An extratropical cyclone forms at the front between which two atmospheric cells?

An extratropical cyclone forms at the front between which two atmospheric cells?

• A. Polar cell and Ferrel cell
• B. Hadley cell and Polar cell
• C. Ferrel cell and Hadley cell
• D. ITCZ and Hadley cell

Answer: (A)

Extratropical cyclones form where there is a strong horizontal temperature gradient in the mid-latitudes, creating a front. This front sits at the boundary between the Polar cell, which moves cold polar air equatorward, and the Ferrel cell, which carries warmer mid-latitude air poleward. The contrasting air masses along this polar front become unstable (baroclinic instability), allowing waves to grow and a low-pressure system to develop, intensify, and organize into a cyclonic storm. The tropical front between the Hadley cell and the Ferrel cell or near the ITCZ lies in the tropics and is a different setting, so the classic mid-latitude extratropical cyclone forms at the polar front between the Polar and Ferrel cells.

Extratropical cyclones form where there is a strong horizontal temperature gradient in the mid-latitudes, creating a front. This front sits at the boundary between the Polar cell, which moves cold polar air equatorward, and the Ferrel cell, which carries warmer mid-latitude air poleward. The contrasting air masses along this polar front become unstable (baroclinic instability), allowing waves to grow and a low-pressure system to develop, intensify, and organize into a cyclonic storm.

The tropical front between the Hadley cell and the Ferrel cell or near the ITCZ lies in the tropics and is a different setting, so the classic mid-latitude extratropical cyclone forms at the polar front between the Polar and Ferrel cells.