Event Selection Guide

 1984 1985 1986 1987 1988 1989 1990
1991 1992 1993 1994 1995 1996 1997 1998  

Magnetic Storms (1991) - *Sources of Information
Date  Day No. Min Dst Solar Wind & IMF Data?Type of Solar Wind Transients AbbreviationsGuide Interesting Aspects Space Weather Effects Solar Source Disturbance Forecasts &Warnings References
 31 Jan - 05 Feb 1991 -79 plot1 plot2No Omniweb  CRRES observations    
 04-10 Mar 1991 -66 plotVery spotty coverage Omniweb      
 24-30 Mar 1991 -298 plotNo Omniweb  22-30Mar: X-ray flares, SEPs CRRESS data show that O+ contributes66% to outer RC energy density at L=5-7 during Dst minimum [Daglis, 1997] INMARSAT lost MARECS-1 on 25 Mar. Japanese TV satellite BS3-A lostpower panel output. GOES-6 and -7 experienced power panel degradation equalto 3-year loss. Hydro-Quebec power outages in spite of mitigation procedures.Damage to transformers in USA, Canada & Sweden. Mineral surveys in Australiadisrupted. Pipeline corrosion in central Australia. Loss of automatic attitudecontrol on NOAA-11. Drag events causing major updating of UCTs. Galileo"hits" reported. Commercial trans-oceanic airline communicationsinterrupted.   Daglis, Magnetic Storms Monograph, 107, 1997
 30 Mar - 07 Apr 1991  -85 plot1 plot2 Very spotty coverage Omniweb      
 26 Apr - 06 May 1991  -97 plot1 plot2 Very spotty coverage Omniweb      
 13-15 May 1991  -74 plot No Omniweb      
 16-19 May 1991  -105 plot No Omniweb      
 23-26 May 1991  -60 plot limited coverage Omniweb      
 30 May - 04 Jun 1991  -84 plot1 plot2 very spotty coverage Omniweb          
 04-08 Jun 1991  -223 plot No Omniweb  Ap* = 196 (new largest storm since Mar89. 3 magnetopause crossings.CRRES observations show RC composition never dominated by O+ at L=3-5 [Roederet al.,1996]. Dst appears to have a 2-phase decay. Flare activity    Roeder et al., AIP Conf Proceedings 383, 131, 1996
 09-16 Jun 1991  -140 plot No Omniweb  CEDARstorm study (11-12 Jun) and Incoherent Scatter Coordinated ObservationDays 11 jun: Polar Cap Absorption Event   
 17-20 Jun 1991  -70 plot No Omniweb      
 21-27 Jun 1991  -79 plot very spotty limited coverage Omniweb      
 30 Jun - 01 Jul 1991  -55 plot1 plot2 No Omniweb      
 02-04 Jul 1991  -57 plot No Omniweb      
 08-11 Jul 1991  -194 plot slightly spotty coverage Omniweb  CRRES observations show O+ 61% at Dst minimum near L=5-7 [Daglis 1997]    Daglis, Magnetic Storms Monograph, 107, 1997
 12-16 Jul 1991  -183 plot No Omniweb  CRRES shows RC O+ dominates during storm maximum. [Daglis 1997]    Daglis, Magnetic Storms Monograph, 107, 1997
 16-23 Jul 1991  -94 plot limited spotty coverage Omniweb      
 01-06 Aug 1991  -114 plotYes UCLA-IMP8 Omniweb      
 11-16 Aug 1991  -99 plot No Omniweb      
 18-24 Aug 1991  -170 plot No Omniweb      
 26-29 Aug 1991  -60 plotYes UCLA-IMP8 Omniweb      
 29 Aug - 04 Sep 1991 241- 247 -107 plot1 plot2Yes UCLA-IMP8 Omniweb      
 09-12 Sep 1991  -96 plotYes UCLA-IMP8 Omniweb      
 24-29 Sep 1991  -86 plot Very spotty coverage Omniweb      
 01-12 Oct 1991  -164 plot Limited spotty coverage Omniweb      
 19-21 Oct 1991  -78 plotslightly spotty coverage UCLA-IMP8Omniweb      
 21-22 Oct 1991  -94 plot No Omniweb      
 23 Oct - 06 Nov 1991  -254 plot1 plot2 slightly spotty coverage UCLA-IMP8Omniweb  28-29 Oct: Ap*=156; 1-2Nov: Ap*=128 Shunt capacitor trips on Columbia River Bonneville system. 3% voltagedips on S. California Edison system; transormer cores saturated. New MexicoHV-DC terminal tripped by overvoltage. New England Hydro-Quebec HV-DC tripped.Wisconsin Electric Power transformer "growled". Virginia Powertripped 2 shunt capacitor banks. Allegheny Power transformer tripped byGIC-detection devices, caused outgassing and overheating. Salem southernNew Jersey nuclear power output reduce 20% to avoid damage. PJM (PA, MD,NJ) Power Pool cut back to "solar storm operating conditions"   
 08-11 Nov 1991  -354 plot limited recovery phase coverage Omniweb  8-9Nov: Ap*=179   
 14-26 Nov 1991  -139 plot Limited spotty coverage Omniweb      
 16-22 Dec 1991  -64 plot Limited spotty coverage Omniweb      
 26-31 Dec 1991  -118 plot No Omniweb