Topic: Weather and Climate II: Seasonal Differences

Below is a list of key ideas related to Weather and Climate II: Seasonal Differences. For each key idea, you will find a list of sub-ideas, a list of items, results from our field testing, and a list of student misconceptions. After clicking on a tab, click on it again to close the tab.

The maximum height that the sun reaches in the sky at any place varies over the course of the year, and how it varies depends on how far the place is from the tropical region.

Students are expected to know that:

  1. From any place on earth, the maximum height that the sun reaches in the sky above that place during a day gradually rises and falls during a year. The maximum height of the sun during a day at any place north of the tropical region is highest in late June (beginning of summer) and is lowest in late December (beginning of winter). The maximum height of the sun during a day at any place south of the tropical region is highest in late December (beginning of summer) and is lowest in late June (beginning of winter).
  2. The maximum height of the sun above places north of the tropical region decreases a little each day from late June to late December, and then increases from late December to late June. The maximum height of the sun above places south of the tropical region decreases a little each day from late December to late June and then increases from late June to late December.
  3. The maximum height that the sun reaches during a day is the same at all places that are the same distance from the equator, but it varies for places that are different distances from the equator, such that for any given day, the maximum height of the sun in the sky decreases the farther the place is north or south of the tropical region.
  4. How much the maximum height that the sun reaches during a day varies over a year differs in different places. The maximum height changes very little at the tropical region, and the farther a place is from the tropical region, the more the maximum height that the sun reaches in the sky during a day increases from winter to summer and decreases from summer to winter.
  5. The higher the sun gets in the sky above any given place, the larger the angle is between the sunlight and the surface of the earth, and the more intense the sunlight is when it hits that place.
  6. The greater the intensity of the sunlight, the more energy the sunlight transfers to that place in a given time.
  7. Because the amount of energy sunlight can transfer to a place depends on the maximum height that the sun reaches in the sky above that place, sunlight transfers the most energy (intensity of the sunlight is greatest) during a day at the beginning of summer than during a day at the beginning of winter. The amount of energy sunlight transfers to a place over a day decreases a little bit each day from the beginning of summer to the beginning of winter, and increases a little bit each day from the beginning of winter to the beginning of summer.

 

Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID
Number

Knowledge Being Assessed

Grades
6–8

Grades
9–12

Select This Item for My Item Bank

CL030002

In the northern hemisphere, the maximum height the sun reaches in the sky is greater in March than in January.

43%

45%

CL040002

In the northern hemisphere, the maximum height the sun reaches in the sky is greater in the summer than in the winter.

42%

46%

CL038001

In the northern hemisphere, if the maximum height the sun reaches in the sky is lower throughout the year at one place than at another place, the place where the maximum height the sun reaches is lower is farther north.

36%

46%

CL032002

For a place in the northern hemisphere, the maximum height the sun reaches in the sky changes each day in both January and December.

40%

41%

CL039002

In the southern hemisphere, if the maximum height the sun reaches in the sky is lower throughout the year at one place than at another place, the place where the maximum height of the sun is lower must be farther south.

38%

41%

CL034002

For places in the northern hemisphere and north of the tropical region, the maximum height the sun reaches in the sky is a little greater each day between January and May.

34%

40%

CL033002

For places that are north of the topical region, the maximum height the sun reaches in the sky increases each day for six months and then decreases each day for the next six months.

31%

40%

CL031002

In the northern hemisphere, the maximum height the sun reaches in the sky gets a little higher each day in January.

33%

38%

CL024002

For a place that is located north of the tropical region, the maximum height the sun reaches in the sky is lower for places north of that place.

32%

36%

CL026002

For a place that is located south of the tropical region, the maximum height the sun reaches in the sky is lower for places south of that place.

31%

34%

CL027002

For two places that are north of the tropical region, the maximum height of the sun in the sky is higher for the place that is less far north.

30%

35%

CL035002

For a place that is north of the tropical region, the maximum height the sun reaches in the sky gets a little lower each day in July.

29%

36%

CL025002

For a place that is north of the tropical region, the maximum height that the sun reaches in the sky is lower for all places north of that place.

30%

33%

CL028002

The maximum height the sun reaches in the sky changes as you move toward the north, but not as you move toward the east.

26%

33%

CL038002

For two places in North America, the one where the maximum height the sun reaches in the sky is lower must be farther north.

26%

30%

CL140001

For a place south of the tropical region, the maximum height of the sun in the sky gradually gets a little lower each day in January.

27%

29%

CL029002

For two places that are north of the tropical region, the maximum height of the sun in the sky is lower for the place that is farther north.

