There is a surplus of energy at the tropics and a deficit in polar areas.

• A. Deficit; Surplus
• B. Balance; Imbalance
• C. Excess; Shortfall
• D. Surplus; Deficit

Answer: (D)

Regional energy balance and the way the Earth redistributes heat from the equator toward the poles are being tested here. The tropics receive abundant solar energy, so they have a net energy input, a surplus. That excess must be moved to higher latitudes, mainly by atmospheric circulation and ocean currents. At the same time, polar regions get far less solar energy, and the energy they emit tends to exceed what they receive, creating a deficit. The global system transports heat from the tropics to the poles to balance this difference, leaving a pattern of surplus in the tropics and deficit in the polar regions. That makes the pairing a surplus for the tropics and a deficit for the polar areas.