Earth Science Exam #1

State a definition of a cloud?

- "A form of condensation best described as visible aggregates of minute droplets of water or tiny crystals of ice."

The concept of latent heat is extremely important to understand cloud formation. Describe latent heat?

- "Hidden Heat." - Latent heat of vaporization causes evaporation, which in turn could become clouds.

What does it mean when we say your temperature is 98.6 degrees Fahrenheit?

- "It is the degree of hotness."

At sea level, how many pounds per square inch does air weigh?

- 14.7 Pounds.

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

- A coastal location where winds blow from ocean onto the shore (California) can have different temperatures than a coastal location where winds blow from the land toward the ocean (New York).

How is wind affected in areas where there are steep pressure gradients?

- A steep pressure gradient cause greater acceleration of a parcel of air than a weak pressure gradient would. - Hence, stronger winds.

What is the subtropical high?

- A zone that is at the center of subsiding dry air. - Encircles globe near 30 degrees latitude. - Great deserts of Australia, Arabi, and Africa exist because of this zone.

What are the basic elements of weather and climate?

- Air Temperature - Humidity - Type and amount of cloudiness - Type and amount of precipitation. - Air pressure - The speed and direction of the wind.

What happens to an object if it absorbs radiant energy?

- An increase in molecular motion, which causes a corresponding increase in temperature.

How are air temperature and saturation related?

- At high temps more moisture is required for saturation, and vice versa.

How can rain droplets grow as it descends through the air?

- At the expense of cloud droplets. - Ice crystals grow large enough to fall as snowflakes, during descent they reach surface temp and melt (The bergeron process).

What are the two outer layers of the atmosphere?

- Mesosphere and Thermosphere.

Why is there abundant precipitation at the equator?

- Because it is a region of ascending moist hot air.

Why do we find the great deserts, Australia, Arabia, North Africa at the subtropical high?

- Because it is a zone that consists of subsiding dry air. It provides the stable dry conditions for theses areas.

Why is latent heat released during the formation of clouds?

- Because it is absorbed by water molecules during evaporation, is used to give them the motion needed to escape the surface of the liquid and become a gas. - "Latent heat of vaporization."

Why does ascending air expand?

- Because latent heat released reduces cooling effect.

Why does the rocket follow a curved path?

- Because of the Coriolis Effect. - The Earth would have rotated 15 degrees during an example of its travel, and it would appear to have cared off its path. It reality it is going strait. Just our perception.

Why is the sun higher in June (summer) than in December (winter)?

- Because of the change in the Earth's orientation.

Why do isotherms shift north and south from season to season?

- Because of the seasonal migration of the Sun's vertical rays.

Why do geostrophic winds blow parallel to the isobars?

- Because the Pressure Gradient Force and the Coriolis Effect are in balance.

Why is air during the Minnesota winter very dry?

- Because the cold temperature results in relative humidity.

A sea breeze (air moves in from ocean to land) during the day. It begins shortly before noon. Why?

- Because the cooler air wants to move to warmer land, the land is heated more intensely during day hours than water is.

Why are high pressure centers associated with fair weather?

- Because these are anticyclones, descending air here is compressed and warmed so cloudy weather and precipitation are unlikely.

Why is solar energy the "ultimate driving force of wind?"

- Because unequal heating of Earth surface generates these pressure differences, solar radiation is the ultimate energy source for most wind.

Why do winds blow inward (cyclone) and counterclockwise around a low pressure area?

- Because winds move from higher pressure to lower pressure and they blow counterclockwise in northern hemisphere.

Why do winds blow outward (anticyclonic) and clockwise around a high pressure area?

- Because winds want to flow from higher pressure to lower pressure.

How are the isobars created? Where are the fastest winds located?

- By lines connecting places of equal air pressure, spacing of isobars indicate the amount of pressure change occurring over a given distance. - Isobars are more closely spaced and the wind speed is faster around the low pressure center than around the high.

How is wind speed measured?

- By speed and direction. - By wind vane or cup anemometer.

How does precipitation form?

- By the bergeron process or the collision-coalescence process.

(Pg 488) What is the percentage of water vapor in the air?

- Can vary from zero to four percent.

Describe the three basic forms of clouds.

