http://adsabs.harvard.edu/abs/2014AAS...22411203H
http://www.sunspotter.org/
http://blog.sunspotter.org/
"...It is well known that sunspot groups with large, complex magnetic field configurations and strong, sheared polarity separation lines produce the largest flares. While methods for determining certain physical properties, such as total magnetic flux and polarity-separation-line length have been successfully developed for characterizing sunspot groups, a reliable automated method for determining sunspot complexity has never been developed. Since complexity can only be measured in a relative sense, we have used crowd-sourcing methods to allow human observers to compare the complexity of pairs of sunspot groups. This allows a large dataset to be ranked in terms of complexity. Sunspotter.org uses the Zooniverse platform and allows the general public to contribute comparisons using a web-browser interface. The results of this project will help to establish the true relationship between sunspot group complexity and flares, which has been discussed in the solar physics community for many decades..."
