Deep Ghuge, Debesh Bhattacharjee, Prasad Subramanian
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引用次数: 0
Abstract
Solar coronal mass ejections (CMEs) directed at the Earth often drive large geomagnetic storms. Here, we use velocity, magnetic field, and proton density data from 152 CMEs that were sampled in situ at 1 AU by the Wind spacecraft. We Fourier analyze fluctuations of these quantities in the quiescent pre-CME solar wind, sheath, and magnetic cloud. We quantify the extent by which the power in turbulent (magnetic field, velocity, and density) fluctuations in the sheath exceeds that in the solar wind background and in the magnetic cloud. For instance, the mean value of the power per unit volume in magnetic field fluctuations in the sheath is 76.7 times that in the solar wind background, while the mean value of the power per unit mass in velocity fluctuations in the sheath is 9 times that in the magnetic cloud. Our detailed results show that the turbulent fluctuation power is a useful discriminator between the ambient solar wind background, sheaths, and magnetic clouds and can serve as an input for space weather prediction.
期刊介绍：
Solar Physics was founded in 1967 and is the principal journal for the publication of the results of fundamental research on the Sun. The journal treats all aspects of solar physics, ranging from the internal structure of the Sun and its evolution to the outer corona and solar wind in interplanetary space. Papers on solar-terrestrial physics and on stellar research are also published when their results have a direct bearing on our understanding of the Sun.
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