Magnetic Clouds

A magnetic cloud is a transient ejection in the solar wind defined by relatively strong magnetic fields, a large and smooth rotation of the magnetic field direction over approximately 0.25AU at 1AU, and a low proton temperature [Burlaga et al., 1981]. Magnetic clouds are ideal objects for solar-terrestrial studies because of their simplicity and their extended intervals of southward and northward magnetic fields [Burlaga et al., 1990].

On-going Research

The figure summarizes the following:

A flux rope magnetic cloud model, in which it was assumed that the internal magnetic tension and compression forces were in balance, was successfully applied to the October 1995 WIND event to obtain the size and orientation of a large local volume of the cloud from observations along only a single path through it; see Burlaga et al., 1996, and Lepping et al., 1997.

The model and related analyses confirmed that the cloud had a dominant magnetic field which acted like a huge magnetosphere departing the Sun, stretched out in the ecliptic plane, and having its own 'bow shock' ('driven' shock).

The cloud's front and rear boundaries and the driven shock were locally analyzed and shown to be strongly related geometrically to the estimated cloud-axis.

The internal 'shock' may be due to a stream ramming into the rear of the cloud, but the orientation of the shock is unexpected.

A magnetic storm occurred in the Earth's magnetosphere due to the passage of the strong southward fields in the early part of the magnetic cloud.

Interval #1 of the First Inter Agency Consultative Group Science Campaign was October 18-21, 1995, which fortuitously encompasses this October 1995 magnetic cloud and related events observed by WIND . Many space science teams have worked on various aspects of this magnetic cloud, its possible solar origin, and its effects on the Earth's magnetosphere. (e.g., see Lepping et al., 1997)

See a means of estimating fit-parameter uncertainties when using the magnetic cloud fitting routine of Lepping et al., 1990. (must download this table as well to run the program)

See a means of performing a transformation from Solar Ecliptic coordinates to a useful magnetic cloud coordinate system used in magnetic cloud studies.

Magnetic Cloud Table 1

MAGNETIC CLOUD BOUNDARY TIMES AS DETERMINED BY MFI DATA

The table consists of estimated start and end times that were estimated by a magnetic field model [Lepping et al., 1990] that assumes that the field within the magnetic cloud is force free, i.e., so that the electrical current and the magnetic field are parallel and proportional in strength everywhere within its volume.

