Secular variations in geomagnetic dipole and non-dipole components: Constrains on the earth's interior process

The correlation function rho of different components of geomagnetic field shows that rho of dipole part keeps nearly unchanged from 1905-1970y, drops a little from 1970-1985y, then goes up from 1985-1995y. While the rho of non-dipole components, which has three wave crests (1915y, 1945y, and 1980y) and two troughs (1935y and 1965y), changes with period about 30y. Compared the variations in rho and the time rate of change of length of day ((Lambda) over dot) , we put forward: (1) the periodical change of geomagnetic non-dipole is relate to the core-mantle coupling, while the dipole component is controlled by the process of the deeper outer-core; (2) the fluid motion of upper outer-core changes periodically with the same period of rho.