Viewing archive of Thursday, 19 April 2001

Geophysical report

Solar and Geophysical Activity Summary 2001 Apr 19 0245 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Solar and Geophysical Activity Summary

SGAS Number 109 Issued at 0245Z on 19 Apr 2001 This report is compiled from data received at SWO on 18 Apr
A. Energetic Events
Begin  Max  End  Rgn   Loc   Xray  Op 245MHz 10cm   Sweep
0211 0214 0216              C2.2     1800   570
0217 0000 0000                                     II
B. Proton Events
C. Geomagnetic Activity Summary
The geomagnetic field has been quiet to minor storm, with severe storm conditions at high latitudes. An interplanetary shock passed the ACE spacecraft at 18/0005 UTC; subsequently the Boulder magnetometer registered a 50 nT sudden impulse at 18/0048 UTC. This shock was likely associated with the X14/2B on 15 April. Greater than 10 MeV and greater than 100 MeV proton events began at 18/0315 UTC and 18/0255 UTC respectively, most likely associated with the activity from old Region 9415 behind the west limb. The greater than 10 MeV protons reached a peak of 321 pfu at 18/1045 UTC, while the greater than 100 MeV reached 12 pfu at 18/0600 UTC. The Thule neutron monitor measured a ground level event between 18/0242 UTC and 18/0914 UTC; polar cap absorption (PCA) event began at 18/0425 UTC and remains in progress. Values for the greater than 2 MeV electrons at geosynchronous orbit were not reported due to sensor contamination by the proton event.
D. Stratwarm
E. Daily Indices: (real-time preliminary/estimated values)
10 cm 132  SSN 063  Afr/Ap 026/050   X-ray Background B5.7
Daily Proton Fluence (flux accumulation over 24 hrs)
GT 1 MeV 5.0e+07   GT 10 MeV 1.2e+07 p/(cm2-ster-day)
(GOES-8 satellite synchronous orbit W75 degrees)
Daily Electron Fluence
GT 2 MeV 2.20e+06 e/(cm2-ster-day)
(GOES-8 satellite synchronous orbit W75 degrees)
3 Hour K-indices
Boulder 5 5 5 3 3 3 3 2 Planetary 5 7 7 4 3 4 1 2
F. Comments

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