The first part of the presentation on the magnetic cloud of October 18-20, 1995, observed by WIND 175 RE upstream of Earth, characterizes its interplanetary features and the potential capability of the cloud/ejecta to act as a trigger for magnetospheric activity. The cloud, lasting 30 hours, acted as a driver of an interplanetary shock upstream and was being compressed by a solar wind stream overtaking it at its rear, which caused a complex interaction boundary. The front boundary, a tangential discontinuity, was exceedingly abrupt as revealed by plasma and magnetic field changes and extremely low plasma beta existed throughout the magnetic cloud. The cloud was well modeled by a linear force-free field, even though a nearly perpendicular shock was propagating through it. The cloud's axis was lying close to the ecliptic plane. Dramatic changes in estimated quantities, such as the sub-solar magnetopause distance, RMP, VBS, and the OE-parameter, demonstrate the cloud's potential ability to affect the magnetosphere in multiple ways. All such properties of the magnetic cloud will be discussed.
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