Salinity's Connections to Climate

Circulation icon
The ocean is our climate system's dominant reservoir for water and heat. Both are transported via ocean circulation and exchanged with the atmosphere. The result? Salinity plays an active role in moving heat, driving Earth’s weather and climate. Salinity trends also reflect long-term changes in the water cycle and climate.

The movement of heat around the globe is important for maintaining Earth as a habitable place. As the climate warms, the ocean's capacity to store heat decreases, affecting the water cycle, global circulation and other physical properties. NASA's record of global salinity measurements - starting with Aquarius and continuing with SMAP - provides insight into changes in circulation and the water cycle over time. The resources on this page tie together heat, circulation and the water cycle, and the potential consequences of a changing climate on these vital processes.

Climate Change and Currents
Climate Change and Currents
hands-on activity
Climate Change and the Global Ocean: Viewing Ocean Change by Satellite
movie | MP4 (49.8 MB)
Raymond Schmitt
Connecting the Global Water Cycle with Climate Change
movie | MP4 (216.8 MB)
First map of the Gulf Stream
First Map of the Gulf Stream
Lesson plan
Gather, Analyze, and Interpret Environmental Data About the Ocean’s Effects on Climate
hands-on activity
PDF cover page
Global Winds and Ocean Currents
hands-on activity | PDF (136 KB)
Global map of change in ocean temperature
Heat Stored Beneath the Ocean Surface
hands-on activity
Gary Lagerloef
How are Humans Affecting Ocean Salinity
movie | MP4 (62.9 MB)
PDF cover page
Investigating the Earth’s Climate System - Energy
hands-on activity | PDF (901 KB)
Carbon dioxide molecules
Keeping Up With Carbon
movie | MP4 (53.7 MB)
Coastal sand dunes
Melting Ice, Rising Seas: Coastal Impacts of Sea Level Rise
movie | MP4 (5.2 MB)
Melting glacier
Melting Ice, Rising Seas: Global Warming & Ocean Change
movie | MP4 (8.0 MB)
Sea ice
Melting Ice, Rising Seas: Ice Melt & Sea Level Rise
movie | MP4 (3.9 MB)
Antarctic ice station
Melting Ice, Rising Seas: Studying Change in Ice Sheets & Glaciers
movie | MP4 (5.0 MB)
NASA Earth Observations: Sea Surface Salinity
online interactive
PDF cover page
Ocean Currents and Coastal Temperatures
hands-on activity | PDF (109 KB)
Susan Lozier
Salinity and Climate
movie | MP4 (6.8 MB)
Sea surface salinity contours
Salinity Trends Over 50 Years
Historic ship
Salt of the Earth: Aquarius Will Reveal Salinity Ties to Climate
movie | MP4 (5.5 MB)
Sea Ice and Salinity
Sea Ice and Salinity: A Classroom Lab
hands-on activity
Block diagram of the water cycle
The Carbon Cycle
movie | MP4 (4.0 MB)
Graph of ocean temperature vs. depth
The Ocean and Climate: Heat Redistribution
hands-on activity
Document cover page: teaching physical concepts in oceanography - 07
Thermal Expansion
hands-on activity | PDF (27.0 MB)
Raymond Schmitt
Warming and the Water Cycle
movie | MP4 (64.1 MB)
Sunset over the ocean
Water, Water Everywhere: Water Cycle & Climate Change
movie | MP4 (4.3 MB)


Over the past 50 years, we see a dramatic freshening of seawater in some parts of the North Atlantic. We also see salinity increasing, or getting saltier, in other regions. So global warming will have a signature in ocean salinity, that is why we want to measure it from space.

At the moment, it's just being used by salinity scientists trying to understand the measurement itself. It's not quite ready for prime time yet but the reason it's flying is to understand the water cycle on the planet, among other things. In this warming world that we have, the oceans are warming, the atmosphere's warming, there's the idea that the water cycle on the planet will accelerate, there'll be more moisture in the atmosphere, more precipitation, more cycling of water through the system. And the ocean can be kind of integrated gauge for that - changes in salinity can indicate changes in evaporation and precipitation over the ocean.

In fact, if you look back over all the measurements that have been made from ships over the last 50 years and you map the changes in salinity you actually find that most of the saltier places in the ocean surface have gotten saltier and the fresher places have gotten fresher, which is exactly the fingerprint that you would think to see in an acceleration of the water cycle. So as Aquarius is coming along ocean scientists are trying to diagnose if this is really true, that there is an acceleration. We have to act like a doctor doing diagnostics on a human, we have to rule out other diseases so what we're trying to do with salinity here is rule out that it's not ocean processes fooling us to make it look like an acceleration of the water cycle. Want to read more from Eric's interview? Click here.