Wednesday, December 14, 2005

Ice bound again.

Since we only made it to Station B yesterday the goal for today was to get out to E and finish the series of samples (this is because we are trying to relate changes between the two).  But last night the ice came in.  At this point in time I thought that all of the ice was gone but to my dismay, the wind brought back loads of brash ice and some large icebergs.  Today was utilized in finishing up sample analysis from yesterday, running an isotope experiment, and starting a grazing experiment.  

Normal sampling for us includes collection of water at specified depths and analyzing them for dimethylsulfoniopropionate (DMSP), dimethylsulfide (DMS), dimethylsulfoxide (DMSO), chlorophyll pigments and chromophoric dissolved organic matter (CDOM).  Experiments that show how these compounds behave under specific conditions are in addition to these measurements.  

DMSP is important to our study because it an organic sulfur compound that is produced by phytoplankton most likely as a cryoprotectant.  What this means is that DMSP might help protect the phytoplankton’s tissue during periods of freezing.  This compound is also suspected of having antioxidant properties, helping protect tissue against oxidation compounds like hydroxyl radicals.  

DMSP is the precursor of DMS.  It is not fully understood why phytoplankton break down DMSP into DMS, but we observe it regularly.  The importance of DMS is that it breaks down under different circumstances to become a sulfate aerosol which acts as a cloud condensation nuclei.  What this means is that the more DMS that is produced, potentially, more clouds will be formed.  This is one of the most important focuses of our studies.  We are most interested in the biogeochemical organic sulfur cycle to see how exactly sulfur effects our environment, and how t is transferring from one place to the other.

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