The CTD is the primary tool to measure
all of the physics and the physical
characteristics of the water.
There are multiple sensors on a CTD.
There’s an oxygen sensor.
A transmissometer, which measures
how much particles are in the water.
There’s a par sensor, which measures
how much irradiance from the sun
gets down to certain depths.
We have an altimeter, which tells us
how far from the bottom of the sea floor we are
and that helps us to not bang the CTD into
the bottom as we drift into more shallow waters.
Another advantage to a CTD,
in this case it’s a real-time CTD,
that communicates all of the data that
it’s seeing in real time up a
conductive c-cable to the ship.
And from there we can instantly see what
pressure it’s at, in that case we can learn the depth.
How much chlorophyll is in the water,
how much oxygen is in the water.
And from there we can decide where
we want to actually close bottles, which in this case,
there’s twenty four different bottles
attached to this carousel.
When we see something interesting,
a spike in chlorophyll or a drop in oxygen,
or something that’s kind of unique,
we can close a bottle at that exact depth
and capture the water from there.
And then the biologists and chemists
can do whatever analysis they want on the water.