July 15, 2004
This morning I notice some blue "chunks" or clumps in my oxygen samples. So Richard and I scurry back to my lab bench and try to figure out if this will affect our results. I experiment by stirring the solution longer: up to three minutes, then even five minutes. Earlier the solution had turned from "blue" to "clear" in just a matter of seconds. Time doesn't seem to be a factor, nor does speed of stirring, as I crank the stir meter to the highest level. There are still blue clumps. Since we can't tell what is causing them, I decide to make a new batch of starch solution, which is used in the procedure. I get out the hot plate and mix up a starchy goo, as if I am making gravy. This new solution seems to solve the problem...the blue chunks disappear immediately. It took us all morning to figure this out!
Over lunch I ask the Mexican scientists about their project. Dr. Eduardo Valdez Holguin and Patricia Celis from the University of Sonora are trying to determine the amount of chlorophyll in the Sea of Cortez by fluorometry. I am fascinated to learn about how the chlorophyll molecule absorbs and emits light. Eduardo offers to teach me how to process some samples. At their lab station we start by calibrating the fluorometer, then use hydrochloric acid to break up the chlorophyll molecule, then read and record the amount of fluorescence.
With their supervision, I help process about 50 samples. After about 90 minutes of experimenting I need a break. Tasks and conversations have become extremely funny to me - I think sleep deprivation is starting to take its toll.
We agree to meet for a cup of tea. Around the galley table Eduardo gives Patty and me a lesson about the relationship of photosynthetic efficiency to fluorescence efficiency. I get lost in wavelengths, decadal cycles and formulas of chlorophyll profiles, but get the big idea that he's is trying to make a three dimensional map of the productivity in the Sea of Cortez. He explains that data can be collected from satellites and remote sensors that respond from the surface down to about 1 optical depth, which is about 6 meters, or 20 feet into the water. Equations and computer modeling are used to get a deeper picture. Since 1994 Eduardo has been on research cruises gathering data about primary productivity from the photic zone. His goal is to build a three dimensional model to show the carbon flux of the water ecosystem. It is amazing to me that by studying something as tiny as a chlorophyll molecule, he is piecing together clues about our global climate change.
My brain is overloaded...so I am relieved to get up and retrieve CTD Cast 17. I realize that I need to stretch my eyes. I need a bigger view and to get some fresh air. The clouds are white and wispy. The sky is the color of morning glories. I wish I could figure out how to paint water.
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