1.2.5 Global Subsystems

Definition: Those portions of the Earth system containing a common media governed by a comon set of physical laws and spanning the entire globe. For purposes of sustainable development, Global Subsystems extend from the Lithosphere (outermost layer of the Earth's crust) to an altitude of approximately 110 nautical miles (660 km). Global Subsystems include the atmosphere and the ionosphere. Global Subsystems do not include the magnetosphere, which extends below 110 nautical miles only in the far polar regions.

Definition Source: None

Global Subsystems Categories:

1.2.5.1 Atmosphere: The gaseous mass or envelop surrounding the Earth, retained by the Earth's gravitational feild. The atmosphere extends from the Earth's surface (commonly called the atmospheric boundry layer) to an altitude of about 110 miles (660 km). The atmosphere is divided into layers based on how the temperature varies with altitude.

------1.2.5.1.1 Exosphere

------1.2.5.1.2 Mesosphere

------1.2.5.1.3 Stratosphere

------1.2.5.1.4 Thermosphere

------1.2.5.1.5 Troposphere

1.2.5.2 Ionosphere: A shell of partially ionized atmosphere surrounding the Earth from approximately 60-1000 km. Absorption of short wavelength radiation from the Sun photoionizes gases in the atmosphere to produce the ionosphere. Gas dynamics and electromagnetic interactions dominate the behavior of the inoized gases. The gases ionize during daytime and recombine during night.

------1.2.5.2.1 D Region

------1.2.5.2.2 E Region

------1.2.5.2.3 F1 Region

------1.2.5.2.4 F2 Region

1.2.5.3 Lithosphere: The outermost layer of the Earth's crust consisting of a mosaic of rigid plates of granite type rock. These plates float upon a solid, but plastic layer of rock called the asthenosphere. The Lithosphere varies in depth from approximately 10 km under the oceans to 30 km under the continents. The Lithosphere includes all land surface and soil, but not the organisms. The Lithosphere also includes the ocean bottom, but not organisms. (Definition Source: None)

1.2.5.4 Oceans: The entire body of salt water that covers approximately 72% of the Earth's surface. (Definition Source: Webster's II New Riverside University Dictionary)