Elemental Abundances of Selected SEP Events

Elemental Abundance of Selected SEP Events

Abundances and inferred charge states for November 6 1997 event
Element Composition for 9 events from 1997 and 1998
Average abundances over 27 large SEP events from Nov 1997 to Jan 2001
Abundances for the large "Halloween" 2003 events
Large SEP events as identified by GOES 1997-2005, and their associated flares, shocks, and radio signatures.
Elemental abundances (11.0–21.8 MeV/nucleon) for 39 small SEP events from Slocum et al., ApJ, 594, 592-604, 2003.
Elemental Composition and spectra for the December 2006 SEP events

SEP event: November 6 1997

Reference: Cohen et al., GRL, 26, 149, 1999

Comment: These abundances were obtained for 1200 Nov 6 - 0000 Nov 10, 1997 by fitting a power law to the SIS elemental spectra over the region 12-60 MeV/nucleon, using a common spectral index for all elements. The charge states were then inferred from the abundances in a manner described in the paper.

SEP event: 9 events from 1997 and 1998 (as indicated in the first table)

Reference: Cohen et al., GRL, 26, 2697, 1999

Comment: The first table gives 3He/4He ratios and Fe/O over energy intervals indicated for 9 large SEP events. The second table gives heavy ion composition from 12-60 MeV/nucleon for 4 Fe-rich large SEP events.

Table 1. Characteristics of Observed SEP Events

Event Time Year Start End	3He/4He (8-14 MeV/nuc)	Fe/O (12-60 MeV/nuc)
1997 306 0600 - 310 1200	0.008	0.588 ± 0.011
1997 310 1200 - 314 0000	0.007	0.900 ± 0.006
1998 110 1200 - 117 0000	< 0.06	0.018 ± 0.001*
1998 122 1200 - 125 0000	< 0.002	0.833 ± 0.016
1998 126 0800 - 128 0000	0.04	0.740 ± 0.014
1998 129 0450 - 131 1200	< 0.002	0.492 ± 0.015
1998 237 0000 - 244 0000	< 0.002	0.016 ± 0.001
1998 273 1200 - 278 0000	< 0.003	0.299 ± 0.003
1998 318 0600 - 322 1200	0.005	0.761 ± 0.006

* measured over 12 to 40 MeV/nucleon

Table 2. Observed Element Composition (12 to 60 MeV/nucleon)

Z	Nov 6 1997 310.5 - 314.0	May 2 1998 122.5 - 125.0	May 6 1998 126.3 - 128.0	Nov 14 1998 318.25 - 322.5
6	1000 ± 12	1000 ± 38	1000 ± 39	1000 ± 15
7	347 ± 6	371 ± 19	385 ± 20	309 ± 7
8	3058 ± 29	3218 ± 99	3010 ± 95	2602 ± 33
10	848 ± 10	1077 ± 40	955 ± 37	672 ± 11
11	54 ± 2	98 ± 8	94 ± 6	69 ± 2
12	625 ± 8	913 ± 35	706 ± 29	915 ± 14
13	74 ± 2	102 ± 7	120 ± 7	101 ± 3
14	558 ± 7	700 ± 28	532 ± 23	776 ± 12
16	216 ± 4	230 ± 13	214 ± 12	164 ± 4
18	66 ± 2	73 ± 6	62 ± 50	32 ± 2
20	177 ± 3	196 ± 11	230 ± 11	112 ± 3
26	2752 ± 26	2680 ± 79	2228 ± 66	1980 ± 24
28	191 ± 3	207 ± 8		106 ± 2

SEP event: Average over 27 large SEP events from Nov 1997 to Jan 2001

Reference: Cohen et al., in Solar and Galactic Composition, ed by R.F. Wimmer-Schweingruber, AIP, 598, p. 107, 2001

Comment: These abundances were calculated over 20-65 MeV/nucleon and are given as ratios to neighboring elements to reduce the effects of FIP and Q/M fractionation.

Element ratio	FIP (eV)	SIS study	Photosphere*	Meteoritic*
P/Si	0.49	5.12 ± 0.47	7.76 ± 0.75	10.00 ± 1.48
Cl/Si	13.00	1.66 ± 0.29	5.24 ± 0.78	5.25 ± 0.78
K/Ca	4.34	60.87 ± 4.78	58.87 ± 20.56	60.26 ± 2.84
Ti/Ca	6.82	38.79 ± 4.22	46.74 ± 6.97	38.90 ± 1.83
Cr/Fe	6.77	20.06 ± 0.85	14.76 ± 1.08	15.49 ± 0.36
Mn/Fe	7.44	12.55 ± 0.68	7.76 ± 0.56	10.72 ± 0.25
Co/Fe	7.86	3.88 ± 0.31	2.63 ± 0.26	2.57 ± 0.06
Ni/Fe	7.64	60.89 ± 1.42	56.23 ± 1.31	56.23 ± 1.31
Cu/Fe	7.73	0.69 ± 0.14	0.51 ± 0.05	0.62 ± 0.06
Zn/Fe	9.39	1.33 ± 0.21	1.26 ± 0.26	1.48 ± 0.14

* from Grevesse, N. and Sauval, A.J., Space Sci. Rev. 85, 161-174, 1998.

