AAVSO: Solar Bulletin February, 2002

Solar Bulletin
THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS - SOLAR DIVISION
Carl E. Feehrer, Editor 9 Gleason Rd. Bedford, MA 01730	Email: cfeehrer@hotmail.com ISSN 0271-8480

Volume 58 Number 2	February 2002

Table I. Mean Sunspot Numbers for February 2002
[boldface = maximum, minimum]

Table II. February Observers

Day	N	Raw	s.d.	K-corrected	s.d.	s.e.
1	28	170	8.4	128	3.5	0.66
2	35	199	9.1	143	3.9	0.66
3	27	212	7.9	170	3.5	0.67
4	36	220	9.2	165	3.9	0.65
5	29	203	9.3	159	3.8	0.71
6	31	174	10.5	128	4.6	0.83
7	28	152	6.6	109	3.2	0.60
8	38	149	6.6	113	3.9	0.63
9	36	157	7.8	118	4.1	0.68
10	32	150	6.9	117	3.1	0.55
11	33	168	6.8	125	3.2	0.56
12	33	153	7.8	115	3.7	0.64
13	27	153	7.7	114	2.9	0.56
14	44	131	7.4	98	3.5	0.53
15	32	124	8.6	95	4.1	0.72
16	37	110	8.1	85	3.3	0.54
17	30	114	7.3	90	3.4	0.62
18	39	104	7.3	80	3.2	0.51
19	32	106	5.5	79	2.4	0.42
20	29	126	8.0	91	2.9	0.54
21	25	120	10.6	81	5.0	1.00
22	31	114	6.1	86	3.3	0.59
23	40	126	5.3	95	2.4	0.38
24	43	148	5.4	115	2.9	0.44
25	35	189	6.7	143	4.7	0.79
26	30	164	8.1	126	4.8	0.88
27	27	149	10.2	115	4.4	0.85
28	31	138	7.8	109	4.5	0.81
29	---	---	---	---	---	---
30	---	---	---	---	---	---
31	---	---	---	---	---	---
Means:		150.8		114.0
No. of Observations: 918 No. of Observers: 71

Reporting Addresses
Sunspot Reports -- email: solar@aavso.org postal mail: AAVSO, 25 Birch St. Cambridge, MA 02138 FAX (AAVSO): (617) 354-0665
SES Reports -- email: noatak@aol.com postal mail: Mike Hill 114 Prospect St. Marlboro, MA 01752
Magnetometer Reports -- email: capaavso@aol.com postal mail: Casper Hossfield PO Box 23, New Milford, NY 10959 FAX: (973) 853-2588 or (407) 482-3963

12	AAP	P.Abbott
7	ANDE	E.Anderson
14	BARH	H.Barnes
3	BATR	R.Battaiola
7	BEB	R.Berg
10	BERJ	J.Berdejo
11	BMF	M.Boschat
23	BOSB	B.Bose
23	BRAB	B.Branchett
8	BRAD	D.Branchett
23	BRAR	R.Branch
21	BROB	R.Brown
2	BURS	S.Burgess
3	CAMP	P.Cambell
13	CARJ	J.Carlson
25	CHAG	G.Morales
16	CKB	B.Cudnik
11	COMT	T.Compton
28	CORA	A.Coroas
22	CR	T.Cragg
5	CVJ	J.Carvajal
12	DELS	S.Delaney
3	DEMF	F.Dempsey
23	DGP	G.Dyck
15	DRAJ	J.Dragesco
13	DUBF	F.Dubois
24	ELR	E.Reed
12	FEEC	C.Feehrer
11	FERJ	J.Fernandez
22	FLET	T.Fleming
20	FUJK	K.Fujimori
19	GIOR	R.Giovanoni
8	GOTS	S.Gottschalk
8	GUNM	M.Gundlach
3	HALB	B.Halls
2	HAYK	K.Hay
21	JAMD	D.James
21	JEFT	T.Jeffrey
2	JENS	S.Jenner
24	KHAR	R.Khan
10	KNJS	J&S Knight
9	LERM	M.Lerman
11	LEVM	M.Leventhal
6	LUBT	T.Lubbers
26	MARJ	J.Maranon
20	MCE	E.Mochizuki
21	MMI	M.Moeller
4	MUDG	G.Mudry
13	OBSO	IPS Observatory
2	RAMJ	J.Ramsey
15	RICE	E.Richardson
18	RITA	A.Ritchie
18	SCGL	G.Schott
10	SCHG	G.Scholl
8	SIMC	C.Simpson
7	STAB	B.Gordon-States
5	STEF	G.Stefanopoulis
11	STEM	G.Stemmler
18	STQ	N.Stoikidis
19	SUZM	M.Suzuki
13	SZUM	M.Szulc
15	TESD	D.Teske
11	THR	R.Thompson
9	TJV	J.Temprano
17	URBP	P.Urbanski
10	VALD	D.delValle
5	VARG	A.Vargas
10	WILW	W.Wilson
6	WITL	L.Witkowski
3	WKW	K.Watts
18	YESH	H.Yesilyaprak

