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| The author getting his hands wet (and dirty) for oceanography by
decoupling flotation spheres during a mooring recovery.
Photo by Rick Krishfield, WHOI. |
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| Another picture of the polar bear that we saw way back in Dispatch
16 climbing effortlessly onto an icefloe. Since then we have seen at least
on other polar bear (just a few days ago) but at a greater distance. Photo
by Will Ostrom, WHOI. |
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| An Arctic sunrise prior to a mooring deployment. Photo by Rick Krishfield, WHOI. |
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Cruise - 2006 Dispatches
Calendar
Dispatch 32, September 5, 2006
By Mike Dempsey, Oceanetic Measurement
Why it is still important to get wet doing oceanographic research
In our wireless connected world we have access to many more things and yet
can become more remote from them. We can email friends all over the world,
yet may never meet or talk to them face to face. While this expands our
world, it also removes us from the immediacy of our surroundings.
In the past 40 years, oceanographic research has benefited greatly from
satellite remote sensing. Satellites give us an overview of ocean processes
that we can not experience from Earth. This exterior perspective on our
world has improved our knowledge of how the ocean and atmosphere interact.
Out here, we use satellite imagery for predicting ice cover, but for the
small detail, ice observers fill in the gaps. Satellites map phytoplankton
blooms and measure sea surface heights. In the field, we directly measure
ocean currents and profile the water column for chlorophyll concentration to
give an added dimension to the satellite imagery. Also often times, ice
observations from ships reveal details in small sale ice coverage not
perceptible to satellites.
Recently we have started to explore the oceans through underwater
observatories. All over the world, researches are laying underwater cables
out to nodes where many sensors can be hooked up to observe the ocean at all
hours of the day, everyday. Through these observatories we can experience
the underwater world in the comfort of our homes and offices. Real-time data
sets from these observatories allow us to continually monitor events beneath
the sea. Observatories offer a tantalizing view of the ocean, but we always
wonder what lies beyond their field of view. Observatories can provide
incredible resolution in data over time, but are limited in their resolution
over area. A mobile platform such as research cruise on a ship provides data
in snapshots in time but over a wide area.
Satellite communications have allowed us to retrieve data remotely from
buoys all over the world. Argo floats, ice buoys and ocean gliders allow
scientists to gather ocean profiles routinely from their office. Some
instruments gather their data and routinely pass it on through the satellite
link. Others have 2 way communications that allows the oceanographer to
program the instrument from their desk.
So where in this expanded connected world does the role of the oceanographer
in the field and research ship fit in?
There are still some things you can only experience by being physically
there. Out here on the Louis S. St. Laurent, scientists can customize their
research to the conditions experienced today. They have years of data sets
to compare their observations to and can alter the spacing of their sampling
stations and depths to reflect this year's conditions. Especially in the
Arctic, ocean processes change over different time scales and the
flexibility and mobility a ship offers is the only way to go. Ocean currents
driven by atmospheric circulation and heat exchange can alter from year to
year. If the water properties show that the movement of a body of water has
changed since a previous study, then the sampling can be modified to best
examine the new phenomena.
On a ship or on the ice, oceanographers can experience the physicality of
our environment. Just as Sir Isaac Newton postulated his theories on gravity
while sitting below an apple tree, oceanographers refine their views of the
ocean while at sea. For me the greatest effect of being close up to the sea
is to be continually reminded of its awesome beauty and power. The other
day, I watched as two sheets of new ice were pushed into each other at the
side of the ship while on station. The edges first crumpled into perfect
miniature pressure ridges and then the ice broke up into smaller pans
imitating the larger floes. On station during a rosette cast, I watched as
the larger floes interacted with the wind, the ship and each other
performing an intricate ballet. Like a child's sliding puzzle, the
house-sized floes gave meaning to the satellite imagery we consult every
spring where ice as big as cities dance around the Beaufort Sea.
While steaming through the ice we sometimes witness polar bears walking on
the floes. Understanding that polar bears hunt seals, and seeing the variety
of ice floes where they hunt are two different experiences. Ridges to stalk
behind as well as the seals breathing holes are both visible sometimes in
the same view. Some describe polar bears as marine mammals because of their
reliance on holes in the ice to hunt their food. I find that seeing a polar
bear sliding into a lead and swimming to the next flow helps me to
understand their tremendous adaptations to this frozen sea.
Oceanography to me means going into the field in all seasons of the year to
experience this part of our environment. The larger processes and theories
become real to me when I can first-hand experience them in action. When I
design a new piece of equipment for research, I fondly remember the
conditions I have seen where it may be used. I think of the cold and the
ice, the wind and the waves and the algae and the salt. All of these
sensations as well as the feel of ocean whether warm or cold embody
oceanography for me. For me, it is always important to get wet while
studying the ocean.
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