Meteorology Chapter 5

Front 1

Study!

Back 1

Keep up the good work!

Front 2

How do clouds form?

Back 2

rising air expands and cools adiabatically, lower temperature causes relative humidity to rise, dew point temperature is reached and condensation begins

Front 3

possible condensation surfaces in the atmosphere

Back 3

condensation nuclei

Front 4

ocean salt crystals that serve as water seeking condensation nuclei

Back 4

hygroscopic particles

Front 5

what is needed for condensation

Back 5

water vapor needs a surface to condense on

Front 6

high, white, thin clouds

Back 6

cirrus

Front 7

high clouds, cover sky. associated with halos

Back 7

cirrostratus

Front 8

high puffball clouds

Back 8

cirrocumulus

Front 9

middle level puffball clouds. AKA sheep back clouds. often signaling approaching cold front

Back 9

altocumulus

Front 10

mid level. covers sky. can form drizzle. approaching warm front.

Back 10

altostratus

Front 11

low overcast

Back 11

stratus

Front 12

chief producer of precipitation. low clouds. associated with warm fronts.

Back 12

nimbostratus

Front 13

low puffballs. instable air. no precipitation

Back 13

stratocumulus

Front 14

puffballs with rain. most sever weather. no height range. anvil shape. updraft forces overshooting top to penetrate tropopause.

Back 14

cumulonimbus

Front 15

puff ball clouds

Back 15

cumulus

Front 16

fair weather clouds

Back 16

cumulus Humilus

Front 17

clouds classification by height

Back 17

cirro- high

alto- mid

strato- low

Front 18

hooked shaped clouds, often precursors of bad weather. cirrus

Back 18

uncinus clouds

Front 19

stratus or cumulus clouds that appear broken.

Back 19

fractus clouds

Front 20

clouds with an udder shape on their bottom surface. associated with stormy weather

Back 20

mammatus clouds

Front 21

lens shapes clouds. common in mountain topographies.

Back 21

lenticular clouds

Front 22

clouds formed by jet airplane exhaust

Back 22

contrails

Front 23

cloud with its base at or near the ground

• Considered an atmospheric hazard

Most form because of

• Radiation cooling of Earth’s surface, or

• Movement of warm moist air over a cold surface

Back 23

Fog

Front 24

results from radiation cooling of the ground and air

Back 24

Radiation fog

Front 25

a blanket of fog caused by warm, moist air blowing over a cold surface.

• Some turbulence is needed

Back 25

Advection fog

Front 26

created when relatively humid air moves up a sloping landform or up the steep slopes of a mountain. (orographic lifting)

Back 26

Upslope fog

Front 27

occurs when rain falls and evaporates, saturating the cooler air below.

• Frontal wedging

Back 27

frontal (precipitation) fog

Front 28

occurs when cool air moves over warm water.

• Moisture evaporates and saturates the air above it.

• Very common over lakes in the fall

Back 28

steam fog

Front 29

the Bergeron process

Back 29

precipitation from cold clouds.

ice crystals collect water vapor to make snowflakes.

super-cooled cloud droplets evaporate to replace water vapor

Front 30

Collision–coalescence process

Back 30

(precipitation from warm clouds)

• Droplets collide with other droplets during their descent and become even larger

• They collide with more droplets and their falling velocity increases.

• Common in the tropics

Front 31

droplets of water with a diameter of at least 0.5mm

Back 31

Rain

Front 32

unusually heavy rainfalls

Back 32

cloudbursts

Front 33

fine, uniform droplets with a diameter less than 0.5mm

Back 33

drizzle

Front 34

contains the smallest droplets

Back 34

mist

Front 35

rain that evaporates before hitting the ground

Back 35

virga

Front 36

precipitation in the form of ice crystals that stays solid all the way to the ground

Back 36

snow

Front 37

ice pellets.

occurs when warmer air is between cold air.

snow turns to rain and then rain freezes as it falls

Back 37

sleet

Front 38

super-cooled rain drops that hit a surface and freeze immediately

Back 38

freezing rain

Front 39

precipitation in the form of hard, round ice pellets.

not possible in winter

created by updrafts and downdrafts in large cumulonimbus clouds

Back 39

hail

Front 40

a deposit of ice crystals formed by super-cooled fog or cloud droplets landing on an object that is below freezing.

Vapor to solid.

Back 40

rime

Front 41

catches rain water and conducts it through a narrow opening into a cylindrical measuring tube.

Back 41

standard rain gauge

Front 42

has two compartments (or buckets). When one bucket fills, it tips and empties its water and the other bucket takes its place at the funnel.

Back 42

tipping bucket

Front 43

collects rain fall in a cylinder that rests on a spring balance. As the cylinder fills, the movement is transmitted to a pen that records the data.

Back 43

weighing gauge

Front 44

what are the 2 ways that snow is measured?

Back 44

The depth is measured with a calibrated stick.

• Average of several locations

To obtain the water equivalent, snow is melted and then weighed or measured as rain.

• General ratio is 10 snow units to 1 water unit

• Varies widely

• Wet snow 4 to 1 vs. dry snow 30 to 1

Front 45

How does weather radar work and what are echoes?

Back 45

Weather radar uses radio waves to measure precipitation.

• The radio waves penetrate small droplets(clouds), but are reflected off larger ones.

• Echoes are sent back and displayed.

• Echo brightens with intensity of precipitation

Front 46

intentional weather modification

Back 46

cloud seeding

Front 47

cloud seeding for fog and cloud dispersal

Back 47

use dry ice, liquid carbon dioxide, mix dry air into saturated air, and warming air near surface (jet engines in Orly, Paris)

Front 48

Hail suppression

Back 48

shown to be ineffective.

hail cannons produce loud whistling noise and ring of smoke.

cloud seeding with silver iodine crystals

Front 49

rain making

Back 49

?

Front 50

making snow

Back 50

silver iodine crystals act as freezing nuclei

Front 51

frost prevention

Back 51

Several methods of frost prevention are being used. (conserve heat or add heat)

• Cover plants

• Water sprinklers add heat from water and from the latent heat of fusion when the water freezes.

• Air mixing uses wind machines to mix warm and cool air.

• Orchard heaters produce the most successful results, but fuel cost can be significant.