How to forecast storms from space

 作者:魏泪     |      日期:2019-03-06 04:12:14
By Nicola Jones PREDICTING when solar storms will arrive has always been hit-and-miss, but a study of how they interact with the normal solar wind will now let researchers predict an accurate 12-hour storm window. The Sun blows out its regular solar wind at a speed of 250 to 800 kilometres per second, but every so often it belches out a bigger mass of material known as a coronal mass ejection (CME)—often the start of a solar storm. The initial speed of a CME can vary from 20 to 2000 km/s. Because of this widely varying speed,