My science task:
Recently I've received more information about what my expected duties will be on board the ship. The principal investigators (PIs) for the DANCE project have decided its a good idea to add measurements of light to our study.
Since sunlight is the principal energy source for phytoplankton, we measure the amount of light that penetrates the water column. When light passes through water, it attenuates, or loses intensity. Atmospheric conditions, such as cloudiness and time of day influence how much light reaches the surface of the water. Oceanic conditions such as size and amount of particles in the water influence how much light penetrates to certain depths.
We are specifically interested in light that falls into the category of PAR, or Photosynthetically Active Radiation. This includes light with wavelengths between 400 and 700 nm, essentially the visible spectrum. PAR is the part of sunlight that phytoplankton actually use. So it makes sense to measure only this portion.
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| The PAR sensor I will be using, shown hooked up to a laptop. The little white knob on top is the actual sensor. |
In order to measure PAR, I will be using an optical device that is lowered through the water column. It first records the PAR at the surface of the water, then, as it descends, it records a continuous profile. By plotting the amount of PAR versus the depth in the water, we can determine how deep the phytoplankton are likely to live.
Of course, there are some technicalities to be observed while measuring PAR. Which I will be trained on by a technician once onboard the ship. These will mainly consist of working with the recording software, and making sure the ship's shadow doesn't interfere with the measurements.
Now that you know more of what I'll be doing, let's move on to...
How to follow along:
Blog - Internet resources on the ship will be very limited. I plan to record the interesting events each day and blog about them. Depending on how much access I have, I might post an update every few days, or I might have to wait until we return. Any updates here will be automatically posted to Facebook as well, but I won't be able to respond to any questions or comments.
Ship track - You can follow along online with the location and status of the R/V Hugh Sharp, our ship. The map gives information about the current location of the ship, where's it been, where it's heading, and the current conditions.
Well, that's all for now. See you on the ocean!
More posts in this series:
Upcoming Cruise
Cruise Delays
Update #1
Update #2
Update #3
Update #4
Update #5
Update #6
Update #7
Update #8
Update #9
