Superoxide

So you may be wondering if we are actually getting any data with all this time and effort.  Of course the answer is "Most assuredly so!"  The picture here is the data trace on the computer screen for one of the photochemical products that we are evaluating for the deep and surface water carbon pools in the Gulf of Alaska.

The red line is the time trace (secs) for the concentration of superoxide in a beaker beneath our solar simulator. The red vertical lines are when the solar simulator is alternatively turned on and off.  As you can see, radiation creates an immediate increase in the superoxide concentration until it reaches a steady state where it's production by sunlight equals its rate of loss due to chemical reactions in the water (it is a very reactive "radical" generated by molecular oxygen in the water picking up an electron from energized organic carbon).  When the solar simulator is turned off, there is an immediate decline in superoxide concentration.  By studying these rates of production and loss, we hope to quantify the photochemical reactivity of the different pools of organic carbon.

OK.  So I went a bit deep on the chemistry there for a while, but it is pretty exciting to see such a clean demonstration of these reactions, that we are measuring in real time at PICO-molar concentrations (that is 0.000000000001 moles per liter of seawater).  All while on a ship in the North Pacific!!  I hope you can appreciate my excitement.

-Bill