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Global Climate System

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Global Climate System

Now, let’s consider the connection between this idea of an energy flow system to the actual Earth. As shown in the figure below, this system includes the atmosphere, the oceans, volcanoes, plants, ice, mountains, and even people — it is intimately connected to the whole planet. We will get to some of these other components of the climate system later, but to begin with, we will focus on just the energy flows — the yellow and red arrows shown below.

Drawing of global climate system, showing flows of energy & greenhouse gases that are key components of the system, see text description
Global Climate System
Click for a text description

The image is a labeled diagram titled "The Global Climate System," illustrating various processes and components that influence Earth's climate. It depicts interactions between the atmosphere, land, ocean, and Earth's interior, with numbered annotations and a key explaining the symbols used.

  • Overall Structure:
    • The diagram is a cross-sectional view of Earth, showing the atmosphere, ocean, land (continental and oceanic crust), and the underlying lithospheric mantle and asthenosphere.
    • The asthenosphere is depicted in red at the bottom, indicating its semi-fluid nature.
  • Atmospheric Components:
    • 1: Short-wavelength (SW) solar radiation (yellow wavy arrows) enters the atmosphere from the top.
    • 2: Some solar radiation is reflected back into space (yellow wavy arrows pointing upward).
    • 3: Long-wavelength (LW) radiation (red wavy arrows) is emitted from the Earth's surface upward.
    • 4: Clouds reflect solar radiation back into space (yellow arrows) and trap long-wavelength radiation (red arrows).
    • 5: Some solar radiation is absorbed by the atmosphere (yellow arrows curving within the atmosphere).
    • 7: Clouds release precipitation (blue arrows pointing downward), contributing to the water cycle.
    • 8: Evaporation from the ocean surface (blue arrows pointing upward) adds water vapor to the atmosphere.
    • 9: Evaporation from land surfaces (blue arrows pointing upward) also contributes to atmospheric moisture.
  • Land and Ocean Components:
    • 6: Ice on land reflects solar radiation (yellow arrows bouncing off ice).
    • 10: Ocean currents (black arrows) show the movement of water within the ocean.
    • 11: Transfer of CO₂ between the ocean and atmosphere (green arrows) indicates carbon exchange.
    • 15: Ice melts, contributing to the water cycle (blue arrows from ice to ocean).
    • 16: Runoff from land to ocean (blue arrows) shows the movement of water.
    • 17: Human activities, depicted as factories and vehicles on land, release CO₂ into the atmosphere (green arrows).
  • Geological Components:
    • 12: A volcano on the continental crust releases CO₂ (green arrows) and ash (gray cloud) into the atmosphere.
    • 13: Volcanic eruptions emit particles and gases (gray cloud) that can influence climate.
    • 14: Weathering of rocks on the continental crust (green arrows) removes CO₂ from the atmosphere.
  • Earth's Interior:
    • The diagram shows the continental crust and oceanic crust as part of tectonic plates.
    • The lithospheric mantle (part of the plate) is labeled beneath both the continental and oceanic crust.
    • Black arrows indicate the movement of plates, with a divergent boundary at the oceanic crust where new crust is formed (red area).
    • The asthenosphere beneath the lithospheric mantle is shown in red, indicating its role in plate movement.
  • Key (Bottom of Diagram):
    • Long-wavelength (LW) radiation: Red wavy arrows.
    • Short-wavelength (SW) solar radiation: Yellow wavy arrows.
    • Transfer of CO₂: Green arrows.
    • Movement of water: Blue arrows.
    • Movement of plates: Black arrows.

The diagram visually represents the complex interactions within the global climate system, highlighting the roles of solar radiation, the carbon cycle, the water cycle, geological processes, and human activities in shaping Earth's climate.

Credit: Penn State Department of Geosciences, Modeling Earth's Climate System with STELLA

Numbers in the figure refer to the following key:

  1. Incoming short-wavelength solar radiation
  2. Reflected short-wavelength solar radiation
  3. Emission of long-wavelength radiation (heat) from surface
  4. Absorption of heat by greenhouse gases and emission of heat from the atmosphere back to the surface (the greenhouse effect)
  5. Emission of surface heat not absorbed by the atmosphere
  6. Evaporation cools the surface, adds water to the atmosphere
  7. Condensation of water vapor releases heat to the atmosphere, precipitation returns water to the surface
  8. Evapotranspiration by plants cools the surface
  9. Chemical weathering of rocks consumes atmospheric CO2
  10. Oceans store and transfer thermal energy
  11. Sedimentation of organic material and limestone (CaCO3) transfers carbon to sediment on the ocean floor
  12. Melting and metamorphism of sediments sends carbon back to surface
  13. Emission of CO2 from volcanoes
  14. Emission of CO2 from burning fossil fuels
  15. Cold oceans absorb atmospheric CO2
  16. Warm oceans release CO2 to the atmosphere
  17. Photosynthesis and respiration of plants and soil exchange CO2 between the atmosphere and biosphere

The figure above includes some new words and concepts, including short-wavelength and long-wavelength radiation, that will make sense if we devote a bit of time to a review of some topics related to energy.