chapter 5-6 Flashcards
weather
the average short-term weather conditions (what we see every day, sunny, cloudy, etc.)
climate
is differences are based on long-term differences in weather, mainly precipitation and temperature.
(long-term)
tropical
hotter,warmer
temperate
in the middle
polar
colder
warm front
warm air mass advances and replaces cool air. It rises over the cool air and moistures condense into clouds, sometimes releasing moisture
cold front
cold air mass advances and replaces warm air. It stays close to the ground and wedges beneath the warm air pushing it up rapidly. This causes thunderclouds to form and results in high surface winds.
high pressure system
When air is cool, the molecules move more slowly in relation to each other. This makes cool air dense and heavy. This air descends toward the surface of the earth slowly and warms up. As the temperature rises, water molecules remain in a gaseous state and don’t condense into clouds, bringing fair weather. This is called a high pressure system.
low pressure system
When air is warm, the molecules move more quickly in relation to each other. This makes warm air less dense and light. This air rises, expands, and cools. As the temperature drops below the dew point, moisture in the air condenses and forms clouds. This produces cloudy and stormy weather.
Jet Streams
are powerful winds that circle the globe near the top of the troposphere. Warm air from the equator moves toward the cold air at the poles. The rotation of the earth deflects the air and causes jet streams to flow from west to east.
Incident Angle of the Sun
The incident angle is the angle at which the sun’s energy hits the surface of the earth. When the angle is 90°, or directly perpendicular to the surface, the energy from the sun is the most direct and the strongest.
latitudes
The earth can be separated into horizontal planes called latitudes. Latitude, measured in degrees, is the location between the equator and one of the poles of the earth.
The Coriolis Effect
The faster-moving warm air from the equator expands and moves toward the poles. As it travels north or south, it moves faster than the ground below. This causes the air to get ahead of the surface resulting in it being deflected to the east. This is called the
trade winds
The warm air that rises leaves an area of low pressure at the surface. Cool, dense air moves toward the equator from an area of high pressure to replace the air that left. This convection cycle of air causes cool surface air to travel east to west, opposite of the jet streams
Hadley Cells.
The rising hot air and the cold air that replaces it creates convection currents that circulate from the equator to the Tropic of Cancer at 30° in the northern hemisphere and the Tropic of Capricorn at 30° in the southern hemisphere. These cells of circulating air are called
Ferrel Cells
Cold air from the poles also sinks at the tropic latitudes, which creates a convection cell called, or mid-latitude cells. These cells pull air toward the equator and pushes surface air toward the poles.
Polar Cells
flow in a similar way to Hadley Cells and rotate air between the 60° latitude to the poles.
gyres
Due to the Coriolis Effect, currents flow clockwise in the northern hemisphere and counterclockwise in the southern hemisphere.
