AAVSO Sudden Ionospheric Disturbance Report September 1999 Observers: A-05 A-50 A-62 A-63 A-72 A-80 A-81 A-83 A-84 A-87 A-90 YYMMDD Event Peak (UT) Importance 990901 1857 2+ 990902 1745 2 990906 2112 2 990907 1400 1 990907 2308 1+ 990908 1215 2+ 990909 1622 2+ 990912 1205 1 990912 1735 2+ 990913 0734 1 990913 1645 2 990914 1320 1+ 990917 1205 2 990917 1435 1- 990917 1802 2 990917 2208 1+ 990918 1415 1 990918 1512 1+ 990918 1556 2+ 990919 1125 3 990919 1435 2+ 990921 0730 1 990921 1050 2+ 990922 1343 2 990928 1534 2+ 990929 1555 2 ******************************************* Importance Summary September 1999 1- events: 1 1 events: 5 1+ events: 4 2 events: 7 2+ events: 8 3 events: 1 3+ events: 0 Total events: 26