Monthly Archives: September 2023

196. Observations of Rossby wave parameter variations during solar cycle 24

Contributed by Mattias Waidele. Posted on September 25, 2023

Equatorial Rossby waves are detected using the HMI’s time-distance subsurface flow fields. It is also found that the power of the Rossby waves show a positive correlation with the sunspot number, while the frequency of the waves shows an anti-correlation with the sunspot number.

195. Cross-Referenced NOAA Active Region List for Multi-Rotation Active Regions, 2011-2019 Now Available

Contributed by Emily Mason. Posted on September 22, 2023

It is well known that many active regions (ARs) last longer than one solar rotation, however, they are often assigned one NOAA AR number for each rotation. This work lists most, if not all, of the ARs that are a same AR but with different AR numbers.

194. Rossby waves and the organization of photospheric magnetic fields

Contributed by Breno Raphaldini. Posted on September 20, 2023

HMI magnetic field synoptic maps are used to evaluate the magnetic field structures’ organization and propagation as a function of time and latitude. It is demonstrated that the organization of longitudinal structures observed on synoptic maps is proportional to the level of activity at given latitudes.