4.7 Solar Radiation and Earth's Seasons

Solar radiation is important because it is the main source of energy for the planet. The amount of energy a location receives is based on season and latitude.

During different seasons, we see variations in the length of daylight and angle of the sun. For example, during the summer, the time of the day spent in daylight is greater and the angle of the sun is at a greater angle. This causes more solar radiation to reach that location. The opposite is true during the winter months.

Another important factor in the amount of solar radiation a location gets is its latitude. At the equator, or 0° latitude, solar radiation hits the surface straight on, so they get more solar radiation per unit of area. However, at higher and lower latitudes, the earth is curved, so the same amount of solar radiation is spread over an area.

Seasons are also largely impacted by the earth’s tilt and rotation around the sun. During certain points of rotation around the sun, the northern or southern hemisphere may lean towards or away from the sun, or the might face away or toward the sun.

For example, during summer in the northern hemisphere, the earth is leaning towards the sun. During winter in the northern hemisphere, the hemisphere is leaning away from the sun. Spring and fall happen between these points of earth’s rotation around the sun.

🎥 Watch: AP Environmental Science - Earths Seasons and Climate