Unit 5- Earth & Environmental Science

Meteorology is the study of _______________________________________.

atmospheric phenomena

-continental polar:

cP cold and dry

The Saffir-Simpson scale classifies hurricanes according to __________________________ _____________________________________________________.

wind speed, air pressure in the center, and potential for property damage.

An anemometer is used to measure ___________________ and a hygrometer measures _____ ___________________.

wind speed. relative humidity

When the axis tilts toward Vega, ____________________________________________________ _________________________________________________________________________________________. This will cause warmer summers and colder winters to occur.

winter will occur in the northern hemisphere when Earth is farthest from the Sun and summer will occur when Earth is closet to the Sun

High-pressure systems are usually associated with __________ weather, while low-pressure systems are associated with ____________ and ________________.

fair. clouds and precipitation

Describe the balanced gas exchange of the Earth's atmosphere:

- Volcanic eruptions release various gases and dust particles into the atmosphere. - Photosynthetic organisms take in carbon dioxide and release oxygen. - Other organisms take in oxygen and release carbon dioxide.

-continental tropical:

(cT) warm and dry

-maritime polar:

(mP) cold and humid

-maritime tropical:

(mT) warm and humid

In the space below, name and describe the characteristics of the 4 types of fronts, including the weather patterns associated with each front:

- Cold Front: cold air displaces warm air and forces it to rise, often creating thunderstorms. - Warm Front: warm air gradually displaces cold air, creating clouds and showers. - Stationary Front: when two air masses meet, and neither is displaced, causing long periods of rain. - Occluded Front: when a cold air mass overtakes a warm front, wedging it upward. This creates precipitation on both sides of the front.

Define and describe the El Nino effect:

- El Nino is a warm ocean current taht occasionally develops off the western coast of South America. - It creates a warmer and wetter climate along the northwestern coast of South America and brings violent storms to California and the Gulf Coast

State how conduction affects the atmosphere:

- Energy is transfered from the particles of air near teh earth's surface to the particles of air in the lowest layer of teh atmosphere. - Conduction only affects a very thin atmosphere layer near the earth's surface.

State the numerous harmful effects of acid precipitation:

- It damages aquatic ecosystems and vegetation - It changes the pH of plants and soil. - It damages stone building and statues by accelerating the rate of weathering.

Describe where and at what time of day and year tornadoes are most likely to occur:

-Most tornadoes form in the spring during the late afternoon and evening. -In the central United States, a region called "Tornado Alley" extends from northern Texas through Oklahoma, Kansas and Missouri

Explain how coal-burning power plants can cause acid precipitation:

-these plants burn coal that contain the mineral pyrite (FeS2). - The sulfer is released as sulfer dioxide when coal is burned, and it combines with mositure in clouds to produce acid precipitation.

Describe the 3 conditions that must exist for a thunderstorm to occur:

1. Abundant moisture in the lower levels of the atmosphere.

Name and describe the four stages of tropical cyclone development:

1.A traveling tropical disturbance is the 1st stage of tropical cyclone. 2. A tropical depression has acquired a cyclonic circulation around a center of low pressure. 3. A tropical storm attains wind speeds of 65 km/h around the low pressure center. 4. A hurricane has winds of at least 120 km/h along with falling air pressure.

Sequence how hail forms in a thunderstorm:

1.Supercooled water droplets encounter ice pallets in a cloud and freeze on contract, causing the ice pellets to grow larger.

The shape of Earth's elliptical orbit appears to change over a ________________ year cycle. When the orbit elongates, _____________________________________________________________, and temperatures ______________________________________________. When the orbit is more circular, ________________________________________________________________________________.

100,000. Earth passes closer to the Sun. become warmer than normal. Earth is farther from the Sun and temperatures dip below average

Describe the 3 conditions that must exist for a thunderstorm to occur:

2. A mechanism must lift the air so that moisture will condense and release latent heat.

Sequence how hail forms in a thunderstorm:

2. Updrafts and downdrafts in a cloud cause more supercooled water droplets to encounter the ice pellets, making them grow even larger.

