  The polar magnetic field of the Sun is a manifestation of certain aspects of
the dynamo process and is a good precursor for predicting a sunspot cycle
before its onset. Although actual synoptic measurements of this field exist
only from the mid-1970s, it has now been possible to determine its evolution
from the beginning of the twentieth century with the help of various proxies.
The recently developed 3D kinematic dynamo model can study the build-up of the
Sun's polar magnetic field more realistically than the earlier surface flux
transport model.
