What are the primary heat absorbing gases in the atmosphere? What wavelength of radiation do they absorb?
Ancient cyanobacteria released ______, which assisted in creating the atmosphere as we know it today.
The primary heat absorbing gases in the atmosphere are carbon dioxide (CO2), methane (CH4), and water vapor (H2O). These gases are commonly known as greenhouse gases because they trap heat in the Earth's atmosphere, causing the greenhouse effect.
To understand the wavelengths of radiation absorbed by these gases, we need to consider the concept of electromagnetic radiation. Electromagnetic radiation includes a broad spectrum of wavelengths, ranging from very short wavelengths (such as gamma rays and X-rays) to very long wavelengths (such as radio waves).
In the case of greenhouse gases, they primarily absorb infrared radiation, which has longer wavelengths than visible light. Infrared radiation is emitted by the Earth's surface in the form of heat. When this radiation tries to escape back into space, greenhouse gases in the atmosphere absorb some of it and re-emit it in all directions, including back toward the Earth's surface. This process traps heat in the atmosphere and contributes to global warming.
Specifically, carbon dioxide, methane, and water vapor have absorption bands in the infrared range. Each gas has its own unique absorption spectrum, meaning it absorbs infrared radiation at specific wavelengths. For example, carbon dioxide absorbs strongly in the range of 13 to 18 micrometers, while methane absorbs in the range of 7 to 14 micrometers.
These absorption characteristics of greenhouse gases play a crucial role in regulating the Earth's temperature.