The angle of tilt of the Earth's axis varies from a minimum of _________________________ to a maximum of ___________________ every 41,000 years. Scientists believe that these changes cause __________________________________________________________.

22.1 degrees. 24.5 degrees. seasons to become more severe.

The temperate zones lie between __________________________ north and south of the equator. Temperatures in these regions are _____________________.

23.5 degrees and 66.5. moderate

Sequence how hail forms in a thunderstorm:

3. Eventually, the ice pellets are too heavy to be held aloft by the updrafts, and they fall to Earth as hail.

Describe the 3 conditions that must exist for a thunderstorm to occur:

3. The portion of the atmosphere through which the cloud grows must be unstable.

The prevailing westerlies occur between ____________________ north and south latitude in a circulation pattern opposite of the _________ ________. In this zone, surface winds move toward the _________ in an easterly direction.

30 and 60 degrees. trade winds. poles

The trade winds occur at ______ north and south latitude. There, the air ________, _________, and moves toward the equator in a ________________ direction.

30 degrees. sinks, warms. westerly

Typical thunderstorms last only about _____ minutes, and individual storms are only about ______________________ in diameter.

30. 24 kilometers

The polar easterlies occur between _______________________________. They flow from the ____________ to the _____________ in the Northern hemisphere.

60 and 90 degrees latitude. northeast. southwest

__________________________________________ is a prime source of atmospheric CO2. Almost any process that involves the ____________________________________ results in the release of carbon dioxide.

Automoblie exhauset. burning of fossil fuels

Describe the 3 stages of thunderstorm development:

Cumulus Stage: air rises vertically, creating updrafts which transport moisture to the upper reaches of the cloud

___________________________________ is the main method used by modern meteorologists. It is highly dependent upon the __________________ of the data available--the more data, _______________________________ the forecast.

Digital forecasting. density. the more accurate

Describe the 3 stages of thunderstorm development:

Dissipation Stage: the supply of warm, moist air runs out because downdrafts spread in all directions as they reach the surface

The amount of solar radiation received by any one place varies because _________________ _________________________ and this affects ________________________________________________ ________________________.

Earth is tilted on its axis. how the Sun's rays strike Earth's surface

Describe the 3 stages of thunderstorm development:

Mature Stage: as precipitation falls, it cools the air around it, creating downdrafts that produce gusty surface winds.

-arctic:

much colder than continental polar

Ozone is a gas formed by the addition of ___________________________ to an oxygen molecule. It is important in the upper atmosphere because _____________________________ _________________. Without an ozone layer, our skin could not __________________________ _________________.

a third oxygen atom, it absorbs ultraviolent radiation from the sun. tolerate exposure to the sun.

A tornado is ___________________________________________. A tornado forms when wind speed and direction _____________________with height, a phenomenon known as ________ ____________.

a violent, whirling column of air in contact with the ground. change suddenly. wind shear.

Climate describes the long-term weather patterns of an area, including ___________________ ___________________________________.

annual variations of temperature, precipitation, wind, and other weather variables.

the ITCZ is characterized by _________________________________________________________ ______________________________________________. This area is also called the doldrums.

a band of cloudiness and occasional showers that provide moisture for tropical forests

Because the motion of moving raindrops is caused by wind, Doppler radar provides _____ _____________________________________________ associated with precipitation areas, especially those experiencing __________________________ and __________________________.

a good estimation of wind speeds. thunderstorms and tornadoes.

Temperature is ____________________________________________________________________.

a measurement oh how rapidly or slowly molecules move around

Of the 100,000 thunderstorms that occur each year in the U.S, only ___________________ are considered to be severe.

about 10 percent

A lightning bolt heats the surrounding air to _________________, which is _______________ hotter than the surface of the Sun. Thunder is the sound ________________________________ ___________________________.

about 30,000 degrees Celcius. five times. produced as the superheated air rapidly expands and contracts.

