NOAA/USAF Report of Solar-Geophysical Activity 8 June 2000

 Report of Solar-Geophysical Activity

:Issued: 2000 Jun 08 2200 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 160 ISSUED AT 2200Z ON 08 JUN 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  07/2100Z

TO 08/2100Z:  SOLAR ACTIVITY WAS LOW.  NUMEROUS MINOR C-CLASS X-RAY

EVENTS OCCURRED.  TWO EVENTS WERE OPTICALLY CORRELATED WITH REGION

9026 (N21W17).  ONLY ONE C1/SF EVENT WAS OPTICALLY CORRELATED WITH

REGION 9033 (N22E42) AT 08/1811Z.  REGION 9026 SHOWED A MODERATE

INCREASE IN THE NUMBER OF SPOTS WHILE THE AREA SLIGHTLY DECREASED,

AND THE MAGNETIC CONFIGURATION OF THE REGION BECAME BETA GAMMA.

OVERALL, IT APPEARS 9026 IS STARTING TO DECAY.  SIGNIFICANT GROWTH

WAS OBSERVED IN REGION 9033.  NEW REGIONS 9035 (S17E15) AND 9036

(S23E73) WERE NUMBERED TODAY.

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

MODERATE TO HIGH.  REGION 9026 AND 9033 ARE EACH CAPABLE OF

PRODUCING M-CLASS AND ISOLATED X-CLASS EVENTS.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 07/2100Z TO 08/2100Z:

THE GEOMAGNETIC FIELD WAS UNSETTLED TO SEVERE STORM.  A SUDDEN

IMPULSE OCCURRED AT 08/0909Z (77 NT, AS MEASURED BY THE BOULDER USGS

MAGNETOMETER).  THE SOLAR WIND VELOCITY JUMPED FROM 520 TO OVER 800

KM/S AT 08/0841Z.  MINOR TO SEVERE STORM LEVELS WERE OBSERVED

FOLLOWING THE SHOCK ARRIVAL.  THIS SHOCK IS PRESUMED TO BE RELATED

TO THE X2/3B EVENT ON 06 JUNE.  THE GREATER THAN 10 MEV PROTON FLUX

AT GEOSYNCHRONOUS ORBIT PEAKED AT 84 PFU’S AT 08/0940Z AND IS

DECREASING AT THIS TIME.  A MODERATE (7.4 PERCENT) FORBUSH DECREASE

PEAKED NEAR 08/1449Z.  A MAGNETOPAUSE CROSSING WAS OBSERVED ON

GOES-8 (W075) BEGAN AT 08/1510Z AND CONTINUED UNTIL APPROXIMATELY

08/1615Z.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO RANGE FROM ACTIVE TO SEVERE STORM LEVELS DURING THE

FIRST DAY.  GEOMAGNETIC STORMING SHOULD START TO DIMINISH DURING THE

MIDDLE OF THE PERIOD.  CONDITIONS BY THE THIRD DAY ARE EXPECTED TO

BE QUIET TO UNSETTLED WITH ISOLATED PERIODS OF ACTIVE CONDITIONS.

HOWEVER, UNSETTLED TO MINOR STORM CONDITIONS MAY PERSIST DURING THE

LATER PART OF THE PERIOD IF MODERATE EFFECTS ARE OBSERVED FROM THE

X1/3B EVENT ON 7 JUNE.

III.  EVENT PROBABILITIES 09 JUN-11 JUN

CLASS M    70/70/60

CLASS X    25/15/15

PROTON     10/10/10

PCAF       YELLOW

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           08 JUN 175

PREDICTED   09 JUN-11 JUN  185/190/200

90 DAY MEAN        08 JUN 188

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 07 JUN  013/014

ESTIMATED AFR/AP 08 JUN  035/055

PREDICTED AFR/AP 09 JUN-11 JUN  060/075-025/040-015/025

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 09 JUN-11 JUN

A.  MIDDLE LATITUDES

ACTIVE                30/40/30

MINOR STORM           40/25/15

MAJOR-SEVERE STORM    25/15/05

B.  HIGH LATITUDES

ACTIVE                10/50/40

MINOR STORM           60/30/20

MAJOR-SEVERE STORM    30/20/10