Table III. Means of Raw Group Counts (RG) and Ratios of Spots to Groups (S:G) in February 2002
Day	RG	S:G	Day	RG	S:G	Day	RG	S:G	Day	RG	S:G
1	8.3	10.5	9	10.2	5.4	17	6.3	8.1	25	10.8	7.5
2	10.0	9.9	10	9.3	6.1	18	5.6	8.6	26	10.2	6.1
3	12.0	7.7	11	10.3	6.3	19	5.6	8.9	27	8.7	7.1
4	12.0	8.3	12	8.9	7.2	20	7.2	7.5	28	7.1	9.4
5	12.6	6.1	13	9.0	7.0	21	6.9	7.4	29	---	---
6	10.7	6.3	14	7.1	8.5	22	7.1	6.1	30	---	---
7	10.2	4.9	15	7.5	6.5	23	7.7	6.4	31	---	---
8	10.5	4.2	16	6.1	8.0	24	8.9	6.6	Mn.	8.8	7.2

Click image to enlarge.
Fig.1.10 cm Solar Flux and Comparison of Ri (provisional) and Ra Estimates for February.
(Ri Source: http://sidc..oma.be/index.php3)
(!0cm Source: http://www.drao.nrc.ca/icarus)

Click image to enlarge.
Fig.2 Maximum, Mean, and Minimum Ra Values for Each Month from January 2000 to Present.

Smoothed Mean Sunspot Number (Rsm) for August 2001: 125.8

Editor's Note

This month I would like to welcome two returning sunspot observers, Brian Gordon-States (STAB), who is located in Guildford, Surrey, England, and Tom Lubbers (LUBT) who lives in Minnetonka, MN. Reports have also been received from two new observers, Susan Delaney (DELS) and Jose Carvajal (CVJ) who live Fairfield, CT and in Madrid, Spain, respectively. Also, a new observer, Francois Steyn (A102) from South Africa, has joined the group of contributors of SID data.Thank you all for your reports and for your interest in the Solar Division of the AAVSO.

Sudden Ionospheric Disturbance Report

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

Sudden Ionospheric Disturbances (SID) Recorded During February 2002

(Analysis performed by Michael Hill, SID Analyst)
Date	Max	Imp	Date	Max	Imp	Date	Max	Imp
020301	2113	2	020317	1929	1	020325	1043	1
020302	1534	1	020317	2019	1+	020325	1209	2
020303	1516	2+	020319	1603	1-	020326	1030	2
020304	1027	2	020320	0256	1+	020326	1357	1
020304	1531	2+	020320	0612	2	020327	1303	2
020304	1906	2	020320	0759	1	020327	1347	1+
020306	1133	2	020320	1002	2	020327	1556	2+
020306	1745	1	020320	1110	1	020328	0928	1
020306	2015	1	020320	1140	1+	020328	1416	1-
020307	1340	1-	020320	1429	1-	020328	1911	2+
020308	1045	1-	020320	1626	2
020310	1848	2	020320	1710	2+
020310	1924	2	020320	2108	2+
020312	1241	2	020321	0937	1+
020312	1438	2	020321	1227	3
020312	1622	1+	020321	1650	2
020313	0712	2	020321	1815	2+
020313	0858	1	020321	2036	1+
020313	0946	1	020322	0631	2
020314	1012	1-	020322	1828	2+
020314	1108	1+	020323	1358	1+
020314	1356	1+	020323	1434	1
020315	0958	1-	020324	1445	1+
020315	1735	2	020324	1538	1+
020317	1900	1+	020324	2034	2

