NOAA/USAF Report of Solar-Geophysical Activity 23 June 2000

Report of Solar-Geophysical Activity

:Issued: 2000 Jun 23 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 175 ISSUED AT 2200Z ON 23 JUN 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  22/2100Z

TO 23/2100Z:  SOLAR ACTIVITY INCREASED TO MODERATE LEVELS. REGION

9046 (N21W34) PRODUCED AN M2/2B FLARE AT 23/0407Z ASSOCIATED WITH A

240 SFU TENFLARE, AND TYPE II AND IV RADIO SWEEPS. REGION 9042

(N23W72) PRODUCED AN M3/1F FLARE AT 23/1431Z ASSOCIATED WITH A 250

SFU TENFLARE, TYPE II AND IV RADIO SWEEPS, AND A PARTIAL-HALO CME.

BOTH REGIONS SHOWED GRADUAL DECAY, BUT RETAINED MIXED-POLARITY

MAGNETIC STRUCTURES. THE REMAINING REGIONS WERE STABLE AND SIMPLY

STRUCTURED, INCLUDING NEWLY NUMBERED REGIONS 9058 (S14W15) AND 9059

(N14E30).

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

LOW TO MODERATE LEVELS. REGIONS 9042 AND 9046 MAY PRODUCE ISOLATED

M-CLASS FLARES.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 22/2100Z TO 23/2100Z:

GEOMAGNETIC FIELD ACTIVITY RANGED FROM QUIET TO MINOR STORM LEVELS. A

SUDDEN IMPULSE (SI) OCCURRED AT 23/1305Z WITH A MAGNITUDE OF 29

NANOTESLA (AS MEASURED BY THE BOULDER USGS MAGNETOMETER). ACTIVITY

INCREASED TO UNSETTLED TO MINOR STORM LEVELS FOLLOWING THE SI. A

PROTON ENHANCEMENT AT GREATER THAN 10 MEV BEGAN AT GEOSYNCHRONOUS

ORBIT AROUND 23/1600Z. THE ENHANCEMENT FOLLOWED THE M3/1F FROM

REGION 9042.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  GEOMAGNETIC FIELD ACTIVITY IS

EXPECTED TO REMAIN AT UNSETTLED TO MINOR STORM LEVELS THROUGH MOST

OF THE PERIOD. THE GREATER THAN 10 MEV PROTON FLUX AT GEOSYNCHRONOUS

ORBIT IS EXPECTED TO RETURN TO BACKGROUND LEVELS EARLY IN THE

PERIOD. THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT

IS EXPECTED TO RISE TO MODERATE TO HIGH LEVELS LATE IN THE PERIOD.

III.  EVENT PROBABILITIES 24 JUN-26 JUN

CLASS M    40/40/35

CLASS X    10/10/05

PROTON     10/10/05

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           23 JUN 175

PREDICTED   24 JUN-26 JUN  175/170/165

90 DAY MEAN        23 JUN 186

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 22 JUN  011/008

ESTIMATED AFR/AP 23 JUN  018/015

PREDICTED AFR/AP 24 JUN-26 JUN  020/025-020/025-020/025

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 24 JUN-26 JUN

A.  MIDDLE LATITUDES

ACTIVE                40/40/40

MINOR STORM           15/15/15

MAJOR-SEVERE STORM    05/05/05

B.  HIGH LATITUDES

ACTIVE                40/40/40

MINOR STORM           20/20/20

MAJOR-SEVERE STORM    05/05/05