Chapter 3 Weather and Climate Earth’s Atmosphere & Climates The four main attributes affecting climate are: • the Sun – one that affects it the most • atmospheric pressure • wind currents • the ocean Global Energy Systems Temperature – the measurement of heat energy Greenhouse Effect – process in which the Earth’s atmosphere traps heat energy • Sunlight passes through atmosphere. • Sunlight is changed into heat energy. • Sunlight is trapped by the atmosphere, and this keeps the planet warm. • Considered to be caused by atmospheric changes Air Pressure & Wind Air Pressure is the force of air around you. Low Pressure Areas = unstable weather High Pressure Areas = stable, clear, dry weather All low-pressure centers are called cyclones. Wind is the horizontal flow of air. Wind always flows from high to low pressure areas. 4 major air pressure zones Equatorial low pressure – at the equator Subtropical high pressure – equator to 30° N and equator to 30° S Subpolar low pressure – 30° N to 60° N and 30° S to 60° S Polar high pressure – 60° N to North Pole and 60° S to South Pole Wind Systems Prevailing Winds – winds that blow from the same direction Doldrums – calm areas with no winds along the equator Westerlies – West-to-East winds at middle latitudes. Polar Winds –mainly come from the east and occur at the poles. Front - two different air masses of widely different temperatures or moisture levels meet; produces stormy weather Jet Stream – high speed westerly moving winds in the upper atmosphere; • Not felt directly, but they steer major weather patterns. http://www.dnr.sc.gov/climate/sc o/Education/wxmap/wxmap.php Ocean Circulation Ocean currents – occur from the prevailing winds blowing across the surface of the ocean Tides - rising and falling of the sea due to the moon’s gravity. Ocean Current Water and the Atmosphere Evaporation –water is changed from liquid to gas Humidity – amount of water vapor in the air Condensation –water vapor changes from a gas into a liquid Precipitation – rain (condensed droplets become large and fall) Elevation and Temperature Orographic Effect – • Air comes off the ocean and hits the mountains. • It is forced to rise and it cools and condensation begins. • This results in rain or snow. Rain Shadow Effect – Deserts form on the side of the mountain away from the wind because areas in the rain shadow do not receive much rain. Orographic & Rain Shadow Effect SECTION 3 Climate and Vegetation Patterns Tropical humid climate • close to equator • warm temperatures, rainfall all year • receives Sun’s rays directly all year • rising warm, unstable air • monsoons Tropical wet and dry climates • north and south of tropical humid • seasonal change in how Sun’s rays hit Earth • alternating wet and dry seasons • savannas The 12 types of climate regions Tropical humid Tropical wet and dry Arid Semiarid Mediterranean Humid Subtropical Marine West Coast Humid Continental Sub artic Tundra Ice Cap Highland Chapter 4 Landforms, Water, and Natural Resources Geology is the study of Earth’s physical structures and the processes that have created them. Earth has 4 distinct parts • Inner Core • Outer Core • Mantle • Crust Forces Beneath The Crust Magma – liquid melted rock Lava – magma that spills out on the planet’s surface Volcano – the opening in the Earth’s crust through which lava flows Earthquakes – he shock waves or vibrations caused by movement along a fault Large Landforms & Plate Tectonics Plate Tectonics – Earth’s crust is divided into more than a dozen plates that slowly move on the upper mantle. Plates can move apart, collide, or move laterally (slip past each other) Plate Boundaries Volcanoes and earthquakes common at plate boundaries. The abyssal plains under the ocean are the world’s flattest, smoothest regions. Continental shelves are shallow ocean water around the continents. When plates collide, one plate slides under the other forming a trench, volcano, fold or fault. Faults are rocks that have broken apart and separated. Ring Of Fire Ring of Fire Erosion Erosion is the process of changing landforms on the Earth’s surface. Water is the most important form of erosion. Wind and ice are other forms of erosion. Thick masses of ice that cause erosion are known as glaciers. SECTION 1 Landforms Weathering and Erosion Weathering physical processes • heating and cooling • freezing and thawing • tree roots chemical processes • substances in air and water Erosion water • rainfall • rivers • waves wind • abrasion • from one place to another ice • glaciers Types of Landforms Formed by tectonics (mountains, valleys) Formed by erosion (plateaus, plains) Formed by sediment deposits (deltas) People and Water Water is earth’s most important resource. Irrigation – the watering of land through pipes, ditches, or canals Hydroelectricity – Dams hold water back and it slowly goes through openings and turns generators to produce electricity. Water Characteristics Only substance that can exist as solid, liquid, or gas Has the ability to dissolve into almost anything over time Heats and cools very slowly compared to other earth materials Water Distribution 97% in the oceans 2% frozen in the polar regions Less than 1% is available as freshwater Hydrologic Cycle – The circulation of water among parts of the hydrosphere. Surface Water Headwaters – where streams are formed by water runoff from mountains and hills Tributary – smaller streams or rivers that flow into a larger stream or river Estuary – semi-enclosed coastal body of water where seawater and fresh water mix Lakes – when water fills a depression on the lands surface Wetlands – land areas that become flooded for at least part of the year Estuary Wetlands Oceans, Seas, & Gulfs Oceans – cover 71 % of planet’s surface Seas – smaller saltwater bodies that are connected to the oceans Gulf – saltwater body near a coast that extends into land Seawater Resources Nonrenewable Resources –not replaced by natural processes or are replaced at extremely slow rates Renewable Resources – replaced by earth’s natural processes Soil Crop Rotation – One year a field is planted with a soil depleting crop, and the next year a soil enriching crop is planted. Desertification – process by which the loss of plant cover and soil eventually leads to desert like conditions Forests Deforestation – clearing of forests • Occurring in rain forests • 1/3 of the world’s remaining rain forests are found in Brazil, The Democratic Republic of Congo, & Indonesia Reforestation –forests renewed through the planting of seeds or young trees Rain Forests Air Pollution Smog – Industrial chemicals interact with sunlight. Acid Rain – Chemicals (acid) combine with water vapor in the atmosphere. Global Air Pollution • Ozone Layer Ozone layer filters out ultraviolet solar radiation. Depletion of layer is leading to increases in skin cancer. Smog in China Acid Rain Effects Fossil Fuels Formed slowly from the buried remains of plants & animals Coal, petroleum, natural gas Fossil Fuels Renewable Energy Sources Water (hydroelectricity) Geothermal Energy (capturing earth’s heat) Solar Energy (capturing solar power) Wind Power (wind turbines) New innovation (tidal, kinetic)