SEP event: Large ‘Halloween 2003’ events; October 26, October 28, October 29, November 2, November 4 2003

Reference: Cohen et al., JGR, in press, 2005

Comment: These figures show the temporal evolution of the oxygen intensity at several energies; the combined O and Fe spectra from ULEIS and SIS, integrated over each event; the resulting Fe/O abundances as a function of energy; and the elemental abundance at 0.64-0.91 MeV/nucleon from ULEIS and 12-60 MeV/nucleon from SIS. The data for these elemental abundances are given in the following table.

Figure 1. Hourly oxygen intensity plotted versus time for several of the ULEIS and SIS energy bands. Flares start times are indicated by the inverted triangles at the top of the plot (with X-ray flare size given above). Shock passages are denoted by vertical solid lines. The 5 identified events are numbered for reference.

Figure 2. Event-integrated oxygen (circles) and iron (squares) fluences plotted versus energy for each of the 5 events. The gaps in the Fe spectra (from ~3 to 10 MeV/nucleon) are due to different measurement techniques of the ULEIS and SIS sensors.

Figure 3. Iron to oxygen fluence ratios plotted as a function of energy for the 5 events.

Figure 4. Event-integrated abundances relative to oxygen plotted versus nuclear charge for two different energy ranges, 0.64 to 0.91 MeV/nucleon from ULEIS (left panels) and 12 to 60 MeV/nucleon from SIS (right panels). The bottom panels are further normalized to the large SEP event abundances of Reames [1999].

SIS Abundances for Figure 4

Nuclear Charge	26 Oct	28 Oct	29 Oct	2 Nov	4 Nov
6	403.00 ± 0.06	483.00 ± 5.78	403.00 ± 0.46	452.00 ± 0.41	524.00 ± 0.03
7	116.00 ± 0.03	162.00 ± 3.69	125.00 ± 0.27	143.00 ± 0.25	138.00 ± 0.02
8	1000.00 ± 0.09	1000.00 ± 8.59	1000.00 ± 0.74	1000.00 ± 0.66	1000.00 ± 0.04
10	143.00 ± 0.03	112.00 ± 2.85	246.00 ± 0.38	134.00 ± 0.25	115.00 ± 0.01
11	12.70 ± 0.01	12.50 ± 1.01	17.90 ± 0.10	12.00 ± 0.08	11.10 ± 0.00
12	188.00 ± 0.04	200.00 ± 4.22	242.00 ± 0.39	195.00 ± 0.34	217.00 ± 0.02
13	14.70 ± 0.01	12.70 ± 1.00	21.60 ± 0.12	11.90 ± 0.08	13.90 ± 0.01
14	151.00 ± 0.03	157.00 ± 4.03	173.00 ± 0.33	120.00 ± 0.27	119.00 ± 0.01
16	38.30 ± 0.02	27.80 ± 1.75	32.60 ± 0.14	19.10 ± 0.10	19.50 ± 0.01
18	2.81 ± 0.00	0.91 ± 0.23	6.11 ± 0.07	1.22 ± 0.02	1.29 ± 0.00
20	12.20 ± 0.01	4.98 ± 0.70	12.20 ± 0.09	5.04 ± 0.05	3.91 ± 0.00
26	147.00 ± 0.03	37.80 ± 1.99	138.00 ± 0.33	42.10 ± 0.13	31.60 ± 0.01
28	8.54 ± 0.01	2.64 ± 0.62	5.44 ± 0.06	2.87 ± 0.04	1.66 ± 0.00

ULEIS Abundances for Figure 4

Nuclear Charge	26 Oct	28 Oct	29 Oct	2 Nov	4 Nov
7	114.08 ± 8.76	232.13 ± 24.88	120.98 ± 12.96	133.17 ± 7.14	123.90 ± 5.01
8	1000.00 ± 34.86	1000.00 ± 62.91	1000.00 ± 49.01	1000.00 ± 26.06	1000.00 ± 18.89
10	173.95 ± 11.17	226.85 ± 24.37	268.20 ± 20.05	114.74 ± 6.53	96.48 ± 4.34
12	226.61 ± 13.00	313.61 ± 30.66	304.44 ± 21.55	215.60 ± 9.42	251.97 ± 7.51
14	307.89 ± 16.05	317.73 ± 30.28	321.70 ± 22.57	251.63 ± 10.24	406.92 ± 10.01
16	111.37 ± 9.03	88.38 ± 13.71	68.04 ± 9.34	72.20 ± 5.09	111.30 ± 4.58
20	57.81 ± 8.85	35.85 ± 8.87	30.24 ± 6.85	20.95 ± 2.78	37.64 ± 3.12
26	1024.40 ± 30.87	388.84 ± 28.42	690.39 ± 35.80	444.82 ± 13.23	755.61 ± 14.51

SEP event: Large SEP events as identified by GOES 1997-2005

Reference: Cane et al., JGR, submitted, 2005

Comment: The table identifies GOES events and their associated flares, shocks, and radio signatures. The peak GOES >10 MeV proton intensity is given as well as the Fe/O ratio from SIS integrated over the event from 12-60 MeV/nucleon. The time profiles of the SIS data are characterized in a manner described in the paper.

