AAVSO Sudden Ionospheric Disturbance Report 
     August 1990
  
     Observers:
     A-01   A-09   A-19   A-40   A-50   
     A-52   A-61   A-62   A-63   A-64   
     A-65   A-66   A-67   A-68   A-69   
     A-70   A-71   
     
     YYMMDD      Event Peak (UT)   Importance
     900801         2001                2+ 
     900801         2130                1+ 
     900802         0550                1- 
     900802         0617                1- 
     900802         1515                1- 
     900802         1535                1  
     900802         1630                1- 
     900803         1321                1  
     900803         1450                2  
     900803         1650                1- 
     900804         0648                1  
     900805         1935                1+ 
     900808         1400                2+ 
     900808         1809                2  
     900808         2234                1  
     900808         2346                2  
     900809         0753                1- 
     900809         1530                1- 
     900809         2032                1+ 
     900810         1815                3  
     900812         2108                2+ 
     900813         0033                1  
     900813         0930                2+ 
     900813         1329                3  
     900813         2230                1+ 
     900814         1957                2  
     900815         1558                2+ 
     900815         1946                2  
     900815         2305                1  
     900817         1701                2+ 
     900817         1859                1- 
     900817         1928                1  
     900817         2150                2  
     900817         2259                2+
     900817         2343                2+
     900818         0520                2
     900818         0852                1
     900818         0914                2+
     900819         0007                1-
     900819         1719                1
     900821         0932                1+
     900821         1605                2
     900822         1624                1+
     900822         1659                1+
     900822         2205                1-
     900823         0905                2+
     900823         2040                2
     900824         0440                1-
     900825         0719                1-
     900825         1555                1-
     900825         1836                1-
     900825         2012                2+
     900826         0736                2
     900826         1352                2+
     900826         1545                2
     900826         1624                2+
     900826         1816                1-
     900827         1613                3
     900827         1831                2
     900827         1911                2+
     900827         2103                2+
     900828         0905                2+
     900828         1015                2
     900828         1250                3
     900828         1500                1-
     900828         1634                1
     900828         1713                1
     900828         1830                2+
     900828         2235                2+
     900829         0433                2
     900829         0721                2
     900829         0820                2+
     900829         1321                1
     900829         1346                1
     900829         1500                2
     900829         2040                2+
     900830         1315                2+
     900831         0413                2
     900831         1630                2+
     *******************************************
     Importance Summary August 1990
        1- events: 16
        1  events: 13
        1+ events: 7
        2  events: 17
        2+ events: 22 
        3  events: 4
        3+ events: 0
     Total events: 79