Weather Maps, Atmosphere, Hurricanes Study Set - 8th

atmosphere

A thin layer of gases surrounding Earth

Atmospheric Composition

A mixture of gases: 78% nitrogen, 21% oxygen, 1% Trace Gases(including carbon dioxide, water vapor…)

atmospheric pressure

the pressure caused by the weight of the atmosphere

Atmospheric Density

decreases with altitude

Layers of the atmosphere

troposphere, stratosphere, mesosphere, thermosphere, exosphere

Troposphere

0-17 km above Earth's surface, site of weather, organisms, contains most atmospheric water vapor. (temperature decreases with increasing altitude, pressure decreases)

cirrus clouds

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

cumulus clouds

Fluffy, white clouds, usually with flat bottoms, that look like rounded piles of cotton.

stratus clouds

look like flat blankets and are usually the lowest clouds in the sky

Stratosphere

2nd layer of atmosphere; extends from 10 to 30 miles up; location of ozone layer; absorbs 95% of Ultraviolet radiation; temperature increases with altitude increase.

ozone layer

Layer of the stratosphere with a high concentration of ozone; absorbs most of the Sun's harmful ultraviolet radiation

Mesosphere

The layer of Earth's atmosphere immediately above the stratosphere. Meteoroids burn up in this layer

Thermosphere

the region of the atmosphere above the mesosphere and below the height at which the atmosphere ceases to have the properties of a continuous medium. The thermosphere is characterized throughout by an increase in temperature with height.

Ionosphere

Layer of electrically charged particles in the thermosphere that absorbs AM radio waves during the day and reflects them back at night.

Exosphere

The outer layer of the thermosphere, extending outward into space.

Magnetosphere

the area surrounding Earth that is influenced by Earth's magnetic field

barometer

An instrument that measures atmospheric pressure

Barometric pressure at sea level

29.92 inHg

high pressure

A mass of sinking cool air that usually bring fair weather.

low pressure

A mass of rising warm air that usually bring wet, stormy weather.

Isobars

Lines joining places on the map that have the same air pressure

Low pressure storms

tornados and hurricanes

Air masses are classified by

temperature and humidity

continental air mass

an air mass that forms over land; it is normally relatively dry

maritime air mass

A humid air mass that forms over oceans

front

A boundary between two air masses

cold front

forms when cold air moves under warm air which is less dense and pushes air up (produces thunderstorms heavy rain or snow)

warm front

a front where warm air moves over cold air and brings drizzly rain and then are followed by warm and clear weather

stationary front

A boundary between air masses that don't move possibly causing rain for several days

occluded front

a front where a warm air mass is caught between two colder air masses and brings cool temperatures and large amounts of rain and snow

back door cold front

When a cold front moves in from the east, or northeast.

anemometer

An instrument used to measure wind speed

thermometer

An instrument used to measure temperature

weather balloon

A balloon released into the atmosphere that carries a package of instruments to record data about temperature, air pressure, and humidity.

compass rose

A tool on a map showing cardinal (N,E,S,W) and intermediate (NE,SE,NW,SW) directions.

wind vane

measures wind direction

tropical depression

a storm near the equator with winds moving in a circle at speeds of up to 38 miles per hour

Tropical Storm

a storm with winds of at least 39 miles per hour

hurricane

A severe storm that develops over tropical oceans and whose strong winds of more than 120 km/h spiral in toward the intensely low-pressure storm center

Cyclones and Typhoons

Two other names for hurricanes

Saffir-Simpson Scale

Classifies hurricanes according to wind speed, air pressure in the center, and potential for property damage.

Movement of Hurricanes

Controlled by the Coriolis effect and steering winds. In Northern Hemisphere they turn counter clockwise. In the Southern Hemisphere they turn clockwise.

storm surge

a rising of the sea as a result of atmospheric pressure changes and wind associated with a storm.