Magnetic Clouds Observed at 1 Au During the Period 2000–2003

摘要

In this work we have performed a systematic study of all the magnetic clouds identified in the time interval 2000–2003. The study shows that the non force-free model of Hidalgo is a good approximation to the magnetic topology of the MCs in the interplanetary medium. This conclusion is reached based on the good fits obtained with the model for most of the clouds, in spite of the variety of profiles found in the magnetic field strength and in every of its components. The model incorporates the distortion and expansion of the cross-section of the MCs. We have compared, when available, the results obtained with those in literature. The unique published global study of the MCs at the same time interval has been provided by Lepping using the circular cross-section model of Burlaga, and the results are available in his web page. From all the parameters he obtained, only the longitude, φ, the latitude, θ, and the distance of maximum approach of the spacecraft to the cloud axis, y 0, may be compared with those obtained by Hidalgo's model. As we show, the main discrepancy between both models refers to the longitude values. Concerning the comparison with other models of literature, only the Bastille day and October 2003 magnetic clouds have been studied by other authors.