The flow of energy into and out of the Earth System.
Click on image for full size
Trenberth, K.E., J.T. Fasullo, and J. Kiehl, 2008: Earth's global energy budget. Bull. Amer. Meteor. Soc., submitted.

Atmospheric Science Literacy - Essential Principle 2

Energy from the Sun drives atmospheric processes.

Fundamental Concept 2.1
Earth receives energy in the form of electromagnetic radiation from the Sun. Some of this solar energy is absorbed by the atmosphere, some is scattered back to space, and some is transmitted through the atmosphere to be absorbed or reflected by Earth's surface. The solar energy reflected by Earth's surface is absorbed, scattered, or transmitted by the atmosphere.

Fundamental Concept 2.2
Energy from the Sun is transformed into other forms of energy in the Earth System. In the atmosphere these other forms include thermal energy of gas molecules, the kinetic energy of wind, and the latent heat of evaporation stored in water vapor.

Fundamental Concept 2.3
On human time scales, the energy emitted by the Sun is nearly constant, varying only very slightly due to solar activity. The amount of solar energy received at a point on Earth's surface varies due to Earth's spherical shape, its daily rotation about its tilted axis, its annual revolution around the Sun, and the slight elliptical shape of Earth's orbit, leading to important cycles such as day and night, and the seasons. In addition, cloud cover and aerosols can reduce the amount of solar energy that reaches Earth's surface.

Fundamental Concept 2.4
Solar energy drives many chemical, biological, and physical processes that affect Earth's atmosphere. These include processes such as photosynthesis, evaporation of liquid water to produce water vapor, formation of smog, and the formation and destruction of ozone.

Fundamental Concept 2.5
Earth also emits energy in the form of electromagnetic radiation. Almost all of the energy emitted comes from the solar energy absorbed by Earth's surface. This terrestrial energy is absorbed by atmospheric trace gases, such as water vapor, carbon dioxide, and other gases in Earth's atmosphere. It may be reemitted from the atmosphere, either to space, where it is lost to the Earth System, or back to Earth, where it is again absorbed, producing a "Greenhouse Effect". This natural Greenhouse Effect is necessary for life to exist on Earth.

Last modified July 29, 2009 by Becca Hatheway.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Electromagnetic Radiation

Electromagnetic radiation is the result of oscillating electric and magnetic fields. The wave of energy generated by such vibrations moves through space at the speed of light. And well it should... for...more

Earth as a System

The first time people got a glimpse of the whole Earth was December 1968. Apollo 8 astronauts, en route to and from the Moon, took pictures of the Earth from space. In their photographs, the Earth looks...more


Wind is moving air. Warm air rises, and cool air comes in to take its place. This movement creates different pressures in the atmosphere which creates the winds around the globe. Since the Earth spins,...more


One process which transfers water from the ground back to the atmosphere is evaporation. Evaporation is when water passes from a liquid phase to a gas phase. Rates of evaporation of water depend on factors...more

Elliptical Orbits

When one object is in orbit around another object, the orbit is usually an elliptical orbit. For example, all of the planets in our Solar System move around the Sun in elliptical orbits. An ellipse is...more

What Causes the Seasons?

Let's get rid of some common misconceptions about the seasons. The Earth's orbit is in the shape of an ellipse, so that sometimes the Earth is a little bit closer to the Sun than at other times. Is this...more

Aerosols: Tiny Particulates in the Air

Aerosols, also called particulates, are tiny bits of solid or liquid suspended in the air. Some aerosols are so small that they are made only of a few molecules so small that they are invisible because...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA