Tag Archives: sunspots

34. Bimodal Distribution of Magnetic Fields and Areas of Sunspots

Contributed by Andrey G. Tlatov and Alexei A. Pevtsov. Posted on January 27, 2015

Are all sunspots created equal or are some sunspots formed by a different mechanism than others? High quality observations from the Helioseismic Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) suggest bimodal distribution in properties of sunspots.

31. The Photospheric Size-Flux Distribution and its Relationship with the Small-Scale and Global Components of the Solar Dynamo

Contributed by Andrés Muñoz Jaramillo. Posted on October 31, 2014

Taking advantage of 11 different databases, we use statistical analysis to probe the nature of photospheric magnetic structures. We find evidence of two separate mechanisms at play, and propose that they are directly connected to the global and small-scale components of the solar dynamo.

11. The long-term trend in magnetic fields of sunspot umbrae

Contributed by Fraser Watson. Posted on April 25, 2014

I investigate the possible long term decrease in umbral magnetic field strengths from 1998-2006. Whereas a decrease of 800 Gauss in umbral magnetic fields has been reported between 1998 and 2012, the HMI and MDI data indicate a decrease of only around 300 Gauss. The continuing availability of the excellent HMI data set will allow us to continue to refine this study as solar cycle 24 evolves.