Geology 101 Exam 2

Front 1

Weather and climate are expressed in terms of the same basic ______

The most important elements are _____

Back 1

Elements

(1) air temperature, (2) humidity, (3) type and amount of cloudiness, (4) type and amount of precipitation, (5) air pressure, and (6) the speed and direction of the wind.

Front 2

What is air?

Back 2

a mixture of many discrete gases, each with its own physical propertie

Front 3

Which two gases mostly make up 99% of air? The other 1%?

Back 3

nitrogen and oxygen—make up 99 percent of the volume of clean, dry air. 1% is argon and other gases

Front 4

About _____ % of additional c02 from fossil fuels remains in the air

Back 4

45%

Front 5

Estimates project that by sometime in the second half of the twenty-first century, CO2 levels will be ____

Back 5

twice as high as the pre-industrial level.

Front 6

Humidity is a reference to __________

Back 6

water vapor in the air.

Front 7

Water vapor is the source of all _______

Back 7

clouds and precipitation

Front 8

When water changes from one state to another it absorbs or releases heat. This energy is termed _______

Back 8

latent heat

Front 9

water vapor in the atmosphere transports _______ from one region to another

Back 9

latent heat

Front 10

tiny microscopic solid and liquid particles in the atmosphere are called _________

Back 10

aerosols

Front 11

Aerosols are significant because they act as surfaces on which ________________

Back 11

water vapor can condense, an important function in the formation of clouds and fog.

Front 12

Aersols can _______________ solar radiation

Back 12

absorb, reflect, and scatter

Front 13

the varied hues of red and orange at sunrise and sunset can be contributed to ______

Back 13

aerosols

Front 14

Ozone is a ________

Back 14

form of oxygen that combines three oxygen atoms into each molecule (O3)

Front 15

Ozone is concentrated in the ______ its distribution is not ________

Back 15

stratosphere, uniform

Front 16

In the stratosphere, ozone is created when __________

Back 16

oxygen molecules (O2) are split into single atoms of oxygen (O) when they absorb ultraviolet radiation emitted by the Sun. Ozone is then created when a single atom of oxygen (O) and a molecule of oxygen (O2) collide.

Front 17

Ozone absorbs _________

Back 17

UV radiation from the Sun.

Front 18

Ozone is regarded as a pollutants when produced ______

Back 18

at ground level

Front 19

Photochemical smog results from when _______

Back 19

strong sunlight triggers reactions among pollutants from car exhaust and industrial sources.

Front 20

chlorofluorocarbons (CFCs) are known to ___

Back 20

deplete ozone

Front 21

CFCs reach the upper atmosphere because they are _________

Back 21

inert (that is, not chemically active) in the lower atmosphere

Front 22

When CFCs reach the upper atmosphere sunlight ______. The ______ released this way _________

Back 22

separates the chemicals into their constituent atoms.

chlorine atoms, break up some of the ozone molecules.

Front 23

In addition to skin cancer, UV radiation also can impair the _________ as well as promote _______

Back 23

human immune system, cataracts

Front 24

The ______ protocol was developed to combat the use of CFCs

Back 24

Montreal Protocol

Front 25

CFCs are expected to remain active in the atmosphere until between __________

Back 25

2060 and 2075

Front 26

The rate of pressure decrease with increase in altitude is not constant. Pressure ___________ near Earth’s surface and ________ at greater heights.

Back 26

decreases rapidly, more gradually

Front 27

One half of the atmosphere lies below an altitude of _____

Back 27

3.5 miles

Front 28

At about 10 miles, ______ percent of the atmosphere has been traversed

Back 28

90%

Front 29

We divide the atmosphere vertically into _____ on the basis of __________

Back 29

four layers, temperature

Front 30

The lowest layer of the atmosphere is the ______

Back 30

Troposphere

Front 31

Essentially all important weather phenomenon occurs in the _____

Back 31

Troposphere

Front 32

The temperature decrease with increasing height in the troposphere is called the ____________

Back 32

Environmental lapse rate

Front 33

The average value of the environmental lapse rate in the troposphere is ______ per 1000 feet. This figure is known as the ________. However, it's value is ______

Back 33

3.5F, normal lapse rate, variable

Front 34

To determine the actual environmental lapse rate as well as gather information about vertical changes in pressure, wind, and humidity, ______ are used.

Back 34

radiosonde

Front 35

An instrument package that is attached to a balloon and transmits data by radio as it ascends through the atmosphere

Back 35

radiosonde

Front 36

The thickness of the troposphere varies with __________

Back 36

latitude and season

Front 37

The outer boundary of the troposphere is the ________

Back 37

the tropopause.

Front 38

Beyond the tropopause is the __________

Back 38

stratosphere

Front 39

In the stratosphere, the temperature remains constant to a height of about _______, and then then begins a gradual __________ that continues until the _______

Back 39

12 miles, increase, stratopause,

Front 40

Below the tropopause, atmospheric properties such as temperature and humidity are readily transferred by _______________

Back 40

large-scale turbulence and mixing.

Front 41

Temperatures increase in the stratosphere because __________

Back 41

it is in this layer that the atmosphere’s ozone is concentrated

Front 42

The third layer of the atmosphere is called the ______

Back 42

Mesosphere

Front 43

In the mesosphere temperatures ______ with height until the __________

Back 43

decrease, mesopause

Front 44

The coldest temperatures anywhere in the atmosphere occur at the __________

Back 44

mesopause.

Front 45

the ________ is one of the least explored regions of the atmosphere.

Back 45

mesosphere

Front 46

The fourth layer of the atmosphere is the _________

Back 46

thermosphere

Front 47

In the thermosphere, temperatures ______ due to the absorption of _______

Back 47

increase, very short-wave, high-energy solar radiation by atoms of oxygen and nitrogen.

Front 48

Temperatures rise to extremely high levels of more than _______ in the thermosphere

Back 48

1800f

Front 49

Temperature is defined in terms of ________

Back 49

the average speed at which molecules move.

