NOAA/USAF Report of Solar-Geophysical Activity 11 August 2000
:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Aug 11 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 224 ISSUED AT 2200Z ON 11 AUG 2000
IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 10/2100Z
TO 11/2100Z: SOLAR ACTIVITY WAS LOW. FREQUENT C-CLASS FLARES
OCCURRED, WITH FIVE REGIONS PARTICIPATING. REGION 9114 (N11W45) IS
STILL THE MOST IMPRESSIVE IN WHITE LIGHT AND H-ALPHA. NEWLY NUMBERED
REGIONS 9126 (N06W41) AND 9127 (S40E20) EACH HAD SUBFLARES. REGIONS
9124 (S14E52) AND 9125 (N25E55) WERE ACTIVE THROUGHOUT THE DAY.
IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE.
IIA. GEOPHYSICAL ACTIVITY SUMMARY 10/2100Z TO 11/2100Z:
THE GEOMAGNETIC FIELD WAS AT UNSETTLED TO SEVERE STORM LEVELS. A
PROLONGED PERIOD OF STEADY SOUTHWARD IMF LASTING MORE THAN 24 HOURS
FUELED THE DISTURBANCE. THE BZ MAGNITUDE WAS NEARLY CONSTANT NEAR 10
NT. AT APPROXIMATELY 1800Z, A SHOCK PASSED ACE AND ENDED THE NEAR
STEADY-STATE OF THE SOLAR WIND. THE SOLAR WIND SPEED AND DENSITY
WERE QUITE AVERAGE PRIOR TO THE SHOCK, BUT ATTAINED VALUES NEAR 600
KM/S, AND 10 P/CC AFTER. THIS TRANSIENT MAY BE RELATED TO THE HALO
CME OF 09 AUGUST. A SATELLITE PROTON EVENT AT GREATER THAN 10 MEV
BEGAN AT 1650Z. THIS VERY SMALL EVENT REACHED A MAXIMUM OF 17 PFU AT
1655Z AND ENDED AT 1740Z. A SMALL PCA OF APPROXIMATELY 2.0 DB
OCCURRED AT THULE CONCURRENT WITH THE PROTON EVENT. THE SOLAR SOURCE
OF THE PARTICLES IS AS YET UNDETERMINED. THE GREATER THAN 2 MEV
ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT ATTAINED HIGH LEVELS LATE IN
THE PERIOD.
IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT ACTIVE TO MINOR STORM LEVELS FOR THE NEXT THREE
DAYS. EFFECTS FROM TODAY'S SHOCK, IN CONJUNCTION WITH THE
PRE-EXISTING AND STILL CONTINUING SOUTHWARD IMF, SHOULD FURTHER
EXTEND THE CURRENT DISTURBANCE. LOCAL NIGHTTIMES SHOULD SEE THE
PERIODS OF THE STRONGEST ACTIVITY.
III. EVENT PROBABILITIES 12 AUG-14 AUG
CLASS M 30/30/30
CLASS X 01/01/01
PROTON 01/01/01
PCAF GREEN
IV. PENTICTON 10.7 CM FLUX
OBSERVED 11 AUG 187
PREDICTED 12 AUG-14 AUG 195/200/205
90 DAY MEAN 11 AUG 190
V. GEOMAGNETIC A INDICES
OBSERVED AFR/AP 10 AUG 016/023
ESTIMATED AFR/AP 11 AUG 050/060
PREDICTED AFR/AP 12 AUG-14 AUG 020/025-020/020-020/020
VI. GEOMAGNETIC ACTIVITY PROBABILITIES 12 AUG-14 AUG
A. MIDDLE LATITUDES
ACTIVE 30/30/30
MINOR STORM 50/50/50
MAJOR-SEVERE STORM 10/10/10
B. HIGH LATITUDES
ACTIVE 20/20/20
MINOR STORM 60/60/60
MAJOR-SEVERE STORM 15/15/15