Presentation on theme: "Earth ’ s Atmosphere Chapter 22 Mr. Sierra. Protects Earth from the sun’s harmful UV rays: “natural sunblock”. No CFCs! 1)Volcanic Ash 2)Dirt/Dust from."— Presentation transcript:
Protects Earth from the sun’s harmful UV rays: “natural sunblock”. No CFCs! 1)Volcanic Ash 2)Dirt/Dust from wind 3)Pollen 4)Salt from sea spray Evaporation is one stage of the water cycle: water becomes a vapor, adding humidity to the air. 78% of the atmosphere - Absorbed through roots of plants after being “fixed” by bacteria. Composition of the Atmosphere Nitrogen Oxygen Water Vapor Particulates Ozone vapor
Nitrogen The “nitrogen cycle” involves microscopic organisms in the soil that capture N from the air and feed it to the roots of plants. = 78% of Earth’s Atmosphere!
Oxygen = 21% of Earth’s Atmosphere. During photosynthesis, plants use sunlight, water and carbon dioxide to produce their food, and they release oxygen as a byproduct.
Water e vapor ates when it is heated by the sun and enters the air as water vapor – an invisible gas. Water Vapor Plants and animals also give off water vapor – through transpiration perspiration transpiration and perspiration
Ozone O 3 is a gas that reflects UltraViolet radiation from the sun (protecting us). It also absorbs sun’s heat which warms the Stratosphere.
The oxygen we breathe has 2 atoms: O 2 However, Ozone has 3 atoms: O 3 Ozone forms a vital layer of our atmosphere that protects us from the sun’s harmful UV radiation. Unfortunately, human produced chloroflorocarbons (CFCs) break down ozone and weaken this important layer Ozone
Tiny, solid particles – in 4 main categories: Particulates
Earth's Atmosphere 99% of atmospheric gases, including water vapor, extend only 30 kilometer (km) above earth's surface. Most of our weather occurs within the first 10 to 15 km.
Layers of the Atmosphere - Based on changes in temperature with altitude. ThermoMeso
Troposphere: Contains all the weather/clouds and 80% of all the air on Earth. Gets colder with altitude (like mountain-tops). Mesosphere: “meso” means middle; the coldest layer (down to - 90°C); where most meteors burn up.
Greenhouse Effect Solar radiation passes through the atmosphere and warms Earth’s surface. Energy from the sun is absorbed by Earth’s surface and then is radiated into the atmosphere as heat, some of which escapes into space. Greenhouse gases also absorb some of the energy from Earth and radiate it back toward the lower atmosphere and Earth’s surface.
Latitude and Seasons Throughout the seasons, which ever area on Earth (based on latitude – from north to south) receives the most direct, intense concentration of Sun’s energy will be the warmest. What season would it be above the equator in this picture?
Winter (Northern Hemisphere tilts away from sun) Spring (sun aims directly at equator) Summer (Northern Hemisphere tilts toward sun) Fall (sun aims directly at equator) 23½° To Polaris
Land heats up and cools down _________ than water. The temperature of the air relates to the temperature of land or water it blows over. Hot air _________ - creating _____ Pressure Cold air _________ - creating ______ Pressure