Front 50

The amount of solar energy the Earth receives depends on ____________

Back 50

latitude, time of day, and season of the year

Front 51

It is the _________ of Earth that creates winds and drives the ocean’s currents.

Back 51

unequal heating

Front 52

Earth has two principal motions—its ______ about its axis and its ________ around the Sun.

Back 52

rotation, orbital motion

Front 53

The axis is an _________ running through the poles.

Back 53

imaginary line

Front 54

Our planet rotates on its axis once every _____

Back 54

24 hours,

Front 55

The line separating the dark half of Earth from the lighted half is called the

Back 55

circle of illumination

Front 56

When the Earth is at its closest to the sun, that is known as the _____

Back 56

perihelion

Front 57

When the Earth is at its furthest from the sun, that is known as the _____

Back 57

aphelion

Front 58

The distance from the Earth to the sun plays a _____ in producing seasonal temperature variations

Back 58

minor role

Front 59

Earth's seasons are due to the ________ of the axis, which is tilted at _______ degrees

Back 59

Inclination, 23.5

Front 60

On June 21 or 22, the vertical rays of the vertical rays of the sun strike a latitude known as _______

Back 60

The Tropic of Cancer

Front 61

For people in the Northern Hemisphere, June 21 or 22 is known as the _________

Back 61

summer solstice

Front 62

On about December 21 or 22, the Sun’s vertical rays strike ________

Back 62

The Tropic of Capricorn

Front 63

For people in the Northern Hemisphere,December 21 or 22 is known as the _________

Back 63

Winter solstice

Front 64

Midway between the solstices are the

Back 64

equinoxes

Front 65

September 22 or 23 is the date of the

Back 65

Fall equinox

Front 66

In the Northern Hemisphere, and March 21 or 22 is the date of

Back 66

The spring equinox

Front 67

During the equinoxes , the vertical rays of the sun strike the _______

Back 67

equator

Front 68

The length of daylight versus darkness is also determined by Earth’s_________

Back 68

Position in orbit

Front 69

The farther north of the equator you are on June 21, the longer the _________

Back 69

period of daylight

Front 70

Heat is a term that is commonly used synonymously with _______

Back 70

thermal energy

Front 71

heat is energy possessed by a material arising from the _______

Back 71

internal motions of its atoms or molecules

Front 72

Whenever a substance is heated, its atoms ________, which leads to an increase in its heat content.

Back 72

move faster and faster

Front 73

heat generally refers to the ______ of energy present, whereas the word temperature refers to the _______

Back 73

quantity, intensity

Front 74

In all situations, heat is ____ from warmer to cooler objects.

Back 74

transferred

Front 75

The flow of energy can occur in three ways: ____

Back 75

conduction, convection, and radiation

Front 76

True or false: all three mechanisms of heat transfer can operate simultaneously

Back 76

True

Front 77

The transfer of heat through matter by molecular activity.

Back 77

Conduction

Front 78

The transfer of heat by mass movement or circulation within a substance.

Back 78

Convection

Front 79

Convection takes place in ______

Back 79

Fluids

Front 80

most of the heat acquired in the lowest portion of the atmosphere by way of radiation and conduction is transferred upward by _____

Back 80

Convection

Front 81

the global convective circulation of the atmosphere is driven by _____

Back 81

the unequal heating of Earth’s surface.

Front 82

Unlike conduction and convection, which need a medium to travel through, ________ energy readily travels through the vacuum of space

Back 82

radiant

Front 83

________ travels out in all directions from its source.

Back 83

radiation

Front 84

All radiation, whether x-rays, radio waves, or heat waves, travels through the vacuum of space at ______

Back 84

186k miles per second

Front 85

______ cannot be seen, but can be detected as heat.

Back 85

infrared radiation,

Front 86

When any form of radiant energy is absorbed by an object, the result is __________, which causes a corresponding increase in temperature.

Back 86

an increase in molecular motion

Front 87

True/False: All objects, at whatever temperature, emit radiant energy.

Back 87

True

Front 88

True/False: Hotter objects radiate more total energy per unit area than do colder objects

Back 88

True

Front 89

True/False: Hotter objects radiate more energy in the form of short-wavelength radiation than do cooler objects

Back 89

True

Front 90

True/False: Objects that are good absorbers of radiation are good emitters as well.

Back 90

True

Front 91

When radiation strikes an object, ___ different results usually occur.

1. some of the energy is ______ by the object

2. Substances such as water and air are transparent to certain wavelengths of radiation. Such materials simply _____ this energy

3 some radiation may _____ the object without being absorbed or transmitted. This is known as ________ and/or ______

Back 91

three

absorbed

transmit

“bounce off” , reflection, scattering

Front 92

_________ and ________ are responsible for redirecting incoming solar radiation.

Back 92

Reflection, scattering

Front 93

On average, about _______ percent of the solar energy that reaches the top of the atmosphere is absorbed at Earth’s surface.

Another ______ percent is reflected back to space by the atmosphere, clouds, and reflective surfaces.

The remaining _____ percent is absorbed by clouds and the atmosphere’s gases.

Back 93

50

30

20

Front 94

What determines whether solar radiation will be transmitted to the surface, scattered, reflected outward, or absorbed by the atmosphere?

Back 94

wavelength of the energy being transmitted, as well as on the nature of the intervening material.

Front 95

The process whereby light bounces back from an object at the same angle at which it encounters a surface and with the same intensity.

Back 95

Reflection

Front 96

A general process in which radiation is forced to deviate from a straight trajectory.

Back 96

Scattering

Front 97

Whether solar radiation is reflected or scattered depends largely on the size of __________

Back 97

The intervening particles and the wavelength of the light.

Front 98

Energy is returned to space from Earth in two ways: ______

Back 98

reflection and emission of radiant energy.

Front 99

The portion of solar energy that is reflected back to space leaves in the same ________ in which it came to Earth.

