AAVSO: Solar Bulletin September, 2001

Sudden Ionospheric Disturbance Report

From the September 2001 Solar Bulletin

Michael Hill, SID Analyst
114 Prospect St
Marlborough, MA 01752 USA
noatak@aol.com

Sudden Ionospheric Disturbances (SID) Recorded During September 2001

(Analysis performed by Michael Hill, SID Analyst)
Date	Max	Imp	Date	Max	Imp	Date	Max	Imp
010901	1351	2	010906	1954	2+	010912	1036	1
010901	2047	2	010907	0110	1	010912	1318	2
010902	0920	2	010907	0403	1+	010912	2147	3
010902	1205	2+	010907	0708	1	010913	1603	2
010902	1317	2	010907	1536	2+	010913	1951	2
010902	1348	2+	010907	2119	1+	010914	0606	2+
010902	1519	2	010908	0456	2	010914	0908	1
010902	1750	2+	010908	0710	1	010914	1846	2+
010903	0946	2+	010908	1306	1	010914	2147	2+
010903	1046	2	010908	1529	1	010914	2304	2+
010903	1654	2+	010908	1647	2	010915	0525	2
010903	1825	3	010908	1920	2+	010915	1128	3
010904	1548	2+	010909	0240	1+	010915	1554	2+
010904	1725	1+	010909	0805	1+	010915	2032	2+
010904	1925	2	010909	1003	1+	010915	2122	2
010904	2018	2+	010909	1337	1+	010916	0748	1-
010904	2201	2+	010909	1516	2+	010916	0919	1
010905	1418	1-	010909	1840	2+	010916	1353	2
010905	1431	2+	010909	2044	2+	010916	1609	1+
010905	1635	1+	010910	0830	2	010916	1645	1+
010905	1910	1+	010911	0701	2	010916	1712	1+
010905	2233	2	010911	0937	2	010916	1847	2+
010906	0346	1+	010911	1950	2	010917	0825	1+
010906	1324	2+	010911	2032	2+	010917	0937	2
010906	1537	1+	010912	0445	2	010917	1117	1-

Date	Max	Imp	Date	Max	Imp	Date	Max	Imp
010917	1253	1	010922	0542	1	010928	2112	2+
010917	1552	2+	010922	0644	1+	010929	1059	3+
010917	2109	1+	010922	1053	1	010930	0843	2+
010917	2143	2+	010922	1507	2	010930	1141	2+
010918	1439	1-	010922	1815	2+	010930	1731	1
010918	1537	1	010923	1005	1+	010930	1747	2
010918	1551	1+	010923	1140	2	010930	2010	2
010918	1707	2+	010923	1400	1	010930	2134	2+
010918	1722	1	010923	1429	2
010918	1845	2	010924	1018	3+
010918	1922	1+	010925	1027	2+
010918	1958	2	010925	1715	2
010918	2047	2	010926	0850	2+
010919	0344	2	010926	1225	2+
010919	0710	2+	010927	1216	3+
010919	1606	2	010928	0833	2+
010919	1852	2	010928	1013	3
010920	1441	2	010928	1715	2
010920	1816	2+	010928	1830	2+
010920	1850	1+	010928	1922	2+

The events listed above meet at least one of the following criteria

Reported in at least two observer reports
Visually analyzed with definiteness rating = 5
Reported by overseas observers with high definiteness rating

Observer	Code	Station(s) monitored
A Clerkin	A29	NAA
J Winkler	A50	NAA, NPM
D Toldo	A52	NWC, NAA, xxx
A Stokes	A62	NAA
J Ellerbe	A63	ICV
A Panzer	A83	NAA
W Moos	A84	FTA, ICV
G DiFillipo	A93	HWU
T Poulos	A95	NAA
R Battaiola	A96	NWU
J Wallace	A97	NAA
M King	A99	GYA
P Campbell	A100	NLK
G Bessen	A101	NDH

Importance	Duration (min)
1-	< 19
1	19 – 25
1+	26-32
2	33-45
2+	46-85
3	86-125
3+	> 125

Solar Events

Once again, we had a very active month. There were 260 X-Ray flares reported by the GOES-8 spacecraft. Of those, 50 were M-Class flares and one was an X-Class flare. A number of the M-Class flares were very close to being X-Class however; A very energetic sun indeed. The most active days were around the 8th and the 18th.

Our observers recorded many SID Events due to the large number of flares. The total number of correlated events came to 123 for September. The most active days were the 5th to the 9th and then again around the 16th to the 19th of September. Of these events 76 had an importance rating of 2 and 2+, while 7 of them had importance ratings of 3 and 3+. It is unusual for so many events with such a high importance rating.