NOAA/USAF Report of Solar-Geophysical Activity 5 Mar 2000

:Product: Report of Solar-Geophysical Activity

:Issued: 2000 Mar 05 2210 UT

# Prepared jointly by the U.S. Dept. of Commerce, NOAA,

#Space Environment Center and the U.S. Air Force.

#

JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY

SDF NUMBER 065 ISSUED AT 2200Z ON 05 MAR 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  04/2100Z

TO 05/2100Z:  SOLAR ACTIVITY HAS BEEN LOW FOR THE PAST 24 HOURS.

REGION 8898 (S14E35) PRODUCED NEARLY ALL OF TODAY’S FLARES INCLUDING

THE LARGEST: A C9/SF AT 1530Z. THE REGION HAS GROWN RAPIDLY OVER THE

PAST 24 HOURS, PRODUCED A TOTAL OF 8 C-CLASS FLARES, AND IS NOW A

140 MILLIONTHS D-TYPE REGION. REGION 8891 (S16W42) CONTINUES TO BE

THE LARGEST REGION ON THE DISK, BUT COULD ONLY MUSTER ONE C-CLASS

EVENT: A C5/SF AT 0902Z. 8891 APPEARS TO BE UNCHANGED OVER THE PAST

24 HOURS. REGION 8900 (S16E02) HAS ALSO SHOWN GROWTH, BUT WAS MUCH

LESS FLARE PRODUCTIVE THAN 8898: THE REGION IS NOW A 230 MILLIONTHS

D-TYPE SUNSPOT GROUP. AN 8 DEGREE FILAMENT NEAR N24W40 DISAPPEARED

BETWEEN 04/2052-2130Z. THE EVENT WAS ACCOMPANIED BY SUBSEQUENT

PARALLEL RIBBONS AND A WEAK LONG-DURATION EVENT IN THE GOES X-RAYS.

HOWEVER, THERE WAS NO OBVIOUS SIGNATURE IN CORONAGRAPH DATA OF AN

ASSOCIATED CME. IN ADDITION A 15 DEGREE FILAMENT NEAR S10W08

DISAPPEARED BETWEEN 0615-0725Z. IN THIS CASE THERE WERE NO OTHER

OBVIOUS ERUPTIVE SIGNATURES, SUGGESTING THAT THE FILAMENT FADED

RATHER THAN ERUPTED. NEW REGION 8901 (S13E71) EMERGED ON THE DISK

TODAY.

IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW

TO MODERATE. THE MOST LIKELY SOURCES FOR M-CLASS LEVEL ACTIVITY ARE

REGIONS 8898 (ESPECIALLY IF THE CURRENT GROWTH CONTINUES) AND 8891

(GIVEN THE STRENGTH OF THE MAGNETIC FIELDS AND THE POSSIBILITY OF

SHEAR DEVELOPMENT ALONG AN E-W PORTION OF THE POLARITY INVERSION

LINE). ALTHOUGH REGION 8882 (S16W90+) IS BEYOND WEST LIMB, IT COULD

ALSO CONTRIBUTE TO X-RAY LEVELS FOR ANOTHER 24 HOURS.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 04/2100Z TO 05/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED FOR THE PAST 24 HOURS.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE QUIET TO UNSETTLED FOR THE NEXT THREE DAYS.

III.  EVENT PROBABILITIES 06 MAR-08 MAR

CLASS M    55/50/50

CLASS X    15/10/10

PROTON     10/05/05

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           05 MAR 220

PREDICTED   06 MAR-08 MAR  225/225/225

90 DAY MEAN        05 MAR 171

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 04 MAR  005/005

ESTIMATED AFR/AP 05 MAR  007/005

PREDICTED AFR/AP 06 MAR-08 MAR  010/012-007/010-007/008

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 06 MAR-08 MAR

A.  MIDDLE LATITUDES

ACTIVE                20/20/20

MINOR STORM           10/10/10

MAJOR-SEVERE STORM    05/05/05

B.  HIGH LATITUDES

ACTIVE                25/25/25

MINOR STORM           15/15/15

MAJOR-SEVERE STORM    05/05/05