Energy From the Sun (Teks 8.10A) • Nuclear Energy is energy in the nucleus (core) of an atom. Atoms are tiny particles that make up EVERY object in the universe. There is enormous energy in the bonds that hold atoms together. • The Sun is made of Hydrogen Atoms. During a process called Fusion, 4 Hydrogen atoms combine to form one Helium atom, with a loss of matter. This matter is emitted as Radiant Energy. Nuclear Energy in Sun Remember the Equator Equals Hot • Our activity with the flashlight and graphing paper demonstrated to us that the equator gets the most direct rays from the Sun. How is Heat from the Sun transferred through the Atmosphere The sun's energy moves through space, then through the earth's atmosphere and finally reaches the earth's surface. The sun's radiation warms the earth's atmosphere and surface and becomes heat (thermal) energy. This heat energy is transferred through the atmosphere by one of three mechanisms: 1. Radiation 2. Conduction 3. Convection Radiation (Radiant Energy) • Energy from the Sun is absorbed by matter (even us) on Earth by Radiant Energy (Radiation) • Radiation is the transfer of heat by electromagnetic waves. Conduction • Conduction is the transfer of heat from one molecule to another in a substance. • Some matter (most metals) are good conductors. Others are not very good insulators. Convection • Convection is the transfer of heat through a fluid, like water and air. • Earth’s surface absorbs heat and warms the air above it. Warm air expands, becomes less dense, and rises. Cooler air rushes in to replace it. This exchange causes a circulation of air (thermal cell). Convection • Convection transfers heat vertically into the atmosphere. In order for heat to be transferred into other regions of the Earth, it must be moved by wind! Where Water Meets Land – There Will Be Wind Land Heats Faster than Water. In the day, warm air over land rises, and cool air over water rushes in to fill the spot. This creates a SEA BREEZE. Because the land also cools faster than water, at night the air above the water is warmer, rises, and the cooler air from land rushes in creating a LAND BREEZE. High and Low Pressure Systems High pressure systems (A.) are generally associated with fair weather. Low pressure systems (B.)are often associated with adverse weather conditions. Experiencing High and Low Pressure • You will be given a piece of wood and a screw. • You will use high pressure to screw into the wood. • As you do this think of the clockwise motion and the pressure you are using. • Then you will unscrew by using low pressure and your motion will be counter-clockwise. When air spirals into the low, it is converging into the low. When air converges near the surface, it is forced to rise. As air rises, it may condense and form clouds and precipitation. This is why low pressure systems are often associated with adverse weather conditions. Conversely, high pressure systems are generally associated with fair weather. When air spirals out of the high, it is actually diverging. As air diverges from the high, the air above the surface must sink in order to replace the air that is moving away from the high. Sinking air warms and tends to evaporate any clouds that may be present.