X.
The most energetic variety of these phenomena does not occur in regions with box-counting fractal dimension less than 1.25. Monica Bobra and Sebastien Couvidat developed a machine learning algorithm to analyze the world's largest data set of these phenomena, and they are the subject of the HTCS and Heyvaerts-Priest-Rust models. These phenomena generate supra-arcade downflows and Moreton waves. Each of these phenomena is classified with one of five letters: A, B, C, M or (*) X. The Neupert effect is the observed correlation between the hard X-ray flux of these phenomena and the derivative of their soft X-ray flux. The RHESSI mission observes these phenomena, instances of which were responsible for the Carrington and Bastille Day events. For 10 points, name these phenomena that are often followed by coronal mass ejections and release lots of energy from the Sun's atmosphere.
The most energetic variety of these phenomena does not occur in regions with box-counting fractal dimension less than 1.25.
solar  flares