When water changes from one state to another, heat is either _______________ or ________________, and this greatly affects atmospheric motions that ______________________ __________________.

absorbed or released, create weather and climate

The Fujita tornado intensity scale ranks tornadoes __________________________________ ___________________________.

according to their path of destruction, wind, speed, and duration.

Glaciers have alternatively _______________ and _______________ over the past 2 million years. Periods of extensive glacial coverage are called _____ _______, during which average global temperatures decrease by _____________________________. Ice ages alternate with warm periods called ___________________________.

advanced and retreated. ice ages. 5 degrees Celicus. interglacial intervals

Frontal thunderstorms are produced by ______________________________________ and rarely, warm fronts. Because they are not dependent on day time heating, these thunderstorms can persist ______________________________________________.

advancing cold fronts. long into the night

The continual motion of ___________ and _______________ reallocates heat energy and brings it into __________________. Virtually everything that we consider to be _______________ is part of the constant redistribution of Earth's _____________ ______________________.

air and water. balance. weather. heat energy

Barometers measure _______________________ using mercury. Changes in air pressure are indicated by ______________________________________________________________________________.

air pressure. changes in the height of a column of mercury

The level of both carbon dioxide and water vapor are critical because they regulate the ___________________________________________________________.

amount of energy that the atmosphere aborbs

Tropical cyclones require 2 basic conditions: ________________________________________ ________________________________________________. In the Pacific Ocean, they are known as ___________________, and in the Indian Ocean, they are simply called _____________.

an abundant supply of very warm ocean water, and some sort of disturbance to lift warm air. typhoons. cyclones.

During the average human lifetime, climates do not ______________________________________. However, climates always have been in a constant ______________________________________.

appear to change significantly. state of change

The amount of ____________ on Earth is constantly changing. It can range from as much as ______ percent to as little as ________.

atmosphere water vapor, 4%. zero

The energy radiated by Earth's surface is absorbed by the ____________________ and warms air through the processes of ____________________ and _________________________.

atmosphere. conduction and convention

Heat is the transfer of energy that fuels ________________________________________, while temperature is used to _____________ and ___________ that energy.

atmospheric process. measure and interpret

A radiosonde is a ______________________ package of sensors that is used to gather upper-level data. These sensors measure ______________________________________________________ and are sent by radio signal to a ground station that tracks the movements of the radiosonde.

balloon-borne. temperature, air pressure and humidity

Convection is the transfer of energy ______________________________. As warm air rises, it ________________ and starts to cool. When it cools enough, it begins to ___________ because it increases in ___________________________.

by the flow of heated matter. it expands. sink. density.

When the stepped leader near the ground, a channel of positively charged ions, ____________________________________________, rushes up to meet it. The return stroke surges from the ground to the _________, illuminating the channel with ___________________ __________________________.

called the return stroke. cloud. about 100 million volts of electrictiy.

The eye is the _____________________________________, while the strongest winds in a hurricane are concentrated in a band surrounding the eye called the _____________.

calm center of the storm. eyewall

Early life forms in the oceans used _________________________ during photosynthesis and released __________________ and _________________________. Over time, oxygen built up to levels that allowed the evolution of ______________________________________________________________ _________________________________.

carbon dioxide, oxygen and water vapor, organisms that required oxygen for life processes.

The human alteration of the carbon cycle has the potential to __________________________ ______________________________________________________________________________________.

change global climate and therefore the environments of food-producing regions.

The weather that we experience is largely the result of ________________________________ ____________________________. Meteorologists must gather _______________________________ at heights of up to _____________________.

changes that take place high in the troposphere. atmospheric data. 30,000 m.

Hydrometeors are _____________________________________________________ that contain water in any phase. Lithometeors are __________________________________________. Thunder and lightning are _____________________________, which are manifestations of atmospheric electricity.

cloud droplets and forms of precipiation. smoke, haze, dust, and other condestation nuclei. are examples of electrometers

Human activities also release sulfur into the atmosphere when _________________________ _____________________________. Sulfur in the atmosphere is converted to ____________________ ________________.

coal and oil are burned to produce electricity. sulfuric acid.

