Well, we're talking about salt in the ocean. We're talking about pretty much the
same salt that you use in cooking: the chemical known as sodium chloride. You've
been to the beach.
You've gone swimming in the ocean. You know that the ocean is salty. What most
people don't recognize is that the concentration of salt, or what we call
salinity, varies quite a bit from one part of the ocean to another. When water
evaporates off the sea surface and goes into the atmosphere, that makes the
water saltier, because you're taking fresh water out and you're leaving more
salt behind.
As the minerals, or the salts, circulate around in the oceans, it moves heat
around. Heat that's carried by the ocean affects the atmosphere. The changes of
the atmosphere and the sea surface temperature is coupled together. It controls
climate.
We have measured sea surface temperature. We've measured winds over water, sea
level rise, color of the ocean, but yet we do not know one of the fundamental
properties that affects climate, which is the density of the concentration of
salt in the ocean. Salinity is one of the missing parameters, never been
measured from space before.
We have no salinity samples at all from parts of the world, particularly in the
southern hemisphere, in the South Pacific and South Atlantic and Southern Indian
Ocean. So there is a big data gap.
This mission called Aquarius is one of the most exciting missions to date. It
measures how salty the ocean is from space.
As you take a pinch of salt and put it in a gallon of water, we can measure that
kind of sensitivity of salt from 408 miles above the Earth. In seven days, we'll
map the entire Earth, and go back to the same point, measuring it over and over
again. And we'll monitor over time how the changes and variability are. By
having salinity information from space, we'll provide this missing link and make
better predictions on the climate change and climate model.
All the measurements that we make in the Earth sciences program within NASA are
really to better understand the climate processes that are happening now, how we
can use that information to better predict the future, so we can plan better.
Salinity is one of those measurements that we need to fill an important gap to
do that very thing. That's how it affects you and me and the person next door.