Back 99

short wavelengths

Front 100

The fraction of the total radiation that is reflected by a surface is called its _______

Back 100

albedo

Front 101

albedo varies considerably both from place to place and from one time to another, depending on the amount of ______ and particulate matter in the air, on the angle of the Sun’s rays, and on the nature of the ________

Back 101

cloud cover, surface

Front 102

Although incoming solar radiation travels in a straight line, small dust particles and gas molecules in the atmosphere scatter some of this energy in all directions. The result is called ____

Back 102

diffused light

Front 103

_______ explains how light reaches into the area beneath a shade tree and how a room is lit in the absence of direct sunlight

Back 103

diffused light

Front 104

_______accounts for the brightness and even the blue color of the daytime sky

Back 104

scattering

Front 105

Overall, ________ of the solar radiation that is absorbed at Earth’s surface arrives as diffused (scattered) light.

Back 105

about half

Front 106

Because gases are ______, they absorb some wavelengths strongly, some moderately, and some only slightly.

Back 106

selective absorbers

Front 107

True/false: Nitrogen, the most abundant constituent in the atmosphere, is a poor absorber of all types of incoming solar radiation.

Back 107

True

Front 108

______ along with oxygen and ozone, accounts for most of the solar radiation absorbed directly by the atmosphere.

Back 108

Water vapor

Front 109

For the atmosphere as a whole, none of the gases are effective absorbers of ____

Back 109

visible radiation.

Front 110

Because Earth has a much lower surface temperature than the Sun, the radiation that it emits has ________ than solar radiation.

Back 110

longer wavelengths

Front 111

_________absorbs roughly five times more terrestrial radiation than do all the other gases combined and accounts for the warm temperatures found in the ________

Back 111

Water vapor, lower troposphere

Front 112

What explains the general drop in temperature with increasing altitude experienced in the troposphere?

Back 112

The atmosphere is heated from the ground up rather than vice versa.

Front 113

An______ is a line that connects points on a map that have the same temperature

Back 113

isotherm

Front 114

all points through which an isotherm passes have identical temperatures for _________

Back 114

the time period indicated.

Front 115

A _________ is any factor that causes temperature to vary from place to place and from time to time.

Back 115

temperature control

Front 116

The most important cause for temperature variations is the

Back 116

differences in the receipt of solar radiation based on latitude.

Front 117

Temperature controls include: differential ______ of land and water, ________, geographic position, cloud cover and albedo, and ______

Back 117

heating, altitude, ocean currents

Front 118

_________ temperatures are much higher than water-surface temperatures

Back 118

Land-surface

Front 119

True/False: land heats more rapidly and to higher temperatures than water

Back 119

True

Front 120

True/False: Land cools more rapidly and to lower temperatures than water.

Back 120

True

Front 121

Variations in air temperatures are much greater over______ than over _________

Back 121

land, water

Front 122

The amount of energy needed to raise the temperature of 1 gram of a substance 1°C is called the _____

Back 122

specific heat

Front 123

Since land surfaces are ________, heat is absorbed only at the surface. Water, being more ______, allows heat to penetrate to a depth of many meters

Back 123

opaque, transparent

Front 124

Because the Southern hemisphere contains more ______ annual temperature variations are smaller than in the Northern Hemisphere

Back 124

Water

Front 125

The fact that high-altitude places are warmer than the value calculated using the normal lapse rate results from the ________ of solar energy by the ground surface.

Back 125

absorption and reradiation

Front 126

A coastal location where prevailing winds blow from the ocean onto the shore is called a ______

Back 126

windward coast

Front 127

a coastal location where the prevailing winds blow from the land toward the ocean is called ____

Back 127

a leeward coast

Front 128

A _____ coast will experience the full moderating influence of the ocean—cool summers and mild winters—compared to an inland station at the same latitude.

Back 128

windward

Front 129

A ______coast, on the other hand, will have a more continental temperature pattern because the winds do not carry the ocean’s influence onshore.

Back 129

leeward

Front 130

at any particular time, about _____ of our planet is covered by clouds

Back 130

half

Front 131

Cloud cover is important because many clouds have a high _____

Back 131

albedo

Front 132

At night, clouds have the _______ as during daylight

Back 132

opposite effect

Front 133

The effect of cloud cover is to reduce the daily temperature range by lowering the _____ maximum and raising the ______ minimum

Back 133

daytime, nighttime

Front 134

______ is composed of water molecules that form a tight, orderly network held together by mutual molecular attractions

Back 134

Ice

Front 135

In the ______ state, water molecules are still tightly packed but are moving fast enough that they are able to slide past one another.

Back 135

liquid

Front 136

________ molecules are widely spaced compared to liquid water and exhibit ________ motion.

Back 136

Water-vapor, energetic random

Front 137

One _______ is the amount of heat required to raise the temperature of 1 gram of liquid water 1°C

Back 137

calorie

Front 138

Because the heat used to melt ice does not produce a temperature change, it is referred to as ________

Back 138

latent heat

Front 139

Heat is absorbed during ______, the process of converting a liquid to a gas

Back 139

evaporation

Front 140

During the process of evaporation, the higher-temperature (faster-moving) molecules escape the surface. As a result, the average molecular motion (temperature) of the remaining water is ______

Back 140

reduced

Front 141

_______, occurs when water vapor changes to the liquid state

Back 141

condensation

Front 142

During _________, water-vapor molecules release energy in an amount equivalent to what was absorbed during _____________

Back 142

condensation, evaporation.

Front 143

When water vapor condenses to form cloud droplets, latent heat of condensation is released, warming the surrounding air and giving it _________

Back 143

buoyancy.

Front 144

The conversion of a solid directly to a gas, without passing through the liquid state.

Back 144

Sublimation

Front 145

The conversion of a vapor directly to a solid. These deposits are called _____

Back 145

Deposition, frost

Front 146

Sscientists agree that _________ is the most important gas in the atmosphere when it comes to understanding atmospheric processes.