Large bodies of water affect the climates of ____________________ because water heats up and cools down more ______________________________________. Many coastal regions are __________________ in the winter and _____________ in the summer than inland areas.

coastal areas. slowly than land. warmer. cooler.

Ground-level ozone is produced when ________________________________________________ ______________ are exposed to sunlight.

combinations of air pollutants

Analog forecasts involve ____________________________________________________________ ____________________. It is useful for conducting ______________ or _________________ forecasts, which are based on the past behavior of _______________________________________.

comparing current weather patterns to patterns that took place in the past. monthly or seasonal. cyclic weather patterns.

The stratosphere is made up mainly of _____________________________, and it increases in temperature to the ________ of the layer.

concentrated ozone. top

A cold front that moves into warmer territory can lift and __________ a continuous supply of warm air. When this happens, a line of __________ can last for hours or days as they ____ ____________________________________________________________________________________.

condense. thunderstorms. coutinually regenrate themselves with the new, warm air introduced into the updrafts.

When air reaches the dew point, water vapor ____________ around condensation nuclei, which are _________________________________________________.

condenses. small particles in the atmosphere around which cloud droplets form. sea salt and dust. cloud

Individuals can combat global warming by ___________________________________________, which reduces consumption of fossil fuels.

conserving energy

While the Earth is absorbing solar radiation, it is also ________________________________ ____________________. Only about 50% of incoming solar radiation is ____________________ by the Earth's surface.

continuously sending energy back into space. absorbed

Mountain climates are usually ________________ than those at sea level.

cooler.

The Coriolis effect causes moving air in tropical cyclone to turn ______________________ in the Northern Hemisphere. This produces a _________________________________.

counterclockwise. cyclonic rotation

As the air in cyclone rises, the air pressure in the center of the storm continues to ___________________, while surface wind speeds _________________.

decrease. increase

Because the Earth rotates from west to east, the Coriolis effect causes moving air particles to __________ to the right in the ____________ hemisphere and to the ______ in the ____________ hemisphere.

deflect. northern. left. southern.

The ________ _______________ is the temperature to which air must be cooled in order to reach saturation, which is the point at which ___________________________________________.

dew point. the air holds as much water vapor as they can

Some satellites use infrared imagery to detect _______________________________________, which are used to map cloud cover or surface temperatures.

differences in thermal energy

Violent _______________ that are concentrated in a local area are called _______________. Based on the size of the area they affect, downbursts are classified as either______________ _______________________ .

downdrafts. downbursts. macrobursts and microbursts.

Climate changes can be triggered by the immense quantities of ________ released by volcanic eruptions. This dust blocks ______________________________________________________ _____________________.

dust. incoming solar radiation and thus lowers global temperatures

The single largest source of air pollution in the U.S. is the ________________________________ ___________________________________________.

exhaust from motor vehicles that burn fossil fuels in the form of gasoline.

Narrow bands of __________________________________________________ called jet streams flow at speeds up to ______________ at elevations of 10 to 12 km.

fast, high-altitude, westerly winds. 185 km/h

Near the equator, the trade winds from both hemispheres converge and are _____________ ___________, creating an area of ______ __________________ called the intertropical convergence zone (ITCZ).

forced upward. low pressure

Polar zones are located ______________________________________________, where solar radiation strikes at a _______________________.

from 66.5 degrees north and south of the equator to the poles. low angle.

Winds are named for the direction _______ _______ they blow. The prevailing westerlies are responsible for __________________________________________________________________.

from which. the movement of weather systems across the U.S. and Canada

Disturbances form along jet streams and _____________________________________________ __________________________________________________.

give rise to large-scale weather systems that transport cold air toward the tropics and warm air toward the poles.

The Coriolis effect combines with imbalances in heat to produce distinct ___________________ _________________ that transport colder air to warmer areas and warmer air to colder areas.

global wind systems

The retention of ______________________________________ results in the greenhouse effect, which is the _____________________________________________________________________________.

heat by the atmosphere. natural heating of Earth's surface caused by certain atmospheric gases called greenhouse gases.

