Changing patterns of high pressure are found in both polar regions. (click here) In the north polar region, the Northern Annular Mode is an area of high atmospheric pressure that moves between a location over the North Pole and a ring around the Pole at 45°N latitude. The changing location of the high-pressure zone causes changes in wind patterns and affects weather patterns from year to year such as how cold it will get in North America and Europe during a winter. In the south polar region, the Southern Annular Mode is similar. It involves a zone of high pressure that moves its location between the South Pole and a ring around the pole at 45°S latitude.
The poles are difficult to explain in relation to "normal" atmospheres. The Arctic Ocean is an ocean at sea level, yet, it is very cold, and due to that reason the atmosphere is less thick/elevation/altitude than at the equator. Cold air compacts and the hot air expands, so while most of the air pressure of Earth is fairly consistent, that is not the case at the poles.
The illustration to the left is fairly simple but shows the difference in height/elevation of the troposphere. E stands for equator and S for the South Pole and N for the North Pole. The troposphere definitely is effected by temperature when it comes to it's height over land.
Antarctica has a different dynamic because its "cold" is over land and not sea. All of the tropospheres is not at sea level in Antarctica. There are mountains there.
Add to all these polar dynamics the changing seasons and the position of the sun and the variation of the height of the troposphere can be dynamic. The height is at it's lowest during winter when less sunlight reaches the poles.
It (the troposphere) contains 75% of the atmosphere's mass and 99% of the total mass of water vapour and aerosols. The average height of the troposphere is 18 km (11 mi; 59,000 ft) in the tropics, 17 km (11 mi; 56,000 ft) in the middle latitudes, and 6 km (3.7 mi; 20,000 ft) in the polar regions in winter.
