We show, for the first time, an analytical relationship between the intermittency level and the magnetic spectral index in the slow-solar-wind turbulence. Our results supply an observational basis for numerical and theoretical studies of the intermittent turbulence. These results will also help to obtain more information on the contributions of the intermittent structures to the power spectra as well as on the physical nature of the energy cascade taking place in the solar wind.

The geomagnetic and solar effect on Es is studied. The negative correlation between Es and geomagnetic activity at mid-latitude is related to the decreased meteor rate during storm period. The increased Es occurrence in high latitude relates to the changing electric field. The positive correlation between Es and solar activity at high latitude is due to the enhanced IMF in solar maximum. The negative correlation in mid and low latitudes relates to the decreased meteor rate during solar activity.

This paper originated from the lecture I gave as the Hannes Alfvén medalist at the EGU General Assembly in Vienna in spring 2018. The paper reviews various aspects of modern solar wind physics and elucidates the role Alfvén waves play in solar wind acceleration and turbulence, which prevail in the low corona and inner heliosphere. Our understanding of the solar wind has recently made considerable progress based on remote sensing, in situ measurements, kinetic simulation and fluid modeling.