Back 146

water vapor

Front 147

The maximum quantity of water vapor that the air can hold at any given temperature and pressure.Savanna 

Back 147

Saturation

Front 148

The total atmospheric pressure that can be attributed to the water-vapor content.

Back 148

Vapor-pressure

Front 149

At higher temperatures, more moisture is required to reach _________

Back 149

saturation

Front 150

The ____________ is the mass of water vapor in a unit of air compared to the remaining mass of dry air:

Back 150

mixing ratio

Front 151

The ratio of the air’s actual water-vapor content to the amount of water vapor required for saturation at that temperature (and pressure).

Back 151

Relative humidity

Front 152

When the water-vapor content of air remains at a constant level, a decrease in air temperature results in ______ in relative humidity, and an increase in temperature causes _____ in relative humidity.

Back 152

an increase , a decrease

Front 153

The temperature at which water vapor begins to condense

Back 153

Dew point

Front 154

Because the dew point is the temperature at which saturation occurs, we can conclude that ______ temperatures indicate moist air and, conversely, _______ temperatures indicate dry air

Back 154

high dew-point, low dew-point

Front 155

Humidity is measured with instruments called ____

Back 155

hygrometers

Front 156

A type of hygrometers, known as a _____ consists of two identical thermometers mounted side by side

Back 156

psychometer

Front 157

Electric Hygrometers operate on the principle of ________, a material’s ability to store an electrical charge.

Back 157

capacitance

Front 158

Temperature changes in which heat energy is neither added nor subtracted, are called ___________

Instead, the change in temperature is caused by a change in ________

Back 158

adiabatic temperature changes, pressure

Front 159

When air is compressed, it ___ and when air is allowed to expand, it ________

Back 159

warms, cools.

Front 160

Unsaturated air cools at a constant rate of ____ for every 1000 meters of ascent.

Conversely, descending air comes under increasing pressure and is compressed and heated by _____ for every 1000 meters of descent

This rate of cooling or heating applies only to unsaturated air and is known as the ________

Back 160

10C

10°C

dry adiabatic rate

Front 161

If an air parcel rises high enough, it will eventually cool to its dew point, triggering the process of ________

Back 161

condensation.

Front 162

The altitude at which a parcel reaches saturation and begins to form clouds is called the _______

Back 162

condensation level

Front 163

At the lifting condensation level, an important change occurs: The ______ that was absorbed by the water vapor when it evaporated is released as ________—energy that can be measured with a thermometer.

Back 163

latent heat, sensible heat

Front 164

Although an air parcel will continue to cool adiabatically as it rises, the release of latent heat slows the rate of cooling. In other words, when a parcel of air ascends above the lifting condensation level, the rate at which it cools is reduced. This slower rate of cooling is called the ________

Back 164

wet adiabatic rate

Front 165

Rising air expands and cools at the ________ rate from the surface up to the lifting condensation level, after which it cools at the slower ________ rate.

Back 165

dry adiabatic, wet adiabatic

Front 166

The type of lifting where air is forced to rise over a mountainous barrier

Back 166

Orographic lifting

Front 167

The type of lifting in which warmer, less-dense air is forced over cooler, denser air

Back 167

Frontal lifting

Front 168

When there's a pileup of horizontal airflow that results in upward movement it is called ___

Back 168

convergence

Front 169

The type of lifting in which unequal surface heating causes localized pockets of air to rise because of their buoyancy is called ______

Back 169

Localized convective lifting

Front 170

As air ascends a mountain slope, ______ cooling often generates clouds and copious precipitation.

Back 170

adiabatic

Front 171

Many of the rainiest places in the world are located on ________

Back 171

Windward mountain slopes.

Front 172

By the time air reaches the ______ side of a mountain, much of its moisture has been lost. If the air ________, it warms adiabatically, making condensation and precipitation even less likely.

Back 172

leeward, descends

Front 173

In central North America, warm and cold air masses often collide, producing boundaries called _________

Rather than mixing, the _______, denser air mass acts as a barrier over which the ________, less-dense air rises.

Back 173

fronts

cooler, warmer

Front 174

When the wind pattern near Earth’s surface is such that more air is entering an area than is leaving—a phenomenon called ______

Back 174

convergence

Front 175

When air is compressed by _______, it escapes by moving upward.

Back 175

convergence

Front 176

________ can occur when an obstacle slows or restricts horizontal airflow (wind). For example, when air moves from a relatively smooth surface, such as the ocean, onto an irregular landscape, increased friction reduces its speed.

Back 176

Convergence

Front 177

On warm summer days, unequal heating of Earth’s surface may cause some pockets of air to be warmed more than the surrounding air.

Consequently, the overlying parcel of air, being warmer (less dense) than the surrounding air, will be buoyed upward.

Such rising parcels of warmer air are called ______

Back 177

thermals.

Front 178

The phenomenon that produces rising thermals is called ___________

Back 178

localized convective lifting

Front 179

Air that is ____ (and hence denser) than the surrounding air, will sink back down to its original location. Air of this type, is called ______

Back 179

cooler, stable air

Front 180

Air that is _______ than the surrounding air (and hence less dense), it will continue to rise. Specifically, it will rise until it reaches an altitude where its temperature equals that of its surroundings. This type of air is called _______

Back 180

warmer, unstable air

Front 181

_________ prevails when the environmental lapse rate is less than the wet adiabatic rate.

Back 181

Absolute stability

Front 182

The most stable conditions occur when the temperature in a layer of air actually increases with altitude rather than decreases. When such a reversal occurs, a ___________ is said to exist.

Back 182

temperature inversion

Front 183

Air is said to exhibit ______ when the environmental lapse rate is greater than the ______________

Back 183

absolute instability, dry adiabatic rate.

Front 184

_________occurs when moist air has an environmental lapse rate between the dry and wet adiabatic rates

Back 184

conditional instability

Front 185

conditional instability depends on whether the rising air is __________

Back 185

conditional instability

Front 186

A column of air is deemed ________ when the air near the bottom of the column is significantly warmer (less dense) than the air aloft, indicating a steep _______________

Back 186

unstable, environmental lapse rate

Front 187

An air column is considered to be _______ when the temperature drops relatively slowly with increasing altitude.