As water vapor in the air condenses, ________________ is released. This heat warms the ______. This latent heat can provide energy to a _________________________, thereby increasing its intensity.

heat. air. weather system

Because the strength of a thunderstorm is related to its ________________, infrared imagery can be used to establish __________________________________________________________ _______________________________.

height. a storm's potential to produce severe weather.

Normals, or standard values, for a location include weather data such as __________________ _________________________________________________________________________________________.

high and low temperatures, amounts of rainfall, wind speed and direction, humidity, and air pressure

When buildings are constructed with _______________________________________________, or if they have cracks in their foundations, ___________________________________________________.

hollow concrete blocks. radon gases can enter and build up to high levels indoors.

Under the right conditions, wind shear can produce a __________________________ near the earth's surface. If this rotation takes place close enough to _______________________ ___________, the column of wind can be tilted from a _________________ to a _____________ position.

horizontal rotation. to the thunderstorm's updrafts. horizontal to a vertical

The amount of water vapor in the air is referred to as _______________. The ratio of water vapor in the air relative to how much water vapor that the air is ___________________ ____________ is called relative humidity.

humidty. capable of holding

A storm surge occurs when _______________________________________________________, where it washes over land. When this occurs during high tide, ___________________________ ________________.

hurricane-force winds drive a mound of ocean water toward coastal areas. the surge can cause enormous damage.

A temperature inversion is an _______________________________________. This can involve the rapid cooling of ________ on a cold, clear winter night when the ____________ is calm. Temperature inversions can worsen __________________________ by acting as a lid to trap pollution under the inversion layer.

increase in temperature with height in a atmospheric layer. wind is calm. air-pollution problems

Scientists theorize that it is possible to ______________________ or ___________________ the greenhouse effect by ___________________________________________________________________. This can lead to a rise in global temperatures, known as _____________________________________.

increase or decrease. changing the amount of atmospheric greenhouse gases, particurlary carbon dioxide. global warming

Usually radon gas seeps upward through the soil and is released ________________________, where it is diluted to __________________________________.

into the atmosphere. harmful levels.

Lines of equal air pressure are called _____________________ and lines of equal air temperature are called _______________________.

isobars. isotherms

What does a ceilometer measure and estimate?

it measures the height of cloud layers and estimates the amount of sky covered by clouds

When cloud droplets collide, they ____________________________________________________. Eventually the droplet becomes too heavy to be held ___________ and the droplet falls to Earth as ________________________.

join together to form a larger droplet in a process called coalescence. precipitation

Over the course of a year, Earth sends back into space ______________________________ ______________________________________. If the Earth sent back too much, _______________ _______________. If it sent back too little, ______________________________________________.

just as much energy as it recieves from the sun. it would gradually cool off. it would warm up to potentially dangerous levels.

The one positive effect of an El Nino is that the strong upper winds _____________________ _____________________________________. This results in fewer hurricanes for the duration of the El Nino.

keep tropical disturbances from increasing to huricanes in the Atlantic Ocean

An air mass is a _____________________________________________________________________. The region over which an air mass forms is the ___________ region, and it can be either _______ or _______________.

large body of air that takes on the charactersitics of the area over which it forms. source. land or water.

Electromagnetic waves in a weather radar system are programmed to bounce off ________ __________________. The radar system rotates in a ______________, allowing meteorologists to gauge where _______________________________________.

large raindrops, circle. rain is falling within the radar's range.

Forecasts in the one- to three-day range are dependent on the behavior of _____________ ________________________________________. At the four- to seven-day range, forecasts must predict changes in the weather based on ________________________________________________ ______________________________.

larger surface and upper-level features. circulation patterns throughout the troposphere and lower stratosphere.

