14 June, 1998
<fontfamily>Times_New_Roman<bigger><bigger>TEA Journal
Day 15
6/14/98
Sunday aboard ship is normally holiday routine and this turned out to
be a day when most the crew was able to enjoy a somewhat less busy
agenda. No flying, no ice ops, no bear watches, and overall a good day
to catch up on needed rest for most the crew. Unless of course one
happened to have 34 ice core samples that needed to be processed.
And so went the day for the dry lab crew. Nothing too exciting but the
kind of work that couldn't be put off or done later. Aaron labeled
bottles, I took salinity readings, Bill helped us filter, and by 8:00
PM we were done! This part of the sampling procedure is a bit dull
because at this point we don't come up with anything quantifiable. Most
of what we do the day after collecting is a series of steps that
readies the samples to be tested in a fluorometer on the third day. The
fluorometer reads total chlorophyll and after addition of a tiny
quantity of hydrochloric acid, a second reading indicates the amount of
phaeopigments in the sample. These readings basically allow one to
determine how "fresh" the algae is by determining what percentage of
the algae has degraded into the secondary substance.
Looking at "freshness" of our chlorophyll samples has become a very
important component of the big picture view of AWS 98. As we travel
north we are comparing our surface and bottom chlorophyll readings in
an effort to determine where the spot is that the ice algae is still
fresh under the ice and has not yet fallen down to the bottom. Exactly
what the benthic community is using for a food source at these
latitudes is of interest and determination of the respiration rates of
the bottom feeders is also something we are trying to quantify. This
combined information will help researchers determine the route of
carbon through the arctic food chain and more
importantly the percentage of carbon that is tied up in both organic
and inorganic compounds.
The cellular processes that provide energy for most all living things
utilize organic carbon in the form of sugars. Respiration is the
process that breaks those sugars down and puts out a waste product
containing inorganic carbon in the form of carbon dioxide. The arctic
is thought to be a huge sink, or holding area, for the earth's
inorganic carbon. As climatic conditions change the amount of carbon
that can be stored in the waters of the arctic will also change. The
amount of dissolved gas that a liquid can hold is directly affected by
the temperature of the liquid so a cold liquid can hold more dissolved
gas than a warmer liquid. The amount of inorganic carbon that might be
released by the arctic ocean should the temperature of the waters
increase even slightly, could greatly increase the amount of greenhouse
gases in the atmosphere which would tend to warm the waters even
faster. This is an example of a positive feedback system where the
results of one action increases the rate of another reaction which in
turn increases the rate of the original action. What role the ice has
in this entire process is being studied because of the abundance of ice
and the amount of time each year that ice is present in the arctic. By
looking at the ratios of organic to inorganic carbon in open water and
in ice covered water the part the ice plays will be better understood.
Once again the work of the mud, water, and ice groups interact to help
give us a clearer picture of the arctic.
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