23%

24%

Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM003

The maximum height the sun reaches in the sky on any given day is the same everywhere on earth (AAAS Project 2061, n.d.).

23%

22%

CLM004

The highest point the sun reaches in the sky does not change throughout the year (AAAS Project 2061, n.d.).

17%

16%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

The annual rise and fall of air temperature at any place and the differences in the rise and fall in air temperatures between two places are explained by the amount of solar energy that reach those places.

Students are expected to know that:

  1. From late December to late June at places north of the tropical region, both the number of daylight hours and the maximum height of the sun in the sky (intensity of sunlight) gradually increases a little bit each day, which means that the amount of solar energy transferred to those places over the course of each day gradually increases. The gradual increase in solar energy transferred leads to a gradual increase in air temperature from December to June at those places. The same pattern occurs at places south of the tropical region from late June to late December.
  2. From late June to late December at places north of the tropical region, both the number of daylight hours and the maximum height of the sun in the sky (intensity of sunlight) gradually decreases, which means that the amount of solar energy transferred to those places over the course of each day gradually decreases. The decrease in solar  energy leads to a gradual decrease in air temperature from June to December. The same pattern occurs at places south of the equator between late December and late June.
  3. Both the number of daylight hours and maximum height of the sun in the sky (intensity) change more over the course of a year the farther a place is north or south of the tropical region, which means that the amount of solar energy transferred to a place changes more over a year the farther the place is from the tropical region . Because the amount of solar energy transferred to a place influences the air temperature at that place, there is a very small rise and fall in air temperature over the course of a year at the tropical region, and the farther a place is north or south of the tropical region, the larger the rise and fall in air temperature over the course of a year.

Boundaries:

  1. Students do not need to know the pattern of changes in solar energy over a year within the tropical region.

The amount of time any place experiences daylight varies over the course of a year, and the farther a place is from the equator the greater the variation is.

Students are expected to know that:

  1. The amount of time that the sun is visible in the sky above any given place over a day changes over the course of a year. In late June in the northern hemisphere the sun rises above the horizon earlier than any other day and sets later than on any other day such that at any place in the northern hemisphere the sun is above the horizon for the longest period of time for the year. The sun gradually rises above the horizon later and moves below the horizon earlier until late December, when the number of daylight hours gradually starts increasing again until late June. The same pattern, where the longest day is at the beginning of the summer (late December) and the shortest day is at the beginning of the winter (late June), occurs in the southern hemisphere.
  2. The length of day varies different amounts at different places on the surface of the Earth. At the equator, the length of day does not vary over the course of the year. The farther a place is north or south of the equator, the more the length of day increases from winter to summer and decreases from summer to winter.
  3. The length of time during which the sun is in the sky above any given place influences the amount of energy sunlight can transfer to that place. The longer sunlight shines on a place, the more energy it transfers to it over the course of a day.
Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM027

The equator always has the most hours of daylight, and the north pole always has the fewest hours of daylight (AAAS Project 2061, n.d.).

35%

35%

CLM026

The number of hours of daylight on a given day is the same everywhere on earth (AAAS Project 2061, n.d.).

15%

13%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

Temperature variations in fluids such as air and water lead to currents that circulate the fluid, and this circulation transfers thermal energy from place to place in the fluid.

Students are expected to know that:

  1. When a region of a fluid (e.g., air or water) is warmer than the fluid around it, it rises, and when a region is cooler than the fluid around it, it sinks.
  2. If the rising or sinking fluid encounters a boundary that blocks its movement (such as the top or bottom of a container, or the surface of a liquid) the fluid will begin to flow horizontally along the boundary.
  3. The combination of warmer regions of a fluid rising, cooler regions sinking, and movement along boundaries causes circulation of the materials that make up a fluid.
  4. The continuous circulation of the material that makes up the fluid creates a current. The current moves fluid from place to place, and in doing so it transfers thermal energy from place to place within the fluid. The movement of a fluid with a lot of thermal energy increases the temperature of the fluid at the place where it moves and the movement of a fluid with little thermal energy decreases the temperature of the fluid at the place where it moves.

Note: This idea addresses the process of convection in general, so examples used for items testing this idea will not necessarily be specific to the earth system.

Boundaries:

  1. Students are not expected to know how much warmer or colder than the fluid around it a fluid needs to be in order to circulate.
  2. Students are not expected to know that as the fluid moves, energy is also transferred out of the circulating system by conduction and radiation.
  3. Students are not expected to know how density differences cause the circulation of fluids as part of this idea.
Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID
Number

Knowledge Being Assessed

Grades
6–8

Grades
9–12

Select This Item for My Item Bank

CL138001

As a jar of water is warmed from the bottom, the water at the bottom of the jar becomes warmer than the water around it and starts to rise.