- Cirrus: High, White, and Thin. - Cumulus: Normally have a flat base and have the appearance of rising domes or towers. - Stratus: Like sheets or layers that cover much or all of the sky.

Middle Clouds?

- Clouds that appear in the middle range (2000-6000 meters) have the prefix of "alto" as part of their name. - Composed of: Altocumulus and Altostratus.

Clouds of Vertical Development?

- Clouds that have bases in the low height range, but often extend upward into the middle or high altitudes. - Associated with unstable air. - Consist of: Cumulus and Cumulonimbus.

Altocumulus?

- Composed of globular masses that differ from cirrocumulus clouds in that they are larger and denser.

Low Clouds?

- Consists of clouds from 0-2000 meters. Consists of: Nimbostratus, Stratus, and Stratocumulus.

Which area on Earth experiences the highest annual temperature range?

- Continental locations, this is due to latitude.

As air expands it ____________?

- Cools.

How are the following temperature data computed: daily mean, daily range, monthly mean, annual mean, annual range?

- Daily Mean: Taking the average of max and min. - Daily Range: The difference between the max and min. - Monthly Mean: Adding the daily means for each day of the month and dividing by the number of days in the month. - Annual Mean: Average of the 12 monthly means. - Annual Range: Found by finding the difference between the highest and lowest monthly means.

Describe the formation of fog?

- Defined as a cloud with its base at or very near the ground. No physical difference between fog and clouds. - Yet clouds come from rising air and cooling, fog must result from radiation cooling or the movement of air over a cold surface. - In some circumstances fog forms when enough water vapor is added to the air to bring about saturation.

What is the Coriolis effect?

- Direction of things change as a result of Earth's rotation. - Deflect to the right in northern hemisphere, deflect to the left in souther hemisphere.

Around a low pressure system, surface convergence needs to be balanced by __________________________ in order to maintain the low pressure system.

- Divergence.

List the forms of precipitation.

- Mist - Drizzle - Rain - Sleet - Glaze - Rime - Snow - Hail - Graupel.

Explain the principle of the sling psychrometer?

- Dry Bulb thermometer gives the current air temp. - Wet Bulb thermometer is covered with a cloth wick that is dipped in water. - The thermometers are spun until the temp of the wet bulb thermometer stops declining. - The larger the difference b/w readings = lower relative humidity. - The smaller the difference b/w readings = the higher the relative humidity. - If air is saturated, no evaporation will occur, and the two thermometers will have identical readings.

How does the dry adiabatic rate differ from the wet adiabatic rate?

- Dry Rate: The rate of cooling or heating that applies only to unsaturated air. - Wet Rate: Slower rate of cooling caused by addition of latent heat. Applies to air that is rising high enough.

What is the other area of high pressure in global circulation?

- Easterlies.

How do you explain the world pattern of precipitation?

- El nino has most significant impact on the climate in North America during winter, but affects areas around topical pacific in both winter and summer. - La nina has most significant impact on North America in the winter but influences other areas during all season.

True or False: A cloud is water vapor?

- False. - It could consist of water droplets, ice crystals, or both.

How do "lows" move across the United States?

- From west to east.

Our atmosphere is heated from ______________ rather than top down?

- Ground up.

How is an anti-cyclone the opposite of a cyclone in its movement of air?

- Has diverging surface winds and descending air. - Outward and clockwise around a high area, rather than inward and C.C. for a low area.

How does heat move?

- Heat always moves by transferring from warmer to cooler objects. - If objects of different temp. come in contact, the warmer object will become cooler and the cooler object will become warmer until both are at the same temperature.

What is the difference between heat and temperature?

- Heat deals with thermal energy, refers to the quantity of energy present. - Temperature deals with average kinetic energy of a materials atoms or molecules. Temperature refers to the intensity of energy present. "Degree of hotness."

(pg 518) Water changes state at ordinary Earth temperatures. What is required for water to change its state?

- Heat of some form.

How does the upper air and surface air move on an Earth that is heated the most at the equator?

- Heated equatorial air rises until it reaches tropopause, which acts like a lid and deflects air poleward. - Eventually this U.L. airflow reaches poles, sinks, spreads out in all directions and moves back towards equator. - Once there it is reheated and starts journey again.

High Clouds?

- High: Take place above 6000 meters. - Consist of: Cirrus, Cirrostratus, and Cirrocumulus.