Back 187

stable

Front 188

The most stable air conditions occur during a ___________, when the temperature actually _____________ with height.

Back 188

temperature inversion, increased

Front 189

When stable air is forced aloft, the clouds that form are widespread and have little vertical thickness when compared to their horizontal dimension, and precipitation, if any, is _________

Back 189

light to moderate.

Front 190

True/False: Clouds associated with the lifting of unstable air are towering and often generate thunderstorms and occasionally even tornadoes

Back 190

True

Front 191

on a dreary, overcast day with light drizzle, _______ air has been forced aloft

Back 191

stable

Front 192

during a day when cauliflower-shaped clouds appear to be growing as if bubbles of hot air are surging upward, we can be fairly certain that the ascending air is ________

Back 192

unstable

Front 193

When condensation occurs high above the ground, tiny bits of particulate matter, known as ________, serve as surfaces for water-vapor condensation

Back 193

cloud condensation nuclei

Front 194

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

Back 194

Clouds

Front 195

louds are classified on the basis of two criteria: ________

Back 195

form and height

Front 196

______ clouds are high, white, and thin.

Back 196

Cirrus

Front 197

_____ clouds consist of sheets or layers that cover much or all of the sky.

Back 197

Stratus

Front 198

______ clouds consist of globular cloud masses that are often described as cottonlike in appearance

Back 198

Cumulus

Front 199

the term ______ is added to the name of a cloud that is a major producer of precipitation.

Back 199

nimbus

Front 200

In terms of their height, clouds are classified as ______, ________, _______, and clouds of vertical development

Back 200

high, middle, low

Front 201

Because of the low temperatures and small quantities of water vapor present at high altitudes, all high clouds are _______ and are made up of __________

Back 201

thin and white, ice crystals.

Front 202

Clouds that appear in the middle range have the prefix ____ as part of their name

Back 202

alto

Front 203

clouds of __________ tend to be associated with unstable air, which rises because of its buoyancy

Back 203

vertical development

Front 204

A cloud with its base at or very near the ground.

Back 204

fog

Front 205

fog occurs because air either is ______ its dew-point temperature or gains water through ________ until it becomes saturated

Back 205

cooled below, evaporation

Front 206

________ results when ground cooled by radiation cools the overlying layer of air.

Back 206

Radiation fog

Front 207

When warm, moist air blows over a cold surface, it becomes chilled by contact with the cold surface below. If cooling is sufficient, the result is a blanket of fog called ________

Back 207

advection fog

Front 208

When relatively humid air moves up a gradually sloping landform or, in some cases, up the steep slopes of a mountain _____ can form

Back 208

upslope fog

Front 209

When air forms fog mainly because of the addition of water vapor, the fog is called an ________

Back 209

evaporation fog.

Front 210

When cool, unsaturated air moves over a warm water body, enough moisture may evaporate to saturate the air directly above, generating a layer of fog called ________

Back 210

steam fog

Front 211

Frontal boundaries where a warm, moist air mass is forced to rise over cooler, dryer air below generate___________ fog

Back 211

frontal

Front 212

fog incidence is highest in ______ areas, especially where ______ currents prevail

Back 212

coastal, cold

Front 213

The __________ process generates much of the precipitation that occurs in the middle and high latitudes.

Back 213

Bergeron

Front 214

The Bergeron process is based on the fact that cloud droplets remain liquid at temperatures as low as ______

Back 214

−40°C

Front 215

Liquid water at temperatures below freezing is termed _______

Back 215

supercooled

Front 216

Supercooled water droplets also freeze upon contact with particles in the atmosphere known as ________

Back 216

ice nuclei

Front 217

The _________ process involves multiple collisions of tiny cloud droplets that stick together to form raindrops large enough to reach the ground before evaporating.

Back 217

collision–coalescence

Front 218

Freezing rain forms when the cold layer of air is not deep enough to refreeze the raindrops, resulting in _________ droplets freezing on contact with objects at the surface.

Back 218

supercooled

Front 219

Snowfall is typically measured by _____ and ____ equivalent.

Back 219

depth, water

Front 220

_____ is the pressure exerted by the weight of air above.

Back 220

air pressure

Front 221

air pressure is exerted in all _________

Back 221

directions

Front 222

When meteorologists measure atmospheric pressure, it is expressed in units called ________

Back 222

millibars.

Front 223

Although the millibar has been the unit of measure on all U.S. weather maps since January 1940, the media use _______

Back 223

inches of mercury

Front 224

An _________ uses a partially evacuated metal chamber to measure air pressure

Back 224

aneroid barometer

Front 225

Do Barometric readings always indicate the weather?

Back 225

No

Front 226

To “predict” the local weather, the _____________ is more important than the current pressure reading.

Back 226

change in air pressure over the past few hours

Front 227

_______ pressure is often associated with increasing cloudiness and the possibility of precipitation, whereas ______ air pressure generally indicates clearing conditions.

Back 227

Falling, rising

Front 228

a _________, provides a continuous record of pressure changes with the passage of time

Back 228

barograph

Front 229

What causes wind?

Back 229

Wind is the result of horizontal differences in air pressure. Air flows from areas of higher pressure to areas of lower pressure

Front 230

__________ is the ultimate energy source for most wind

Back 230

solar radiation

Front 231

The __________ of Earth’s surface generates the pressure differences that cause wind

Back 231

unequal heating

Front 232

If Earth did not rotate, and if there were no friction between moving air and Earth’s surface, air would flow in a ________ from areas of higher pressure to areas of lower pressure.

Back 232

straight line

Front 233

Wind is controlled by a combination of three factors: _____________

Back 233

pressure gradient force, Coriolis effect, and friction.

Front 234

_________ cause the wind to blow, and the greater these differences, the greater the _________

Back 234

pressure differences, wind speed.

