5/31 Air Masses, Fronts And Weather Climate

Front 1

: horizontal air flow (advection).

Back 1

Wind

Front 2

Winds blow in response to differences in what?

Back 2

pressure

Front 3

Wind speed is determined by the magnitude of the pressure difference overdistance, called the. . . .

Back 3

pressure gradient

Front 4

Rising ___-_____ air creates clouds andprecipitation. Air flows inward toward the ________-_____ zone, creating _______ winds.

Back 4

low-pressure, surface

Front 5

Sinking high pressure air creates _____skies. Airflows outward from the high-pressure zone, andalso creates surface winds.

Back 5

clear

Front 6

A surface map marked with H's and L's indicate high and low pressurecenters. Surrounding these "highs" and "lows" are lines called_____ .

Back 6

isobars

Front 7

"Iso" means "equal" and a "bar" isa unit of pressure so an isobar means. . .

Back 7

equal pressure.

Front 8

The closer the isobars are packed together the ______ the pressure gradient is.

Back 8

stronger

Front 9

Pressure gradient is the ______ ___ pressure between high and low pressure areas.

Back 9

difference in

Front 10

Wind speed isdirectly ______ to the pressure gradient.

Back 10

proportional

Front 11

the strongest winds are in the areas where thepressure gradient is the _____ .

Back 11

greatest

Front 12

Wind direction is ____ around a high pressure system and _____ around a lowpressure system.

Back 12

clockwise, counter-clockwise

Front 13

The _____ _____ deflects winds tothe right in the Northern Hemisphere,and to the left in the SouthernHemisphere.

Back 13

Coriolis effect

Front 14

: a low pressure region with an accompanying surface wind

Back 14

Cyclone

Front 15

: a high pressure system with accompanying winds

Back 15

Anticyclone

Front 16

In the Northern Hemisphere,a cyclone consists of windsspiraling ________ into a low pressure region.

Back 16

counterclockwise

Front 17

An anticyclone consists ofwinds spiraling _______ out from a high-pressurezone.

Back 17

clockwise

Front 18

Low barometric pressure is anindication of _____ weather.

Back 18

wet

Front 19

A(n) ____ has converging surface winds and rising air causing cloudy conditions.

Back 19

cyclone

Front 20

A(n) ______ has diverging surface winds and descending air which leads to clear skies and fair weather.

Back 20

anticyclone

Front 21

An _____ _____ is a large body of air with approximately uniform _______ and humidity at anygiven altitude.

Back 21

air mass, temperature

Front 22

The boundary between a warmer air mass and a cooler one is called a ____.

Back 22

front

Front 23

Air masses are classified by their ____ regions

Back 23

source

Front 24

Distinguish continental, maritime, polar, and tropical air masses.

Back 24

Continental-dry

Maritime - wet

Tropical - warm

Polar - cold

Front 25

Fronts are classified by whether a ____ air mass moves toward astationary (or more slowly moving) ____ mass, or visa versa.

Back 25

warm, cold

Front 26

A ____ _____ forms when moving warm air collides with a stationary (or more slowly moving)cold mass.

Back 26

warm front

Front 27

A warm front. The moving ___ air rises over the ____dense air as the two air masses collide.The rising ___ air cools adiabatically and the _____ generates clouds and precipitation.Precipitation is generally ____ because the air rises slowly along the gently sloping frontalboundary.

Back 27

warm, cooler, warm, cooling, light

Front 28

A ______ forms when moving cold air collides with stationary or slower moving warm air.

Back 28

cold front

Front 29

A cold front. The dense, cold air distorts into a blunt wedge and pushes ___ the warmer air. Thus theleading edge of the cold front is much _____ than that of a warm front. The steep contactbetween the air masses causes the warm air to rise rapidly, creating a narrow band of severweather commonly accompanied by ______ and cumulonimbus clouds.

Back 29

under, steeper, cumulus

Front 30

An _____ _____ forms when a faster moving cold mass traps a warm air mass against asecond mass of cold air.

Back 30

occluded front

Front 31

A ____ ____ occurs along the boundary between two stationary air masses. Underthese conditions, the front can remain in an area for several days.

Back 31

stationary front

Front 32

A ______-______ desert forms where moist air rises over a mountain range and precipitates mostof its moisture on the ______ side and crest of the range. The dry, descending air on the ___ side absorbs moisture, forming a desert.

Back 32

rain-shadow, windward, lee

Front 33

Sea breezes blow inland during the day , and land breezes blow out to sea at night .

Back 33

day, night

Front 34

A ______ is a seasonal wind and weather system caused by uneven heating andcooling of continents and oceans.

Back 34

monsoon

Front 35

Rain-shadow is a type of _______ lifting.

Back 35

orographic

Front 36

The sun heats the earth's surface during the day. The heat on the surface warms the air around it.Since warm air is lighter than cool air, it starts to rise (known as an _____ ).

Back 36

updraft

Front 37

If the air in an updraft is moist, then thewarm air condenses into a _____ cloud. The cloud will continue to grow as long as warm air below itcontinues to rise.

Back 37

cumulus

Front 38

When a cumulus cloud becomes very large, the water in it become large and heavy. Raindrops startto fall through the cloud when the ______ air can no longer hold them up. Meanwhile, cool dry air startsto enter the cloud. Because cool air is heavier than warm air, it starts to descend in the cloud (knownas a _________). The ______ pulls the heavy water downward, making rain.

Back 38

rising, downdraft

Front 39

A cumulus cloud has become a cumulonimbus cloud because it has an updraft, a downdraft, and rain.Lightning and thunder start to occur, as well as heavy rain. The cumulonimbus is now a _______ cell.

Back 39

thunderstorm

Front 40

After about 30 minutes, a thunderstorm begins to dissipate. This occurs when the _______ in thecloud begins to dominate over the _______. Since warm _____ air can no longer rise, cloud dropletscan no longer form. The storm dies out with light rain as the cloud disappears from ______ to _____.

Back 40

downdrafts, upodrafts, moist, bottom to top

Front 41

A ______ is a small, short-lived funnelshapedstorm that protrudes from thebase of a cumulonimbus cloud.

Back 41

tornado

Front 42

Surface air spirals ____ toward a hurricane, rises through the towering wall of clouds, andthen flows outward above the storm. _____ air near the storm’s center creates the eeriecalm in the eye of the hurricane.

Back 42

inward, Falling

Front 43

:the state of the air and atmosphere at a particular timeand place (hour by hour or day by day)

Back 43

Weather

Front 44

:the average course or condition of the weather at aplace usually over a period of years (long-term trends)

Back 44

Climate

Front 45

mean annual temperature decreases as we move from the equator to the poles. T or F

Back 45

True

Front 46

Highest mean annual precipitation is found where?

Back 46

Around the equator, at the ITCZ

Front 47

The mean annual precipitation decreases towards the equator or towards the poles?

Back 47

the poles

Front 48

The subtropical highs are found at what latitudinal degrees?

Back 48

30 degrees N and 30 degrees S

Front 49

Eastern margins of the continental 48 are _____ than the western margins with respect to mean annual precipitation.

Back 49

wetter

Front 50

Eastern margins receive _____ winds, whereas, the Western receive ______ winds

Back 50

tropical, polar

Front 51

The ITCZ varies with the _______.

Back 51

seasons

Front 52

Autumn and Spring, ITCZ found....

Back 52

at the equator

Front 53

Summer, ITCZ found

Back 53

about 30 degrees north of the equator

Front 54

Winter, ITCZ found

Back 54

about 30 degrees south of the equator.