Version Date: 4/28/08

MAGNETIC CLOUD INTERVALS
START TIME					END TIME
Code No.	Year	Month	Day	(DOY)	Hour	Month	Day	(DOY)	Hour	Quality ⁺
1	95	Feb	8	039	5.8	Feb	9	040	0.8	2
2	95	Mar	4	063	10.8	Mar	5	064	3.8	3
2.2	95	Apr	3	093	7.8	Apr	4	094	10.8	2
3	95	Apr	6	096	7.3	Apr	6	096	17.8	2
4	95	May	13	133	10.9	May	13	133	16.4	3
5	95	Aug	22	234	21.3	Aug	23	235	19.3	2
6	95	Oct	18	291	19.8	Oct	20	293	1.3	1
7	95	Dec	16	350	5.3	Dec	16	350	22.3	3
8	96	May	27	148	15.3	May	29	150	7.3	2
9	96	Jul	01	183	17.3	Jul	02	184	10.3	2
10	96	Aug	07	220	12.3	Aug	08	221	10.8	1
11	96	Dec	24	359	2.8	Dec	25	360	11.3	1
12	97	Jan	10	010	5.3	Jan	11	011	2.3	1
13	97	Feb	10	041	3.4	Feb	10	041	18.4	3
14.1	97	Apr	11	101	5.6	Apr	11	101	19.1	2
14.2	97	Apr	21	111	14.5	Apr	23	113	6.5	3
15	97	May	15	135	9.1	May	16	136	1.1	2
16	97	May	16	136	6.1	May	16	136	13.9	3
17	97	Jun	09	160	2.3	Jun	09	160	23.3	2
18	97	Jun	19	170	5.1	Jun	19	170	15.9	3
19	97	Jul	15	196	8.8	Jul	15	196	23.8	3
20	97	Aug	03	215	14.1	Aug	04	216	1.9	3
21	97	Sep	18	261	0.5	Sep	20	263	12.5	3
22	97	Sep	22	265	0.8	Sep	22	265	17.3	2
23	97	Oct	01	274	16.3	Oct	02	275	22.8	2
24	97	Oct	10	283	23.8	Oct	12	285	0.8	1
25	97	Nov	07	311	15.8	Nov	08	312	4.3	2
26	97	Nov	08	312	4.9	Nov	08	312	14.9	2
27	97	Nov	22	326	15.8	Nov	23	327	12.3	3
28	98	Jan	07	007	3.3	Jan	08	008	8.3	1
29	98	Jan	08	008	14.9	Jan	08	008	21.6	3
30	98	Feb	04	035	4.5	Feb	05	036	22.5	2
31	98	Mar	04	063	14.3	Mar	06	065	6.3	1
32	98	May	02	122	12.3	May	03	123	17.3	3
33	98	Jun	02	153	10.6	Jun	02	153	15.9	2
34	98	Jun	24	175	16.8	Jun	25	176	21.8	2
35	98	Aug	20	232	10.3	Aug	21	233	19.3	1
36	98	Sep	25	268	10.3	Sep	26	269	13.3	2
37	98	Oct	19	292	5.1	Oct	19	292	14.6	3
38	98	Nov	08	312	23.8	Nov	10	314	1.3	1
39	99	Feb	18	049	14.3	Feb	19	050	12.3	3
40	99	Apr	16	106	20.3	Apr	17	107	21.3	3
41	99	Aug	09	221	10.8	Aug	10	222	15.8	1
42	99	Sep	21	264	21.1	Sep	22	265	5.1	3
43	00	Feb	12	043	17.1	Feb	13	044	0.6	3
44.1	00	Feb	21	052	9.8	Feb	22	053	13.3	3
44.2	00	Jun	24	176	8.3	Jun	25	177	20.3	3
44.3	00	Jul	01	183	8.8	Jul	02	184	3.3	1
45	00	Jul	15	197	6.8	Jul	15	197	14.3	2
46	00	Jul	15	197	21.1	Jul	16	198	9.9	2
47	00	Jul	28	210	21.1	Jul	29	211	10.1	2
48	00	Aug	01	214	0.1	Aug	01	214	15.9	3
49	00	Aug	12	225	6.1	Aug	13	226	5.1	2
50	00	Sep	18	262	1.9	Sep	18	262	15.1	3
51	00	Oct	03	277	17.1	Oct	04	278	14.1	1
52	00	Oct	13	287	18.4	Oct	14	288	16.9	2
53	00	Oct	28	302	23.3	Oct	30	304	0.3	3
54	00	Nov	06	311	23.1	Nov	07	312	18.1	2
55.1	01	Mar	19	078	23.3	Mar	20	079	18.3	1
55.2	01	Mar	20	079	17.8	Mar	22	081	14.8	3
56	01	Apr	04	094	20.9	Apr	05	095	8.4	1
57	01	Apr	12	102	7.9	Apr	12	102	17.9	2
58	01	Apr	22	112	0.9	Apr	23	113	1.4	2
59	01	Apr	29	119	1.9	Apr	29	119	12.9	2
60	01	May	28	148	11.9	May	29	149	10.4	1
61	01	Jul	10	191	17.3	Jul	12	193	8.8	2
62	01	Oct	31	304	21.3	Nov	02	306	10.3	3
63	01	Nov	24	328	15.8	Nov	25	329	13.3	3
64	02	Mar	19	078	22.9	Mar	20	079	15.4	2
65	02	Mar	24	083	3.8	Mar	25	084	22.8	2
66	02	Apr	18	108	4.3	Apr	19	109	2.3	1
67	02	Apr	20	110	11.8	Apr	21	111	16.8	3
68	02	May	19	139	3.9	May	19	139	23.4	1
69	02	May	23	143	23.4	May	24	144	16.9	3
70	02	Aug	01	213	11.9	Aug	01	213	22.6	3
71	02	Aug	02	214	7.4	Aug	02	214	21.1	2
72.1	02	Sep	03	246	0.3	Sep	03	246	18.8	2
72.2	02	Sep	30	273	22.6	Oct	01	274	11.9	3
73	03	Mar	20	079	11.9	Mar	20	079	22.4	1
74	03	Jun	17	168	17.8	Jun	18	169	8.3	3
75	03	Jul	10	191	19.9	Jul	11	192	8.9	3
76	03	Aug	18	230	11.6	Aug	19	231	4.4	2
77	03	Nov	20	324	10.8	Nov	21	325	2.3	2
78	04	Apr	04	095	2.8	Apr	05	096	14.8	2
79	04	Jul	22	204	15.4	Jul	22	204	23.1	3
80	04	Jul	24	206	12.8	Jul	25	207	13.3	2
81	04	Aug	29	242	18.7	Aug	30	243	20.8	1
82	04	Nov	08	313	3.4	Nov	08	313	16.6	2
83	04	Nov	09	314	20.9	Nov	10	315	3.4	2
84	04	Nov	10	315	3.6	Nov	10	315	11.1	2
85	05	May	15	135	5.7	May	15	135	22.3	2
86	05	May	20	140	7.3	May	21	141	5.3	2
87	05	Jun	12	163	15.6	Jun	13	164	7.1	2
88	05	Jun	15	166	5.8	Jun	16	167	7.8	3
89	05	Jul	17	198	15.3	Jul	18	199	3.8	2
90	05	Oct	31	304	2.9	Oct	31	304	20.4	3
91	05	Dec	31	365	14.8	Jan	01	001	10.8	2
92	06	Feb	05	036	19.1	Feb	06	037	13.1	2
93	06	Apr	13	103	14.8	Apr	13	103	20.8	3
94	06	Apr	13	103	20.6	Apr	14	104	9.9	2
95	06	Aug	30	242	21.1	Aug	31	243	14.9	2
96	06	Sep	30	273	8.6	Sep	30	273	21.6	3
97	06	Dec	14	348	22.8	Dec	15	349	19.8	3
98	07	Mar	24	083	3.1	Mar	24	083	16.9	3
99	07	May	21	141	22.9	May	22	142	13.6	2
100	07	Nov	19	323	23.4	Nov	20	324	12.9	2

