Heating the Earth’s Surface What drives weather?

Heat can be transferred by radiation, conduction, or convection. Solar radiation, or energy for the sun is a major source of energy for weather phenomena The surfaces of the earth and the atmosphere both absorb and reflect the sun’s radiant energy; absorbed energy is converted to heat and can be radiated back into the atmosphere Temperature is an indication of the amount of heat energy in a solid, liquid or gas. The composition, color, and moisture content of a material can affect the rate at which it absorbs or reflects solar energy The atmosphere, which has different properties at different altitudes, is a mixture of nitrogen, oxygen, and trace gases, including water vapor. C O N E P T S

It takes a lot of energy to heat up water It takes a lot of energy to heat up water. Large bodies of water, like the ocean, don't change temperature very much throughout the year. That is partly why, in coastal areas, the temperature doesn't change much throughout the year, or between day and night. The ocean keeps the temperature on land relatively stable. It takes less energy to heat up sand. That is part of the reason why deserts like the Sahara and the Mojave are so hot — the sand heats up very quickly. And deserts are usually pretty cold at night — because once the sun sets, the sand cools off very quickly. (Note that deserts don't necessarily have sand, and deserts are not necessarily hot! By definition, deserts are places that get very little precipitation — the Arctic and the Antarctic are deserts, and they are neither sandy nor hot!) The materials that make up the Earth's surface (water, sand, rock) are not the only things that determine an area's climate. Characteristics like latitude, altitude, wind and current patterns, and precipitation are also really important in determining an area's climate.

VOCABULARY weather seasons climate soil atmosphere water radiation precipitation conduction convection solar energy absorb reflect Troposhere Stratosphere Mesosphere Ionosphere Thermosphere Exosphere