GOES SEP Events (1997-2005)

Event				Flare		Particles				Shock
Number^a	Year	Date	Time^b	Location	Xray Peak	>10MeV^cPeak (pfu)	Fe/O^d ¸ 0.134		Profile^e	Transit^fSpeed (km/s)	Radio^g
Number^a	Year	Date	Time^b	Location	Xray Peak	>10MeV^cPeak (pfu)	Ratio	Uncertainty	Profile^e	Transit^fSpeed (km/s)	Radio^g
1	1997	Nov 04	0555	S14W33	X2	72	3.11	0.17	P	640
2	1997	Nov 06	1150	S18W63	X9	490	6.40	10.08	P	500
3	1998	Apr 20	1000	S43W90	M1	1700	0.032	0.003	O	520	km
4	1998	May 02	1335	S15W15	X1	150	5.23	0.22	O	1120
5	1998	May 06	0800	S11W65	X2	210	3.59	0.25	P	...
6	1998	Aug 24	2205	N30E07	X1	670	0.88	0.29	S	1260	km
7	1998	Sep 23	0700	N18E09	M7	44	*0.46	0.02	S	1032	km
8	1998	Sep 30	1320	N23W81	M2	1200	2.03	0.06	O	1010	km
9	1998	Nov 05	1900	N26W18	M9	11	*0.50	0.02	O	740
10	1998	Nov 14	0518	N28W90	C1	310	5.02	0.11	P	...
11	1999	Jan 20	2004	N27E90	M5	14	8.57	1.74	O	PS
12	1999	Apr 24	1300	NW150	...	32	1.22	0.40	P	...
13	1999	May 03	0602	N15E32	M4	14	*0.155	0.007	S	720
14	1999	Jun 01	1930	NW120	...	48	4.88	0.23	P	...
15	1999	Jun 04	0703	N17W69	M3	64	2.86	0.27	P	...
16	2000	Feb 18	0925	N W120	...	13	3.29	1.47	P	...
17	2000	Apr 04	1541	N16W66	C9	55	0.80	0.19	P	870	km
18	2000	Jun 06	1525	N20E18	X2	84	3.0	1.5	O	990	km
19	2000	Jun 10	1702	N22W38	M5	46	5.86	0.54	P	PS
20	2000	Jul 14	1024	N22W07	X5	24000	0.62	0.14	S	1600	km
21	2000	Jul 22	1134	N14W56	M3	*17	...	…	P	...
22	2000	Jul 27	1130	NW120	...	*18	...	…	P	...
23	2000	Aug 09	1525	N11W11	C2	*17	...	…	O	805
24	2000	Sep 12	1213	S17W09	M1	320	3.06	0.31	P	640	km
25	2000	Oct 16	0728	N04W90	M2	15	4.92	0.35	P	...
26	2000	Oct 25	1125	N00W95	C4	15	0.98	0.41	P	PS
27	2000	Nov 08	2328	N10W75	M7	14800	0.049	0.004	O	1300
27b	2000	Nov 09	1613	S11E10	M					1200	km
28	2000	Nov 24	1455	N22W07	X2	100	2.55	0.42	P	PS
29	2000	Nov 25	0100	N07E50	M8	940	0.81	0.04	S	1000
30	2001	Jan 28	1600	S04W59	M1	49	4.48	0.38	P	630
31	2001	Mar 29	1015	N14W12	X1	35	3.28	0.22	O	690
32	2001	Apr 02	2151	N18W82	X20	1110	2.30	0.04	O	1020
33	2001	Apr 10	0526	S23W09	X2	355	0.94	0.04	S	1220
34	2001	Apr 12	1028	S19W42	X2		2.11	0.34	P	...
35	2001	Apr 15	1350	S20W85	X14	951	5.79	0.15	P	700
36	2001	Apr 18	0214	S20W120	C2	321	3.31	0.15	P	...
37	2001	Apr 26	1312	N17W31	M7	*57	...	…	S	1010	km
38	2001	May 07	0855	NW140	...	30	3.01	0.48	P	...
39	2001	Jun 15	1520	SW130	...	26	0.77	0.49	P	...
40	2001	Aug 09	1122	S17E19	C3	17	*0.887	0.008	O	640
41	2001	Aug 15	2355	W140	...	493	0.90	0.04	O	PS
42	2001	Sep 15	1128	S21W49	M1	*11	...	…	P	...
