NASA: Aquarius Mission Web Site

Education

+ Salinity Basics + Classroom Activities + Concept Map + Salinity Data & Tools + Links

After its 2010 launch, the Aquarius instrument will measure Sea Surface Salinity (SSS) with unprecedented resolution. Our highly integrated and complementary Education & Public Outreach (EPO) goal is to demonstrate how better understanding of salinity-driven ocean circulation – and its influence on climate and the water cycle – can benefit student learning and society as whole. We will bridge the gap between what people know and what they can learn about our oceans:

YOU MAY KNOW THESE FACTS...	BUT DO YOU KNOW THESE?
Oceans are salty	Salinity has NEVER been measured over 24% of the ocean's surface
On land, the availability of salt varies (e.g., salt flats have high concentrations of salt)	Ocean salinity patterns vary over time and space
Salt affects water’s freezing point (e.g., roads are salted as a de-icing mechanism)	Salinity is key to understanding interactions among the ocean, climate, and water cycle
Salinity affects water density (e.g., the Dead Sea's high salinity makes it easier for people to float)	The North Atlantic is a key area for sinking of dense, cold, high-salinity water masses that drive "thermohaline" ("temperature-salinty") circulation... studies show that past climate shifts are tied to the strength of "thermohaline" circulation
Melting of icebergs can raise sea level (because icebergs are formed by land-based glaciers)	Melting of sea ice does not raise sea level (because it is formed from seawater itself)
Icebergs form in polar regions & are made of fresh water	Sea ice -- which is frozen seawater -- has zero salinity (i.e., is "fresh water")
Climate warming could cause polar ice to melt, sea level to rise, etc.	Tracking high latitude freshening (i.e., decreases in salinity) will help to predict climate fluctuation
El Niño and La Niña influence weather patterns; both are related to ocean temperature	El Niño and La Niña are both influenced by ocean salinity
Hurricanes can devastate coastal cities with heavy downpours & flooding	Hurricanes can dump hundreds of trillions of gallons of freshwater on the ocean surface (see 1 MB animation of Hurricane Isabel's rain accumulation where red colors show heavy rain; original source: NASA Scientific Visualization Studio)

Throughout the life of the Aquarius mission, we will create classroom activities and data-driven tools that allow non-scientists to see the implications of ocean change on the environment. Our first installment is "Salinity Patterns & the Water Cycle," offering physical science resources for elementary through high school grades.

To be notified about updates, join the Aquarius Education Mailing List: Contact Annette deCharon, Senior Marine Education Scientist and Aquarius EPO Manager.

Glossary Words

climate: The prevailing or normal pattern of weather at a place, or in a region, averaged over a long period of time; in contrast to weather, which is the state of the atmosphere at a particular time.

conductivity: A measure of the ability of a material to conduct or transmit an electric charge.

practical salinity unit (psu): Used to describe the concentration of dissolved salts in water, the UNESCO Practical Salinity Scale of 1978 (PSS78) defines salinity in terms of a conductivity ratio, so it is dimensionless. Salinity was formerly expressed in terms of parts per thousand (ppt) or by weight (parts per thousand or 0/00). That is, a salinity of 35 ppt meant 35 pounds of salt per 1,000 pounds of seawater. Open ocean salinity is generally in the range from 32 to 37.

salinity : A measure of the quantity of dissolved solids in ocean water. In general, salinity reflects the total amount of dissolved solids in ocean water in parts per thousand by weight after all carbonate has been converted to oxide, the bromide and iodide to chloride, and all the organic matter oxidized. Salinity is now measured as practical salinity units (psu).