SOLAR ACTIVITY
SOLAR OSCILLATIONS
The surface of the sun oscillates in certain modes defined by the number¿of latitudinal and longitudinal modal planes. The sun vibrates in¿multiple modes simultaneously, each mode typically having a different¿amplitude. Observing the amplitudes of the various solar oscillation¿modes is a way to look inside the sun. A commonly observed phenomena is the¿"5-minute" oscillation, but other periods have been observed from 10 to 160¿minutes on the long period scale to about 10 seconds on the short period¿scale. Also observed are so-called "g-mode" oscillations (internal gravity¿waves) generated by turbulent convection below the photosphere.¿These oscillations are the result of internal motions of the sun and their study is known as helioseismology.