Physical Geography Exam 2 pt. 1

Absolute Humidity

The real, actual amount of humidity

Unit used for absolute and saturation humidity

Gr/ft³

Saturation humidity

The maximum amount of water vapor air can hold

Saturation humidity depends on

The air’s temperature

The warmer the air =

The more capacity humidity can be held

Humidity

Water vapor

Relative humidity

the ratio of real and saturation humidity

Relative humidity’s equation

AH/SH x 100%

How humid it feels is from which humidity

comes from the relative humidity

33% humidity is

Dry

67% humidity is

Humid

Dew point temp

The temperature that the air would have to cool to have relative humidity 100%

How does absolute humidity saturates the air

When AH = SH meaning the RH = 100%

What happens when the air can not hold anymore water

Condensation

What do we need cooling air for

Condensation and precipitation

Normal environmental lapse rate (ELR)

The actual rate at which temperature decreases with height in the atmosphere

Example of ELR

Increase in altitude = decrease in temperature

Dry adiabatic lapse rate

The rate at which vertical moving air cools as it rises or warms as it decreases

What is the RH for dry adiabatic lapse rate

RH < 100%

What is the RH for moist adiabatic lapse rate

RH = 100%

Windward

Wet

Leeward

Warm and dry

What is the rain shadow effect

Warm and moist air moves in, air rises then descends, creating this effect that causes no precipitation

Windward side of a mountain

Heavy precipitation

Leeward side of a mountain

Little to no precipitation

Condensation

Only forms, does not fall

How many forms of condensation are there

4 types

What are the 4 types of condensation

Dew, Frost, Fog, Clouds

Acronym for how to remember the types of condensation

Dont Forget Forming Condensation!

What is Dew?

Forms on clear nights when the ground loses heat (radiation cooling) the ground cools adjacent air (conduction) and forms on cold surfaces

What is Frost?

Same as dew, air near ground cools below DPT and if it is below, ice crystals form

What is Fog?

Clouds near ground : 50 ft, air near ground cools to dew point and it has no surface for condensation, suspended water droplets

What are Clouds?

Suspended water droplets above 50 feet, limit sunlight, provides percepitation

How many types of precipitation are there?

5 types

What are the 5 types of precipitation?

Rain, Snow, Sleet, Freezing Rain, and Hail.

What is the acronym to remember the types of precipitation?

RSSFH

What is Rain

Liquid

What is Snow

Crystal form of water

What is Sleet

Frozen raindrops, cold rain freezes before hitting ground

When does sleet occur

Late autumn

What is Freezing Rain

rain that freezes on cold ground, ice storm

When does freezing rain occur?

Late fall / winter

What is Hail

Strong updrafts add layers of ice

What cloud does hail come from

Comes from cumulonimbus clouds

When does hail occur

Summer

6,500 ft - low cloud

strato

~20,000 ft - medium cloud

alto

+20,000 ft - high cloud

cirrus

Stratus cloud

horizontal, cover most of sky

Cumulus cloud

vertical, individual clouds, blue sky between

low horizontal cloud

stratostratus

low vertical cloud

stratocumulus

medium horizontal cloud

altostratus

medium vertical cloud

altocumulus

high horizontal cloud

cirrostratus

high vertical cloud

cirrocumulus

what height cloud type usually has precipitation

precipitation with cirrus

Nimbus (nimbo) clouds

Dark and rainy

what is a lifting mechanism

air must rise and cool to form clouds and percipitation

there are 4 types of this

lifting mechanisms

what are the 4 types of lifting mechanisms

Orographic, Convectional, Cyclonic, and Frontal

Oro =

mountain

orographic

rising over a mountain

convectional

differential heating of warm, humid air

what latitudes are in convectional lifting

Mid for summer / Low all year

Cyclonic

air circulating into a low pressure cell

front =

border between unlike air masses (warm and cold)

frontal

warmer air rises over cooler air

air mass

large body of air with fairly uniform conditions (humidity and temp)

source region of air masses

supplies air mass; air masses move, changes characteristics

m=

maritime (humid / wet)

c=

continental, dry

E=

equatorial, hot

T=

tropical, warm

P=

Polar, cool

A (AA)=

arctic (antarctic), cold

What air masses do not exist?

cE and mA

cE=

dry hot (doesnt exist)

mA=

wet cold (doesnt exist)

Cold Front

cool advancing into warm air

how is a cold front shown on a map

triangles (icicles) - point where air is moving

warmer air has

high pressure, clear

Cooling air has

low pressure, cumulonimbus

cold air has

very high pressure, clear

What front travels faster? Warm or Cold?

Cold

Warm front

warm advancing into cool air

how are warm fronts displayed on a map

half circles

cirrus clouds with warm fronts:

high pressure and low temp.

stratiform clouds with warm fronts:

low pressure, light rain (drizzle)

clear skies with warm fronts:

high pressure

Frontal storms (mid-latitude cyclone)

low pressure cell, cyclonic circulation, travel east —>, jetstreams, westerlies

where do frontal storms originate

along the polar front (50-60 degrees) - rossby waves

Occluded Front

cold front caught up to warm front, warmer air lifted off ground

How are occluded fronts represented on the map

alternation of cold and warm front symbols, point to cold air

Stationary Front

neither air mass are pushing

how are stationary fronts represented on a map

cold and warm front symbol placed if the air were to move