50%

58%

CL021002

The rising and falling of warm and cold air causes the circulation of air that causes wind to blow along the surface of the earth.

46%

54%

CL015002

Warm air that is blown across a cool room causes the thermal energy on the other side of the room to increase.

42%

46%

CL002002

As a jar of water is warmed from the bottom, the water at the bottom of the jar becomes warmer than the water above it and starts to rise, and its thermal energy rises with it.

39%

47%

CL137001

When a container of water is warmed over a flame, warmer water at the bottom rises toward the top and the colder water at the top sinks toward the bottom.

42%

42%

CL006002

Air currents form when warm air rises and cold air sinks.

37%

46%

CL010002

When warm air blows into a classroom and the air is the same temperature as the air inside the room, the air coming in will neither rise nor sink because it is the same temperature as the air around it.

38%

46%

CL003002

Air moves from place to place, and its thermal energy moves with it.

37%

43%

CL011002

When a container of water is warmed from the bottom, the warmer water at the bottom of the container rises to the top and colder water at the top sinks toward the bottom of the container.

36%

39%

CL007002

Ocean currents form when warm water rises and cold water sinks.

38%

37%

CL008002

When cold air comes into contact with warmer air around it, the cold air will sink.

35%

39%

CL016002

Warm air around an electric heater will rise toward the ceiling, move toward the walls, and then sink back to the floor.

32%

37%

CL014002

Convection currents can occur in gases and liquids but not in solids.

33%

35%

CL001002

When warm air comes in contact with colder air around it, the warm air rises and its thermal energy rises with it.

34%

35%

Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM037

When air moves, its thermal energy moves separately from the moving air (AAAS Project 2061, n.d.).

48%

42%

CLM034

When water is moving, its thermal energy moves separately from the water (AAAS Project 2061, n.d.).

31%

31%

CLM029

When a container of water is heated from the bottom, the water will not rise until it starts to boil (AAAS Project 2061, n.d.).

31%

27%

CLM041

Convection currents occur in solids (AAAS Project 2061, n.d.).

26%

23%

CLM039

Cold air sinks only if it is a lot colder than the air around it (AAAS Project 2061, n.d.).

26%

22%

CLM036

Warm air always rises regardless of the temperature of the air around it (AAAS Project 2061, n.d.).

26%

21%

CLM040

Cold air has "coldness" that can cool the air around it (AAAS Project 2061, n.d.).

24%

22%

CLM042

Convection currents cannot occur in liquids (AAAS Project 2061, n.d.).

21%

21%

CLM043

Convection currents cannot occur in gases (AAAS Project 2061, n.d.).

19%

21%

CLM038

Ocean currents form only because wind pushes the water, not from the rising and falling of warm and cold water (AAAS Project 2061, n.d.).

18%

21%

CLM030

Moving air does not carry thermal energy (AAAS Project 2061, n.d.).

17%

18%

CLM031

Only very warm air carries thermal energy (AAAS Project 2061, n.d.).

19%

14%

CLM035

Air currents form only because of the rotation of the earth, not because of the rising and sinking of warm and cold air (AAAS Project 2061, n.d.).

15%

11%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

The transfer of thermal energy from one place to another by the movement of air in the atmosphere and water in the oceans increases the air temperature at some places and decreases the air temperature at other places.

Students are expected to know that:

  1. As air and ocean currents move around the earth they influence the air temperature of the places along their path by transferring thermal energy to and from the air as they move. Air and ocean currents can have a lot of thermal energy and, therefore, increase air temperature where they move, and currents can have little thermal energy and, therefore, decrease air temperature where they move.
  2. Because the air at the equator tends to be warmer than the air in surrounding regions, air at the equator tends to rise high into the atmosphere and move toward the north and south. As the air rises upward at the equator, colder air moves along the surface of the earth and replaces the rising warmer air at the equator. Because the air at the poles tends to be colder than the air in surrounding regions, air tends to sink toward the surface of the earth and move toward the equator.
  3. Water also moves around the surface of the earth, and it generally moves along the same path that brings cold water from the poles toward the equator and warm water toward the poles.
  4. The movement of warm air and water away from the equator and of cold air and water away from the poles results in the transport of thermal energy around the surface of the earth.

