The atmospheric circulation cell centered over each pole.

The atmospheric circulation cell centered over each pole.

• A. Monsoon
• B. Polar Cell
• C. Storm
• D. Precipitation

Answer: (B)

The pattern is a Polar Cell, one of the large-scale atmospheric circulation loops formed by differential heating. At high latitudes, cold air near the surface sinks over the poles, creating a high-pressure region. This surface air moves away from the poles toward lower latitudes as a cool, dense flow. Around roughly 60 degrees latitude, this air meets warmer air and begins to rise, forming a region of ascent. The air that rises then moves aloft toward the poles and sinks again near the poles, closing the loop. This circulation sets up surface easterlies and upper-level flow that helps drive weather patterns in the polar regions. This is different from a monsoon, which is a seasonal reversal of winds tied to land–sea heating; a storm, which is a transient weather system; or precipitation, which is a result of condensation processes, not a circulation cell.

The pattern is a Polar Cell, one of the large-scale atmospheric circulation loops formed by differential heating. At high latitudes, cold air near the surface sinks over the poles, creating a high-pressure region. This surface air moves away from the poles toward lower latitudes as a cool, dense flow. Around roughly 60 degrees latitude, this air meets warmer air and begins to rise, forming a region of ascent. The air that rises then moves aloft toward the poles and sinks again near the poles, closing the loop. This circulation sets up surface easterlies and upper-level flow that helps drive weather patterns in the polar regions.

This is different from a monsoon, which is a seasonal reversal of winds tied to land–sea heating; a storm, which is a transient weather system; or precipitation, which is a result of condensation processes, not a circulation cell.