METEROLOGY EXAM 3 ALRDICH MIZZOU

Definition of fronts

Transition zones between air of different densities

Warm Fronts

red ovals pointing in the direction of warm air advancing, light rain

IMAGE: warm fronts

most warm at inner center

Cold Fronts

blue triangles pointing in the direction cold air is advancing, active weather along the cold front

IMAGE: cold fronts

coldest on the center of the line

Stationary Front

red and blue, essentially no movement, difference in air masses (north and south of front)

IMAGE: Stationary Front

Occluded Front

Purple drawn in alternating "pips" (pointing parts) where cold and warm air collide, attatched to STRONG low-pressure systems

IMAGE: Occluded Front

colder within circle, warmer on outside

Dryline Front

yellow tight "pips", separates dry and moist air

IMAGE: Dryline Front

lol sorry no image was available but tight half circles on outer edge

Frontogenesis definition

an increase in temperature contrast across a front can cause it to strengthen

Frontolysis definition

as the temperature contrast across a front lessens, the front will weaken and dissipate

REGION: Continental Polar (cP) and Continental Arctic (cA)

forms over ice and snow covered regions of Alaska and Canada and moves cold air south to Central US

WEATHER: Continental Polar (cP) and Continental Arctic (cA)

cold air moving south, but as it moves south it warms. cP air moving over Gulf of Mexico gains moisture and becomes maritime.

REGION: Maritime Polar (mP)

forms over cold waters like the North Atlantic or Pacific and moved inland over the Pacific Northwest (Washington/Oregon)

WEATHER: Maritime Polar (mP)

causes major winter storms, precipitation to west coast, moisture to New England storms

REGION: Maritime Tropical (mT)

warm moist air from sub-tropical Pacific, Gulf of Mexico and other south atlantic areas. moves inland

WEATHER: Maritime Tropical (mT)

warm, moist and unstable weather

REGION: Continental Tropic (cP)

hot and dry air masses originate over the deserts of Mexico

WEATHER: Continental Tropic (cP)

hot and very dry

What is a jetstream?

fast flowing air currents found in the atmosphere around 36,00 ft (just under tropopause)

How is the jetstream separated?

north is cold, stormy and wet weather (trough). south is warm, calm weather (ridge)

Subtropical jetsream

"southern jetstream", around latitutde 30

Polar jetstream

"northern jetstream", around latitude 30 and 60

Low Level Jetstreams (LLJ)

close earth's surface, forms over central plains. strongest at night, weakest at midday

What is a high pressure system?

clockwise wind flow, pushes air away, weather is fair and settled

What is a low pressure system?

counter clockwise wind flow, brings air in, inclement weather

What is the general circulation of the atmosphere

wind, movement of air around the planet

Where are the midlatitudes?

30-60 (middle of the world)

Why is weather so changeable?

Because wind blows jet stream around and changes weather

WHERE: Hadley Cell

0 to 30

WHAT: Hadley Cell

surface winds North to South and turning right by Coriolis, starts at equator with warm rising air

MOTION: Hadley Cell

heat up, direct, cold down

WHERE: Ferrell Cell

30 to 60

WHAT: Ferrell Cell

surface winds move south to north and turn right, large air contrast, air sinks over subtropical high

MOTION: Ferrell Cell

cold down, indirect, heat up

WHERE: Polar Cell

60 to 90

WHAT: Polar Cell

surface winds north to south and turn right, sinks at polar high because dense and cold. meets air from subtropical high and rises

ITCZ: Inter Tropical Convergance Zone

belt of low pressure close to equator where trade wints of north and south hemispheres meet

El Nino:

WARM, ocean current in Pacific around Christmas

La Nina:

COOL

Land and Sea Breezes

- a type of thermal circulation

- uneven heating rates of land vs. water create mesoscale coastal winds

- caused by temperature difference

Land breeze

wind blows from high pressure water to low land during NIGHT

Sea Breeze

wind blows from high pressure water to low land during the DAY

Monsoons

seasonally driven change in wind direction caus eby high pressure on land, wind blows from land to water

Wet Monsoon

summer, wind blows from sea to land

Dry Monsson

winter, wind blows from land to see

Wind direction

the direction from which the wind is blowing

Wind vane

spins on a post until arrow points into the wind (direction only)

Barometer

measures air pressure

Anemometer

cups on a poll and spins around faster in stronger wind (speed only)

Pilot Balloon (Weather Balloon)

instrument that takes in temperature, humidity, pressure and wind, radisonde

Radiosonde

instrument package on a weather balloon to measure air pressure, humidity, temperature, wind speed, and wind direction of the upper atmosphere

Planetary

longwaves in westerlies, 10,000 km or large, weeks or longer

Synoptic

high and low pressure systems and hurricanes, 500-2,000 km, days to weeks

Mesoscale

fronts and thunderstorms (severe weather), few-500 km

Microscale

tornados and smaller winds, less than 1 km, minutes to hours

PBL (planetary boundary layer)

microscale and mesoscale, atmospheric boundary and friction layer, SURFACE FRICTION

PGF: Pressure Gradient Force

makes wind move due to change in air pressure, measured by isobars, moving high pressure to low pressure

Coriolis Force

makes wind move due to rotation of the earth, causes wind to deflect to the right of intended path

Friction Force

reduces wind and Coriolis Force

Air will always flow from areas of ____ pressure to areas of ____ pressure

high, low

Equation of State

demonstrates that pressure, temperature, and density are related