Our sun and its variation in solar activity have a large effect on terrestrial radio communications. NASA’s Solar Dynamics Observatory, the SDO, has been collecting data since launch in early 2010. Since then it has been sending data to dedicated ground station near Las Cruces, New Mexico. While the SDO project is managed at NASA’s Goddard Space Flight Center, scientists study the data at universities all over the world. The Stanford SOLAR Center is just one example.
NASA has compiled a time-lapse movie of the Sun in visible light and extreme UV. The Sun rotates on it’s axis about every 27 days when viewed from the Earth. See Monica Bobra’s Sky & Telescope paper for a longer explanation of the SDO data. Check out this link to watch the sunspots and corona rotate by for the last seven years. It clearly shows why we are near the solar minimum of the current solar cycle.
73,
Fred KJ6OOV
Thumbnail image courtesy of NASA SDO/AIA. https://www.nasa.gov/feature/goddard/sdo-images-of-a-mid-level-solar-flare