Which statement best describes how axial tilt affects seasons?

Which statement best describes how axial tilt affects seasons?

• A. Amount of sunlight
• B. Magnetic field
• C. Ocean currents
• D. Sunlight duration varies with axial tilt

Answer: (D)

Axial tilt changes how long the Sun is above the horizon and how high the Sun climbs in the sky across the year. Because the axis is tilted, the Sun appears higher in the sky and daylight lasts longer in summer, while in winter the Sun stays lower and the days are shorter. This variation in daylight duration is the primary way seasons differ from month to month. That’s why describing seasons as sunlight duration varying with axial tilt is the best fit. The other ideas—magnetic field or ocean currents—don’t drive the yearly cycle of day length. Saying simply the “amount of sunlight” can be less precise, because what changes most with tilt is when and for how long sunlight is available, not just the total amount of sunlight energy.

Axial tilt changes how long the Sun is above the horizon and how high the Sun climbs in the sky across the year. Because the axis is tilted, the Sun appears higher in the sky and daylight lasts longer in summer, while in winter the Sun stays lower and the days are shorter. This variation in daylight duration is the primary way seasons differ from month to month.

That’s why describing seasons as sunlight duration varying with axial tilt is the best fit. The other ideas—magnetic field or ocean currents—don’t drive the yearly cycle of day length. Saying simply the “amount of sunlight” can be less precise, because what changes most with tilt is when and for how long sunlight is available, not just the total amount of sunlight energy.