4.15: Earth's Seasons

Solstice characterisitcs

Causes hot or cold temperatures Has most or least daylight of year Occurs in June and December Sun is at highest or lowest point in sky North or South Pole is most directed to sun

What happens at an equinox?

a. equal days and nights

What causes seasons?

a. tilt

Northern Hemisphere characteristics

The longest day of the year in the northern hemisphere happens around June 21. This is the summer solstice, and it occurs when the North Pole is most directly tilted toward the sun. Places near the North Pole on the summer solstice have 24 hours of daylight.

summer solstice | northern hemisphere

The summer solstice occurs when the earth is in a position so that the North Pole is tilted most directly toward the sun. occurs on about june 21, it is the longest day of the year.

What causes the seasons of the year?

The tilt and revolution of the earth as it moves around the sun cause the different seasons of the year.

How the height of the sun affects the seasons:

During the summer, the sun is higher in the sky, there are more hours of daylight, and the weather is warmer. During the winter, the sun is the lowest in the sky, the days are shorter, and it's colder. In the spring and fall, the weather conditions are somewhere in between these two extremes.

Why is it warmer in the summer in the northern hemisphere?

b. There are more daylight hours.

Why is winter colder? northern hemisphere

because the tilt of the earth exposes the hemisphere to less direct light during that time.

Why is summer warmer? northern hemisphere

because the tilt of the earth exposes the hemisphere to more direct light during that time.

Which of these will have the coolest temperatures?

c. sun hitting Florida at a 45 degree angle The smaller angle spreads the sun's rays over a larger area, making it cooler.

earths revolution

- Causes the seasons. The temperature of the earth's surface during different seasons is also affected by the passage of the sun's rays through the atmosphere. The atmosphere absorbs some of the sun's energy before it reaches the surface. Also, the sun's rays that hit the earth's surface less directly must go through more atmosphere before they reach the surface. If the earth were not tilted, areas would experience the same level of light intensity year around, and there would be no seasons.

earths rotation

- Causes day and night. As Earth's rotation moves you into night, the sun sets, and now you are on the side of the earth facing away from the sun. Since there is no sun shining at night, the temperatures go down. Even during sunset, when the sun can still be seen but is at an angle to the earth, the temperature will begin to turn cooler.

winter solstice | northern hemisphere

On the winter solstice, the North Pole is in a position so that it is tilted the farthest from the sun. The winter solstice, about December 21, is the shortest day of the year in the northern hemisphere.

Equinox characteristics

Causes moderate temperatures Has equal amounts of day and night Occurs in September and March Noon sun directly over the equator

earth's position and climate

Earth's tilted axis makes the seasons. The sun is hottest when it is directly overhead. The atmosphere absorbs some of the sun's rays.

Southern Hemisphere characteristics

The longest day of the year in the southern hempishere happens aorund December 21. during the summer solstice in the northern hemisphere, the southern hemisphere is experiencing winter, when nights are longest and days are shortest. Some places near the South Pole will be in 24 hours of darkness.

Which of these will have the warmest temperatures? a. sun hitting the equator at a 90 degree angle b. sun hitting the equator at a 45 degree angle c. sun hitting the North Pole at a 45 degree angle

a. sun hitting the equator at a 90 degree angle The sun is mostly overhead, concentrating it on a small area.

fall and spring equinoxes

days and nights are equal length, and the noon sun is directly overhead.

What causes day and night on Earth?

rotation

Does the distance between the sun and earth change?

the distance doesn't change much because earth's orbit is close to a perfect circle. In fact, earth is slightly closer to the sun in January than in July!