AAVSO Sudden Ionospheric Disturbance Report April 2012 Observers: A112 A118 A119 A120 A122 A124 A125 A129 A130 A131 A132 A80 A94 A96 A97 YYMMDD Event Peak Importance 120401 1341 1 120401 1511 1- 120401 2116 1+ 120402 2118 1- 120402 2226 1 120404 1058 3 120404 1311 2+ 120404 1611 1- 120404 1627 1+ 120404 1640 2+ A94 - XRA 120404 1830 3 120404 1902 2 120404 2137 3+ 120405 1033 3 A130 - XRA 120405 1319 2+ A130 - XRA 120405 1327 1 120405 1611 2+ 120405 1624 1 120405 2109 1 120406 0359 1- A122 - XRA 120407 1708 1- 120408 0306 2+ A122 - XRA 120408 1640 1 120408 1844 2 A130 - XRA 120408 2022 2 A130 - XRA 120408 2146 1 120409 0122 1- A122 - XRA 120409 1238 2+ 120409 1245 2+ 120409 1309 2+ A132 - QUAL 120409 1421 3 120410 1115 1- A130 - XRA 120410 1137 1- 120410 1152 1+ A132 - XRA 120410 2143 1 120411 1203 1+ 120411 1326 2 120411 1706 1 A130 - FLA 120411 1939 2+ 120411 2204 1 120413 0504 1- A122 - XRA 120413 1432 2 A130 - XRA 120413 1441 2+ A130 - XRA 120413 1811 1+ 120414 1516 1- 120415 0145 1- A122 - XRA 120415 0247 1- A122 - XRA 120415 0418 1- A122 - XRA 120415 0911 1- A131 - XRA 120415 1631 1+ 120415 1924 1 120416 1441 2+ A130 - XRA 120416 1737 1+ 120416 1744 2+ 120417 1117 1- A130 - XRA 120417 1303 1- 120417 1623 1- A130 - FLA 120417 1726 1- 120417 2140 1 120417 2221 1 A122 - XRA 120417 2239 1+ A130 - XRA 120418 1136 2 120418 1146 1+ 120418 1224 1 A97 - XRA 120418 1240 2 120418 1514 2 120418 1706 1+ 120418 1815 1- A80 - XRA 120419 0008 1- A122 - XRA 120419 0259 1 A122 - XRA 120419 1123 2 120419 1455 2 120419 1515 3+ A80 - XRA 120419 2143 1 120420 1204 1- A130 - FLA 120420 1455 1- 120420 1512 1- 120420 1648 1- 120420 1730 1 A94 - XRA 120420 1750 1- A129 - FLA 120420 1820 3+ A130 - FLA 120420 2245 2+ A130 - XRA 120421 0117 1- A122 - XRA 120421 1116 2 120421 1748 1 120421 2015 1- A94 - XRA 120422 1406 1 120422 1755 1+ A94 - XRA 120422 2016 1- 120422 2058 2 A94 - XRA 120422 2139 2 A130 - XRA 120422 2150 1- A94 - XRA 120423 0522 2 A129 - QUAL 120423 1753 2 A94 - XRA 120424 0751 2 120424 1312 1- 120424 1447 1- A131 - FLA 120424 1643 1 120425 1215 2 120425 2235 1- A130 - XRA 120426 1722 1 A118 - XRA 120426 1722 1 A118 - XRA 120426 1728 1- A130 - XRA 120427 0823 2+ 120427 1102 2 120427 1326 1- 120427 2033 2 A130 - FLA 120427 2149 1- A130 - FLA 120427 2202 1- A130 - FLA 120428 0902 2+ 120428 1217 2 A130 - XRA 120428 1426 1- A130 - XRA 120428 1442 1- A130 - FLA 120429 1100 1- A132 - QUAL 120429 1422 1- A112 - XRA 120429 1540 1 A132 - QUAL 120430 0723 3+ A118 - XRA 120430 0742 3 A131 - XRA 120430 0919 1 120430 1029 1- 120430 1040 1+ 120430 1439 1- 120430 1802 1+ A130 - FLA ************************************************** Importance Summary - Apr 2012 1- events: 42 1 events: 24 1+ events: 13 2 events: 20 2+ events: 15 3 events: 5 3+ events: 4 ------------------ Total events: 123