Coronal holes are regions where the sun's magnetic fields have opened up, allowing solar wind, to escape freely into space, according to spaceweather.com. These areas appear darker in ultraviolet images because the hot, glowing gases typically trapped within the magnetic fields are no longer contained, instead streaming outward into space.
The solar wind escaping from this coronal hole — the diameter of which measures over 62 times that of the diameter of Earth — is moving at speeds of more than 310 miles per second (500 kilometers per second). According to spaceweather.com, this flow is expected to reach Earth by Jan. 31, where it could spark minor (G1) geomagnetic storm conditions. While these storms are not severe, they can intensify auroral displays, creating vibrant northern and southern lights at higher latitudes. For an up-to-date breakdown of geomagnetic activity over the next 3 days, check out NOAA's SWPC 3-day forecast. NOAA classifies geomagnetic storms using a G-scale, which ranks their intensity from G1 (minor) to G5 (extreme). The recent geomagnetic storm watch NOAA issued is rated as a G1.
Auroras occur when solar wind interacts with Earth's magnetic field. The charged particles from the sun collide with gases in the upper atmosphere, such as oxygen and nitrogen, transferring energy to them. This energy is released as light, producing the colorful displays seen in the night sky. The stronger the solar wind, the more dynamic and widespread the auroras can become.
Source: www.space.com
No comments:
Post a Comment