Synoptic magnetograms for three successive Carrington rotations (CRs 2152, 2153, and 2154) show some longitudinal patterns of evolving active regions; in each hemisphere the two circled active regions are evolving in such a way that the distance between them is increasing, as roughly depicted by the magenta and aquamarine lines connecting active region centroids in the left three panels (a). The northern hemisphere active region shows prograde propagation in longitude while the southern hemisphere one shows retrograde propagation. (b) The right panels (gray-scale magnetogram images) show images in a Carrington grid and the full disk. What causes such pattern changes and what are the implications for space weather?
A recent publication by Mausumi Dikpati was featured by AAS Nova in November 2020. The AAS Nova website is designed to highlight some of the most interesting recent results being published in AAS journals. Congratulations to Mausumi for her outstanding publication titled: Physics of Magnetohydrodynamic Rossby Waves in the Sun.