by Tracy Hampton
Because the oceans are so vast, researchers have a long way to go
before they uncover the mysteries lying beneath the sea surface. A new
observatory on the south side of Martha's Vineyard is now helping
meteorologists and other scientists understand the important impacts
that oceans have on things like hurricanes, coastal erosion, and global
Wade McGillis of the Woods
Hole Oceanographic Institution,
or WHOI, has seen the development
of the Martha's Vineyard Coastal Observatory since the very
beginning. Standing next to the tower by the lifeguard station on South
Beach, he acts like a proud father as he shows off its elaborate
"It's about twenty-five feet tall, and
the sensors on it measure atmospheric pressure, air temperature, air
relative humidity, carbon dioxide. We also have three anomometers up
there - sonic anomometers measure the wind speed through
changes in sonic velocities - and a camera.
The observatory-s been collecting data since last summer, and now
scientists are starting to get some meaningful results about the
relationship between the oceans and the atmosphere. Jim Edson also
helped get the observatory up and running. Looking out towards the
water, he explains how he uses it to study meteorology.
"So here we are at the top of the dunes, and you
can feel the wind pushing on us. It's generating waves off shore, and
I'm sure it's generating wave driven currents. And what
we're doing with those instruments is that these fluctuations that
you're feeling are the turbulence, and that's driving the waves
and currents offshore. And we measure that with the sonic anomometer
at the very top of the mast.
Edson says the observatory will provide new and reliable data that
couldn't be measured before. Usually, scientists who study the
oceans rely primarily on boating trips to gather information.
"Too often, we go out for three weeks and collect
data, and we come back and we're never really sure if we see
something interesting, is that anomalous, or is that normal? This
allows you to put that into context. These are normal conditions for this
time of year, or it's not. We're having a warm summer vs. a cool
Data from the observatory will be useful for studying a wide variety of
topics from coastal erosion to global warming. For example, McGillis
studies the exchange of carbon dioxide between the atmosphere and the
ocean, a process at the heart of global warming. He says the observatory
is like a natural laboratory, and it's unlike the conditions that're
typically used to study his area of research.
"What I personally was frustrated with was
providing students with a facility that mimicked the real world, so a lot of
our research was done in test tanks in the laboratory, and we really
didn't have the scales and the right conditions that nature provides.
So the observatory provides an immediate access, low cost, facility where
they can come up with ideas and implement them. Researchers are
already using the facility and as these users spread the word, more and
more people will hopefully take advantage of the site."
Scientists and the public can see all of the data the observatory collects
- in real time - at the WHOI
In addition to the onshore
tower, there's also what's called a seafloor node. It's a box-
like instrument sitting on the bottom of the ocean about a mile offshore. It
measures things like currents, waves, water temperature and salinity and
other oceanographic variables. Edson says that information is a nice
complement to the information they get from the tower on land.
"When you combine those data sets, that's
really when you understand air-sea interaction, sediment transport,
beach erosion. That's where we have a chance to do that. We want
to be able to predict in cases of severe weather, how much of the beach
will we lose? We're not necessarily going to do anything about it
but in order to figure out if you want to do anything, you need to understand
the processes. We're hopefully coming up with a better
understanding of what's happening offshore.
The observatory is designed to withstand severe weather conditions, and
it should be in operation for at least twenty-five years with minimal
maintenance. Edson says the lifeguards on South Beach are doing a
good job keeping watch over it.
Tracy Hampton is a reporter for the Cape & Islands' NPR