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⁺ QUALITY: 1 = EXCELLENT, 2 = GOOD, 3 = POOR

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RESULTS OF AN ANALYSIS COMPARING MODEL FIELDS OF MAGNETIC CLOUDS (FLUX ROPES) ARE PRESENTED: ELLIPTICAL VS CIRCULAR CROSS-SECTION.

AND A DESCRIPTION OF THE BASTILLE DAY SOLAR EVENT IS PRESENTED.

References:

Berdichevsky, D. B., et al. (15 coauthors), Evidence for multiple ejecta: April 7-11, 1997, ISTP Sun-Earth connection event, Geophys. Res. Lett., 25, 2473, 1998.

Berdichevsly, D.B., I.G, Richardson, B.J. Thompson, D.V. Reames, R. MacDowall, S.P. Plunkett, D.J. Michels, M.L. Kaiser, R.P. Lepping, K.W. Ogilvie, R.G. Stone, Examples of fast solar wind transients, their sources and the forecast of possible geomagnetic impact, Berdichevsky, Geof�sica Internacional, 39, issue 1, 5, 2000.

Berdichevsky, D. B., C. J. Farrugia, B.J. Thompson, R. P. Lepping, D. V. Reames, M. L. Kaiser, J. T. Steinberg, S. P. Plunkett, and D. J. Michels, Halo-Coronal Mass Ejections Near the 23rd Solar Minimum: Lift-off, Inner Heliosphere, and In-Situ (1AU) Signatures, Annales Geophysicae, 20,891 - 916, 2002.

Berdichevsky, D. B., C. J. Farrugia, R. P. Lepping, I. G. Richardson, A. B. Galvin, R. Schwenn, D. V. Reames, Ogilvie, and M. L. Kaiser, Solar-Heliospheric-Magnetospheric Observations on March 23 - April 26, 2001: Similarities to Observations in April 1979, eds. M. Velli, R. Bruno, F. Malara, AIP Proceedings of the Solar Wind X, Pisa June 2002 Meeting ISBN 0-7354-0148-9, V679, 758-761, 2003.