43	2001	Sep 24	1038	S16E23	X2	12900	0.120	0.006	S	1220	km
44	2001	Oct 01	0515	S22W91	M9	2360	0.51	0.05	O	PS
45	2001	Oct 19	1630	N15W29	X1	11	2.84	0.65	P	870	km
46	2001	Oct 22	1759	S18E16	X1	24	5.44	0.56	P	640
47	2001	Nov 04	1620	N06W18	X1	31700	0.373	0.008	S	1240	km
48	2001	Nov 17	0525	S13E42	M2	34	*0.17	0.01	S	680
49	2001	Nov 22	2330	S15W34	M9	18900	0.44	0.02	S	1300	km
50	2001	Dec 26	0540	N08W54	M7	779	4.94	0.10	P	570
51	2001	Dec 28	2045	S26E90	X3	108	0.81	0.08	S	870
52	2002	Jan 08	2025	NE100	C9	91	*0.111	0.004	S	902	km
53	2002	Jan 14	0627	SW90	M4	*15	...	…	O	...
54	2002	Feb 20	0612	N12W72	M5	13	6.86	1.05	P	...
55	2002	Mar 15	2310	S08W03	M2	13	*0.369	0.007	O	670
56	2002	Mar 18	0231	S09W46	M1	53	1.43	0.59	O	710
57	2002	Mar 22	1114	SW90	M1	16	*0.039	0.004	S	660
58	2002	Apr 17	0824	S14W34	M2	24	1.31	0.19	P	860	km
59	2002	Apr 21	0151	S14W84	X1	2520	0.18	0.007	O	800	km
60	2002	May 22	0354	S19W56	C5	820	0.52	0.05	S	1323	km
61	2002	Jul 07	1143	SW110	M1	22	1.81	0.56	P	...
62	2002	Jul 15	2008	N19W01	X3	234	0.73	0.13	O	955
63	2002	Jul 20	2130	SE90	X3	28	0.59	0.06	S	1300
64	2002	Aug 14	0212	N09W54	M2	26	1.46	0.42	P	1400	km
65	2002	Aug 22	0157	S07W62	M5	36	5.34	0.40	P	PS
66	2002	Aug 24	0112	S08W90	X3	317	5.62	0.17	P	710
67	2002	Sep 05	1706	N09E28	C5	208	0.52	0.17	S	880	km
68	2002	Nov 09	1323	S12W29	M4	404	0.43	0.12	O	900
68b	2002	Nov 10	0321	S12W37	M2
69	2003	May 28	0027	S07W17	X3	121	1.62	0.15	O	990
69b	2003	May 29	0105	S06W37	X1					1100
70	2003	May 31	0224	S07W65	M9	27	3.96	0.75	P	...
71	2003	Jun 17	2255	S08E61	M6	24	*0.21	0.006	O	730
72	2003	Oct 26	1819	N02W38	X1	466	1.44	0.05	O	1300
73	2003	Oct 28	1110	S16E08	X17	29500	0.097	0.007	O	2210	km
74	2003	Oct 29	2049	S15W02	X10	1570	1.02	0.02	O	2120
75	2003	Nov 02	1715	S20W56	X8	353	0.69	0.02	O	1130
76	2003	Nov 04	1929	S19W83	X28	100	0.49	0.03	O	880
77	2003	Nov 20	0747	N01W08	X1	13	1.24	0.14	P	PS
78	2003	Dec 02	0948	S13W65	C7	86	0.87	0.49	O	...
79	2004	Apr 11	0419	S14W47	C9	35	2.66	0.31	P	1100
80	2004	Jul 25	1514	N08W33	M1	2086	0.28	0.06	S	1300	km
81	2004	Sep 12	0056	N04E42	M5	273	*0.02	0.01	S	980	km
82	2004	Sep 19	1712	N03W58	M1	57	1.59	1.1	P	690
83	2004	Nov 01	0650	W90	...	63	1.21	0.51	P	...
84	2004	Nov 07	1606	N09W17	X2	495	0.49	0.08	O	1031	km
85	2004	Nov 10	0213	N09W49	X3	300	1.18	0.05	O	...
86	2005	Jan 15	2302	N15W05	X3	300	0.28	0.02	O	1200	km
87	2005	Jan 17	0952	N15W25	X4	4000	0.142	0.007	O	1300	km
88	2005	Jan 20	0701	N14W61	X7	1680	1.65	0.04	O	1200	km