Boundaries:

  1. Students are not expected to know about circulation patterns of air around the earth away from the equator and poles.
  2. Students are not expected to know about the circulation
  3. Students are not expected to know factors aside from temperature that cause currents to form, such as the humidity of air and the salinity of water.
  4. Students are not expected to know what factors influence the directions that fluids move around the surface of the Earth as part of this idea, such as the Coriolis Effect.
  5. Students are not expected to know why the ocean circulates according to the pattern described, and they are not expected to be able to describe the path of ocean circulation.
  6. Students are not expected to know that the path of ocean circulation has changed in the past.
Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM044

Thermal energy cannot be transferred between air and water (AAAS Project 2061, n.d.).

25%

21%

CLM037

When air moves, its thermal energy moves separately from the moving air (AAAS Project 2061, n.d.).

16%

11%

CLM034

When water is moving, its thermal energy moves separately from the water (AAAS Project 2061, n.d.).

16%

11%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

The air temperature at any place depends on the amount of energy that is transferred to that place by sunlight, the amount of thermal energy transferred to it by currents in the ocean and atmosphere, how high the place is above sea level, and how close it is to a large body of water.

Students are expected to know that:

  1. Air temperature follows a pattern such that places that are the same distance from the equator (where the greatest amount of energy is transferred from the sun to earth over the course of a year) tend to have about the same average daily temperature, and the average daily temperature tends to decrease the farther a place is from the tropical region. Several additional factors can disrupt this pattern, including the transfer of thermal energy by air and ocean currents, how high the place is above sea level, and how close a place is to a large body of water.
  2. The air temperature during a day tends to rise and fall less at places that are close to the ocean than at places at the same latitude that are farther from the ocean. And the average air temperature tends to rise and fall less over the course of a year at places that are close to the ocean than at places at the same latitude that are farther from the ocean.
  3. Currents in the ocean and atmosphere transfer thermal energy so that currents with little thermal energy can make a place cooler than it would be if there were no circulation of air and water, and currents with a lot of thermal energy can make a place warmer than it would otherwise be.
  4. The temperature of air decreases the higher the air is above sea level (with all other factors that influence air temperature being equal) such that the greater the altitude of a given place, the cooler the air is.

The earth’s spherical shape causes differences in the intensity of sunlight and thus the amount of energy from sunlight to be greater at some places than at other places. Sunlight is most intense at the single point where the sun is directly overhead (90° angle to the earth’s surface).

Students are expected to know that:

  1. Because the sun is so far away from the earth, all sunlight that reaches the earth from the sun is in a straight line. And because the earth is spherical in shape, sunlight hits different parts of the earth at different angles.
  2. Because the sun is so far away from the earth, the different distances that sunlight travels to reach different places on the surface of the earth cause no appreciable difference in the intensity of sunlight reaching those places.
  3. Because the earth is spherical in shape, at any given time there is only one place on earth’s surface (the sub-solar point) where light from the sun strikes at a 90° angle and the intensity of sunlight is greater than at any other place. From the perspective of a person at that place, the sun appears to be directly overhead.
  4. Because the earth is spherical in shape, the angle at which sunlight strikes any given place decreases the farther a place is from where the sun is directly overhead. Therefore, from the perspective of a person on earth, the farther the person is from where the sun is directly overhead, the smaller the angle at which sunlight strikes the earth and the lower the intensity of sunlight at that place. For example, for a person at a place that is on the boundary between the sunlit half of the earth and the half of the earth that sunlight cannot reach, the light striking the surface at that place is parallel to the surface (a 0° angle) and the sunlight is the least intense compared to the rest of the sunlit area of the earth.

Note: Because the earth is a sphere but from the perspective at any given place it appears to be flat, in the clarification the angle at which the sunlight strikes the tangent to a place on the surface of the earth will be referred to as the angle at which sunlight strikes a place on the surface of the earth. When referring to the angle that sunlight strikes the surface of the earth, we will always refer to the smaller of two supplementary angles, the one that is less than 90°.

Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID
Number

Knowledge Being Assessed

Grades
6–8

Grades
9–12

Select This Item for My Item Bank

CL074001

For two places at the same latitude, sunlight is more intense at the place where the sun is directly overhead.

45%

44%

CL074002

For two places at the same latitude, sunlight is more intense at the place where the sun is directly overhead.

42%

47%

CL073002

For two places at the same longitude, sunlight is more intense at the place where the sun is directly overhead.

41%

46%

CL079002

For two places at the same latitude, sunlight is less intense at the place where the sun is less directly overhead.

39%

41%

CL077002

For two places at the same longitude, the sun is higher in the sky at the place where the sun is striking the earth at a 90° angle.