Berdichevsky, D. B., R. P. Lepping, and C. J. Farrugia, On Geometric Considerations of the Evolution of Magnetic Flux Ropes, Phys. Rev., E 67, 036405-1 - 8, 2003.

Berdichevsky, D. B., I.Richardson, R. P. Lepping, and S. F. Martin, On the origin and configuration of the March 20, 2003 interplanetary shock and magnetic cloud at 1 AU, J. Geophys. Res., submitted, 2004.

Burlaga, L. F., E. Sittler, F. Mariani, and R. Schwenn, Magnetic loop behind an interplanetary shock: Voyager, Helios and IMP-8 observations, J. Geophys. Res., 86, 6673, 1981.

Burlaga, L. F., R. Lepping, and J. Jones, Global configurations of magnetic cloud, in Physics of Flux Ropes, p.373, edited by C. T. Russell, E. R. Priest and L. C. Lee, AGU Geophysical Monograph 58, American Geophysical Union, Washington D. C., 1990.

Burlaga, L. F., R. P. Lepping, W. H. Mish, K. W. Olgilvie, A. Szabo, and A. J. Lazarus, J. T. Steinberg, A magnetic cloud observed by WIND on October 18-20, 1995, NASA/GSFC Laboratory for Extraterrestrial Physics Internal Document, February 1996.

Burlaga, L. F., R. J. Fitzenreiter, R. P. Lepping, K. W. Ogilvie, A. Szabo, A. J. Lazarus, J. T. Steinberg, G. Gloeckler, R. A. Howard, D. J. Michels, C. J. Farrugia, R. P. Lin, and D. E. Larson, A magnetic cloud containing prominence material: January 1997, J. Geophys. Res., 103, 277-285, 1998.

Collier, M. R., A. Szabo, W. Farrell, J. A. Slavin, R. P. Lepping, R. Fitzenreiter, B. Thompson, D. C. Hamilton, G. Gloeckler, G. Ho, P. Bochsler, D. Larson, and L. Ofman, Reconnection Remnants in the Magnetic Cloud of October 18-19, 1995: A Shock, Monochromatic Wave, Heat Flux Drop Out and Energetic Ion Beam, J. Geophys. Res., 106(A8), 15,985,2001.

Collier, M. R., R. P. Lepping, and D. Berdichevsky, A Statistical Study of Interplanetary Shocks and Pressure Pulses Internal to Magnetic Clouds, J. Geophys. Res., in press, 2005.

Farrugia, C. J., L. A. Janoo, R. B. Torbert, J. M. Quinn, K. W. Ogilvie, R. P. Lepping, R. J. Fitzenreiter, J. T. Steinberg, A. J. Lazarus, R. P. Lin, D. Larson, S. Dasso, F. T. Gratton, Y. Lin, and D. Berdichevsky, A uniform-twist magnetic flux rope in the solar wind, Monograph of the Am. Institute of Phys. (Dec. 18), 1999.

Farrugia C. J., et al. (14 coauthors), in The Solar Wind-Magnetosphere System 3, eds., H. K. Biernat, C. J. Farrugia, and D. F. Vogl, A Multi-Instrument study of the December 1996 magnetic cloud, Proceedings of the International Workshop, Graz, Sept. 23-35, 1998, p. 99, 2000.

Gopalswamy, N., A. Lara, R. P. Lepping, M. L. Kaiser, D. Berdichevsky, and O. C. St Cyr, Interplanetary acceleration of coronal mass ejections, Geophys. Res. Lett., 27, 145, 2000.

Lepping, R. P., J. A. Jones, and L. F. Burlaga, Magnetic field structure of interplanetary magnetic clouds at 1 AU, J. Geophys. Res., 95, 11,957, 1990.

Lepping, R. P., L. F. Burlaga, A. Szabo, K. W. Ogilvie, W. Mish, D. Vassiliadis, A. J. Lazarus, J. T. Steinberg, C. J. Farrugia, J. Janoo, and F. Mariani, The WIND magnetic cloud and events of October 18-20, 1995: Interplanetary properties and as triggers for geomagnetic activity, J. Geophys. Res., 102, 14,049, 1997.

