AT 12/1050 UTC

ACCOMPANIED BY SUDDEN INCREASES IN VELOCITY, DENSITY, TOTAL FIELD

INTENSITY, AND TEMPERATURE. IMF BZ WAS VARIABLE FOLLOWING THE

PASSAGE, WITH A RANGE OF PLUS 14 TO MINUS 13 NT (GSM). THE PASSAGE

WAS IN PROGRESS AS THE PERIOD ENDED.



A PROTON EVENT AT GREATER THAN 10 MEV BEGAN AT 10/1020 UTC, REACHED A

PEAK OF 17 PFU AT 10/1155 UTC, AND ENDED AT 10/1440 UTC. THIS EVENT

WAS LIKELY ASSOCIATED WITH THE FILAMENT CHANNEL ERUPTION DESCRIBED

ABOVE.



THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS AT

NORMAL TO MODERATE LEVELS.



THE GEOMAGNETIC FIELD WAS AT UNSETTLED TO MINOR STORM LEVELS ON 06 -

07 AUGUST WITH ISOLATED MAJOR STORM INTERVALS AT HIGH LATITUDES.

MOSTLY QUIET TO UNSETTLED CONDITIONS OCCURRED DURING 08 - 11 AUGUST.

A CME-RELATED DISTURBANCE OCCURRED ON 12 AUGUST. THE DISTURBANCE

BEGAN WITH A SUDDEN IMPULSE AT 12/1136 UTC (23 NT, BOULDER USGS

MAGNETOMETER) FOLLOWED BY AN INCREASE TO UNSETTLED TO MINOR STORM

LEVELS. THIS DISTURBANCE WAS IN PROGRESS AS THE PERIOD ENDED.



FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY

15 AUGUST - 10 SEPTEMBER 2001



SOLAR ACTIVITY IS EXPECTED TO BE AT LOW TO MODERATE LEVELS. ISOLATED

M-CLASS FLARES ARE POSSIBLE. THERE WILL BE A SLIGHT CHANCE FOR A

MAJOR FLARE DURING THE PERIOD.



THERE WILL BE A SLIGHT CHANCE FOR A SOLAR PROTON EVENT DURING THE

PERIOD.



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 23 - 24

AUGUST AND 03 - 04 SEPTEMBER.



THE GEOMAGNETIC FIELD DISTURBANCE IS EXPECTED TO OCCUR DURING 17 -

18 AUGUST DUE TO AN EXPECTED CME PASSAGE. ACTIVE TO MAJOR STORM

CONDITIONS MAY OCCUR DURING THIS DISTURBANCE. ACTIVE PERIODS WILL BE

POSSIBLE AROUND 21 AND 27 AUGUST, 01 - 02 AND 09 - 10 SEPTEMBER DUE

TO CORONAL HOLE EFFECTS.





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