Topic 7 & 8 Earth Science

How do clouds form?

1. Air rises and cools 2. Air reaches dew point 3. Water begins to condense (gas to liquid) 4. Water droplets form on condensation nuclei (dust particles/aerosols)

Continental: Maritime: Polar or arctic: Tropical:

1. Dry 2. Wet 3. Cold 4. Warm

When gas expands, temperature _____. When gas compresses, its temperature _____.

1. decreases 2. increases

Lower temperature air = _____ density air = _____ air pressure

1. higher 2. higher

Higher temperature air = _____ density air = _____ air pressure

1. lower 2. lower

If air temperature = dew point, relative = _____%

100

How many millibars in 1 atmosphere?

1013.2 mb

What percent of Earth's water is in icecaps and glaciers

2.2%

What percent of Earth's water is in the oceans?

97.2%

Hurricane

A strong storm of tropical origin with sustained winds

What changes more rapidly: air temperature or dew point temperature?

Air temperature

What are areas of high atmospheric pressure called?

Anticyclones

Air pressure gradient

Change in air pressure over a distance

cA

Continental arctic (dry and frigid)

cP

Continental polar (dry and colr)

cT

Continental tropical (dry and warm)

What are areas of low atmospheric pressure called?

Cyclones

How does the Coriolis Effect affect winds in the Northern and Hemispheres?

Deflects to the right in the N. Hemisphere Deflects to the left in the S. Hemisphere

Which is heavier: dry air or wet air?

Dry air

Evapotranspiration

Evaporation and transpiration into atmosphere

How does water enter the atmosphere?

Evaporation, transpiration, evapotranspiration

Precipitation

Falling liquid or solid from clouds

Runoff

Flow over surface

How are occluded fronts formed?

Form when a cold front catches up to a warm front, stronger more developed storms

Stationary fronts

Fronts that are not moving forward

What drives weather?

Heat energy (insolation)

Wind

Horizontal movement of air parallel to the Earth's surface

What is needed for hurricane formation?

Humid air, warm ocean water, weak jet stream, line of thunderstorm

Hurricane vs. Nor'easter

Hurricanes are strong storms of tropical origin (low pressure) with sustained winds >74 mph. Nor'easter are coastal storms (low pressure) caused by an arctic high pressure meeting a warm low pressure system; usually E to NE winds

Water cycle

Hydrologic cycle; model used to illustrate movement/phase changes of water

Hail

Ice pellets

How are snowfall and rain measured?

In inches

Sling Psychrometer

Instrument used to measure relative humidity and dew point

How is wind deflected?

It's deflected by the Coriolis Effect

Air masses

Large body of air in the troposphere with similar characteristics (pressure, moisture, temp.)

What percent of Earth's water is drinkable?

Less than 1%

Greater degree of saturation = _____ evaporation

Lower

Higher altitude = _____ pressure

Lower

mP

Maritime polar (wet and cold)

mT

Maritime tropical (wet and warm)

Wind vane

Measures wind direction

Anemometer

Measures wind speed

What units are used for air pressure?

Millibars, inches, and atmosphere

Sleet

Mix of rain and snow

Why does convection occur?

Occurs due to differences in density.

What is Lake Effect Snow?

Occurs when cold dry air gains humidity over large lakes; winds move the cold humid air towards the land; heavy snow occurs

Where is most of the Earth's water?

Oceans

Air pressure

Pressure due to the weight of the underlying atmosphere pushing down on any given area

Freezing rain

Rain hits the ground and freezes on contact

Tornadoes

Rapidly rotating and extremely low pressure funnels that hang down from thunderstorm clouds

Relative humidity

Ratio of the amount of water vapor in the air to maximum amount it can hold; the one you see in forecasts

Where does infiltration occur?

Regolith (all loose material at the Earth's surface)

How is wind reported?

Reported by the direction wind is coming from (Wind E 5 mph)

Would a baseball travel further on a night where the air is saturated or dry?

Saturated

Infiltration

Seep, water sinks in to the ground; when water seeps into the ground and becomes subsurface water or groundwater

What factors affect infiltration?(7)

Slope, porosity, saturation, permeability, capillarity, vegetation, construction

What is the water cycle drive by?

Solar energy/Insolation

Where does moisture exist?

Solids, liquids, and gases in the atmosphere

Describe anticyclones

Spin clockwise; winds blow out from the center; clockwise and outward; high (clock)

Describe cyclones

Spin counter-clockwise; winds blow toward the center; counter-clockwise and inward; low (counter)

Weather

State or condition of the variables of the atmosphere at a given time.

How does slope affect infiltration?

Steeper slope = less infiltration

Water retention

Stored on land as ice or snow, held on leaves

Why does a weak jet stream matter for hurricane formation?

Strong jet streams causes shearing which hurts development

Dew point

Temperature at which air is saturated (filled with water)

Weather variables

Temperature, air pressure, wind moisture, cloud cover, precipitation, storms

What is the dry bulb temperature equal to?

The ordinary thermometer

Dew point temperature

The temperature at which air is saturated (filled with water)

What is the wet bulb temperature?

The temperature of the thermometer with a wet wick around it

How is air pressure often shown on weather maps?

The use of isolines called isobars

How do warm fronts move?

They are forced upward as they overtake a cold air mass, steady precipitation (lighter side)

Why do ice crystals/water fall in precipitation?

They become big enough so that they will fall by gravity

How do convection currents move?

They move in circular patterns.

How do cold fronts move?

They push forward like a wedge, showery precipitation

Why does line of thunderstorm matter for hurricane formation?

Tropical waves can merge together and form a series of convection cells (weather systems)

Where does weather occur?

Troposphere (lower layer of the atmosphere)

Fronts

Two air masses of different characteristics meet

Weather station models

Used to describe weather conditions of cities on maps

How is air pressure measured?

Using barometers

What does a warm front look like?

Warm air travels up cold air like a ramp; steady light rain or snow

What can be used as a surface for condensation to occur on?

Water droplets

What happens to precipitation?

Water retention, infiltration, runoff, evapotranspiration

Does hotter air hold more water vapor or cold air

Water vapor

Absolute humidity

Water vapor in each unit volume of air (or moisture capacity)

What weighs more: water or air?

Water weighs less than air (nitrogen and oxygen)

What does a cold front look like?

Wedge shape forcing warm air upward; rain or snow showers

When do air masses form?

When air remains stationary over an area.

When do tornadoes form?

When cold air rapidly meets with warm air

What determines an air mass's characteristics?

Where the air mass originates determines its characteristics.

Where does wind blow?

Wind blows from area of high pressure to areas of low pressure

Storm surge

Wind piling water up on coastal areas causing flooding

How catastrophic are tornadoes?

Winds can reach 200-300 mph; can cause catastrophic damage and death

When air sinks, it

compresses and warms

If the air temperature drops to the dew points, water vapor _____ to liquid water

condenses

When air rises, it

expands and cools

Greater surface area of the water = _____ evaporation

faster

More energy = _____ evaporation

faster

Faster winds = _____ damage

greater

Greater wind speed = _____ evaporation

greater