Solar g modes?

Abstract

Due to the importance g modes for understanding the solar interior, the search for them has been going on for decades, so far without any definite detections. Mostly the search has been done at low degrees, both for physical reasons and because these modes can be detected by the very stable instruments which observe in integrated sunlight. However, instead of searching for such g modes, I use MDI observations to follow the f-mode and low order p-mode ridges towards lower degrees. It was estimated (Schou, 1998) that at least half a solar cycle of data would be required to detect these modes down to the first avoided crossing with the g modes. The necessary observations are now available and I will make such an attempt. I will also estimate mode parameters such as frequencies, amplitudes and linewidths, the knowledge of which may improve our inferences regarding the deep solar interior and enable better predictions for the amplitude of g modes.