32%

36%

CL083001

At all times during a day there is only one point where sunlight is striking the surface of the earth at a 90° angle.

28%

32%

CL071002

Sunlight strikes the earth at a 90° angle at only one place at any given time.

29%

27%

CL081001

27%

30%

CL076002

For two places at the same longitude, sunlight is more intense at the place that is closer to being directly beneath the sun.

27%

25%

CL081002

Sunlight hits different places on the earth's surface at different angles because the earth is spherical.

25%

27%

CL083002

At any time during a day there is only one point on the surface of the earth where sunlight strikes at a 90° angle.

24%

26%

CL084002

Sunlight strikes only one point on the sunlit side of the earth at a 90° angle at any given time.

21%

27%

CL082002

For two places equally close to the place where the sun is directly overhead, the sun will be the same height in the sky at those two places at the same moment in time.

22%

24%

CL080002

The sun is directly overhead at only one place on earth at a single moment.

21%

22%

Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM057

Sunlight can strike more than one place on the surface of the earth at a 90° angle at the same time (AAAS Project 2061, n.d.).

62%

60%

CLM061

Sunlight is always more intense at the equator than at any other place on earth (AAAS Project 2061, n.d.).

36%

34%

CLM062

Sunlight is more intense at some places on the surface of the earth because sunlight travels a shorter distance to get to those places (AAAS, Project 2061).

30%

37%

CLM055

The sun is higher in the sky the farther a place is from where the sun is directly overhead (AAAS Project 2061).

29%

28%

CLM058

Sunlight reaches the earth at different angles at different places because the earth's axis is tilted (AAAS Project 2061).

24%

28%

CLM060

Sunlight reaches the earth at different angles at different places because sunlight does not travel in parallel lines (AAAS Project 2061).

28%

22%

CLM059

Sunlight reaches the earth at different angles at different places because sunlight does not travel in straight lines (AAAS Project 2061).

22%

21%

CLM054

How close a place is to where the sun is directly overhead is not related to the intensity of sunlight at that place (AAAS Project 2061).

20%

23%

CLM056

Sunlight does not strike any point on the surface of the earth at a 90° angle (AAAS Project 2061, n.d.).

13%

15%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

As the earth turns, the intensity of the energy from sunlight striking a place rises and falls over the course of a day. The maximum intensity of the energy from sunlight striking a place is greater the closer the place comes to passing directly beneath the sun.

Students are expected to know that:

  1. As the earth rotates on its axis, a place that is in darkness rotates into sunlight, crosses through the sunlit side of the earth, and then rotates back into darkness.
  2. When any given place rotates into sunlight, the sun at that place appears at the eastern horizon, and the sunlight strikes at an angle that is parallel to the surface of the earth (0° angle). As the earth rotates toward the east, the sun gets higher and higher in the sky and the angle at which sunlight strikes the place gets larger and larger. When the place is directly north or south of the place that is directly under the sun, it is the middle of the day at that place and the sun is as high as it will get in the sky (the closest it will get to 90°). As the earth continues to rotate, the sun at that place appears lower and lower in the sky, and the angle that sunlight strikes that place gets smaller and smaller. Finally the place rotates out of sunlight. At sunset, the sun appears at the horizon and sunlight reaches that place at an angle that is parallel to the earth’s surface (0° angle).
  3. As the earth rotates on its axis, the location where the sunlight is striking the surface of the earth at 90° (sub-solar point) is shifted. All places that pass directly beneath the sun during a given day are the same distance from the equator (are at the same latitude), and they all receive higher intensity sunlight over the course of that day than any other place on the surface of the earth.
  4. The farther a place is north or south of the place that passes directly beneath the sun, the lower the intensity of sunlight that place receives over the day.
Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID
Number

Knowledge Being Assessed

Grades
6–8

Grades
9–12

Select This Item for My Item Bank

CL085002

The intensity of sunlight at a place on the surface of the earth changes over the course of a day because the height of the sun above the horizon at that place changes over the course of the day.

31%

37%

Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM064

The intensity of sunlight at a place changes during the day because the distance sunlight travels to reach that place changes throughout the day (AAAS Project 2061, n.d.).

29%

35%

CLM065

The intensity of sunlight at a place changes during the day because the amount of atmosphere sunlight travels through changes throughout the day (AAAS Project 2061, n.d.).

22%

17%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

The orientation of earth's axis of rotation with respect to the sun changes as the earth moves around the sun.