Lepping, R.P. and D. Berdichevsky, Interplanetary magnetic clouds: Sources, properties, modeling, and geomagnetic relationship, Recent Res. Devel. Geophysics, 3, Research Signpost, Trivandrum-8, India, 7 7-96, 2000a.

Lepping, R.P., D. Berdichevsky, A. Szabo, A.J. Lazarus, and B.J. Thompson, Upstream shocks and interplanetary magnetic cloud speed and expansion: Sun, WIND, and earth observations, Space Weather Study Using Multipoint Techniques, L.-H. Lyu, ed. 87-96,- Proceedings of COSPAR Colloquium, September, 2000b, Pergamon Press, New York, NY, 2001.
Upstream shocks and interplanetary magnetic cloud speed and expansion: Sun, WIND, and earth observations.

Lepping, R.P., D. Berdichevsky, Magnetic clouds as intermediary agents between their solar sources and the magnetosphere, Eos, Transactions, American Geophysical Union, vol, 82, No.20, May 15, 2001a.

Lepping, R.P., D.B. Berdichevsky, L.F. Burlaga, A.J. Lazarus, J. Kasper, M.D. Desch, C.-C. Wu, D.V. Reames, H.J. Singer, C.W. Smith and K. Ackerson, The Bastille day magnetic clouds and upstream shocks: near earth interplanetary observations, Solar Phys., in press, 2001b.

Lepping, R.P., D. Berdichevsky, A. Szabo, C. Arqueros, and A.J. Lazarus, Profile of a generic magnetic cloud at 1 AU for the Quiet Solar Phase: WIND Observations, Solar Phys., 212, 425-444, 2003a.

Lepping, R. P., D. Berdichevsky, and T. Ferguson, Estimated Errors in Magnetic Cloud Model Fit-Parameters with Force Free Cylindrically Symmetric Assumptions, J. Geophys. Res., 108, 1356, doi:10.1029/2002JA009657, 2003b.

Lepping, R. P., D. B. Berdichevsky, C.-C. Wu, Sun-Earth electrodynamics: The solar wind connection,Recent Res. Devel. Astrophys., 1:139-171 ISBN: 81-271-0004-8, 2003c.

Lepping et al., ERRATUM (for paper by Lepping, R. P., D. Berdichevsky, and T. Ferguson, entitled Estimated errors in magnetic cloud model fit-parameters with force free cylindrically symmetric assumptions, J. Geophys. Res., 108(A10), 1356, doi10.1029/2002JA009657, 2003) by the same authors, J. Geophys. Res., in press, 2004a.

Lepping, R. P., C.-C. Wu, and D. B. Berdichevsky, Automated Identification of Magnetic Clouds and Cloud-like Regions at 1 AU: Occurrence Rate and Other Properties, Ann. Geophysicae, 23, 2687-2704 (SRef-ID: 1432-0576/ag/2005-23-2687), 2005.

Lepping, R. P., D. B. Berdichevsky, C.-C. Wu, A. Szabo, T. Narock, F. Mariani, A. J. Lazarus, and A. J. Quivers, A Summary of WIND Magnetic Clouds for the Years 1995 - 2003: Model-Fitted Parameters, Associated Errors, and classifications, Annales Geophysicae, 24(no. 1), 215-245, 2006. Sref-ID: 1432-0576/ag/2006-24-215, 2006.

Mulligan, C. T. Russell, B. J. Anderson, D. A. Lohr, D. Rust, B. A. Toth, L. J. Zanetti, M. H. Acuna, R. P. Lepping, and J. T. Gosling, Intercomparison of NEAR and Wind Interplanetary Coronal Mass Ejection Observations, J. Geophys. Res., 104, 28,217, 1999.

Narock, T. W., and R. P. Lepping, Anisotropy of Magnetic Field Fluctuations in an Average Interplanetary Magnetic Cloud at 1 AU, J. Geophys. Res., submitted 2006.

Riley, P., J. A. Linker. Z. Mikic, D. Odstrcil, T. H. Zurbuchen, D. Lario, and R. P. Lepping, Using an MHD Simulation to Interpret the Global context of a Coronal Mass Ejection observed by Two Spacecraft, J. Geophys. Res., 108(A7), 1272, doi:10.1029/2002JA009760, 2003.