Tropical cyclones occur most frequently in the ______________________________, when the Earth's ocean contain ________________________________________________.

late summer and early fall. their greatest amount of stored heat energy

To plot weather data, meteorologists use isopleths, which are ____________________________ ___________________.

lines that connect points of equal or constant values

The Sun's rays are more spread out when they strike the Earth at a ________________________. Thus, solar radiation at the poles is _________________________. This explains why the tropics are _____________ than the poles.

low angle. therefore less intense. warmer

A wave cyclone is a type of _________________________ system. It usually begins as a _________________ front. An imbalance causes part of the front to move ____________ as a ________ front and another part to move __________ as a __________ front. This sets up a counter-clockwise, or ____________________ circulation.

low pressure. stationary. south. cold. north. warm. cyclonic

In the lower atmosphere, air generally moves from areas of ________ density to areas of _______ density. The air moves in response to __________________________________________ ________________. Wind can be thought of as ___________________________________________ __________________.

low. density imblanaces created by the equal heating and cooling on Earth's surface. air moving from one area of high pressure to an area with low pressure.

Deforestation, the _________________________________________________, plays a role in increasing levels of atmospheric CO2 because vegetation _________________________________ ____________________________________.

mass removal of trees. removes carbon dioxide from the atmosphere

A front is the ________________________ separating two air masses of different _________ ____________. There are four main types of fronts: ________, _________, ______________, and ______________.

narrow region. densities. cold fronts, warm fronts, stationary fronts, and occluded fronts

An air mass undergoes air mass modification when it acquires some of the characteristics of the ___________________________. Eventually an air mass's characteristics are the same as the new surface over which it is travelling. At this point, _________________________________ ______________________________________________________________________.

new surface beneath it. the air mass has losts it original identify and is now simply part of the air over the new source region.

Nitrogen oxides are converted to _____________________, which return to Earth in ________ ________________________.

nitric acid. acid precipitation

About 99 percent of the earth's atmosphere is composed of ___________ and ____________. The percentages of these components are _______________ to life on Earth.

nitrogen and oxygen, critical

Air contains substances that all organisms need to survive, including _______________________ __________________________________________________________________________________________.

nitrogen, oxygen, carbon dioxide, hydrogen, methane, and ozone.

You can tell how fast the wind is blowing in an area by __________________________________ ______________. If they are close together, they indicate a __________________________________ _______________________, which causes strong winds.

noticing how closely the isobars are spaced. large pressure difference over a small area

Mountain thunderstorms occur when an air mass rises because of ____________________ _________________.

orographic lifting

The major chemical in smog is _______________, a gas molecule made up of _______________ _____________________________.

ozone (O3). three oxygen atoms.

Since the 1980's, atmospheric studies have indicated a thinning of the ____________ __________, especially over __________________________. This depletion is entirely the result of ______________________________________.

ozone layer. Antarctica. human activity

Smog is a ____________________________ caused by the action of solar radiation on an ______ ______________ polluted by _________________________ and ____________________ mostly from automobile exhaust.

photochemical haze. atmosphere. hydorcarbons and nitrogen oxides

If the current trend of rising global temperatures continues, ____________________________ _________________________________________________________________________.

polar ice caps might melt, sea level might rise and flood coastal cities, deserts could spread into fertile regions, and the frequency of storms could increase

Air pollution results when ___________________________________________________________ _____________________________________________________________.

pollutants in the air occur quanites that become harmful to human health and the health of the enivornment.

Acid precipitation is defined as _____________________________________________________. It forms when sulfur dioxide and nitrogen oxides combine with ______________________________ ________________ to create sulfuric acid and nitric acid.

precipitation with pH less than 5.0. atmospheric moisture

All forecasts become less reliable when they attempt to _______________________________ _________. The most accurate and detailed forecasts are ________________________ in nature.

predict long-term changes in the weather. short-term

In the atmosphere, temperature is directly proportional to ______________. The relationship between temperature and density is _______________ proportional. Temperature varies with changes in both ___________________________________. The ratio of pressure to density decreases with increasing ______________________.

pressure. inversely. pressure and density. altitude

The ozone layer in the stratosphere serves as a _________________________________________ as it absorbs and filters out ___________________________________________, which has been linked to eye damage and _______________________________________.

protective shield. harmful ultraviolet radiation. skin cancer

The Sun is shining on and warming some portion of the Earth's surface at all times through the method of energy transfer called ______________________.

radiation

Examples of precipitation include ___________________________________________________.

rain, snow, sleet, and hail

By burning fossil fuels and using fertilizers that contain nitrogen, humans _________________ ________________________________________ into the atmosphere as do the natural processes of the nitrogen cycle.

release about three times as much nitrogen oxide and ammonia gases.

