Module 8

• Direct rays


  The rays of the Sun hit the ground at 90 degrees
• In June, the Northern hemisphere


  Receives more direct rays from the sun
• In December, the Southern hemisphere


  Receives more direct rays from the sun
• There are months of the year when it is cold and months when it is hot. These seasons follow each other regularly and you can tell in advance when it is going to be warm or cold and when it is going to be rainy or not.
• In June, the Northern Hemisphere will receive more direct rays from the sun. Therefore, it is summer in the Northern Hemisphere at this time. While, in December, the North Pole will be pointing away from the Sun, and the Southern Hemisphere will receive more direct rays from the sun. The Northern Hemisphere will then experience a time of cold temperature.
• Direct rays


  Rays of the Sun that hit the ground at 90°. The rays are vertical or perpendicular to the ground.
• When the Sun's rays strike the ground at a high angle


  Each square meter of the ground receives a greater amount of solar energy
• When the Sun's rays come in at an angle


  Each square meter of the ground will receive a lesser amount of solar energy
• The seasons change because the direct rays of the Sun shift from one hemisphere to the other as the Earth goes around the Sun.
• If the Sun is positioned directly overhead or at 90 degrees from the horizon, the incoming insolation strikes the surface of the Earth at right angles and is most intense. If the Sun is at 45 degrees above the horizon, the incoming insolation strikes the Earth's surface at an angle, causing the rays to be spread over a larger surface area reducing the intensity of radiation.
• Activity 1.2: The Angle of Light


  1. Study the figure

  2. Write your answer on a separate sheet of paper

  3. Refer to the rubric below in completing this activity
• If sun is not present in the sky due to a bad weather, use the given pictures below.
• Activity


  1. Try to stand-up under the sun at 12 noon for a minute. What have you observed in your shadow? How intense is the heat of the sun during this time (12 noon)? Write your observations.

  2. Look in your surroundings at 3:00 in the afternoon. What have you noticed with the shadows of the plant outside? How intense is the heat of the sun during this time?

  3. Refer to the scoring rubric below in accomplishing this task.
• When it is summer in southern hemisphere, the tilting of the Earth in the northern hemisphere is towards the sun
• During equinox, the length of day and night is equal
• Seasons


  The changing of weather due to varied amounts of sunlight
• At latitude 23.5° N, the sun can be observed directly overhead during summer solstice
• A person facing his shadow at noon is facing west
• Seasonal changes on Earth

  Primarily caused by the tilt of the Earth's axis as Earth revolves around the Sun
• The sun seems to rise in the east due to the Earth's rotation on its axis
• Very cold climates at the North and South Poles


  Because the polar regions receive low-angle insolation
• During summer, countries in the Northern Hemisphere experience warm temperatures because sunlight then is most intense and of longest duration
• At 12 PM, the sun's rays are represented in the diagram
• On December 21st, the latitude that experiences direct sun rays is 23.5° S
• Equatorial region


  Has the same temperature throughout the year because it always receives sunlight at high angles
• Seasons change because the direct rays of the Sun shift from one hemisphere to the other as the Earth goes around the Sun