Solar Radiation and Earth's Climate: Key Factors

Solar Radiation and Its Impact on Earth

The energy produced in the interior of the Sun is emitted in all directions into space. This is solar radiation. The closer a planet is to the Sun, the greater the quantity of energy it receives.

Earth's Atmospheric Layers

• Troposphere: The lowest layer. It contains most of the atmospheric gases. Clouds and all meteorological processes occur in this layer.
• Stratosphere: Contains the ozone layer, which absorbs ultraviolet rays.
• Ionosphere: A thin layer (up to 600km).
• Exosphere: Gradually transitions into outer space; there is no sudden change.

Albedo and Absorption

Albedo is the portion of solar energy that is immediately reflected back into space and does not heat the Earth's surface. Another part of the solar radiation is absorbed by the atmosphere (clouds and the Earth's surface), the soil, the sea, and living creatures.

The atmosphere filters solar radiation. Only about 50% reaches the surface (30% is reflected by the atmosphere, 20% is absorbed by the atmosphere, and 50% is absorbed by the surface).

Root Causes of Unequal Distribution of Solar Radiation on Earth

• The Earth's sphericity.
• The inclination of its axis of rotation.

Impact of Earth's Sphericity

• Solar radiation strikes at different angles, affecting different sized areas.
• The length of the path of solar radiation through the atmosphere varies.

Implications of Earth's Axial Tilt

• Changes in the length of day and night.
• Changes in the angle at which the Sun's rays strike the Earth.

(The seasons are a consequence of the inclination of Earth's axis of rotation and its translation along the ecliptic).

Greenhouse Effect

Greenhouse gases "trap" heat emitted by the Earth's surface and reduce energy loss. (Carbon dioxide + water vapor).

Climate Change

Climate change refers to variations in climate relative to historical climate patterns, either globally or regionally. Such changes occur on very different time scales and affect all climatic parameters: temperature, precipitation, cloudiness, etc. They are due to both natural causes and human actions.

Visible Changes

Temperature rise, shrinking glaciers, rising sea levels, increased extreme meteorological events, and altered ecosystems.

The massive burning of fossil fuels increases greenhouse gases and generates the greenhouse effect, leading to climate change.

Air Movements

• Vertical Movements: Caused by density differences. Warm air, being less dense, rises and cools in the troposphere.
• Horizontal Movements: Wind, or air that moves to occupy the space left by the rising warm air.