Science 3/9 test

Pressure

Pressure

force per unite area exerted by the atmosphere

Temperature

A measure of how hot or cold something is. This can affect the amount of water the air can hold. Warm air holds more water than cold air.

dew point

Temperature at which dew forms and is a measure of atmospheric moisture. The higher the dew point, the greater amount in the air mass

relative humidity

The amount of moisture in the air compared to what the air can "hold" at a specific temperature. This is expressed as a percentage.

wind

the movement of air caused by differences in air pressure. This is the movement from high pressure (cool) to low pressure (warm)

Cumulus

a cloud forming rounded masses heaped on each other above a flat base at fairly low altitude. fluffy ones

Cirrus

Wispy, feathery clouds made of ice crystals that form at high levels.

Stratus

Clouds that form in flat layers and often cover much of the sky.

cold front

cold air mass overtakes a warm air mass, quickly forcing the warm air up. This usually creates heavy precipitation.

warm front

warm air mass overtakes a cold air mass. This is slow moving and usually creates light precipitation

stationary front

warm air mass staying still next to a cold air mass, causing lots of precipitation. The precipitation is usually long lasting.

occuled front

a warm air mass is caught between two cooler air masses. It slowly overtakes a cold air mass but is then pushed by another cold air mass. Usually creates cyclones and severe weather.

rain

water falling in drops from vapor condensed in the atmosphere

snow

precipitation falling from clouds in the form of ice crystals

hail

precipitation of ice pellets when there are strong rising air currents

sleet

clear ice pellets precipitation, forms when rain falls through layer of freezing air. This one hurts

freezing rain

raindrops that freeze after they hit the ground or other cold surfaces

dew

tiny drops of water that form on cool surfaces at night, when atmospheric vapor condenses.

frost

Ice formed when water vapor changes directly into ice crystals

Water Cycle

1. Water from precipitation gets collected in bodies of water.

2. Water is heated up and evaporated into water vapor.

3. The water vapor accumulates until the air is completely saturated with water and condenses.

4. The condensed water vapor comes down as precipitation.

Tropical

Air from the South, warm weather

Polar

Air from the north, cold weather

Maritime

Air from the sea, moist weather

Continental

Air from land, dry weather

Air Masses

• mP- Maritime Polar= wet+cold

• mT - Maritime Tropical= wet+warm

• cP- Continental Polar= dry+cold

• cT- Continental Tropical= dry+warm