In which latitude band is there a net gain of solar energy?

• A. Polar regions
• B. Tropical latitudes
• C. Equator region
• D. Mid-latitudes

Answer: (B)

In this idea, the amount of solar energy a latitude gains or loses over a year depends on how directly the sun’s rays strike the surface and how long daylight lasts. In tropical latitudes, the sun is high in the sky for most of the year and day length varies little, so the surface receives a lot of shortwave radiation consistently. That strong and sustained input often exceeds the amount of energy the Earth loses back to space as heat, giving these regions a net gain of solar energy. In polar regions, the sun stays low and daylight is limited for much of the year, so the annual solar input is much smaller and a net loss can occur. Mid-latitudes have pronounced seasonal swings, with periods of gain and loss, making the annual balance less firmly positive. The equator lies within this high-insolation zone, but the tropical belt is the broad band characterized by a sustained net energy gain.