Question

why is the air pressure high in polar areas in boyh the hemispheres

Answer 1

The air pressure is high in the part of the polar areas in the boyh hemisphere is due to the low temperatures.

Then air gets completed the vertical cycle around the polar cell in the part of the each latitudinal hemisphere.

The polar high atmospheric pressure around north and south poles and it is more convergence of improving the air completes the vertical cycle around the polar cell in latitudinal.