^aThe ‘b’ numbered events are additional solar events that probably produced energetic particles in addition to the main event listed.

^bThe time is that of Xray maximum intensity or of the start of the type III bursts when the flare was behind the limb.

^cIntegral intensities from GOES spacecraft. 1 pfu = 1 particle/(cm -s-ster). The events in which the value is preceded by a * are small ones that were not included in this study.

^dNormalized Fe/O ratios in the range 25—80 MeV/nuc except for the values preceded with a *. These are at a lower energy (3-10 MeV/nuc or 12—25 MeV/nuc for the event in 2004) and probably are upper limits.

^eParticle profiles of the type ‘P’ show a prompt onset followed by a slower decay. ‘S’ profiles peak at the time of an associated shock. Most events with an ‘O’(i.e. other than P or S) profile show a prompt onset but have elevated intensities until the associated shock passes.

^f‘...’ indicates no shock near Earth. ‘PS’ indicates there was a passing shock i.e. a shock not related to the solar event of interest.

^gThe shocks designated ‘km’ are ones in which there was radio emission below 100 kHz that lasted for more than 20 hours.

Abundances for small SEP events from Slocum et al., ApJ, 594, 592-604, 2003

Table 1 Characteristics of the 39 Small SEP Events Included in This Study

Event Number	Date	Days	0.5–2.0 MeV nucleon-13He/4He	V-disp.	Shock
1...	1998 Apr 3	93.1–104.8	8.15 ± 0.42 x 10^-3	...	...
2...	1998 Apr 29	119.7–121.3	2.62 ± 1.45 x 10^-3	...	F
3...	1998 May 1	121.3–122.2	7.01 ± 2.70 x 10^-3	...	F
4...	1998 May 27	147.4–148.6	4.00 ± 0.23 x 10^-2	Yes	...
5...	1998 Jun 16	167.7–170.6	1.60 ± 0.34 x 10^-3	Yes	F
6...	1998 Sep 8	251.6–254.2	2.10 ± 0.06 x 10^-1	Yes	...
7...	1998 Sep 27	270.2–272.1	1.16 ± 0.02 x 10^-1	...	...
8...	1998 Oct 21	294.1–297.0	3.03 ± 0.87 x 10^-3	...	F
9...	1998 Nov 5	309.7–311.7	<1.1 x 10^-3	Yes	...
10...	1998 Nov 7	311.7–316.4	2.16 ± 0.10 x 10^-2	...	F
11...	1998 Nov 23	327.5–334.9	3.22 ± 0.38 x 10^-3	...	...
12...	1999 May 27	147.3–148.4	1.30 ± 0.12 x 10^-1	...	...
13...	1999 Jun 21	172.7–176.0	3.50 ± 0.17 x 10^-2	...	...
14...	1999 Nov 17	321.8–327.3	5.62 ± 0.48 x 10^-3	...	...
15...	1999 Dec 28	362.0–364.2	1.58 ± 0.07 x 10^-1	...	...
16...	2000 Jan 9	9.2–13.5	1.21 ± 0.10 x 10^-2	...	F
17...	2000 Mar 7	67.2–68.8	3.24 ± 0.21 x 10^-1	Yes	...
18...	2000 Mar 22	82.4–87.2	1.48 ± 0.29 x 10^-3	...	R
19...	2000 May 1	122.3–123.0	6.62 ± 0.43 x 10^-2	Yes	...
20...	2000 May 4	125.3–126.7	6.38 ± 1.11 x 10^-2	...	...
21...	2000 May 15	136.7–138.8	1.57 ± 0.46 x 10^-3	...	...
22...	2000 May 17	138.8–140.7	2.08 ± 0.46 x 10^-3	...	F
23...	2000 May 23	144.7–147.9	2.06 ± 0.05 x 10^-1	...	...
24...	2000 Jun 15	167.8–169.1	2.46 ± 0.17 x 10^-2	Yes	...
25...	2000 Jun 17	169.2–172.9	9.84 ± 0.71 x 10^-3	Yes	...
26...	2000 Jun 23	175.3–177.2	1.97 ± 0.16 x 10^-2	...	F
27...	2000 Jun 25	177.2–180.6	2.80 ± 0.38 x 10^-3	...	...
28...	2000 Aug 11	224.0–225.4	6.29 ± 1.54 x 10^-3	...	F
29...	2000 Aug 12	225.4–226.6	8.70 ± 0.72 x 10^-3	...	...
30...	2000 Aug 13	226.6–228.6	1.43 ± 0.38 x 10^-3	...	F
31...	2001 Mar 10	69.2–73.9	4.47 ± 0.26 x 10^-1	...	...
32...	2001 Mar 25	84.5–87.4	5.31 ± 0.75 x 10^-3	...	F
33...	2001 Apr 26	116.4–119.6	3.16 ± 0.53 x 10^-3	...	F
34...	2001 May 20	140.3–143.3	1.52 ± 0.42 x 10^-2	...	...
35...	2001 Jun 15	166.6–167.3	3.54 ± 1.20 x 10^-3	...	...
36...	2001 Jun 16	167.3–169.4	3.02 ± 0.71 x 10^-3	...	...
37...	2001 Jul 19	200.6–203.4	2.80 ± 1.68 x 10^-3	...	...
38...	2001 Sep 10	253.4–255.7	1.38 ± 0.07 x 10^-1	...	...
39...	2002 Feb 20	51.0–57.0	3.00 ± 0.30 x 10^-2	...	...

Notes.— Shown in the table from left to right are the event numbers, the event times, the 0.5–2.0 MeV nucleon^-1 ³He/⁴He ratios from ULEIS, one column noting velocity dispersion in the ~0.1–10 MeV nucleon^-1 ion data from ULEIS, and one column indicating interplanetary shocks detected using the MAG and SWEPAM instruments. Forward shocks are denoted by "F" and reverse by "R." Ellipses indicate an event without clear velocity dispersion (fifth column) or an event in which there was no shock detected at ACE (sixth column). The event times used to calculate the ³He/⁴He ratios from ULEIS are displaced by 2.7 hr from the times shown in the table to account for the difference in energy ranges between the SIS and ULEIS instruments.

