What is Winter?
- Grade Level:
- Third Grade-Fifth Grade
- Science and Technology
- Group Size:
- Up to 24
- National/State Standards:
- MT.SCI.K-12.4.5: Students, through the inquiry process, demonstrate knowledge of the composition, structures, processes and interactions of Earth’s systems and other objects in space.
- seasons, winter
OverviewStudents will learn how the movement of the earth around the sun (as well as the tilt, for older groups) causes the winter season. This activity will use group participation, demonstations, diagrams, and a globe.
- List the two main characteristics of winter: cold and dark
- Explain that we get heat and light from the sun
- Explain that the Earth both rotates on its axis and revolves around the sun
- Explain different characteristics for each season
- Explain that all places have winter, but winters in different places are not all the same
As the earth travels around the sun, different regions receive more direct sunlight than others. The tilt of the earth on its axis is responsible for the different seasons in the northern and southern hemispheres. In the summer, when the North Pole is tilted toward the sun, the northern hemisphere gets more direct sunlight and the days are longer than during spring, fall and winter. In winter, the tilt is away from the sun and sunlight strikes the northern hemisphere at a lower angle. Latitude is what determines both the length of the day and the angle of the sun (Waterton/Glacier International Peace Park is pretty far north and straddles the 49th parallel along the Canadian border). The amount of sunlight striking the earth’s surface (solar insolation) and the length of the day are determined by the position of the sun in the sky. The reduced amount of winter sunlight striking the earth due to shorter days and angle of the sun causes colder temperatures. As the land and its air mass cools, surface waters turn to ice and precipitation freezes to cover the land with snow.
At northern latitudes and in mountainous terrain, winter comes early and stays late. At higher elevations the atmosphere is thinner and holds less warmth. Consequently, it’s colder, snow lasts longer, and the length of the growing season is greatly reduced. Elevations in Glacier range from less than 3,200 feet in the Lake McDonald valley to 6,646 at Logan Pass, to more than 10,000 feet on the tallest mountains in the park. In Glacier National Park, the seasons are jokingly referred to as “June, July, August and winter.” There is some truth to this as the high country may be snow-free for only about 3 months of the year. It is not unusual to see visitors skiing at Logan Pass in June and occasionally even into July. Winter lasts a long time throughout most of the park.
Lamp or flashlight
- Discuss the differences between winter, spring, summer, and fall that they notice as the seasons change. Ask students how the weather is different in each season and why these changes happen. What happens to the Earth to make the seasons change?
- Show them the globe and have them all gather in a circle around it. Put an X on the globe near students hometown.
- Place a lamp, flashlight, or other light source in the center of your circle.
- Explain (either by having them actually move or by passing the globe around) that the Earth both rotates on its axis and revolves around the sun.
- For younger children, it is enough to know that the Earth and sun are responsible for the seasons and the way that heat and light hit us throughout the year changes – causing our seasons.
- For older kids, introduce the idea that the Earth is on a tilt and the use of a flashlight may be helpful.
- Pass the Earth around the circle having the students rotate and revolve it and as they come to each season talk about how the light and heat is hitting the earth and what some of the characteristics we have of that season are.
- More details could be added like the tilt of the Earth, the speed of the rotations and revolution, and the distance from the sun.
- Ask students how many times they have been around the sun (in other words, their age). See if they can figure out that it takes a whole year to go around the earth one time. This leads right into talking about the use of the calendar and the months, as well.
Have students draw a picture of the Earth and sun. Labeling with an X the part of the Earth where it would be summer and an O showing the parts of Earth where it would be winter. Write 2-3 sentences describing why we have different seasons in Montana. Also students should answer the question, "What will the weather be like in Montana next season?" giving evidence about the sun and Earth to back up their answer.
This activity will help the students understand that all places have winter, but winters in places like Glacier National Park and northwest Montana are a lot different from places farther south. In Montana, we get a greater degree of darkness and cold than in other places in the world. This is why it is important that our animals and plants have adaptations to survive the winter.
Have students locate the following places on the globe: Santiago, Chile; Belem, Brazil (at the mouth of the Amazon); and Fairbanks, Alaska. Discuss how weather/seasons would be different in these locations throughout the year.