  Using magnetic and microwave butterfly diagrams, we compare the behavior of
solar polar regions to show that (i) the polar magnetic field and the microwave
brightness temperature during the solar minimum substantially diminished during
the cycle 23/24 minimum compared to the 22/23 minimum. (ii) The polar microwave
brightness temperature (b) seems to be a good proxy for the underlying magnetic
field strength (B). The analysis indicates a relationship, B = 0.0067Tb - 70,
where B is in G and Tb in K. (iii) Both the brightness temperature and the
magnetic field strength show north-south asymmetry most of the time except for
a short period during the maximum phase. (iv) The rush-to-the-pole phenomenon
observed in the prominence eruption activity seems to be complete in the
northern hemisphere as of March 2012. (v) The decline of the microwave
brightness temperature in the north polar region to the quiet-Sun levels and
the sustained prominence eruption activity poleward of 60oN suggest that solar
maximum conditions have arrived at the northern hemisphere. The southern
hemisphere continues to exhibit conditions corresponding to the rise phase of
solar cycle 24.