Table 4 11.0–21.8 MeV nucleon-1 Heavy-Element Intensities Relative to C

Event

Num

C ÷ 1.00

N/C ÷

2.51 x 10^-1

O/C ÷ 2.04

Ne/C ÷

3.63 x 10^-1

Na/C ÷

6.46 x 10^-3

Mg/C ÷

1.15 x 10^-1

Al/C ÷

8.91 x 10^-3

Si/C ÷

1.07 x 10^-1

S/C ÷

6.46 x 10^-2

Ar/C ÷

7.59 x 10^-3

Ca/C ÷

6.92 x 10^-3

Fe/C ÷

9.55 x 10^-2

1...

4.09 ± 0.37 x 10^-7

2.36 ± 0.33

1.58 ± 0.10

0.84 ± 0.14

3.92 ± 2.52

3.11 ± 0.37

1.69 ± 1.29

2.64 ± 0.37

0.81 ± 0.28

<1.66

<1.82

0.97 ± 0.34

2...

6.40 ± 1.17 x 10^-7

0.84 ± 0.45

0.47 ± 0.13

0.56 ± 0.23

5.59 ± 4.41

1.97 ± 0.59

7.33 ± 4.96

2.38 ± 0.73

<0.91

<7.74

<8.49

6.19 ± 1.43

3...

1.08 ± 0.20 x 10^-6

0.67 ± 0.39

0.49 ± 0.12

0.49 ± 0.22

<9.57

2.41 ± 0.70

2.23 ± 1.88

2.43 ± 0.77

1.62 ± 0.75

<8.14

<8.93

5.36 ± 1.35

4...

8.39 ± 1.50 x 10^-7

1.26 ± 0.49

1.44 ± 0.17

1.39 ± 0.33

<9.25

7.58 ± 1.24

6.59 ± 4.03

7.96 ± 1.33

3.28 ± 1.14

<7.87

13.43 ± 7.29

10.19 ± 1.82

5...

1.13 ± 0.11 x 10^-6

1.20 ± 0.24

1.00 ± 0.08

0.86 ± 0.15

3.94 ± 2.54

5.70 ± 0.59

5.73 ± 1.77

3.84 ± 0.51

2.50 ± 0.54

1.92 ± 1.59

3.48 ± 2.20

2.91 ± 0.55

6...

2.14 ± 0.60 x 10^-7

1.17 ± 0.96

1.94 ± 0.33

4.54 ± 0.83

24.84 ± 14.96

17.12 ± 2.39

39.42 ± 12.94

15.34 ± 2.38

8.25 ± 2.51

10.17 ± 8.34

32.59 ± 14.92

34.48 ± 4.52

7...

1.17 ± 0.14 x 10^-6

0.95 ± 0.26

0.97 ± 0.09

2.43 ± 0.28

8.23 ± 3.46

7.45 ± 0.75

9.08 ± 2.92

9.29 ± 0.94

6.54 ± 1.04

12.88 ± 4.42

14.30 ± 5.16

24.62 ± 1.89

8...

1.92 ± 0.54 x 10^-7

<0.96

0.82 ± 0.30

0.67 ± 0.42

<16.70

5.42 ± 1.52

<12.10

3.63 ± 1.26

<1.67

<14.22

<15.59

<1.13

9...

2.32 ± 0.18 x 10^-6

1.16 ± 0.18

0.75 ± 0.05

0.80 ± 0.11

2.61 ± 1.49

4.23 ± 0.39

5.14 ± 1.79

3.06 ± 0.37

1.32 ± 0.33

2.67 ± 1.41

6.92 ± 2.50

4.37 ± 0.55

10...

2.12 ± 0.11 x 10^-6

1.51 ± 0.14

0.96 ± 0.04

1.11 ± 0.09

3.87 ± 1.25

4.86 ± 0.29

6.33 ± 1.35

4.79 ± 0.32

1.61 ± 0.24

0.90 ± 0.62

2.48 ± 1.03

3.71 ± 0.35

11...

6.75 ± 0.55 x 10^-7

0.56 ± 0.20

0.61 ± 0.06

0.80 ± 0.12

<1.87

2.94 ± 0.35

1.32 ± 0.95

2.36 ± 0.34

1.22 ± 0.33

<1.59

4.39 ± 2.03

2.03 ± 0.40

12...

1.11 ± 0.17 x 10^-6

1.03 ± 0.33

1.27 ± 0.13

0.95 ± 0.24

7.44 ± 5.55

3.00 ± 0.70

5.67 ± 3.35

6.26 ± 1.07

3.55 ± 1.05

<6.51

6.66 ± 4.89

7.99 ± 1.46

13...

2.57 ± 0.55 x 10^-7

1.01 ± 0.47

1.23 ± 0.18

0.41 ± 0.24

<10.97

3.45 ± 0.80

<7.95

1.64 ± 0.61

1.20 ± 0.78

<9.34

<10.24

1.68 ± 0.92

14...

3.51 ± 0.47 x 10^-7

0.39 ± 0.24

0.85 ± 0.10

1.24 ± 0.23

7.68 ± 3.92

7.16 ± 0.80

10.23 ± 3.65

6.07 ± 0.81

2.05 ± 0.66

<4.10

3.36 ± 2.94

5.20 ± 0.97

15...

