AAVSO Sudden Ionospheric Disturbance Report August 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 A-72 A-73 A-74 YYMMDD Event Peak (UT) Importance 910801 0633 2 910801 0917 1 910801 1101 1- 910801 1109 1 910801 1151 2 910801 1451 1+ 910801 1517 2+ 910801 1819 2 910801 1914 1- 910801 1922 2 910801 2155 2+ 910802 0315 1+ 910802 0444 2 910802 0526 2+ 910802 1030 2+ 910802 1232 1- 910802 1322 1- 910802 1400 2 910802 1833 1- 910803 0123 2 910803 1157 1 910803 1348 1 910803 1421 1- 910803 1550 1+ 910803 1723 3 910803 1843 2+ 910803 2040 2+ 910803 2218 1- 910803 2234 2+ 910804 0947 1- 910804 1340 1- 910804 1515 1 910804 1800 1- 910804 1814 2+ 910804 1930 2 910804 2145 2 910804 2246 1 910805 1404 1 910805 1524 1 910805 1831 1 910805 2214 1- 910805 2244 1 910805 2300 1+ 910806 0046 2 910806 0443 2+ 910806 0807 2 910806 1415 1+ 910806 1928 1+ 910806 2239 1 910807 0643 1- 910807 1150 1- 910807 1421 1+ 910807 1833 1 910807 1907 2+ 910808 0622 1- 910808 0858 1+ 910808 1409 2 910808 1800 1 910809 1035 1- 910810 1926 1- 910811 1304 1 910811 1520 2+ 910811 1642 1 910811 1718 1- 910812 1914 1+ 910812 2012 2 910813 1524 1- 910813 1914 2+ 910813 2115 1 910814 1152 1- 910814 1320 1 910814 1417 1+ 910814 1611 1 910814 1844 1 910815 0735 1+ 910815 1344 1+ 910815 1618 1- 910815 1801 2 910815 2304 1+ 910816 0051 2+ 910816 0620 2+ 910816 1102 1 910816 1315 1 910816 1434 1- 910816 1603 2+ 910816 1806 2 910816 1904 1 910816 1948 1+ 910816 2136 2+ 910817 0032 2 910817 1428 1- 910817 1743 1 910817 1919 1- 910817 1930 1 910817 2131 1 910817 2206 1 910817 2345 1 910818 0945 1- 910818 1023 1 910818 1140 1+ 910818 1236 1- 910818 1251 1+ 910818 1313 1- 910818 1445 2+ 910818 1544 2 910818 1740 1+ 910818 1817 1+ 910818 1833 2 910818 1937 1- 910818 2011 1- 910819 0659 1- 910819 1329 2 910819 1443 1- 910819 1622 1+ 910819 1805 1- 910819 1845 1- 910820 1052 1+ 910820 1217 1- 910820 1232 2+ 910820 1545 1- 910820 1609 1- 910820 2000 2 910820 2104 1- 910820 2119 1+ 910820 2228 1+ 910821 1131 1- 910821 1438 1- 910821 1731 1 910822 0558 1+ 910822 1525 1 910822 1715 1- 910822 1910 1+ 910822 2230 2 910823 1158 1+ 910823 1238 2 910823 1737 1 910823 1850 1 910823 1938 2 910823 2143 1 910824 0034 2+ 910824 1000 1- 910824 1201 1- 910824 1221 2 910824 1305 1- 910824 1319 1 910824 1345 1+ 910824 1420 2 910824 1636 2 910824 1726 1- 910824 1736 2+ 910824 1822 2 910824 1934 2 910824 2040 2 910824 2135 1 910825 0055 3+ 910825 0514 2 910825 0930 1- 910825 0942 2 910825 1310 2 910825 1443 2 910825 1538 1+ 910825 1609 1+ 910825 1701 1+ 910825 1744 2 910825 1827 2+ 910825 2332 2+ 910826 0649 1 910826 0800 1 910826 0913 2 910826 1017 2 910826 1200 2 910826 1426 2 910826 1553 2+ 910826 1945 1- 910826 2016 2 910827 0456 1+ 910827 0558 1- 910827 1414 1+ 910827 1436 1- 910827 1619 1- 910827 1804 1- 910827 2313 1+ 910828 0633 1+ 910828 1223 1+ 910828 1624 2 910828 1600 2 910828 1652 2 910828 1721 1- 910828 1949 1 910829 0506 2+ 910829 1317 2 910829 1357 2 910829 1630 2+ 910829 2015 1+ 910829 2055 1 910829 2146 1 910830 0120 1+ 910830 1321 1+ 910830 1422 1 910830 2232 1- 910831 0204 2+ 910831 1215 1 910831 1806 1- 910831 2123 1- ******************************************* Importance Summary August 1991 1- events: 53 1 events: 42 1+ events: 37 2 events: 44 2+ events: 26 3 events: 1 3+ events: 1 Total events: 204