Front 235

pressure measurements are shown on surface weather maps using ________

Back 235

isobars

Front 236

The spacing of ________ indicates the amount of pressure change occurring over a given distance, which is called the _________

Back 236

isobars, pressure gradient force

Front 237

Pressure gradient is analogous to ________ acting on a ball rolling down a hill

Back 237

gravity

Front 238

Closely spaced isobars indicate ____________and strong winds; widely spaced isobars indicate ______________ and light winds.

Back 238

a steep pressure gradient, a weak pressure gradient

Front 239

the __________ gradient is the driving force of wind.

Back 239

horizontal pressure

Front 240

Wind does not cross isobars at right angles, as the pressure gradient force directs it to do. The direction deviates as a result of Earth’s rotation. This has been named the ________

Back 240

Coriolis effect

Front 241

All free-moving objects or fluids, including the wind, are deflected to the ______ of their path of motion in the Northern Hemisphere and to the ______ in the Southern Hemisphere.

Back 241

right, left

Front 242

The Coriolis effect is always directed at _____ to the direction of airflow; affects only _________, not wind speed; is affected by wind speed (the stronger the wind, the ______ the deflection); and (4) is strongest at the ______ and weakens ____________, becoming nonexistent at the __________

Back 242

right angles, wind direction, greater, poles, equatorward, equator.

Front 243

The effect of ______ on wind is important only within a few kilometers of Earth’s surface

Back 243

friction

Front 244

Upper air winds are called ________

Back 244

geostrophic winds

Front 245

The lack of ______ with Earth’s surface allows __________ to travel at higher speeds than do surface winds.

Back 245

friction, geostrophic winds

Front 246

The most prominent features of upper-level air flow are _______

Back 246

jet streams

Front 247

Friction lowers the _______ so it reduces the Coriolis effect.

Back 247

wind speed,

Front 248

_______, or lows, are centers of low pressure, and ________ or highs, are high-pressure centers.

Back 248

Cyclones, anticyclones,

Front 249

When the controls of airflow are applied to pressure centers in the Northern Hemisphere, the result is that winds blow ______ and counterclockwise around a low. Around a high, they blow _________ and _________

Back 249

inward, counterclockwise, outward, clockwise

Front 250

In the Southern Hemisphere, the Coriolis effect deflects the winds to the _____; therefore, winds around a low blow ______, and winds around a high move ________

Back 250

left, clockwise, counterclockwise

Front 251

In either hemisphere, friction causes a net inflow ______ around a cyclone and a net outflow _________ around an anticyclone.

Back 251

convergence, divergence

Front 252

In a surface low-pressure system where the air is spiraling inward. The net inward transport of air causes a shrinking of the area occupied by the air mass, a process that is termed ________

Back 252

horizontal convergence.

Front 253

Whenever air converges ________, it must pile up—that is, increase in height to allow for the decreased area it now occupies

Back 253

horizontally

Front 254

A low, or cyclone, has________ surface winds and _______ air, resulting in cloudy conditions. A high, or anticyclone, has ______ surface winds and________ air, which leads to clear skies and fair weather.

Back 254

converging, rising, diverging, descending

Front 255

The atmosphere acts as a giant heat-transfer system, moving ______ poleward and _______ equatorward

Back 255

warm air, cool air

Front 256

Near the equator, the rising air is associated with the pressure zone known as the __________.

Because this region of low pressure is a zone where winds from the north and south converge, it is also referred to as the ____________

Back 256

equatorial low

intertropical convergence zone

Front 257

As the diverging upper-level flow from the equatorial low reaches 20° to 30° latitude, north or south, it sinks back toward the surface.

This subsidence and associated adiabatic heating produce hot, arid conditions.

The center of this zone of subsiding dry air is the ________, which encircles the globe near 30° latitude, north and south.

Back 257

subtropical high

Front 258

At the surface, airflow is outward from the center of the subtropical high. Some of the air travels equatorward and is deflected by the Coriolis effect, producing the _________

The remainder travels poleward and is also deflected, generating the _________

As the westerlies move poleward, they encounter the cool _______in the region of the ________. The interaction of these warm and cool winds produces the stormy belt known as the ________

Back 258

trade winds

westerlies

polar easterlies, subpolar low, polar front

Front 259

The source region for the variable polar easterlies is the ________

Back 259

polar high

Front 260

The subtropical and polar highs are areas of dry subsiding air that flows ______at the surface, producing the ________

Back 260

outward, prevailing winds.

Front 261

The low-pressure zones of the equatorial and subpolar regions are associated with _____ and _________ airflow accompanied by clouds and precipitation.

Back 261

inward, upward

Front 262

The only truly continuous pressure belt is the _______in the Southern Hemisphere, where the ocean is ___________ by landmasses

Back 262

subpolar low, uninterrupted

Front 263

large landmasses, become cold in the winter and develop a seasonal ________ system from which surface flow is directed _____ the land.

In the summer, the opposite occurs: The landmasses are heated and develop a _______, which permits air to flow ______ the land. These seasonal changes in wind direction are known as the __________

Back 263

high-pressure, off

low-pressure cell, onto, monsoons

Front 264

Because the paths of low-pressure centers are guided by the flow aloft, we can expect the ________ of states to experience more of their stormy weather in the winter season. During the hot summer months, the storm track is across the ________

Back 264

southern tier, northern states.

