Rudolf Komm

TL;DR: Changes in the rotation of the sun near the base of its convective envelope are detected, including a prominent variation with a period of 1.3 years at low latitudes, which may generate the 22-year cycles of magnetic activity.

TL;DR: It is established, using complementary helioseismic observations over 4 yr from the GONG network and from the MDI instrument on board SOHO, that the banded flows are not merely a near-surface phenomenon: rather, they extend downward at least 60 Mm and thus are evident over a significant fraction of the nearly 200 Mm depth of the solar convection zone.

TL;DR: In this article, a critical review of the existing sunspot models and an overview of numerical methods employed to model wave propagation through model sunspots is provided, along with a helioseismic analysis of the sunspot in Active Region 9787 and address the serious inconsistencies uncovered by Gizon et al.

TL;DR: In this article, the authors analyzed 27 3 month sets of Global Oscillaiton Network Group (GONG) data from the end of cycle 22 and the beginning of cycle 23 and found evidence of significant shifts in the central frequencies and the even a-coefficients of the frequency splittings of the modes.

TL;DR: In this paper, the authors compare frequency-splitting data and resulting inversions about the Sun's internal rotation using contemporaneous helioseismic data from the Global Oscillation Network Group (GONG) and Michelson Doppler Imager (MDI) onboard SOHO.