In surface low-pressure systems, air _____________. This air is replaced by air from ______ ______ of the system, so the net flow is ________________ and ______________. In the northern hemisphere, air in a low-pressure system moves in a _____________________________________.

rises. outside. inward and outward. counter-clockwise direction

Seasons are _______________________________________________________ caused by regular variations in __________________________________________________. These variations are the result of changes in the amount of _________________________________ that an area receives.

short-term periods of climatic change. daylight, temperature, and weather patterns. solar radiation

In a surface high-pressure system, air ___________ and spreads away from the __________. This air is deflected to the __________ by the Coriolis effect, making the overall circulation move in a __________________________ in the northern hemisphere.

sinks. center. right. clockwise direction

Evidence of a possible link between __________________________ and ____________________ was proposed by E. W. Maunder in 1893. He correlated a period of very low sunspot activity with an unusually ____________________________________ called the ________________________.

solar activity and the Earth's climate. cold climate episode. "Little Ice Age"

Over a period of about 26,000 years, Earth wobbles as it _____________________________. Currently the axis points toward _______________________, Polaris. By the year 14,000, the axis will point toward ___________, another star.

spins on its axis. the North Star. Vega

The National Weather Service in the U.S. has established a _____________________________ ________________________, which gathers data in a _______________ manner at ________________ intervals.

surface observation network across the country. consistent. regular

Cameras mounted aboard a weather satellite ________________________________________ _____________. Satellites track _______________, but not necessarily precipitation. Scientists combine data from radar and satellites to determine where _______________________________ ______________.

take photos of Earth at regular intervals. clouds. both clouds and precipitation are occuring

Sea-breeze thunderstorms are local air-mass thunderstorms caused by __________________ __________________________________. They are most common in coastal areas during the ____________, especially in the _______________ and ________________________.

temperature differences between the air over land and the air over water. tropics. subtropics

Meteorologists measure the atmospheric variables of ____________________________________ ________________ in order to make accurate weather forecasts.

temperature, air pressure, wind, relative humidity

Relative humidity varies with _________________________ because warm air is __________ __________________ than cool air. Relative humidity is expressed as a _____________. If a volume of air is holding the maximum amount of water vapor, then its relative humidity is _____%.

temperature. capable of holding more moisture. percentage. 100

Infrared images allow meteorologists to determine the __________________________ of a cloud, from which they can infer ________________________________________________________. This is especially useful in detecting ______________________________ that extend to great heights in the atmosphere.

temperature. its type and its height. strong thunderstorms

Sometimes clouds form when two air masses of differing __________________ collide. As warm air moves into an area of cool air, the bulk of it will be forced to _____________________ ____________________________. As warm air rises and cools, _______________________________ ____________________________.

temperatures. rise over the more-dense, cold air. the water vapor in ti condenses and forms a cloud

Two of the most important factors in weather forecasting are _____________________________ ___________________, which refers to the amount of data available.

the accuracy and the density of the data

Carbon monoxide interferes with _____________________________________________________ __________________________________________________________.

the body's ability to absorb oxygen and cause headaches, chest pain, and nausea.

When 20% of the occupants of a building experience symptoms caused by indoor air pollutants, _______________________________________________________________. New buildings are more likely to be "sick" because _______________________________________________________ _______________________________________________________________.

the building is said to be "sick". they are more air tight, in order to keep heating and cooling costs lower.

