Lesson 2 Subsystems.pdf

Earth Science Earth’s Subsystems Earth System’s Four Spheres Viewing Earth as a system means understanding each of the system’s parts and how they work together. Earth is made up of four overlapping subsystems containing all the planet’s land masses, water sources, living organisms, and ga...

Earth Science Earth’s Subsystems Earth System’s Four Spheres Viewing Earth as a system means understanding each of the system’s parts and how they work together. Earth is made up of four overlapping subsystems containing all the planet’s land masses, water sources, living organisms, and gases. These four subsystems are known as “spheres.” Abiotic and Biotic Spheres Earth is the only planet known with “just right” characteristics supporting life. The immensely diverse forms of life interact continuously with the planet’s abiotic components. Earth’s systems consist of four interconnected subsystems in which across their boundaries, matter and energy flow. Learning Competency Explain that Earth consists of four subsystems, across whose boundaries matter and energy flow Specific Learning Outcomes ✓ Identify the four subsystems that make up the planet Earth as a system ✓ Distinguish the components and characteristics of each subsystem ✓ Trace the movement of matter and energy across the boundaries of the subsystems Atmosphere Earth’s atmosphere extends from the surface to around 10,000 km. It can be divided into five (5) main layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Dry air contains 78.08% nitrogen, 20.95% oxygen, and 0.93% argon. Trace gases (0.04%) include the greenhouse gases ozone, carbon dioxide, and methane. Troposphere The temperature usually declines with increasing altitude because this layer is mostly heated through energy transfer from the surface. The lowest part is typically the warmest. Most of Earth’s weather occurs in the troposphere because this layer contains almost all water vapor in the atmosphere. Most types of clouds are found in the troposphere, from low- lying fogs to thunderheads to high-altitude cirrus clouds. Clouds are aerosols consisting of visible accumulations of tiny water droplets or ice crystals in the atmosphere. They form when the air becomes saturated with water vapor and is cooled to its dew point. Stratosphere The temperature rises with increasing altitude due to the absorption of the Sun’s ultraviolet radiation by the ozone layer at the top of the stratosphere. It is almost completely free of clouds and other forms of weather. Air is coldest in the lower part of this layer where nacreous clouds are occasionally seen. Antarctic stratospheric cloud (nacreous clouds) Nacreous clouds or ice polar stratospheric clouds, are rare clouds that form in icy conditions and at high altitudes. They are known for their iridescent colors created when sunlight interacts with the tiny ice crystals they are made of. Mesosphere Temperature decreases as altitude increases. It is the coldest atmospheric layer, dipping as low as -143 °C. This layer has the highest clouds in the atmosphere called noctilucent clouds detectable as a diffuse scattering layer of water ice crystals. Noctilucent clouds over Kuresoo bog, Viljandimaa, Estonia Meteor a visible passage of a glowing meteoroid or asteroid through Earth’s atmosphere, after being heated to incandescence by collisions with air molecules, creating a streak of light via its rapid motion. Thermosphere This atmospheric layer is completely free of vapor and cloudless. Within this layer, the International Space Station (ISS) orbits the Earth between 408 and 410 km. The thermosphere and parts of the mesosphere and exosphere constitute the ionosphere which forms the inner edge of magnetosphere. A view of the completed ISS as seen from Shuttle Atlantis, 23 May 2010 Aurora a natural light display in the Earth’s sky that appears as curtains, rays, spirals, or dynamic flickers. Auroras are the result of disturbances in Earth’s magnetosphere caused by the solar wind. The resulting ionization and excitation of the particles in the atmosphere emit light of varying colors and complexity. Exosphere the uppermost layer where the atmosphere thins out and merges with outer space. The pull of the Earth’s gravity is so small here that gas molecules escape into outer space. It contains many of the artificial satellites that orbit Earth. Geosphere In Earth system science, the geosphere refers to the solid parts of the Earth. The geosphere includes all the rocks and minerals on Earth, from the molten rock and heavy metals in the deep interior of the planet to the sand on beaches and peaks of mountains. It also includes the abiotic (non-living) parts of soils. Hydrosphere the combined mass of water found on, under, and above the surface of a planet or a natural satellite. It includes water that is on the planet’s surface, underground, and in the air. The hydrosphere of a planet can be liquid, vapor, or ice. Earth’s Hydrosphere Water is found in all three states on Earth which are solid, liquid, and gas. Water as gas is found as water vapor in the atmosphere. As liquid, water is found in streams, rivers, lakes, ponds, and oceans along with mist in the air and as dew on the surface of the ground. Water is found as solid in ice and snow.  