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Solar Bulletin, February 2004
Solar Bulletin |
| THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS - SOLAR COMMITTEE |
Carl E. Feehrer, Editor
9 Gleason Rd.
Bedford, MA 01730 | Email: cfeehrer@hotmail.com
ISSN 0271-8480 |
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| Volume 60 Number 2 | February 2004 |
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Table I. Mean Sunspot Numbers for February 2004
[boldface = maximum, minimum] | Table II. February Observers
|
| Day |
N |
Raw Mean |
Ra |
| 1 |
31 |
69 |
50 |
| 2 |
21 |
92 |
68 |
| 3 |
21 |
101 |
69 |
| 4 |
25 |
95 |
68 |
| 5 |
23 |
89 |
69 |
| 6 |
20 |
76 |
51 |
| 7 |
27 |
63 |
47 |
| 8 |
38 |
78 |
57 |
| 9 |
31 |
79 |
57 |
| 10 |
29 |
78 |
53 |
| 11 |
36 |
69 |
49 |
| 12 |
30 |
73 |
50 |
| 13 |
28 |
67 |
47 |
| 14 |
29 |
59 |
41 |
| 15 |
37 |
69 |
49 |
| 16 |
31 |
55 |
37 |
| 17 |
27 |
32 |
24 |
| 18 |
31 |
31 |
21 |
| 19 |
33 |
32 |
22 |
| 20 |
28 |
37 |
25 |
| 21 |
25 |
50 |
33 |
| 22 |
26 |
53 |
38 |
| 23 |
26 |
82 |
57 |
| 24 |
20 |
71 |
53 |
| 25 |
28 |
79 |
58 |
| 26 |
29 |
90 |
63 |
| 27 |
35 |
100 |
72 |
| 28 |
37 |
93 |
66 |
| 29 |
38 |
73 |
55 |
| 30 |
--- |
--- |
--- |
| 31 |
--- |
--- |
--- |
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Means: | 29.0 | 70.2 | 50.0 |
No. of Observers: 65
No. of Observations: 840
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Reporting Addresses |
Sunspot Reports -- email: solar@aavso.org
- postal mail: AAVSO, 25 Birch St. Cambridge, MA 02138
- FAX (AAVSO): (617) 354-0665
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SID Solar Flare Reports -- email: noatak@aol.com
- postal mail: Mike Hill
114 Prospect St. Marlboro, MA 01752
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|
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17
|
AAP
|
P.Abbott
|
|
22
|
ARAG
|
G.Araujo
|
|
4
|
BARH
|
H.Barnes
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|
1
|
BATR
|
R.Battaiola
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|
11
|
BEB
|
R.Berg
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12
|
BERJ
|
J.Berdejo
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|
5
|
BLAJ
|
J.Blackwell
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|
7
|
BMF
|
M.Boschat
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|
24
|
BOSB
|
B.Bose
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|
19
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BRAR
|
R.Branch
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19
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BROB
|
R.Brown
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|
3
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BURS
|
S.Burgess
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|
1
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BXA
|
A.Baransky
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|
5
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CAMP
|
P.Campbell
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15
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CARJ
|
J.Carlson
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26
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CHAG
|
G.Morales
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|
14
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CKB
|
B.Cudnik
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12
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CLZ
|
C.Laurent
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4
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COMT
|
T.Compton
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24
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CR
|
T.Cragg
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25
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DEJV
|
J.van Delft
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|
10
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DGP
|
J.Dyck
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17
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DRAJ
|
J.Dragesco
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17
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DUBF
|
F.Dubois
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13
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FEEC
|
C.Feehrer
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16
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FERJ
|
J.Fernandes
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17
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FLET
|
T.Fleming
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24
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FUJK
|
K.Fujimori
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5
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GOEM
|
M.Goetz
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3
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GOLA
|
A.Golovin
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29
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GUNM
|
M.Gundlach
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10
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HAYK
|
K.Hay
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15
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HRUT
|
T.Hrutkay
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20
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JAMD
|
D.James
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13
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JEFT
|
T.Jeffrey
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11
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KAPJ
|
J.Kaplan
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8
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KHAR
|
R.Khan
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13
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KNJS
|
J&S Knight
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5
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KROL
|
L.Krozel
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6
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LARJ
|
J.Larriba
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3
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LERM
|
M.Lerman
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16
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LEVM
|
M.Leventhal
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4
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MARE
|
E.Mariani
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20
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MARJ
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J.Maranon
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25
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MCE
|
E.Mochizuki
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15
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MMI
|
M.Moeller
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17
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OBSO
|
IPS Observatory
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5
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RICE
|
E.Richardson
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18
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RITA
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A.Ritchie
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14
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SCGL
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G.Schott
