This mini-lesson features time-series graphs of mean salinity at the surface for the Arctic and Antarctic regions. A series of questions guides students in their analysis.

In this mini lesson, students use in-water profiles of historical ocean data to analyze how sea surface salinity varies with depth. 

What is the hydrosphere and why is it important?

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

This investigation is part of the NASA: Mission Geography Module "What are the causes and consequences of climate change?" that guides students through explorations in climatic variability and evidence for global climate change.