1.67 ± 0.15 x 10^-6

1.29 ± 0.21

1.23 ± 0.07

1.89 ± 0.20

11.56 ± 3.55

6.21 ± 0.58

14.06 ± 3.24

6.36 ± 0.61

2.25 ± 0.48

3.00 ± 1.57

18.87 ± 4.62

16.91 ± 1.22

16...

7.98 ± 0.76 x 10^-7

0.91 ± 0.19

1.16 ± 0.07

0.66 ± 0.12

3.70 ± 1.96

4.13 ± 0.49

4.69 ± 2.11

4.71 ± 0.55

2.35 ± 0.52

1.66 ± 1.35

<2.54

4.10 ± 0.63

17...

6.89 ± 1.15 x 10^-7

1.27 ± 0.36

0.45 ± 0.08

1.60 ± 0.33

8.43 ± 4.59

5.13 ± 0.94

1.87 ± 1.59

4.71 ± 0.95

2.69 ± 0.94

<7.19

18.42 ± 8.63

20.11 ± 2.44

18...

3.98 ± 0.50 x 10^-7

1.07 ± 0.26

0.63 ± 0.07

0.32 ± 0.11

<4.88

2.07 ± 0.44

3.18 ± 2.17

1.43 ± 0.40

<0.49

<4.15

<4.55

<0.33

19...

1.82 ± 0.28 x 10^-6

1.62 ± 0.34

1.65 ± 0.13

5.33 ± 0.54

26.52 ± 8.41

18.94 ± 1.66

28.04 ± 7.46

12.65 ± 1.49

1.98 ± 0.78

17.07 ± 6.59

23.80 ± 8.76

38.65 ± 3.12

20...

4.58 ± 1.01 x 10^-7

1.34 ± 0.51

1.23 ± 0.16

1.81 ± 0.44

<14.54

11.01 ± 1.87

16.41 ± 8.48

9.12 ± 1.69

4.77 ± 1.77

<12.38

30.01 ± 14.00

35.70 ± 4.26

21...

1.58 ± 0.14 x 10^-6

0.61 ± 0.13

0.92 ± 0.06

0.83 ± 0.13

5.16 ± 2.46

3.85 ± 0.45

2.00 ± 1.23

1.69 ± 0.32

0.58 ± 0.26

<2.39

<2.62

0.67 ± 0.29

22...

4.05 ± 0.81 x 10^-7

0.67 ± 0.31

0.85 ± 0.13

0.76 ± 0.28

<12.11

3.63 ± 0.98

<8.78

1.70 ± 0.64

1.09 ± 0.74

<10.31

<11.31

<0.84

23...

1.60 ± 0.41 x 10^-7

1.32 ± 0.57

1.98 ± 0.24

4.79 ± 0.83

<18.24

7.58 ± 1.53

<13.21

12.88 ± 2.27

9.55 ± 2.73

42.97 ± 17.03

19.87 ± 13.68

38.67 ± 5.05

24...

6.83 ± 1.27 x 10^-7

0.48 ± 0.25

0.90 ± 0.12

1.36 ± 0.34

17.37 ± 9.37

7.11 ± 1.29

9.27 ± 4.82

6.93 ± 1.19

2.10 ± 0.90

<8.93

<9.79

11.05 ± 2.04

25...

2.51 ± 0.14 x 10^-6

0.96 ± 0.10

0.83 ± 0.03

0.78 ± 0.08

4.37 ± 1.33

4.82 ± 0.32

5.01 ± 1.10

4.12 ± 0.30

1.28 ± 0.23

2.08 ± 0.91

9.55 ± 2.01

6.07 ± 0.46

26...

5.62 ± 0.94 x 10^-7

0.67 ± 0.29

1.26 ± 0.13

2.52 ± 0.42

14.88 ± 7.54

5.60 ± 0.92

9.57 ± 4.99

6.93 ± 1.13

2.21 ± 0.97

10.91 ± 5.83

25.97 ± 10.23

14.98 ± 2.16

27...

8.55 ± 0.85 x 10^-7

0.92 ± 0.19

1.17 ± 0.07

0.70 ± 0.13

6.59 ± 3.07

6.80 ± 0.64

5.48 ± 2.29

3.34 ± 0.49

0.36 ± 0.23

<2.73

<2.99

1.61 ± 0.47

28...

3.94 ± 0.85 x 10^-7

1.66 ± 0.48

1.17 ± 0.16

0.56 ± 0.23

<16.91

4.68 ± 1.13

6.35 ± 4.04

2.84 ± 0.93

<1.69

<14.39

<15.78

<1.14

29...

5.73 ± 1.14 x 10^-7

0.78 ± 0.32

1.46 ± 0.17

1.06 ± 0.32

9.18 ± 7.03

5.26 ± 1.15

4.85 ± 3.06

4.31 ± 1.14

3.09 ± 1.31

<11.53

34.92 ± 14.53

12.05 ± 2.41

30...

4.04 ± 0.76 x 10^-7

0.81 ± 0.34

0.84 ± 0.12

0.56 ± 0.21

<11.54

5.59 ± 1.11

<8.36

4.25 ± 1.09

1.50 ± 0.81

<9.83

<10.77

1.69 ± 0.97

31...