Riley, P., J. A. Linker, R. Lionello, Z. Mikic, D. Odstrcil, M. A. Hidalgo, Q. Hu, R. P. Lepping, B. J. Lynch, and A. Rees, Fitting Flux Ropes to a Global MHD Solution: A Comparison of Techniques, J. of Atmospheric and Solar-Terrestrial Phys., Vol. 66, Issue 15-16,p. 1321-1331, 2004.

Shodhan, S., N. U. Crooker, S. W. Kahler, R. J. Fitzenreiter, D. E. Larson, R. P. Lepping, G. L. Siscoe, and J. T. Gosling, Counterstreaming electrons in magnetic clouds, J. Geophys. Res., 105, 27,261, 2000.

Tsurutani, B. T., W. D. Gonzalez, X.-Y. Zhou, R. P. Lepping, and V. Bothmer, Properties of Slow Magnetic Clouds, J. Atmos. Solar Terr. Phys., 66, no. 2 (Jan.), pp 147 - 152 (doi:10.1016/j.jastp.2003.09.007), 2004.

Webb, D. F., R. P. Lepping, L. F. Burlaga, C. E. DeForest, D. E. Larson, S. F. Martin, S. P. Plunkett, and D. M. Rust., The Origin and Development of the May 1997 Magnetic Cloud, J. Geophys. Res., 105, 27,251, 2000.

Wu, C.-C., and R. P. Lepping, The Effects of Magnetic Clouds on the Occurrences of Geomagnetic Storms: The First Four Years of WIND, J. Geophys. Res., 107, Paper no. 0148-0227/02, 2002a.

Wu C.-C.,and R. P. Lepping, The Effect of Solar Wind Velocity on Magnetic Cloud- Associated Magnetic Storm Intensity, J. Geophys. Res., 107, No. A11, 1346, doi:10.1029/2002JA009396, 2002b.

Wu, C.-C., R. P. Lepping, and N. Gopalswamy, Variations of Magnetic Clouds and CMEs with Solar Activity Cycle, Proceedings of International Solar Cycle Studies Symposium 2003: Solar Variability as an Input to the Earth�s Environment, Tatranska Lomnica, Slovakia, June 23-28, pp. 429-432, 2004.

Wu C.-C., and R. P. Lepping, Relationships for Predicting Geomagnetic Storm Intensity, Journal of Atmospheric and Solar-Terrestrial Physics, 67, 283-291, 2005.

Wu C.-C., and R. P. Lepping, Comparison of the Characteristics of Magnetic Clouds and Magnetic Cloud-like Structres for the Events of 1995-2003, Solar Phys., submitted, 2006.

Wu C.-C., and R. P. Lepping, and N. Gopalswamy, Relationships Among Magnetic Clouds, CMES and Geomagnetic Storms, Solar Phys., in press, 2006.

Wu C.-C., and R. P. Lepping, Solar Cycle Effect on Geomagnetic Storms Caused By Interplanetary Magnetic Clouds, Ann. Geophysicae, in press, 2006.

Wu, D. J., J.-K. Chao, and R. P. Lepping, Interaction Between an Interplanetary Magnetic Cloud and the Earth's Magnetosphere: Motions of the Bow Shock, J. Geophys. Res, 105, 12,627-12,638, 2000.

For more references see the WIND MFI Bibliography page.

See Summary of magnetic cloud fit parameters using model of Lepping et al. [1990] - Table 2

See Summary of average magnetic cloud parameters - Table 3

See Summary of Averages for the Years 1995-1998 - Table 3A
See Summary of Averages for the Years 1999-2001 - Table 3B
See Summary of Averages for the Years 2002-2006 - Table 3C

See list of magnetic cloud quality parameters - Table 4

See list of closest approach parameters - Table 5

See uncertainties of magnetic cloud fit parameters - Table 6

See parameter variation measured by σ/mean and σmedian - Table 7A,B

See magnetic cloud-like events from the program described by Lepping et al. [2005] - new Table 8

See refined magnetic cloud boundary times - Table 9

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