Are short-term variations in solar oscillation frequencies the signature of a second solar dynamo?

Broomhall, Anne-Marie; Fletcher, Stephen T.; Salabert, David; Basu, Sarbani; Chaplin, William J.; Elsworth, Yvonne; García, Rafael A.; Jiménez, Antonio; New, Roger
Referencia bibliográfica

Journal of Physics: Conference Series, Volume 271, Issue 1, pp. 012025 (2011).

Fecha de publicación:
1
2011
Número de autores
9
Número de autores del IAC
0
Número de citas
11
Número de citas referidas
9
Descripción
In addition to the well-known 11-year solar cycle, the Sun's magnetic activity also shows significant variation on shorter time scales, e.g. between one and two years. We observe a quasi-biennial (2-year) signal in the solar p-mode oscillation frequencies, which are sensitive probes of the solar interior. The signal is visible in Sun-as-a-star data observed by different instruments and here we describe the results obtained using BiSON, GOLF, and VIRGO data. Our results imply that the 2-year signal is susceptible to the influence of the main 11-year solar cycle. However, the source of the signal appears to be separate from that of the 11-year cycle. We speculate as to whether it might be the signature of a second dynamo, located in the region of near-surface rotational shear.