Front 265

________ are small-scale winds produced by a locally generated pressure gradient.

Back 265

Local winds

Front 266

In coastal areas during the warm summer months, the land is heated more intensely during the daylight hours than is the adjacent body of water. As a result, the air above the land surface heats, expands, and rises, creating an area of ________

A ______ then develops because cooler, _______ air over the water moves toward the warmer, _________air over the land

At night, the reverse may take place: The land cools more rapidly than the sea, and the _______ develops

Back 266

lower pressure,

sea breeze , higher pressure, lower pressure

Land Breeze

Front 267

During daylight hours, the air along the slopes of the mountains is heated more intensely than the air at the same elevation over the valley floor. Because this warmer air is less dense, it glides up along the slope and generates a _________

Back 267

valley breeze

Front 268

Rapid radiation cooling along the mountain slopes produces a layer of cooler air next to the ground. Because cool air is denser than warm air, it drains downslope into the valley. This movement of air is called a _________

Back 268

mountain breeze

Front 269

Warm, dry winds sometimes move down the eastern slopes of the Rockies, where they are called ___________________.

the winds occur mostly in the ___________

Back 269

Chinooks

winter and spring

Front 270

Two basic wind measurements, __________, are particularly significant to weather observers.

Back 270

direction and speed

Front 271

Winds are always labeled by the _____________

Back 271

direction from which they blow

Front 272

The instrument most commonly used to determine wind direction is the __________

Back 272

wind vane

Front 273

Wind speed is commonly measured using a _________

Back 273

cup anemometer

Front 274

When the wind consistently blows more often from one direction than from any other, it is called a ____________

Back 274

prevailing wind

Front 275

During an __________, strong equatorial countercurrents amass large quantities of warmer-than-normal water along the west coast of South America.

The unusually warm water and associated low pressure cause arid areas of Peru and Chile to receive ____________ that can lead to___________

Back 275

El Niño,

unusually heavy rains, major flooding.

Front 276

During an El Niño event, the pressure over the eastern Pacific _______, while the pressure over the western Pacific ______

This causes the trade winds to _________, leading to an __________ movement of warm water along the equator.

Back 276

drops, rises.

diminish, eastward

Front 277

During a ______ event, strong trade winds drive the equatorial currents toward the west.

This circulation pattern is often associated with flooding in _________ whereas especially dry conditions prevail along the west coast of South America.

Back 277

La Niña,

northeastern Australia and Indonesia,

Front 278

During an ______ event, winter temperatures are warmer than normal in the north-central United States and parts of Canada

In addition, significantly ____ winters are experienced in the southwestern United States and northwestern Mexico, while the southeastern United States experiences _______ and cooler conditions.

Back 278

El Niño

wetter, wetter

Front 279

One major benefit of El Niño is a lower-than-average number of ___________

Back 279

Atlantic hurricanes.

Front 280

La Niña winter weather includes _______ conditions over the northwestern United States and especially _______ winter temperatures in the Northern Plains states, while _______ conditions occur in the Southwest and Southeast

Back 280

cooler and wetter, cold, unusually warm

Front 281

El Niño and La Niña events are intimately related to changes in the global _______ patterns.

Back 281

pressure

Front 282

Each time an El Niño occurs, the barometric pressure _______ over large portions of the eastern Pacific and ________ in the tropical portions of the western Pacific.

Back 282

drops, rises

Front 283

The seesaw pattern of atmospheric pressure between the eastern and western Pacific is called the ____________

Back 283

Southern Oscillation

Front 284

_______ in the western Pacific strengthens the trade winds, which move warm, tropical water toward Australia and Indonesia

Back 284

Low pressure

Front 285

A _______ in pressure in the eastern Pacific weakens the trade winds and strengthens the _________, which amass large quantities of warm water along the coasts of Peru and Chile.

Back 285

drop, equatorial countercurrents

Front 286

The link between the weather occurring in widely separated regions of the globe is called a _______

Back 286

teleconnection.

Front 287

National Weather Service predictions for periods from 1 to 13 months into the future are called ________

Back 287

climate outlooks.

Front 288

In general, regions influenced by high pressure, with its associated subsidence and diverging winds, experience relatively ________

Back 288

dry conditions

Front 289

Regions under the influence of low pressure and its converging winds and ascending air receive _______

Back 289

Ample precipitation

Front 290

Large landmasses in the middle latitudes commonly experience ______ precipitation toward their interiors.

Back 290

decreased

Front 291

An _______, is an immense body of air, usually 1,600 kilometers (1,000 miles) or more across and perhaps several kilometers thick, that is characterized by a similarity of temperature and moisture across a given altitude.

Back 291

air mass

Front 292

Since it may take several days for an air mass to move across an area and be modified, the region under its influence will likely experience fairly constant weather, a situation called _______

Back 292

air-mass weather

Front 293

The area where an air mass acquires its characteristic properties of temperature and moisture is called its _________

Back 293

source region

Front 294

Air masses are classified according to their ______

_______ air masses and ________ air masses originate in high latitudes toward Earth’s poles, whereas those that form in low latitudes are called _________ air masses

In addition, air masses are classified according to the nature of the surface in the source region. ________ air masses form over land, and _______ air masses originate over water.

Back 294

Source region.

Polar (P), arctic, tropical (T)

Continental, maritime (m)

Front 295

The basic types of air masses are _________

Back 295

continental polar (cP), continental arctic (cA), continental tropical (cT), maritime polar (mP), and maritime tropical (mT).

Front 296

_________ masses influence the weather of North America most, especially east of the ________

Continental polar air masses originate in ___________

Back 296

Continental polar and maritime tropical air, Rocky Mountains.

northern Canada, interior Alaska, and the Arctic

Front 297

Although cP air masses are not, as a rule, associated with heavy precipitation, those that cross the ___________ during late autumn and winter sometimes bring snow to the leeward shores.

These localized storms often form when the surface weather map indicates no apparent cause for a snowstorm. These are known as________

Back 297

Great Lakes

lake-effect snows

Front 298

Maritime tropical air masses affecting North America most often originate over the warm waters of the ___________________

Back 298

Gulf of Mexico, the Caribbean Sea, or the adjacent Atlantic Ocean

Front 299

______ air is the source of much, if not most, of the precipitation in the eastern two-thirds of the United States.

Back 299

Maritime tropical

Front 300

During the winter, maritime polar air masses coming from the North Pacific often originate as ________ air masses in ____________

Back 300

continental polar, Siberia.

Front 301

______ are boundary surfaces that separate air masses of different densities—one of which is usually warmer and contains more moisture than the other.

