Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Atmosphere An Ocean of Air Atmospheric Composition Nitrogen 78% Oxygen 21% Other gases 1% Water vapor 0 - 4.0% Argon .93% Carbon Dioxide .03% Trace gases .01% • (Neon, Helium, Methane, Krypton, Hydrogen, Ozone, Xenon) Water in the Atmosphere Varies from near zero to four percent Other gases remain in the same relative proportions Water exists in all three states in the atmosphere When it changes states it releases or absorbs energy creating weather Structure of the Atmosphere Layers - Troposphere Contains most of the mass Weather occurs here Gradual decrease in temperature 16 km at equator 9 km at the poles Layers - Stratosphere Layer of concentrated Ozone Absorbs Ultraviolet (UV) radiation Temperature rises with altitude Heat vs. temperature Top of the Troposphere to about 50 km Layers - Mesosphere Temperature goes down with altitude No heat absorbing molecules 50 km to about 80 km Layers - Thermosphere Temperature goes up with altitude Molecules are very thin so it would not feel warm 80 km to about 110 km Layers - Exosphere Basically this is the start of outer space Very few light molecules - Helium and Hydrogen Starts at about 110 km (70 miles) Solar Energy absorption Solar energy is absorbed by the Earth. The sun is overhead at 23.5 degrees North at the summer solstice The sun is overhead at 23.5 degrees south latitude at the winter solstice Some of the Sun’s energy is reflected back into space. (Clouds 25%, Atmosphere 6%, Surface 4%) Some is absorbed and radiated back into space as infrared energy. (Surface 50%, Atmosphere 15%) Energy transfer Energy is transferred by Radiation - wave energy emitted Conduction - heat flows from warm to cold Convection - currents within an object Ocean currents bring energy in the form of heated water to polar latitudes. Atmospheric wind currents transfer energy in the form of warm air. Vertical Temperature As air rises it cools Air contains moisture At LCL water condenses and forms clouds Air Pressure and Density Cold air more dense Cold air has a higher pressure Warm air less dense Warm air has a lower pressure Relationships of temperature and pressure in the atmosphere. Humidity Humidity is the amount of water vapor in the air. Relative humidity is the percent of water vapor in the air versus the maximum amount it can hold at a given temperature. Classroom practice Problem solving lab on page 283 More on cloud formation Clouds form when warm are rises and hits the LCL (lifted condensation level) Clouds can also form with orographic lifting along mountain ranges Clouds can form at frontal boundaries. Warm front - warm air overrides cold air Cold front - cold air pushes warm air up. Types of Clouds Cirrus Cumulus Stratus Cirrus Clouds Cumulus Clouds Stratus Clouds Latent Heat of Condensation Energy is transferred to the gas when water evaporates Energy is released when water condenses (changes from gas to a liquid) Allows cumulus cloud air to continue rising allowing clouds to grow higher