What causes wind?

- Horizontal differences in air pressure. - Air flows from areas of higher pressure to areas of lower pressure.

What is humidity? The mixing ratio? How is the relative humidity related to the mixing ratio?

- Humidity is the general term for the amount of water vapor in the air. - Mixing ratio is the mass of water vapor divided by mass of dry air. - Relative humidity on the other hand is airs actual water vapor content divided by around if water vapor required for saturation at that temperature.

Where does a wind vane point?

- Into the wind.

How is wind speed influenced by the Coriolis effect?

- It is not affected.

What is Earth Science? What part will be studied this semester?

- It is the name for all the sciences that collectively see to understand Earth and its neighbors in space. - It includes geology, oceanography, meteorology, and astronomy. - Earth Science is an environmental science that explores many important relationships between people and the natural environment.

What happens to the air that rises from the equator?

- It reaches a certain latitude then sinks back to surface. Create hot and arid conditions.

Quito, Ecuador, is located on the equator and is not a coastal city. It has an average annual temperature of only 13 degrees C (55 degrees F). What is the likely cause for this low average temperature?

- Its elevation, which causes the the temperature to drop.

Why is a land breeze the reverse of a sea breeze? Why does it form?

- Land cools more rapidly than sea at night, so air moves towards water. An offshore flow is created.

Where do isotherms shift most, over land or water? Why?

- Land. Land has a stronger differential heating effect than the one on water, so land experiences higher highs and lower lows.

In either hemisphere, winds move inward (converge) around a _______ pressure system or cyclone.

- Low.

When air pressure is measured in inches, it refers to inches of what?

- Mercury.

What is the primary air pollutant and where does it come from? What is the single greatest polluter in most cities?

- Most significant is chlorofluorocarbons (CFC's). - Can be used as coolants for ac and fridges, cleaning solvents for electric components, and propellants for aerosol sprays.

What are the major components of the atmosphere?

- Nitrogen and oxygen are the most abundant. - The last 1% is mostly argon and tiny quantities of a number of other gases.

Is the Earth heated evenly across its surface? Why or Why not? Hint: Figure 16.11

- No. Solar energy is not evenly distributed across Earth's land-sea surface. - Varies with latitude, time of day, and season of the year.

Will the Big Bang Theory or the Nebular Theory ever become a law? Why or Why not?

- Not necessarily. These two are theories just explain an aspect of how nature worked, not how it works under certain circumstances.

What are the principal absorbing gases in our atmosphere?

- Oxygen and ozone, they are the efficient absorbers with oxygen removes the shorter uv radiation high in atmosphere while the ozone absorbs most of the remaining UV rays in the stratosphere.

How is ozone made in the stratosphere? How is ultraviolet radiation absorbed? Why has ozone been depleted in the stratosphere?

- Oxygen molecules are split into single oxygen atoms when they absorb uv radiation emitted by sun. Ozone is created when single atom of oxygen and molecule of oxygen collide. - It has been depleted by chemicals produced by people, which break up ozone molecules in stratosphere.

What other factors besides latitude influences the temperature of an area?

- Parts of Earth's surface present different heating properties: soil, water, trees, ice, etc. - Biggest contrast comes between land and water. - Land heats more rapidly and to high temps than water, and cools more rapidly and to lower temps.

Texas has just come out of a drought condition. Does soil moisture act as a positive or negative feedback mechanism to contribute to precipitation?

- Postive. - Moisture from Earth's surface evaporates and turns into water vapor in the atmosphere, which in turn condenses into clouds and provides precipitation. That precipitation in turn provides moisture for the Earth's surface and restarts the cycle.

Describe the atmosphere in terms of air pressure?

- Pressure decreases rapidly near Earth's surface and more gradually at greater heights. - This shows that bulk of gases making up atmosphere is very near Earth's surface and that the gases gradually merge with the emptiness of space.

If the temperature remains unchanged and the amount of water vapor in the air decreases, how will relative humidity change?

- Relative humidity would decrease.

List three measures that are used to express humidity?

- Saturation - Mixing Ratio - Dew Point Temp.

Scattering, Reflection, and Absorption?

