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

My NASA Data has recently released several new resources, StoryMaps, for use in educational settings.

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. 

Air quality is a measure of the pollution level in the air. Polluted air can be caused by many things. There are manmade and natural sources of emissions. 

Phytoplankton distribution background information.