Substorm probabilities are best predicted from solar wind speed

Newell, P. T., K. Liou, J. W. Gjerloev, T. Sotirelis, S. Wing, E. J. Mitchell (2016), Substorm probabilities are best predicted from solar wind speed, J. Atmospheric and Solar-Terrestrial Physics, doi.org/10.1016/j.jastp.2016.04.019 (pdf)