WEBVTT

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The CTD is the primary tool to measure 

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all of the physics and the physical 

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characteristics of the water. 

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There are multiple sensors on a CTD. 

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There’s an oxygen sensor. 

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A transmissometer, which measures 

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how much particles are in the water. 

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There’s a par sensor, which measures 

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how much irradiance from the sun 

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gets down to certain depths. 

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We have an altimeter, which tells us 

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how far from the bottom of the sea floor we are 

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and that helps us to not bang the CTD into 

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the bottom as we drift into more shallow waters.

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Another advantage to a CTD, 

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in this case it’s a real-time CTD, 

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that communicates all of the data that 

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it’s seeing in real time up a 

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conductive c-cable to the ship. 

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And from there we can instantly see what 

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pressure it’s at, in that case we can learn the depth. 

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How much chlorophyll is in the water, 

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how much oxygen is in the water. 

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And from there we can decide where 

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we want to actually close bottles, which in this case, 

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there’s twenty four different bottles 

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attached to this carousel. 

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When we see something interesting, 

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a spike in chlorophyll or a drop in oxygen, 

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or something that’s kind of unique, 

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we can close a bottle at that exact depth 

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and capture the water from there. 

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And then the biologists and chemists 

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can do whatever analysis they want on the water.