Importance rating: Duration

-1: <19

1: 19-25

1+: 26-32

2: 33-45

2+: 46-85

3: 86-125

3+: >125

Observer	Code	Station(s) monitored
A Clerkin	A29	NAA
J Winkler	A50	NAA, NPM
J Ellerbe	A63	ICV
P King	A80	FTA
A Panzer	A83	NAA
W Moos	A84	FTA, ICV
M Hill	A87	NAA
G Difillipo	A93	HWU
T Poulos	A95	NAA
R Battaiola	A96	HWU
J Wallace	A97	NAA
NJAA	A98	NAA
M King	A99	HWU
P Campbell	A100	NLK
F Steyn	A102	NWC

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

Solar Events

February was fairly active for solar flares and associated SID events. There were 200 solar flares recorded by the GOES-8 Spacecraft. Of these only 17 were M-Class. There were no X-Class flares. SID Observers recorded a total of 60 SID events. Five of these were not part of the GOES-8 data set. The most active day was certainly the 20th of February, with 12 X-Ray flares and 11 SID events. Most events were of medium duration, with only one with an importance rating of 3.

Please note the new format of the previous page. I have moved the importance rating legend up to just below the SID Event listings. In its place, I have included a new graph of the SID Events grouped by importance. I don't know why I didn't think of this before. It just hit me this month as I was doing the analysis and it seemed like such a natural thing to include. I will, therefore, include this second graph every month from now on. If I can find the time, I will try to compile set of graphs for past months since I have been doing the analysis.

Last but not least, I would like to welcome a new SID Observer. His name is Francois Steyn (A102) and he is from South Africa. He is going to be a valuable asset, along with Domenic Toldo, in reporting the early hours that most of us in the USA and Western Europe do not get to record. Welcome Francois.

Solar Flare Summary

Sudden Ionospheric Disturbances Supplement

Casper H. Hossfield, SID Sup. Editor
PO Box 23
New Milford, NY 10959, USA

SUDDEN IONOSPHERIC DISTURBANCES
RECORDED DURING February, 2002

capaavso@aol.com
Fax 973 853 2588

There is good news to report. We have a new Sudden Ionospheric Disturbance, SID, observer in South Africa. He is Francois Steyn, A102, who lives in Villiersdorp about 100 km from Cape Town on the west coast. Francois first became interested in monitoring VLF radio signals to detect solar flares in 1974 when he met and got to know Walton de Villiers, a well known South African SEA observer. He built an SEA receiver then to detect flares as sudden enhancements of atmospherics, SEA, but only recently became interested again when he retired from working for TELKOM SA, the South African telephone service. He now runs a small electronics repair shop from his home and has time to pursue his other interests in radio. He is a ham radio operator, ZR1AIK, but mostly interested in experimenting and building things. He dusted off an old SEA receiver he had built long ago and tuned it to NWC in Norhwest Cape, West Australia transmitting on 19.8 kHz and about 8700 km east Villiersdorp. This receiver was used to make the Rustrak chart recording below of a Sudden Enhancement of signal, SES, in response to a solar flare. Francois's receiver is a very good design with many good features not the least of which is the remote outdoor loop antenna with its antenna amplifier which Francois has located 100m from his house. He uses an OP07A instrumentation amplifier to preamplify the signal from the untuned loop and 100m of coax to bring the preamplified signal to the indoor receiver. The coax connects the 12-Volt power supply to the preaamp and is decoupled from the RF signal with RF chokes A remote outdoor loop and amplifier is an excellent way eliminate much of the powerline interference that indoor loop antennas often suffer from. A schematic and parts list are shown below. The receiver is tunable over the VLF band using the tunable Ferrite pot-core coils which are similar to the Merrit 6319 slug-tuned Ferrite coils we used to use before they were discontinued. If you would like to know more about this receiver you can contact Francois at << fsteyn@worldonline.co.za >>.

Click image to enlarge.

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