Understanding the relationships between the ocean and air is essential if weather forecasting in the future is to be more precise. Most living on Martha's Vineyard know the ocean keeps the Island cooler when the mainland is suffering in the dog days of July, and warmer in the winter when the temperature inland is bitter cold. But scientists can't be precise about why.
Partly this is because the ocean is an unkind place for sensitive scientific gear. Two and a half miles south of the Vineyard, some of the world's most sophisticated atmospheric and oceanographic equipment resides on a platform and takes a beating. The wind can be unmercifully strong and the waves can continue to pound the place for days at a time.
"Sea salt sucks," says Jim Edson, a Woods Hole Oceanographic Institute scientist who heads up a project involving 50 researchers across the country. after getting a good look at the tower. "It corrodes everything."
On Wednesday, Mr. Edson, along with project leaders from around the country, went out to visit the yellow, tripod-like structure rising 76 feet above the ocean, It is one of the oddest objects to appear in proximity to the Vineyard shoreline. Any bather standing on the shore of South Beach, at the right fork, can see the tower on the southwest horizon.
The platform is part of a $3 million WHOI study of the ocean and the air that began last year. It looks like an oil rig, a weird, stick-like creature or a gigantic photographer's tripod.
Some of the weather instrumentation that has been put on the tower has shown evidence of corrosion. Oceanographic research requires an extra amount of effort, an extra amount of technological skill. That explains why this research is so significant. The research being done has never been done before. It is too difficult and dangerous. There is not another station quite like this one.
"Large-scale models that predict weather are driven by small-scale data," says Tim Stanton, 48, a research scientist with the Naval Post Graduate School in Monterey, Calif. Mr. Stanton has taken on a project to study the power of a wave. For five and a half weeks he has worked to design a device that will measure the turbulence in a breaking wave.
"It is a mystery how the wind transfers its energy into the ocean, or how it makes the currents," Mr. Stanton says. The currents of the world are driven by winds. "You know we still don't understand the way energy is transferred to the atmosphere from a wave breaking, or when it doesn't break."
Understanding weather at sea is incredibly complex when compared to the work of a meteorologist watching a weather system passing over land, says Mr. Edson. "That is why there are only a handful of marine meteorologists and thousands of meteorologists."
More than 70 per cent of the Earth's surface is ocean, yet scientists can't tell you the details of how energy from a rolling wave transfers its energy into the air, or how the power of a breeze gets passed into a wave and creates the currents that travel the globe.
Scientists are trying to figure out the invisible dance that takes place between ocean and atmosphere. "If the air were visible, you'd be so amazed at what happens between the ocean and the atmosphere, you wouldn't stop looking," Mr. Edson says.
The tower erected south of the Vineyard is loaded with as many as 25 instruments above the water line and at least as many below. The water depth is 50 feet. There is an array of instruments measuring greenhouse gases such as carbon dioxide from different heights above the ocean. There are devices at the top of the tower. An airplane making daily trips over the tower with instrumentation gathers data above the sea in the vicinity of the tower. Wind speed, direction, barometric pressure and the like are but a fraction of the data collected. The tower's formal name is Air-Sea Interaction Tower or ASIT. There are so many acronyms to the projects it is confusing to Marguerite K. McElroy, senior research assistant. The whole project is called CBLAST, which stands for Coupled Boundary Layers/Air-Sea Transfer. The Martha's Vineyard Coastal Observatory is called MVCO.
More than a gigabyte of data is collected each day from just the tower alone and wired to the Woods Hole institution.
"It is amazing being able to control the instruments from my desktop, at my office. It's like I'm there," say Mr. Edson.
Information is also being collected by as many as 20 moored buoys or floating buoys and bottom-measuring devices. They all reside within an 11-by-22-nautical-mile scientific playground mostly south and southwest of the tower.
Nobska, a 99-foot fishing boat from Woods Hole, is four miles south of the tower, towing instruments underwater. The vessel runs in a field of buoys. Lara Hutto, a research assistant with WHOI, watches the vessel from aboard the Minuteman. She says data collected by the buoys and the fishing boat give scientists a profile of sea water temperature at varying depths. It is the same thing as when a weatherman puts balloon carrying instruments aloft, trying to identify air currents and eddies of warm and cold air.
The cable being towed by the fishing boat contains more than 20 measuring instruments, Ms. Hutto says. Later the data from the vessel will be collated and matched with the data collected by the buoys.
Fishermen and marine scientists have long known fish feed in areas where warm and cold currents meet. Melanie Fewings, a student working on her doctorate at the institution, says she and her team are looking at the layers of water temperatures below the surface and the seasonal changes that take place. Ms. Fewings says marine biologists are also interested in understanding how plankton and algae grow within these layers.
The tower is principally funded by the Office of Naval Research, and a project like this suits the Navy's interest in advancing military science. The weather of the atmosphere and the ocean have a big influence on the precision of their radar and sonar.
Steve Murray, a project manager with the Office of Naval Research, is a retired college professor. He came up from Arlington, Va., to see the tower for the first time. Mr. Murray says the Navy is very supportive of ocean research even in peacetime. The Navy philosophy is that this country's scientists should be the most knowledgeable in the world. "The Navy feels it is a good investment to support and train these oceanographers." he says. "We want the best in the team."
Much of the Navy's research work is available on the Internet. For years the Navy has offered meteorological information and wave and current information. Advances brought forward by their research will benefit the public, Mr. Murray says. The Navy is already posting a comprehensive, though scientifically complex, daily weather forecast for Martha's Vineyard, available on the Internet. Data collected from the tower is sent by underwater cable to the Martha's Vineyard Coastal Observatory at South Beach. The only visible evidence of the observatory is a tower next to the lifeguard headquarters, formerly the Donnelly House. Much of the observatory's instrumentation is below the surface. The beach side mast has weather instruments and a 24-hour video camera on top. That portion of the project, valued at $1.8 million, is focused on studying the power of hurricanes, northeasters and winter storms. The National Oceanic and Atmospheric Administration is not participating in the project research.
The ocean is an adverse workplace. Many of the sensors on and around the tower will be removed by this fall knowing that winter will be brutal at sea. Mr. Edson said they'll put the gear back next spring.
Mr. Stanton learned that divers had a hard time deploying his wave measuring device. It was just too rough. The stainless steel and plastic device needs to be four feet under the surface. It uses Doppler sonar to measure all the parts of an overhead wave. A similar instrument of this kind, pointed down, has been used to watch the movement of sediment.
High seas and rough weather conditions are a big factor in working with equipment. So now Mr. Stanton is working on a mechanical system with which the divers can more easily install his gear. If the device doesn't get put in soon, Mr. Stanton said, he will be back next summer to try again.