If rain falls faster than __________________________, flooding can occur. Floods are the main cause of _______________________________________in the U.S. each year.

the ground can absorb it. thunderstorm-related deaths

Thunderstorms are classified according to ____________________________________________. An air mass thunderstorm forms if ______________________________________________________ ___________________. This reaches its maximum during _________________________, so air-mass thunderstorms are most common then.

the mechanism that caused the air to rise. the air rose because of unequal heating of Earth's surface within one air mass. mid-afternoon

The tropics, between 23.5 degrees North and South of the equator, receives _____________ __________________________ because the Sun's rays ________________________________________ __________________________.

the most solar. strike that area from almost directly overhead.

Lightning is electricity caused by __________________________________. A lightning bolt forms when ______________________________________ separates electrons from some of their atoms either in the cloud or near the ground. To relieve the electrical imbalance, ________

the rapid rush of air in a cumulonimbus cloud. friction between updrafts and downdrafts. an invisible channel of negatively charged air moves from the cloud to the ground.

As the instability of the air increases, the strength of _________________________________. The storm may develop into ___________________________________________________________.

the storm's updrafts and downdrafts intensifies. a self-sustaining, extremely powerful supercell, characterized by intense, rotating updrafts.

Climatology is the _____________________________________________________________________.

the study of Earth's climate and the factors that affect past, present, and future climatic changes.

Scientists still disagree about what is causing global warming. However, mounting evidence indicates that ________________________________________________________________ ___________________________________________________________________.

the warming trend is a result of increase in atmospheric carbon dioxide

Heat is the ____________________________________________________________________________.

transfer of energy that occurs because of a difference in temperatures between substances

Air masses eventually move from their source regions and ______________________________, establishing a heat balance in the process.

transform heat from one region to another

Studies of _____________________________________________ and _______________________ provide evidence of past climatic changes.

tree rings, ice-core samples, fossils, and radiocarbon samples

Tropical cyclones thrive on the ______________________________________________________.

tremendous amount of energy in warm, tropical oceans.

Large, rotating, low-pressure storms that are born in the tropics are called _____________ _____________. The strongest of these storms are known in the Atlantic Ocean as ______________.

tropical cyclones. hurricanes

The ______________ contains most of the mass of the atmosphere, including the water vapor. This is the layer in which most ________________ takes place, and it is characterized by a decrease in ________________ from bottom to top.

tropshere, weather, tempature

Some pollutants undergo _________________________________ that are triggered by reactions with __________________________________. An example is _________________________, which forms when a mixture of nitrogen oxides and volatile organic compounds _____________ __________________________________________________________.

ultraviolet (UV) radation. photochemical smog. interact under the influence of sunlight.

Air can become ___________________ if it is cooler than the surface beneath it. If temperature conditions are right and the air mass ______________________, it can produce the types of clouds associated with thunderstorms.

unstable. rises rapidly

Convection currents are one of the main mechanisms responsible for the ____________ _____________________, which in turn cause the different types of weather

vertical motions of air

Clouds form when ______________________________________________________________ in a convection current.

warm, moist air rises, expands, and cools

Studies indicate that increased solar activity coincides with ____________________________ _________, while periods of low solar activity coincide with ________________________________.

warmer-than-normal climates. cold climatic conditons

Normals are the average ______________________________________________________________.

weather conditions over a long period of time

__________________ is the current state of the atmosphere. Usually this refers to short-term variations. Long-term variations in weather for a particular area is the _________________. It is usually averaged over a ______ year period.

weather. climate. 30

The climate on the windward side of a mountain is usually ____________________________. On the leeward side, the air is ________, and it ______________ as it descends. _______________ are common on the leeward sides of mountains.

wet and cool. dry. warms.

Clouds also form through orographic lifting, which is ____________________________________ _________________.

when wind encounters a mountain and the air has no place to go but up.

Tropical cyclones move according to the ______________________________________. They move steadily toward the ________, then turn poleward when______________________________________ ____________________.

wind currents that steer them. west. they reach the far edges of the high-pressure systems.