Students are expected to know that:

  1. The earth moves in a nearly circular path around the sun over the course of one year, approximately 365 days.
  2. The earth’s axis of rotation is tilted about 23.5° relative to a line that is perpendicular to the plane formed by earth’s circular path around the sun.
  3. As the earth moves around the sun and it rotates on its axis, its axis always points to the same place in the sky.
  4. Since the earth’s axis is tilted relative to the plane of its path around the sun and the angle at which it is tilted does not change as the earth moves around the sun over the course of a year, the orientation of the earth with respect to the sun changes gradually and continually over the year.
  5. Changes in the orientation of the earth with respect to the sun can be described by changes in the angle formed by a line between the north pole and the center of the earth and the line from the center of the sun to the center of the earth. This angle continually changes as the earth moves along its path around the sun. The angle is largest on the same day in late December each year, when the north pole is tilted away from the sun (90° + 23.5° = 113.5°) and is smallest on the same day in late June each year, when the north pole is tilted toward the sun (90° - 23.5° = 66.5°).

Changes in the orientation of earth’s axis of rotation with respect to the sun over the course of a year causes the intensity of energy from the sun to be highest in the northern hemisphere when the north pole is tilted toward the sun and highest in the southern hemisphere when the south pole is tilted toward the sun.

Students are expected to know that:

Late June:

  1. On the same day each year in late June, the north pole is tilted 23.5° toward the sun, and the south pole is tilted 23.5° away from the sun. On that date, the sun is directly overhead at the northern border of the tropical region, i.e., the sub-solar point is at 23.5° north latitude, and the sun reaches a maximum angle of 90° along all places that are 23.5° north of the equator. As the earth turns on its axis, every place on the northern border of the tropical region is directly under the sun at some point during that day.
  2. The farther a place is from the northern border of the tropical region in late June, the smaller the maximum angle at which sunlight strikes that place during a day, the lower the intensity of the sunlight at that place over a day, and the less energy that is transferred from the sun to that place over a day.
  3. Because any place at a particular latitude in the northern hemisphere is closer to the northern border of the tropical region than a place at that same latitude in the southern hemisphere (i.e., at an equal distance from the equator), sunlight strikes the place in the northern hemisphere at a larger angle, and therefore transfers more energy to it from the sun than to a place at the same latitude in the southern hemisphere.

Late March and late September:

  1. On the same day each year in late March and late September, the north and south pole are not tilted toward or away from the sun, and the sun passes directly over the equator (i.e., the sub-solar point is at the equator). As the earth turns on its axis, every place on the equator is directly under the sun at some point during that day.
  2. In late March and late September, the maximum angle that sunlight hits the earth at the equator is 90°. Because the earth is a sphere and sunlight travels from the sun to the earth in a straight line, the maximum angle at which sunlight strikes a place on the surface of the earth is smaller the farther a place is from the equator. The smaller the maximum angle at which sunlight strikes a place during a day the lower the intensity of the sunlight at that place over a day, which means that less energy is being transferred from the sun to that place over a day. Therefore, the farther a place is from the equator, the less energy is transferred from the sun to that place over the course of a day in late March and late September.
  3. Because any place in the northern hemisphere has sunlight strike it at the same angle as a place in the southern hemisphere that is the equal distance from the equator, sunlight transfers the same amount of energy to both places.
Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM073

In the middle of July, the place that receives the greatest intensity of sunlight is the equator (AAAS project 2061, n.d.).

32%

35%

CLM070

The sun is directly overhead at the equator in late June (AAAS project 2061, n.d.).

32%

33%

CLM072

The northern and southern hemispheres never receive the same amount of sunlight (AAAS project 2061, n.d.).

24%

23%

CLM071

The total amount of sunlight reaching the northern and southern hemispheres is the same every day of the year (AAAS project 2061, n.d.).

18%

15%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

Changes in the orientation of earth’s axis with respect to the sun over a year causes the length of daytime to be longer in the northern hemisphere when the north pole is tilted toward the sun and longer in the southern hemisphere when the south pole is tilted toward the sun.

Students are expected to know that:

  1. As the earth rotates on its axis, every place on the earth spends some part of the day in sunlight and some part of the day in darkness.
  2. The more time a place on the earth is in sunlight, the more daytime (and less nighttime) that place will have.

Late June:

  1. Because the northern hemisphere is tilted 23.5° toward the sun and the southern hemisphere is tilted 23.5 degrees away from the sun in late June, more of the northern hemisphere is in sunlight than is the southern hemisphere in late June.
  2. In late June, the farther north a place is from the equator, the more time it will be in sunlight and the more hours of daytime it will have. The farther south a place is from the equator, the less time it will be in sunlight and the fewer hours of daytime it will have. Places on the equator spend half of the day in sunlight and half of the day in darkness and therefore experience 12 hours of daytime and 12 hours of nighttime.