Back 301

Fronts

Front 302

The process of warm air gliding up and over a cold air mass is termed _________

Back 302

overrunning

Front 303

When the surface position of a front moves so that warm air occupies territory formerly covered by cooler air, it is called a _________

Back 303

warm front

Front 304

When dense cold air is actively advancing into a region occupied by warmer air, the boundary is called a _______

Back 304

cold front

Front 305

On average, cold fronts are about _____ as steep as warm fronts,

Back 305

twice

Front 306

Occasionally, the flow on both sides of a front is neither toward the cold air mass nor toward the warm air mass but almost parallel to the line of the front. Thus, the surface position of the front does not move. This condition is called a ______

Back 306

stationary front

Front 307

An active cold front that overtakes a warm front is called a

Back 307

occluded front

Front 308

Middle latitudes refers to the region between _________.

The primary weather producers here are _______

Back 308

southern Florida and Alaska

middle-latitude, cyclones

Front 309

________ cyclones are large centers of low pressure that generally travel from west to east. Lasting from a few days to more than a week, these weather systems have a __________ circulation, with an airflow inward toward their centers.

Back 309

Midlatitude, counterclockwise

Front 310

With respect to surface cyclones , as long as _________ aloft is equal to or greater than surface inflow, the low pressure and its accompanying ______ can be sustained.

Back 310

divergence, convergence

Front 311

The surface air that feeds a cyclone, generally originates as air flowing out of _______

Back 311

an anticyclone.

Front 312

Tornadoes and hurricanes are both _________ than midlatitude cyclones

Back 312

smaller and more violent

Front 313

The greatest number of thunderstorms occur in the ________

Back 313

tropics

Front 314

Pressures within some tornadoes have been estimated to be as much as ________ lower than pressures immediately outside the tornado.

Back 314

10 percent

Front 315

Usually the most intense tornadoes are those that form in association with huge thunderstorms called ___________

Back 315

supercells

Front 316

___________ is a vertical cylinder of rotating air, typically about 3 to 10 kilometers (2 to 6 miles) across, that develops in the updraft of a severe thunderstorm. The formation of this large vortex often precedes tornado formation by 30 minutes or so.

Back 316

A mesocyclone

Front 317

________ is a change in wind speed and/or direction with height

Back 317

Wind shear

Front 318

Mesocyclone formation depends on the presence of ____________

Back 318

wind shear

Front 319

___________ of all mesocyclones produce tornadoes.

Back 319

half

Front 320

Supercell thunderstorms are likeliest to form during the ______, when the air masses associated with midlatitude cyclones are most likely to have greatly contrasting conditions.

The two contrasting air masses are most likely to meet in the central United States because there is no ______________

Back 320

spring

significant natural barrier

Front 321

The commonly used guide to tornado intensity is the ___________________

Back 321

Enhanced Fujita intensity scale, or EF-scale

Front 322

The EF-scale is determined by assessing the ________ produced by a storm.

Back 322

worst damage

Front 323

_________ alert the public to the possibility of tornadoes over a specified area for a particular time interval

Back 323

Tornado watches

Front 324

A ______ is issued by local offices of the NWS when a tornado has actually been sighted in an area or is indicated by weather radar.

Back 324

A tornado warning

Front 325

__________ are intense centers of low pressure that form over tropical oceans and are characterized by intense convective activity and strong cyclonic circulation

Back 325

Hurricanes

Front 326

The source of energy that produces and maintains hurricane-force winds is the huge quantity of _______ liberated during the formation of the storm’s cumulonimbus towers.

Back 326

latent heat

Front 327

In the western Pacific, hurricanes are called _____

Back 327

typhoons

Front 328

Hurricanes develop most often in the late _____, when ocean waters have reached temperatures of 27°C (80°F) or higher and thus are able to provide the necessary _______ to the air

Back 328

summer, heat and moisture

Front 329

Hurricanes diminish in intensity whenever they _______

Back 329

(1) move over ocean waters that cannot supply warm, moist tropical air;

(2) move onto land;

or (3) reach a location where the large-scale flow aloft is unfavorable.

Front 330

Hurricanes are measured using the _________

Back 330

the Saffir–Simpson hurricane scale

Front 331

Damage caused by hurricanes can be divided into three categories: _____

Back 331

1) storm surge, (2) wind damage, and (3) heavy rains and inland flooding.

Front 332

With respect to hurricanes, the most devastating damage in the coastal zone is usually caused by _____

Back 332

storm surge

Front 333

The predicted path of a hurricane is called the _______

Back 333

track forecast.

Front 334

The Earth's climate system includes:

Back 334

the atmosphere, hydrosphere, geosphere, biosphere, and cryosphere.

Front 335

The _________ refers to the portion of Earth’s surface where water is in solid form

Back 335

cryosphere

Front 336

The______ Classification is used for climates

Back 336

Koppen

Front 337

The 5 principal groups under the Koppen classification system are

Back 337

Humid tropical (A)

Dry (B)

Humid-middle lattitude, mild winters (C)

Humid-Middle Latitude, severe winters (D)

Polar (E)

Front 338

Within the A group of climates, two main types are recognized: _________

Back 338

wet tropical climates (Af and Am) and tropical wet and dry (Aw).

Front 339

In the latitude zone poleward of the wet tropics and equatorward of the subtropical deserts lies the transitional _____________

Back 339

tropical wet and dry climate

Front 340

Climatologists define a dry climate as one in which the __________ is not as great as the potential loss of water by __________

Back 340

yearly precipitation, evaporation

Front 341

Unlike most other aerosols, _________ warms the atmosphere because it is an effective absorber of incoming solar radiation.

Back 341

black carbon

Front 342

Climate feedback mechanisms that reinforce the initial change, are called __________

Back 342

positive-feedback mechanisms

Front 343

Climate feedback mechanisms that produce results the opposite of the initial change, are called __________

Back 343

negative-feedback mechanism