Argumentation is an important practice whereas the scientist develops explanations using evidence and reasoning to explain observed phenomena.

Background information on ocean circulation.

The electromagnetic spectrum is comprised of all frequencies of electromagnetic radiation that propagate energy and travel through space in the form of waves. 

The Earth System Satellite Images help students observe and analyze global Earth and environmental data, understand the relationship among different environmental variables, and explore how the data change seasonally and over longer timescales.  

What is the hydrosphere and why is it important?

The Earth's system is characterized by the interaction of processes that take place on molecular (very small) and planetary (very large) spatial scales, as well as on short and long time scales. Before scientists may begin their work with these data, it is important that they understand what the data are.

The Cryosphere refers to any place on Earth where water is in its solid form, where low temperatures freeze water and turn it into ice. The frozen water can be in the form of solid ice or snow and occurs in many places around the Earth. People often think of the polar regions of our planet as the main home of the Cyrosphere; the North Pole in the Arctic, as well as the South Pole in the Antarctic. The cryosphere exists in the polar regions, but is also found wherever snow, sea ice, glaciers, permafrost, ice sheets, and icebergs exists. In these places, surface temperatures remain below freezing for a portion of each year. 

The world's surface air temperature is getting warmer. Whether the cause is human activity or natural changes in the Earth System—and the enormous body of evidence says it’s humans—thermometer readings all around the world have risen steadily since the beginning of the Industrial Revolution. 

Review this page to learn about the background of volcanoes and their eruptions.

Phytoplankton distribution background information.