Dew formed on the surface of strawberry leaves Dew When surface temperature drops, eventually reaching the dew point, atmospheric water vapor condenses to form small droplets on the surface. When temperatures are low enough, dew takes the form of ice called frost. Cryosphere the portions of Earth’s surface where water is solid, where low temperatures freeze water and turn it into ice. This sphere includes glaciers, ice caps, sea ice, snow and ice on land, and permafrost. It helps maintain the planet’s climate by reflecting incoming solar radiation into space. An iceberg in the Arctic Ocean Iceberg a piece of freshwater ice more than 15 meters long that has broken off a glacier or an ice shelf and is floating freely in open water. Permafrost a permanently frozen layer on or under the Earth’s surface that usually remains at or below 0°C for at least two years. It consists of soil, gravel, and sand, usually bound together by ice. A collapsed block of ice-rich permafrost along Drew Point, Alaska Graphical Distribution of the Locations of Earth’s Water Total global water Freshwater Surface water and other freshwater Biosphere It is made up of the parts of Earth where life exists; also termed the zone of life. It extends from the deepest root systems of trees to the dark environment of ocean trenches, to lush rainforests and high mountaintops. Biodiversity the measure of variation of life on Earth at the genetic, species, and ecosystem level. Biodiversity is not distributed evenly on Earth; it is usually greater in the tropics because of the warm climate and high primary productivity (e.g., photosynthesis) in the regions near the equator. Energy flows, but matter is recycled. Energy flows unidirectionally through Earth’s ecosystems, typically entering as sunlight and exiting as heat. However, the chemical components that makeup living organisms are different; they get recycled.  Yellow indicates usable energy and red indicates energy lost in the unusable form of heat. Green arrows show the continual recycling of chemical nutrients. Image credit: Biogeochemical cycles: Figure 1 by Eva Horne and Robert A. Bear; source article is CC BY 4.0 Biogeochemical Cycle any natural pathway by which a chemical substance, such as water, is turned over or moves through the Earth’s abiotic and biotic compartments. It is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth’s crust.  Water (or Hydrologic) Cycle a biogeochemical cycle that involves the continuous movement of water on, above, and below the Earth’s surface. WATER CYCLE CARBON CYCLE Additional Resources Earth as a System https://scied.ucar.edu/learning-zone/earth-system Earth's Systems https://education.nationalgeographic.org/resource/earths-systems/ Earth System Science in a Nutshell https://serc.carleton.edu/introgeo/earthsystem/nutshell/index.html What are the Earth System’s Four Spheres? https://www.geographyrealm.com/what-are-the-earths-systems/ Creating an Earth System: Interactions in the Earth System https://ucmp.berkeley.edu/education/dynamic/session4/sess4_interactions.htm Earth Systems Interactions https://www.csun.edu/science/books/sourcebook/chapters/8-organizing/files/earth- systems-interactions.html About the Earth as a System: Background Information https://mynasadata.larc.nasa.gov/basic-page/about-earth-system-background- information What is the Earth system? https://www.sciencelearn.org.nz/resources/1256-what-is-the-earth-system SHS EARTH SCIENCE Q1 Ep2: Subsystems of the Earth https://www.youtube.com/watch?v=AsJPV-P0szk Four Spheres Part 1 (Geo and Bio): Crash Course Kids #6.1 https://www.youtube.com/watch?v=VMxjzWHbyFM Four Spheres Part 2 (Hydro and Atmo): Crash Course Kids #6.2 https://www.youtube.com/watch?v=UXh_7wbnS3A&list=RDQMbQDCuVDdTxM&index=3 Cycles of Matter https://www.etsu.edu/uschool/faculty/tadlockd/documents/bio_newchpt4sec3show.pdf The Cycling of Nutrients in the Biosphere https://www.wilsonswebpage.com/uploads/5/4/1/8/54188641/nutrient_cycles.pdf Biogeochemical Cycles https://openstax.org/books/concepts-biology/pages/20-2-biogeochemical-cycles Biogeochemical Cycles https://www.khanacademy.org/science/biology/ecology/biogeochemical- cycles/a/introduction-to-biogeochemical-cycles