Novel technique developed to trace solar storm

A study led by a Chinese scientist has discovered a novel technique to track solar coronal mass ejections (CMEs), hazardous interplanetary ejections of matter, between the sun and Earth, China's main science body announced on Thursday. The study by Liu Ying, space physicist with the Chinese Academy of Sciences (CAS), and scientists from the United States and Europe, has been published by the U.S. academic periodical Astrophysical Journal, the CAS said. With data from NASA's twin spacecraft, STEREO, Liu and his foreign colleagues developed a novel technique, called geometric triangulation, which can determine the trajectory and velocity of CMEs continuously when they travel in interplanetary space, a CAS statement said. Triangulation means use of two separated points to observe a third, as done in fields such as surveying and navigation. STEREO for the first time gave scientists those needed two "eyes" off the Sun-Earth line, according to the statement. The technique's unique capability enables a detailed study of how CMEs, which are of great danger to life and technology on Earth and in space, propagate through the vast Sun-Earth space, the statement said. It also allows predictions of when a CME will reach Earth and at what velocity, it added. CMEs, or large-scale expulsions of ionized gas and magnetic field from the solar corona, can produce solar cosmic rays hazardous to spacecraft, satellites and astronauts, and disrupt power grids, satellite navigation and mobile phone networks on Earth. With the new technique's assistance, Liu and his colleagues discovered a scenario that seems to generalize the whole Sun-to-Earth propagation of these fast and dangerous phenomena: first an impulsive acceleration, then a rapid deceleration, and finally a nearly constant speed propagation or gradual deceleration. "Once a CME has occurred, we will be able to track it continuously and determine its path and velocity with the triangulation measurements, in much the same way the terrestrial weather forecast works," the statement quoted Liu as saying.