Chapter 7, Lesson 3 Notes
*Climate is the typical weather pattern in an area over a long period of time.
*Weather refers to the conditions of Earth’s atmosphere at a particular time and place.
*Climate refers to the average, year-after-year weather patterns in a given area.
*Scientists classify climates according to temperature and precipitation.
*In tropical rainy climates, rainy days and afternoon thunderstorms are common.
*Forests in which large amounts of rain fall year-round are called rain forests and can be found in some tropical rainy climates. Savannas, or tropical grasslands, are common in these areas.
*Florida is the only place in the United States with a tropical rainy climate.
*A desert is a very dry region with extreme temperatures.
*Only specialized plants can survive there.
*Dry climates on the edge of deserts that are large and semiarid are steppes that generally receive enough rainfall for short grasses and low bushes to grow.
*Climates that are temperate continental are not influences by the oceans and often have extreme temperatures. Forests and grasslands grow well in these climates.
*Other temperate climates have short cool summer and long, bitterly cold winters.
*Subarctic climates lie north of some continental climates. Firs and spruce forests often grow in these climates.
*Temperate marine climates are found on the coasts of continents in latitudes just outside the tropics. Due to the oceans, these climates are humid and have mild winters.
*Humid subtropical climates are warm temperate marine climates, but they are not constantly as hot as the tropics.
*Polar climates are the coldest climate with short, cool summer followed by bitterly cold winters.
*A tundra covers great areas and is a treeless plain beneath which the ground may always be frozen.
*Permafrost is permanently frozen ground.
*Possible natural factors that cause major climate changes include the movement of the continents, changes in the position of Earth relative to the sun, major volcanic eruptions, and changes in the sun’s energy output.
*The movements of continents over time affected the global patterns of winds and ocean currents, which slowly changed climates.
*Over a period of 100,000 years, the shape of Earth’s orbit varies. When the orbit is more elliptical, less sunlight reaches Earth and causes a cold ice age, a period of glacial advance covering large parts of Earth’s surface.
*Major volcanic eruptions release huge quantities of ash and aerosols, solid particles or liquid drops in gas, into the atmosphere.
*Scientists think aerosols in the upper atmosphere reflect some incoming solar radiation, lowering temperatures on Earth.
*Short-term changes in climate have been linked to changes in the amount of light given off by the sun.
*Scientists use sunspots to measure solar output over the past 400 years.
*The number of sunspots, dark, cooler regions on the surface of the sun, increases when the sun gives off more light.