Late March and late September:

  1. In late March and late September, the sun is directly over the equator, so half of the northern hemisphere and half of the southern hemisphere are in sunlight at any given time. This means that every place on earth experiences 12 hours of daytime and 12 hours of nighttime.

Late December:

  1. Because the southern hemisphere is tilted 23.5° toward the sun, and the northern hemisphere is tilted 23.5 degrees away from the sun in late December, more of the southern Hemisphere is in sunlight than is the northern hemisphere in late December.
  2. In late December, the farther south a place is from the equator, the more time it will be in sunlight and the more hours of daytime it will have. The farther north a place is from the equator, the less time it will be in sunlight and the fewer hours of daytime it will have. Places on the equator spend half of the day in sunlight and half of the day in darkness and, therefore, experience 12 hours of daytime and 12 hours of nighttime.
Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID
Number

Knowledge Being Assessed

Grades
6–8

Grades
9–12

Select This Item for My Item Bank

CL110002

Of three places in the northern hemisphere that are at the same latitude but different longitudes, when the north pole is pointed toward the sun all three places receive the same number of hours of daylight.

27%

32%

CL135002

On a day when the north pole is not tilted toward or away from the sun, all places receive the same number of hours of daylight but not the same intensity of sunlight over the course of the day.

27%

30%

CL111002

Of two places in the northern hemisphere at the same longitude and different latitudes, the place that is the farthest north will have a longer daytime in May but not in February.

26%

30%

CL112002

During a day in August, of the north pole, the south pole, and the equator, the north pole has the greatest number of hours of daylight.

24%

30%

CL148001

For two places at different latitudes and different longitudes, the place that is farther north of the equator has more hours of daylight in July.

27%

26%

CL109002

Of three places in the northern hemisphere that are at the same longitude but different latitudes, when the north pole is pointed toward the sun the place closest to the north pole receives the greatest number of hours of daylight.

24%

27%

CL113002

During a day when the earth’s axis is not tilted at all toward or away from the sun, all places on earth would have an equal number of hours of daylight on that day.

21%

20%

CL136002

All places on earth have the same number of hours of daylight on September 21, but not on June 21 or August 21.

15%

17%

As the earth moves around the sun over the course of a year, the orientation of earth’s axis with respect to the sun changes and the latitude of the place that is directly beneath the sun changes. This shift causes the intensity of energy from the sun that any place receives to change over the course of a year.

Students are expected to know that:

  1. As the earth moves around the sun over the course of a year, the orientation of earth’s axis relative to the sun changes, which gradually shifts the place on the earth where the sun is directly overhead (the sub-solar point). In late June the sub-solar point is at its northernmost location on the earth’s surface, 23.5° north of the equator (the northern border of the tropical region). From late June to late September it gradually moves toward, over, and then away from the equator until it reaches a point 23.5 degrees south of the equator in late December. Then it moves back toward and past the equator, reaching the equator in late March.
  2. The gradual north-south shift in the position of the sub-solar causes a gradual change in where the sunlight is most intense. Because the intensity of sunlight that reaches a place over a day decreases the farther north or south a place is from the latitude of the sub-solar point on that day, the greatest intensity of sunlight hitting the earth’s surface is in the northern hemisphere in late June and gradually shifts toward the southern hemisphere until late December, when it begins shifting north again.
Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID
Number

Knowledge Being Assessed

Grades
6–8

Grades
9–12

Select This Item for My Item Bank

CL117002

At a given place, the sun is higher in the sky in the middle of the day in summer than in winter because the orientation of the earth’s axis relative to the sun is different in summer than it is in winter.

36%

43%

CL114002

The sun passes directly overhead during the month of May at a place that is a little farther north of the equator than it passed over the day before.

32%

36%

CL116002

The intensity of sunlight striking the surface of the earth is always greater the closer a place is to where the sun passes directly overhead.

30%

36%

CL115002

The place where sunlight strikes the earth’s surface at a 90° angle during the months of May and October is a little farther north each day in May and a little farther south each day in October.

29%

37%

CL120002

The point on the surface of the earth where sunlight is most intense from June of one year until June of the next year shifts from 23.5° north of the equator to 23.5° south of the equator, then back to 23.5° north.

26%

34%

CL117001

At a given place, the sun is higher in the sky in the middle of the day in summer than in winter because that place is closer to where the sun is directly overhead in the summer than it is in the winter.

25%

25%

CL119002

For a place where the sun is directly overhead in the middle of the day in late December, the sun would not pass directly overhead at any time in February.