7.28 ± 0.67 x 10^-7

0.74 ± 0.16

0.67 ± 0.05

0.85 ± 0.14

3.67 ± 1.92

4.61 ± 0.52

4.30 ± 1.75

4.09 ± 0.53

1.49 ± 0.42

3.66 ± 1.91

11.57 ± 3.82

8.30 ± 0.90

32...

9.32 ± 0.91 x 10^-7

0.93 ± 0.17

0.87 ± 0.06

0.50 ± 0.10

1.37 ± 0.59

3.81 ± 0.43

1.63 ± 0.95

2.39 ± 0.40

0.36 ± 0.25

<2.93

<3.22

0.88 ± 0.38

33...

3.57 ± 0.54 x 10^-7

0.98 ± 0.29

0.83 ± 0.10

0.79 ± 0.21

7.33 ± 4.37

5.62 ± 0.81

<5.91

2.27 ± 0.63

<0.82

<6.95

<7.62

1.46 ± 0.80

34...

2.05 ± 0.47 x 10^-7

1.26 ± 0.50

1.24 ± 0.18

0.40 ± 0.24

<15.15

3.99 ± 1.19

<10.97

5.90 ± 1.40

2.83 ± 1.40

<12.89

26.75 ± 13.28

34.48 ± 4.32

35...

5.19 ± 0.44 x 10^-6

1.27 ± 0.17

1.05 ± 0.06

0.51 ± 0.09

2.61 ± 1.41

3.77 ± 0.41

4.19 ± 1.78

3.69 ± 0.48

0.84 ± 0.29

<2.18

3.24 ± 1.91

2.14 ± 0.44

36...

3.89 ± 0.22 x 10^-6

0.80 ± 0.09

0.78 ± 0.03

0.29 ± 0.04

3.17 ± 1.11

2.65 ± 0.23

3.55 ± 0.95

1.97 ± 0.21

0.37 ± 0.13

<0.97

0.94 ± 0.73

0.36 ± 0.13

37...

3.09 ± 0.58 x 10^-7

0.90 ± 0.35

1.08 ± 0.14

0.88 ± 0.28

11.88 ± 7.87

3.81 ± 0.94

3.51 ± 2.52

1.76 ± 0.67

<1.08

9.97 ± 6.03

<10.03

2.05 ± 1.05

38...

3.26 ± 0.65 x 10^-7

<0.32

1.06 ± 0.14

1.95 ± 0.42

2.68 ± 1.62

5.15 ± 1.08

8.93 ± 5.46

6.13 ± 1.36

3.97 ± 1.39

18.09 ± 9.27

20.30 ± 10.71

29.00 ± 3.57

39...

2.27 ± 0.10 x 10^-6

1.62 ± 0.11

0.83 ± 0.03

0.97 ± 0.07

2.94 ± 0.85

3.56 ± 0.22

4.79 ± 0.91

4.18 ± 0.25

1.17 ± 0.18

4.61 ± 1.08

7.95 ± 1.55

11.09 ± 0.51

Notes.— The table shows the 11.0–21.8 MeV nucleon^-1 heavy-element intensities relative to C, divided by photospheric abundances (Grevesse & Sauval 1998) for the 39 SEP events in this study; 1 standard deviation of uncertainty is reported. The photospheric ratios used for the normalization are listed in the top row. The first column of the table denotes the event number. The C intensities are reported in units of particles (cm² sr s MeV nucleon^-1)^-1, while all other abundances are given as dimensionless ratios. The uncertainties in each ratio (X/C)/(X/C)_PH are statistical in nature and include only the uncertainty on X in the small SEP event.

Elemental abundances and Spectra for the December 2006 events

From Cohen et al., 2008, AIP Conf. Proc. 1039, pp. 118-123; doi:10.1063/1.2982432

U+S+L O timeline

Hourly oxygen intensities as a function of time from the ACE/ULEIS, STEREO-B/LET, and ACE/SIS instruments. Interplanetary shock passages are marked by vertical lines and the times of X-class flares are indicated at the top. The shaded regions indicate averaging intervals for abundances.

O Fe spectra

Event-averaged oxygen and iron spectra for the two SEP events associated with flares on 12/6 and 12/13.

Abundance rel Reames

Abundances integrated from 12-60 MeV/n normalized to the SEP average composition of Reames [1999] as a function of nuclear charge for the two SEP events.

From Cohen et al., 2008, Proc. ICRC, 1, 95-98.

icrc1150_fig3a

Event integrated spectra for the event starting on day 340 using observations from ULEIS and SIS on ACE and LET on STEREO.

icrc1150_fig3b

Event integrated spectra for the event starting on day 347 using observations from ULEIS and SIS on ACE and LET on STEREO.

icrc1150_fig4

Event integrated abundances (relative to oxygen) obtained over 12-60 MeV/nucleon for the two events. The gradual and impulsive SEP composition (at 5-12 MeV/nucleon) reported by Reames [1999] is also plotted for comparison.

icrc1150_fig6

Event integrated O and Fe fluences (left scale) and the Fe/O abundance ratio (right scale) versus energy for the second December event (starting on day 347).

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