Month: June 2017

Predicting the arrival of coronal mass ejections (CMEs) in near-Earth space is a challenging and important problem, as CMEs are the main driver of severe space weather. The Heliospheric Imager (HI) cameras provide observations of the plasma between the Sun and Earth and can be used to track the evolution of CMEs as they flow away from the Sun, toward Earth. Techniques have been developed to use the HI observations to predict the arrival of CMEs in near-Earth space, potentially allowing the HI observations to be used in a space weather forecasting context. We assess how well these methods work for four CMEs observed by the HI cameras. We found that for these four events the techniques that use HI observations do not perform as well as the standard CME forecasting techniques used by the Space Weather Prediction Center. We try to improve the HI-based predictions by using a citizen science approach to develop a better method of tracking the...

The heliospheric magnetic field (HMF) varies over all observed timescales, from millennia (top), though decades/centuries (middle) to days/hours (bottom). In this study we used sunspot records to reconstruct the global solar wind and heliospheric magnetic field for the first time. We find that during the Maunder minimum, a period of anonymously low sunspot numbers from AD 1650 to 1715, the solar wind speed was approximately half its modern value, with a similar drop in HMF intensity. This is likely to have led to a much larger terrestrial magnetosphere and a much reduced heliosphere.Owens, M. J., M. Lockwood, P. Riley, Global solar wind variations over the last four centuries Scientific Reports, 7, Article number: 41548 (2017) doi:10.1038/srep41548...