- Scattering: Produces a larger number of weaker rays that travel in different directions. Energy can be dispersed forward or backward, but more is dispersed forward. - Reflection: The process where light bounces back from an object at the same angle at which it encounters a surface and with the same intensity. - Absorption: When a gas molecule absorbs radiation, the energy is transformed into internal molecular motion, which is detectable as a rise in temperature.

The hotter the radiating body, the ___________ the wavelength of maximum radiation?

- Shorter.

How does cloud cover influence the maximum temperature on an overcast day? How is the nighttime minimum influenced by clouds?

- Since clouds have a high albedo they reflect a big part of sunlight back into space. - Cloud cover reduces the amount of incoming solar radiation, and daytime temps will be lower than if the clouds weren't present and the sky is clear. - At night clouds act as a blanket by absorbing radiation emitted by Earth's surface and reradiates a portion back to space. So nighttime air don't drop as low as they would on a clear night.

What does friction do to winds?

- Slows air down, which in turn alters direction. - Only important within a few km of Earth's surface.

Local winds?

- Small winds produced by a locally generated pressure gradient. - Can be caused by variations in surface composition in the immediate area.

List the factors that cause land and water to heat and cool differently?

- Specific Heat (Water requires a great deal more heat to raise its temp the same amount than does an equal quantity of land). - Land surfaces are opaque, so heat is absorbed only at the surface. Water, being more transparent, allows heat to penetrate to a depth of many meters. - The water that is heated often mixes with water below, thus distributing the heat through an even larger mass. - Evaporation from water bodies is greater than that from land surfaces.

What is the difference between stable and unstable air?

- Stable: Air that resists vertical movement. - Unstable: When air parcel is warmer and hence less dense than surrounding air, it will continue to rise until it reaches altitude where temp of parcel equals surroundings.

Where is the Coriolis effect the strongest? Weakest?

- Strongest at the poles, weaker towards equator where at that point it becomes non existent.

What other factors besides pressure influence the direction of the wind?

- The Coriolis Effect.

How is our atmosphere like the glass in a greenhouse?

- The Earth's surface is continually heated from the atmosphere as well as the Sun. - The gases in the atmosphere allow shorter wavelength solar radiation to enter where it is absorbed by the objects inside, and these objects radiate energy in the form of longer wavelengths. Glass is nearly opaque in this case. - The heat is "trapped.

What is adiabatic temperature change?

- Variations in temperature in air due to compression (or lack there of), rather than rather than an addition or subtraction of heat being applied.

How does an aneroid barometer work?

- The black pointer shows the current air pressure. When the barometer is read, the observer moves the other pointer to coincide with the current air pressure. Later when the barometer is checked, the observer can see whether the air pressure has been rising, falling, or has remained steady. An aneroid barometer has a partially evacuated chamber that changes shape, compressing as air pressure increases and expanding as pressure decreases.

How is the wind flow around different pressure centers different in the Southern Hemisphere? Why?

- The coriolis effect causes winds to be deflected to left.

What are the Westerlies?

- The dominant west to east motion of the atmosphere that characterizes the regions on the poleward side of the subtropic highs.

How does wind speed affect the Coriolis effect?

- The faster the wind speed, the greater the deflection.

What is albedo?

- The fraction of the total radiation that is reflected be a surface. - Earth's is 30 percent as a whole, but different spots can vary.

What is the environmental lapse rate?

- The rate of decreasing temp with increasing height in troposphere.

Why is the solid Earth only one component of Earth itself? What is the solid Earth called? The other spheres? How is Earth a system?

- The solid earth is called the geosphere, and it is just one of four spheres. However, it is the largest. It deals with the Earth's surface features. - The other three are the: Hydrosphere, Atmosphere, and Biosphere. - The Earth is a system because all four spheres work in unison.

Describe convection?

- The transfer of heat by mass movement or circulation within a substance. It takes place in fluids (like liquids in ocean or gases like air) where the atoms and molecules are free to move about.

Describe conduction?

- The transfer of heat through matter by molecular activity. - The energy of molecules are transferred through collision from one molecule to another, with the heat flowing fro the higher temperature to the lower temperature.

The Earth system is powered by two sources of energy, describe the sources and what Earth processes they power?