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7
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SCHG
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G.Scholl
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5
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SIMC
|
C.Simpson
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2
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STEF
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G.Stefanopoulis
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9
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STEM
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G.Stemmler
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19
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STQ
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N.Stoikidis
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26
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SUZM
|
M.Suzuki
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13
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SZUM
|
M.Szulc
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14
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TESD
|
D.Teske
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14
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THR
|
R.Thompson
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17
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TJV
|
J.Temprano
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11
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URBP
|
P.Urbanski
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13
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VARG
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A.Vargas
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4
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VELM
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M.Velea
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11
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WILW
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W.Wilson
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16
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YESH
|
H.Yesilyaprak
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| Table III. Means of Raw Group Counts (RG) and Ratios of Spots to Groups (S:G) in February 2004 |
| Day |
RG |
S:G |
Day |
RG |
S:G |
Day |
RG |
S:G |
Day |
RG |
S:G |
| 1 |
3.9 |
7.8 |
9 |
4.1 |
9.3 |
17 |
2.8 |
1.7 |
25 |
3.6 |
11.9 |
| 2 |
5.1 |
7.9 |
10 |
4.6 |
7.2 |
18 |
2.6 |
1.7 |
26 |
4.0 |
12.6 |
| 3 |
5.7 |
7.8 |
11 |
4.2 |
6.5 |
19 |
2.8 |
1.8 |
27 |
5.2 |
9.3 |
| 4 |
5.0 |
8.9 |
12 |
4.7 |
5.6 |
20 |
3.1 |
1.9 |
28 |
4.6 |
10.2 |
| 5 |
5.0 |
7.9 |
13 |
4.4 |
5.2 |
21 |
3.5 |
4.3 |
29 |
3.9 |
8.7 |
| 6 |
3.3 |
13.3 |
14 |
4.1 |
4.3 |
22 |
3.2 |
6.4 |
30 |
--- |
--- |
| 7 |
2.6 |
14.0 |
15 |
5.4 |
2.8 |
23 |
4.4 |
8.5 |
31 |
--- |
--- |
| 8 |
3.6 |
11.7 |
16 |
4.5 |
2.2 |
24 |
3.6 |
9.8 |
Mn. |
4.4 |
7.3 |
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Click image to enlarge.
Fig. 1. 10 cm Solar Flux and American Relative Sunspot Numbers (Ra) for February 2004
(10cm Source: http://www.drao.nrc.ca/icarus) |
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Click image to enlarge.
Fig.2 Maximum, Mean, and Minimum Ra Values for Each Month from January 2001 to Present. |
Michael Hill, SID Analyst
114 Prospect St
Marlborough, MA 01752 USA
noatak@aol.com |
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Sudden Ionospheric Disturbances (SID) Recorded During February 2004
| (Analysis performed by Michael Hill, SID Analyst) |
| Date |
Max |
Imp |
Date |
Max |
Imp |
Date |
Max |
Imp |
| 040201 |
0608 |
2 |
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| 040202 |
0759 |
2 |
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| 040203 |
0853 |
1 |
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| 040203 |
1339 |
2 |
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| 040204 |
1119 |
1 |
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| 040205 |
0637 |
1+ |
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| 040205 |
0706 |
1+ |
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| 040205 |
0755 |
1+ |
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| 040208 |
2051 |
2+ |
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| 040209 |
0947 |
1 |
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| 040209 |
1102 |
1+ |
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| 040209 |
1405 |
1 |
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| 040211 |
1807 |
3 |
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| 040222 |
2002 |
1 |
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| 040225 |
1227 |
2 |
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| 040225 |
1622 |
2 |
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| 040226 |
0203 |
2 |
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| 040226 |
0449 |
1 |
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| 040226 |
0537 |
2 |
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| 040226 |
1420 |
2 |
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| 040226 |
2017 |
2+ |
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| 040226 |
2231 |
2 |
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| 040227 |
0851 |
1+ |
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| 040228 |
1711 |
1- |
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| 040228 |
1728 |
1+ |
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| 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 NAU |
| J Winkler |
A50 |
NAA NML NPM |
| D Toldo |
A52 |
NAA NPM NWC |
| P King |
A80 |
FTA |
| W Moos |
A84 |
FTA |
| M Hill |
A87 |
NAA |
| L Anderson |
A91 |
NWC |
| G DiFillipo |
A93 |
DHO |
| T Poulos |
A95 |
NAA |
| R Battaiola |
A96 |
DHO |
| J Wallace |
A97 |
NAA |
| P Campbell |
A100 |
NLK |
| F Steyn |
A102 |
NWC |
| B Bose |
A103 |
VTX |
| P Mortfield |
A108 |
NLK |
| A Son |
A112 |
DHO |
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| The events listed above meet at least one of the following criteria |
- Event reported by two or more observers within +/- 5 minutes
- Event matched to GOES-8 XRA event to within +/- 15 minutes and event time < 1000 UT
- Reported by observer with a high quality rating > 8 (scale 1-10)
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February was a pretty slow month for SID events, especially in the middle of the month. Also the solar activity level was somewhat erratic with some days having a lot of activity followed immediately with days of inactivity and then active again. I wonder if this is symtomatic of this time frame within the solar cycle, kind of like the end of a particular season, when the temperatures begin to fluctuate between what is normal in one season and what is normal in the next one about to begin. As we approach minimum we are apt to see this erractic behaviour more often than not.
Observers reported only 25 correlated events this month while the GOES-12 satellite reported only 113 X-Ray flares. Of these, two were M-Class and one was an X-Class event towards the end of the month. No long duration SID events resulted from any of these flares. Overall most of the SID events had an average importance rating of 1, 1+, and 2. Thanks to all that have sent in reports. Note that if your format your reports manually, which a couple of you do, the importance rating ‘sign' comes AFTER the numerical value not before. (i.e. 1- not -1)
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