9th Sci.- Ch 17 Assessment

Why are carbon dioxide and water vapor such important components in Earth's atmosphere? What would happen to life forms on Earth if these gases were no longer present in the atmosphere?

Greenhouse gases that absorb heat OR Water vapor is the source of all clouds and precipitation. Both water vapor and carbon dioxide are efficient absorbers of heat in the troposphere. Without these gases most life forms on earth could not exist.

Why are temperature variations greater over dry land than they are over water?

Land heats up faster and cools down faster OR Land heats more rapidly and to higher temperatures than water. Land also cools more rapidly and to lower temperatures than water. Temperature variations, therefore, are considerably greater over land than over water.

Speculate on the changes in global temperatures that might occur if Earth had substantially more land area and less ocean area than it does at present. How might such changes influence the biosphere?

Less water would result in more extreme temperatures. OR Less ocean area would lead to much larger temperature extremes on earth. Many organisms that exist on earth today might not be able to survive such extremes.

Yakutsk is located in Siberia at about 60 degrees north latitude. This Russian city has one of the highest average annual temperature ranges in the world:62.2°C. Explain the reasons for the very high annual temperature range.

Located high latitude and away from water. OR Yakutsk is located at a high latitude and in the center of a large landmass, far from any marine influence

In what ways can geographic position be considered a temperature control?

Near water, change in elevation, or change in latitude. OR A coastal location where prevailing winds blow from the ocean onto the shore experiences considerably different temperatures than does a coastal location where the prevailing winds blow from the land toward the ocean.

Describe how the ozone in the stratosphere forms.

O3, found in the stratosphere, it protects us. OR Oxygen molecules are split into single atoms of oxygen when they absorb ultraviolet radiation emitted by the sun. Ozone is then produced when a single atom of oxygen and a molecule of oxygen collide. This collision must happen in the presence of a third, neutral molecule that acts as a catalyst.

Why do temperatures increase in the stratosphere?

Ozone absorbs some UV from the Sun. OR Temperatures increase in the stratosphere because the atmosphere's ozone is concentrated here.

Describe the two principle motions of Earth.

Rotation = spinning of Earth, day and night, Revolution = moving around the Sun to give a year. OR Rotation: the spinning of Earth about its axis; Revolution: the movement of Earth in its orbit around the sun.

Using the data in the table, determine which types of surfaces have the highest albedos. ALBEDO OF VARIOUS SURFACES Clouds, stratus <meters thick 25-63 150-300 meters thick 45-75 300-600 meters thick 59-84 Average of all types And thickness 50-55 Concrete 17-27 Crops, green 5-25 Forest, green 5-10 Meadows, green 5-25 Ploughed field, moist 14-17 Road, blacktop 5-10 Sand, white 30-60 Snow, fresh-fallen 80-90 Snow, old 45-70 Soil, dark 5-15 Soil, light (or desert) 25-30 Water 8* *Typical albedo value for a water surface. The albedo of a water surface varies greatly depending upon the sun angle. (this chart is used for questions 21 and 22)

Snow, clouds, and white sand

Give an example of how the Earth system might be affected if Earth's axis were perpendicular to the plane of its orbit instead of being tilted 23.5 degrees.

The altitude of the noon sun and the length of day would remain the same at each latitude throughout the year and no seasonal variations would occur.

Select the best description of air.

a mixture

What is a description of atmospheric conditions over a long period of time?

climate

On a map showing temperature distributions, what are the lines connecting points of equal temperature?

isotherms

Which gas is most abundant in clean, dry air?

nitrogen

Earth's atmosphere is thought to have become enriched in which gas about 2.5 billion years ago?

oxygen

Which form of radiation has the longest wavelength?

radio waves

This layer of atmosphere contains ozone that filters UV radiation.

stratosphere

The average kinetic energy of all the atoms and molecules that make up a substance is referred to as ______

temperature

The bottom layer of the atmosphere in which we live is called the _____

troposphere

The two principle absorbers of radiation emitted by Earth's surface are carbon dioxide and ______

water vapor

Describe the three types of heat transfer in the atmosphere.

Convection:transfers heat by mass movement ot circulation(solids) Conduction: heats through matter by molecular activity the energy or molecules is transferred by collision from one to another Radiation: travels through the vaccum of space solar energy reaches earth by radiation OR Conduction: the transfer of heat through matter by molecular activity; Convection: the transfer of heat by mass movement or circulation with a substance; Radiation: travels out in all directions from its source.

Determine the date after which the length of daylight gets progressively longer going south from the equator. Use Figure 8 to explain your answer.

December 21

The illustration on the side shows two ways that radiation bounces off objects. Identify the process shown in each diagram. What clues in the illustration helped you identify these processes?

Diagram A shows refraction, because it bounces off the object and keeps all its energy. Diagram B shows scattering, because it hits the object and scatters, losing some of its energy.

Describe the effects of cloud cover on air temperature.

During the daytime it will be cooler and nighttime it will make it warmer. OR The clouds reflect and absorb solar radiation, so the temperature drops.

Explain why Earth's atmosphere is mainly heated from the ground up.

Earth absorbs UV and heats up OR About 50 percent of the solar energy that strikes the top of the atmosphere reaches Earth's surface and is absorbed. Most of the energy is then radiated skyward.

What causes the position of the noon sun to vary by up to 47 degrees over a year's time?

Earth's tilt, 23.5 tilted towards the sun in summer and 23.5 tilted away from the sun in winter = 47° OR The orientation of the Earth relative to the sun and the constant movement of Earth cause the angle of the noon sun to vary by up to 47 degrees for many locations during the year.

Assume that the average rate of temperature decrease in the troposphere is 6.5°C/km. Using this rate, determine the air temperature at a height of 2 kilometers if the temperature at sea level were 23°C.

10°