17%

17%

Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM082

The intensity of sunlight striking the surface of the earth is always greater the closer a place is to the equator (AAAS Project 2061, n.d.).

37%

37%

CLM083

The point on the surface of the earth where sunlight is most intense is always at the equator (AAAS Project 2061, n.d.).

29%

28%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

As the earth moves around the sun over the course of a year, the orientation of earth’s axis with respect to the sun changes. This shift causes the length of daytime and nighttime at a place to change and the amount of energy the place receives from the sun to change over the course of a year.

Students are expected to know that:

  1. As the earth moves around the sun between late December and late June and the angle between the center of the sun, center of the earth, and the north pole gradually becomes smaller, places in the northern hemisphere gradually spend more time each day in sunlight, and places in the southern hemisphere gradually spend less time in sunlight. Between late June and late December as the angle between the center of the sun, center of the earth, and the north pole gradually becomes larger, places in the northern hemisphere gradually spend less time each day in sunlight, and places in the southern hemisphere gradually spend more time in sunlight.
  2. The farther a place is north or south of the equator, the more the length of daytime changes over the course of a year such that places near the north and south poles can experience as much as 24 hours of daytime and and as little as 0 hrs of daytime at different times of the year. At the equator, however, the length of daytime does not change over the course of a year because the equator is a circumference of the earth, so half of it is illuminated at any given time.
  3. The longer sunlight of a given intensity reaches a place on the surface of the earth, the more energy is transferred to that place.
Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM090

No two places on the surface of the earth ever receive the same number of hours of daylight on the same day (AAAS Project 2061, n.d.).

37%

42%

CLM086

The number of hours of daylight a place receives changes over the course of the year because of changes in the how far the earth is from the sun (AAAS Project 2061, n.d.).

28%

37%

CLM088

There is one day each year when every place in the northern hemisphere receives 12 hours of daylight and 12 hours of darkness, and there is another day each year when every place in the southern hemisphere receives 12 hours of daylight and 12 hours of darkness (AAAS Project 2061, n.d.).

31%

29%

CLM087

There is never a day when every place on earth receives 12 hours of daylight and 12 hours of darkness (AAAS Project 2061, n.d.).

26%

27%

CLM085

The number of hours of daylight a place receives changes over the course of a year because of changes in how fast the earth turns on its axis (AAAS Project 2061, n.d.).

27%

22%

CLM074

Places at the same latitude receive different amounts of daylight (AAAS project 2061, n.d.).

20%

19%

CLM089

There is never a time when places near the south pole receive a greater number of hours of daylight than anywhere else on earth (AAAS Project 2061, n.d.).

20%

16%

CLM084

There is never a time when the south pole receives a greater number of hours of daylight than anywhere else on earth (AAAS Project 2061, n.d.).

19%

16%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.

The seasonal changes in air temperature are caused by changes in the intensity of energy from sunlight and changes in the number of hours that energy from sunlight is transferred, both of which are brought about by earth's annual movement around the sun.

Students are expected to know that:

  1. Each day, some amount of energy is transferred to a place on earth by sunlight, and some amount of energy is transferred (radiated) away from that place.
  2. The earth’s movement around the sun over a year causes the intensity of sunlight at a place, how long the sun is shining on that place, and, therefore, the amount of energy that is transferred to that place to gradually increase and decrease over the course of a year.
  3. The amount of energy that is transferred away from a place on the earth into space over a day depends on the temperature of the place on that day and on the amount of cloud cover and elevation of the place.
  4. If the amount of energy that is transferred to a place on a given day is greater than the amount of energy that is transferred away from the place, the total amount of energy at that place increases, and the air temperature increases. If the amount of energy that is transferred to a place on a given day is less than the amount of energy that is transferred away from the place, the total amount of energy at that place decreases, and the air temperature decreases.
  5. During the summer, as the amount of energy transferred to a place begins to decrease, the air temperature at that place will continue to increase as long as the amount of energy transferred to that place is greater than the amount of energy being transferred away from it. Similarly, during the winter, as the amount of energy transferred to a place begins to increase, the air temperature at that place will continue to decrease as long as the amount of energy transferred to the place is smaller than the amount of energy being transferred away from the place. The combination of these two effects causes the annual rise and fall of air temperature at any place to be about a month behind the annual rise and fall in the amount of energy received from the sun at that place.
Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CLM094

When the average temperature at a place changes over the course of the year, it is due only to changes in the amount of energy transferred from the sun to the earth, not to changes in the amount of energy transferred from earth into space (AAAS Project 2061, n.d.).

33%

35%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.