IB Geography 2.1.1 the Atmospheric System and Energy Balance Notes

The Earth’s Atmosphere Balances Energy and Sustains Life

1. The Earth’s atmosphere is a mixture of gases, liquids, and solids that regulate energy flow and influence weather systems.
2. It plays a vital role in supporting life and maintaining climate stability.

Weather Happens in the Troposphere

1. The troposphere contains most of the atmosphere’s water vapor, making it the primary layer for weather phenomena, such as clouds, wind, precipitation, and storms.
2. Temperatures decrease by an average of 6.5°C per km with altitude.

The Atmosphere Redistributes Solar Energy

1. The Sun emits energy, whereas the Earth receives it and either reflects it back to space or absorbs it and re-radiates it later.
2. This energy drives global weather systems and climate patterns:
   1. Energy Absorption: Most solar energy is absorbed in tropical regions near the equator.
   2. Energy Redistribution: To maintain balance, wind and ocean currents move energy from warmer tropical regions to cooler polar regions.

The Energy Budget Maintains Climate Balance

1. This balance ensures stable global temperatures and weather patterns.
2. Components of the Energy Budget include:
   1. Incoming Solar Energy (insolation):
      1. 46% absorbed by the Earth’s surface.
      2. 22% drives the hydrological cycle (e.g., evaporation and condensation).
      3. 31% is reflected back into space by clouds, gases, and surfaces.
   2. Outgoing Energy:
      1. Heat is emitted as long-wave radiation, transferred back to the atmosphere.
      2. Processes like conduction (direct contact) and convection (air and liquid movement) facilitate heat transfer.

Insolation is Affected by Latitude, Season, Clouds, and the Composition of the Atmossphere