AAVSO Sudden Ionospheric Disturbance Report January 1991 Observers: A-01 A-03 A-09 A-19 A-40 A-50 A-52 A-59 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 910101 0830 1- 910102 1445 1- 910104 0711 1+ 910104 1127 1- 910104 1337 1- 910104 1814 1- 910105 1202 1+ 910105 1956 1- 910106 0915 1- 910106 1615 3+ 910106 1706 1- 910106 1735 1 910107 1315 2+ 910107 1334 1 910107 1415 2 910107 1741 1- 910107 1919 1 910108 0425 2+ 910108 0651 2+ 910108 1125 2+ 910108 1607 1 910108 1759 1- 910108 1832 2+ 910108 2034 1+ 910108 2203 2+ 910109 0634 1+ 910109 0810 2+ 910109 1336 1 910110 0448 1 910110 0705 2+ 910110 0932 1+ 910110 1415 1+ 910110 1515 1- 910110 1528 1- 910110 1715 1- 910111 0520 2 910111 0658 2+ 910111 0751 2+ 910111 0859 1+ 910111 1528 1+ 910111 1544 3 910111 1829 2+ 910111 1924 1- 910111 2009 1- 910111 2025 2 910112 0712 1 910112 0825 1- 910112 0830 1+ 910112 1245 1+ 910112 1413 1- 910112 1438 1+ 910112 1613 1- 910112 1910 2 910112 2107 1+ 910112 2215 1 910113 2101 2+ 910114 0808 1+ 910114 1713 1- 910114 1736 1+ 910114 1839 1- 910115 0802 1- 910115 0824 2 910115 1012 1- 910115 1426 1 910115 1738 1- 910115 2212 1 910116 2025 1 910116 2245 1- 910117 0845 1- 910117 1228 1- 910117 1302 1- 910117 1416 1- 910117 1453 1- 910117 1501 2+ 910117 1854 1 910117 2118 1 910118 0405 2+ 910118 0828 1 910118 0955 2 910118 1306 1+ 910118 1409 1+ 910118 1548 1 910119 1134 2 910119 1322 1 910119 1347 1+ 910119 1434 1+ 910119 1607 1- 910119 1757 1 910119 1848 2 910119 1956 1 910119 2038 2 910119 2147 2 910119 2358 2 910120 0720 2 910120 0924 1+ 910120 1345 1+ 910120 1537 1 910120 2054 2+ 910120 2252 1+ 910121 0019 1- 910121 0028 2+ 910121 0638 2 910121 0822 2 910121 0918 1- 910121 1117 2+ 910121 1158 1 910121 1250 1+ 910121 1355 2+ 910121 1507 1+ 910121 1534 1 910121 1738 1- 910121 1859 2 910121 2022 1+ 910121 2101 1 910121 2116 2+ 910122 0548 2+ 910122 0750 2+ 910122 1318 2 910122 1525 2+ 910122 1806 2 910122 1952 3+ 910123 0818 1- 910123 1116 1- 910123 1321 1 910123 1441 1+ 910123 1510 1 910123 1742 1 910123 1821 2 910124 0324 2+ 910124 0815 1- 910124 1229 1+ 910124 1449 1- 910125 0250 2+ 910125 0458 1 910125 0633 3+ 910125 1110 1- 910125 1331 2 910125 1445 1 910125 1724 2 910125 1901 1- 910125 1939 1 910125 2010 1 910126 0845 1 910126 0908 1- 910126 1343 1- 910126 1409 1 910126 1513 1 910126 1720 2+ 910126 1850 1+ 910126 1928 1 910126 2117 1+ 910127 0009 2 910127 0107 1 910127 0335 1+ 910127 0536 1 910127 0815 2 910127 0856 1 910127 1005 1- 910127 1152 1+ 910127 1448 1 910127 1529 1+ 910127 1544 2+ 910128 0755 2+ 910128 0914 1 910128 0928 1 910128 1247 1+ 910128 1406 1 910128 1543 1 910128 1631 1+ 910128 1706 1- 910128 1736 1 910128 1759 2 910128 1831 1- 910128 1957 2+ 910128 2101 2 910128 2143 1 910128 2206 1+ 910129 0653 2+ 910129 0748 1 910129 1016 2+ 910129 1216 1- 910129 1314 1- 910129 1348 1 910129 1420 1 910129 1435 1- 910129 1458 2+ 910129 1609 1- 910129 1726 1 910129 1756 2+ 910129 1845 2 910129 2008 1 910129 2207 1- 910129 2236 1 910130 0105 2 910130 0858 2+ 910130 1350 1- 910130 1401 1- 910130 1422 1- 910130 1432 1- 910130 1445 1 910130 1514 2+ 910130 1559 1 910130 1616 1+ 910130 1716 1+ 910130 1758 2 910130 1916 1 910130 2000 1+ 910130 2219 1 910130 2238 1- 910130 2258 1 910131 1153 2+ 910131 1332 1 910131 1615 1 910131 1630 1+ 910131 1803 2 910131 1944 1- 910131 2030 2 910131 2127 1- ******************************************* Importance Summary January 1991 1- events: 56 1 events: 56 1+ events: 38 2 events: 29 2+ events: 35 3 events: 1 3+ events: 3 Total events: 218