- The two forms of energy are: The sun and the Earths interior. - The Sun droves external processes in the atmosphere, hydrosphere, and at the Earths surface. Things like Weather, Climate, ocean circulation, and erosional processes. - Heat remaining from when our planet was formed and heat that is continuously generated by radioactive decay power the internal processes that produce: volcanoes, earthquakes, and mountains.

How does a mercury barometer work?

- The weight of the column of mercury is balanced by the pressure exerted on the dish of mercury by the air above. If the pressure drops, the column of mercury falls; if the pressure increases, the column rises.

If you were ascending from the surface of the Earth to the top of the atmosphere, which of the following would be most useful for determining the layer of the atmosphere you were in? A. Doppler radar B. Hygrometer (humidity) C. Weather satellite D. Barometer (air pressure) E. Thermometer. Explain.

- Thermometer, since the four layers are divided based on temperature.

Altostratus?

- These clouds create a uniform white to grayish sheet covering the sky, with the Sun or Moon visible as a bright spot. - Infrequent light snow or drizzle may accompany these clouds.

How do free-moving or fluid objects move in the Northern Hemisphere?

- They are deflected to the right of their path of motion. - Vice versa in the souther hemisphere.

The pressure gradient force is at right angles to the How do the isobars change around the low pressure center?

- They are more closely spaced, and wind is faster.

Why are aerosols important in their influence on weather?

- They can act as surfaces on which water vapor can condense, which is important for formation of clouds and fog. - They can also absorb, reflect, and scatter incoming solar radiation.

Describe the paths taken by incoming solar radiation.

- They can scatter, reflect or be absorbed.

What do isotherm lines represent?

- They connect lines of equal temperature. - They show weather distribution in a way that makes patterns easier to see. - Area between isotherms is labeled, rather than the isotherms themselves.

What roles does water vapor play in our atmosphere?

- This water vapor is the source of all clouds and precipitation. - Absorbs heat given off by Earth as well as solar energy.

Describe radiation?

- Travels out in all directions from its source. - Unlike the other two forms of heat transfer, radiant energy readily travels through the vacuum of space. This, radiation is the heat transfer mechanism by which solar energy reaches our planet.

How big are cloud droplets?

- Typical ones are .02 mm. - Large ones are .05 mm.

How big can raindrops grow?

- Typical ones are 2 mm. - Can grow as big as 5 mm.

Describe the unstable conditions that will produce clouds of vertical development? Include environmental lapse rate in your explanation?

- Unstable air.

The movement of air as it moves into a surface low and then upward causes the development of ________________.

- Unstable conditions and stormy weather.

Cumulonimbus Clouds?

- Vertical Cloud. - Can be a result of cumulus clouds that experience enough upward movement, powerful acceleration, and enough vertical ascent. - Can have an "anvil head."

Cumulus Clouds?

- Vertical Cloud. - Often associated with fair weather, but can drastically grow under the proper circumstances. If circumstances are right, can turn into cumulonimbus cloud.

When air is compressed it _____________?

- Warms.

What are the components of the atmosphere that vary?

- Water Vapor, Aerosols, and Ozone.

Describe a natural disaster that incorporates one or more of Earth's spheres. How did they interact?

- When a volcano erupts, lava from Earth's interior may flow out at the surface and block a nearby valley, which in turn will affect the region's draining system and create lakes. - Or the large quantities of volcanic ash and gases emitted will be blown high into the atmosphere and influence the amount of solar energy that can reach the Earth's surface.

When does saturation of air occur?

- When the relative humidity reaches 100 percent.

How is a steep pressure gradient indicated by isobars?

- When there is spacing this indicates the amount of pressure change occurring over a given distance. - Closely spaced isobars indicate a steep pressure gradient and strong winds.

San Francisco, California does not have temperature extremes. Why?

- Winds that blow onto shore from the ocean have an influence on temp, since it is a windward coastal location. - Wind causes cool summers and mild winters here.

What are the trade winds?

- Winds that create westerlies. - Air that travels equatorward and is deflected by coriolis effect.

Do all objects emit radiation? Do telephones emit radiant energy?

- Yes all objects, at whatever temperature, emit radiant energy. Thus, not only got objects like the Sun but also earth.

Does our atmosphere absorb the long wavelength radiation emitted by Earth?

- Yes, and it heats up.

At what point do we leave the atmosphere and enter outer space?

Thermosphere.