AAVSO Sudden Ionospheric Disturbance Report May 1989 Observers: A-01 A-03 A-09 A-19 A-26 A-40 A-46 A-49 A-50 A-52 A-59 A-60 A-61 A-62 A-63 A-64 YYMMDD Event Peak (UT) Importance 890501 1944 1+ 890501 2049 1 890501 2128 2 890501 2203 1+ 890502 1406 2+ 890502 1615 2+ 890502 1852 2+ 890503 1548 1 890503 1732 1- 890503 1940 2+ 890503 2102 2+ 890504 0423 2 890504 0823 2 890504 1116 2 890504 1520 1+ 890504 1619 2 890504 1730 2 890504 1845 1- 890504 1917 2 890504 2032 2+ 890504 2226 2 890505 0532 2+ 890505 0730 3+ 890505 1723 1- 890506 0533 2+ 890506 1500 2+ 890506 1702 2 890506 1939 2 890507 0745 2+ 890507 1758 1 890507 1915 1- 890507 2118 1+ 890509 1702 3 890510 0431 2+ 890511 0800 2 890511 1745 1- 890512 1230 1 890512 1305 1+ 890512 1415 1- 890512 1526 2 890513 1500 1- 890514 0700 1 890514 1649 2 890518 1814 1- 890519 1449 1- 890519 1657 1 890520 1134 2 890520 1313 1 890520 1501 1- 890521 1515 1 890521 1743 1 890521 1801 2 890521 1856 2 890521 2251 1 890522 1532 2 890522 1853 1+ 890522 1938 1+ 890523 0715 1 890523 0735 1- 890523 0810 2+ 890523 1300 2 890523 1454 2+ 890523 1730 1+ 890523 1826 1- 890523 2004 2 890523 2115 2+ 890524 1352 2+ 890524 1507 1 890524 1935 2+ 890524 2145 2+ 890525 1533 1 890525 1558 2+ 890526 1855 1+ 890526 2058 2 890526 2230 2+ 890528 1230 2+ 890528 1559 1- 890528 2215 2+ 890528 2302 1 890529 1328 2+ 890529 1833 2 890530 0730 2+ 890530 1316 2+ 890530 1735 1+ 890530 1915 1+ 890530 1934 2 890531 1938 1 ******************************************* Importance Summary May 1989 1- events: 13 1 events: 15 1+ events: 11 2 events: 22 2+ events: 24 3 events: 1 3+ events: 1 Total events: 87