A magnetic cloud observed by WIND
on October 18 - 20, 1995

L. F. Burlaga, R. P. Lepping, W. Mish, K. W. Ogilvie, A. Szabo
Laboratory for Extraterrestrial Physics, NASA/Goddard Spaceflight Center, Greenbelt, MD

A. J. Lazarus, J. T. Steinberg, Center for Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139

Table Of Contents

* Acknowledgments

M. Acuna, the ISTP Project Scientist, deserves special thanks for his role in this complex project. The arrival of the event which we have identified as a magnetic cloud was communicated to one of us (WHM) in near real time by R. Zwickl at NOAA/ERL. We thank J. Jones for running the fitting program for the magnetic cloud, and D. Berdichevsky for providing some of the data in a useful form, and M. Peredo for helpful comments on the manuscript. The work at MIT was supported in part by NASA/GSFC under grant NAG 5-2839.

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Figure Captions

Figure 1. Magnetic field and plasma proton observations of the magnetic cloud and surrounding flows measured by WIND 1275 RE upstream of the earth from October 18 (calendar day 291) through October 20 (day 293) (see text). The magnetic field is in GSM coordinates.

Figure 2. A sketch of the geometry of a magnetic cloud and the field lines in the magnetic clouds, which are helices viewed here in projection. The figure, drawn by A. Burlaga, is reproduced from Burlaga et al. [1990].

Figure 3. The dots show the magnetic field observations: the X, Y, Z components are in the top three panels, and the magnetic field strength and direction are shown in the bottom three panels. The curve is a fit of the data between the vertical lines to the Lundquist solution for a constant-alpha, force-free, static, cylindrical magnetic cloud.