Question

What is the most likely reason that the air temperature is warmest at the tropical latitudes? A. These latitudes receive the most solar radiation because there are no clouds. B. These latitudes receive the most solar radiation because the sun's angle is high. c. These latitudes receive the least solar radiation because the sun's angle is low. D. These latitudes receive the least solar radiation because of heavy cloud cover.

Short answer

B is the best answer because tropical latitudes receive direct solar radiation when the sun's angle is high.

Step-by-step solution

Analyze the Options Based on Solar Radiation

Examine why solar radiation is crucial for affecting air temperature. The more solar radiation received by an area, the warmer its air temperature is likely to be. Tropical latitudes are known for high temperatures, suggesting they receive more solar radiation.

Evaluate Each Choice

- **Option A:** This suggests no clouds, but cloud cover can vary widely; it's not a definitive reason for high temperatures. - **Option B:** The sun's angle is often high in tropical regions, which means sunlight is more direct, leading to more solar radiation and warmer temperatures. - **Option C:** This is incorrect because tropical latitudes actually receive the most solar radiation, not the least. - **Option D:** Heavy cloud cover would reduce solar radiation, making this option incorrect.

Identify the Logical Reason

Considering the explanations, the most logical reason tropical latitudes are warm is due to receiving the most direct and intense solar radiation, attributed to the high angle of the sun.

Key concepts

Tropical Latitudes

Tropical latitudes are regions of the Earth that lie near the equator, specifically between the Tropic of Cancer and the Tropic of Capricorn. These areas experience a consistent amount of sunlight year-round, which contributes to their warm climate.

In these regions, the sun's path across the sky stays relatively high throughout the year. This ensures that sunlight strikes the Earth's surface more directly compared to other latitudes. More direct sunlight means that these areas receive a greater concentration of solar energy.

The consistent intensity of solar radiation makes tropical latitudes some of the warmest areas on the planet. They do not have the stark seasonal changes in radiation that are experienced by higher latitudes. Instead, they enjoy relatively constant and abundant solar energy, supporting a lush, biodiverse environment.

• High solar radiation.
• Minimal variation in sunlight throughout the year.
• Rich biodiversity supported by warm temperatures.

Air Temperature

Air temperature is a measure of how hot or cold the atmosphere is at a given time and place and is greatly influenced by solar radiation. In tropical latitudes, the air temperature tends to be consistently higher due to greater exposure to solar radiation.

When the sun's rays hit the Earth directly, they heat it efficiently. This energy is absorbed by the Earth's surface and then re-emitted as heat. The air near the surface warms up as a result. Tropical regions benefit from this process more than polar regions, where sunlight arrives at a steep angle, dispersing energy over larger areas.

• Direct solar radiation leads to higher temperatures.
• The Earth's surface absorbs and re-emits heat.
• Tropical climates have relatively stable, high air temperatures.

Sun's Angle

The sun's angle is crucial in determining the intensity of solar radiation any place on Earth receives. Tropical latitudes benefit from the sun being almost overhead at noon for a significant part of the year, meaning the sun's angle is very high.

High angles of sunlight mean that solar radiation covers a smaller surface area, concentrating the energy and thus increasing its effect. This is why tropical areas receive more intense and direct sunlight compared to higher latitudes where the sun's angle is lower. In places with a high sun angle, the likelihood of solar radiation being deflected by the atmosphere is reduced.

• High sun angles result in concentrated solar energy.
• Sunlight strikes the Earth more directly in tropical regions.
• Lower atmospheric deflection in the tropics.