The sun’s 11-year activity cycle is currently approaching solar minimum, and during this time powerful solar flares become scarce and coronal holes become the primary space weather phenomena – this one in particular initiated aurora throughout the polar regions. Coronal holes are areas where the sun’s corona appears darker because the plasma has high-speed streams open to interplanetary space, resulting in a cooler and lower-density area as compared to its surroundings.
The solar corona is so hot that it is best observed with X-ray and extreme-ultraviolet (EUV) cameras. Various elements emit light at specific EUV and X-ray wavelengths depending on their temperature, so by observing in several different wavelengths, a picture of the complete temperature structure of the corona can be made. The GOES-16 SUVI observes the sun in six EUV channels.
Read the Complete NASA Blog Post
This animation from January 29, 2017, shows a large coronal hole in the sun’s southern hemisphere from the Solar Ultraviolet Imager (SUVI) on board NOAA’s new GOES-16 satellite.
SUVI observations of solar flares and solar eruptions will provide an early warning of possible impacts to Earth’s space environment and enable better forecasting of potentially disruptive events on the ground.
This animation captures the sun in the 304 Å wavelength, which observes plasma in the sun’s atmosphere up to a temperature of about 50,000 degrees. When combined with the five other wavelengths from SUVI, observations such as these give solar physicists and space weather forecasters a complete picture of the conditions on the sun that drive space weather.