o The closer to shore you get, the tougher it is to use optical technology to analyze ocean water. In the open ocean, you have water and single-celled plants. Coastal waters include suspended sediment that comes from rivers or has been churned up from the ocean bottom, plus colored dissolved organic matter. Additional factors near shore include rocks, coral reefs, algae and the ocean floor.
o The Hyperspectral Imager for the Coastal Ocean website is at: http://hico.coas.oregonstate.edu
As the Columbia River flows past Washougal, Camas and Vancouver toward the Pacific Ocean, it picks up sediment and organic material.
Now scientists are analyzing samples of the water and comparing their findings with photographs of the Columbia and the ocean taken from space.
o The closer to shore you get, the tougher it is to use optical technology to analyze ocean water. In the open ocean, you have water and single-celled plants. Coastal waters include suspended sediment that comes from rivers or has been churned up from the ocean bottom, plus colored dissolved organic matter. Additional factors near shore include rocks, coral reefs, algae and the ocean floor.
o The Hyperspectral Imager for the Coastal Ocean website is at: http://hico.coas.oregonstate.edu
It’s part of a new imaging system that uses a scanner aboard the International Space Station to explore coastal regions from a viewpoint 200 miles above the Earth.
The images contain more data and have a finer resolution, which will give scientists a much closer look at such complex coastal systems as estuaries, where rivers flow into oceans.
That’s why the Columbia River is part of the demonstration phase, said Curt Davis, an Oregon State University oceanographer and the project scientist.
“It has been a good test location for us,” Davis said.
His team has been working with a research center at Oregon Health & Science University that studies the Columbia River from Bonneville Dam to the coast.
“They are doing good measurements of what’s in the river. That’s a reference database for us,” Davis said. “And a fair number of people at OSU do measurements in the ocean.”
Columbia River water that flows into the Pacific — the river’s plume — contains suspended sediments, clays, phytoplankton, nutrients and dissolved organic material, Davis said.
The Hyperspectral Imager for the Coastal Ocean scanning system can gather and transmit the data required to unravel that complex brew.
“With all the information in HICO, we can sort it out,” he said. Those data are compared with analyses of water samples, Davis said. “This is what HICO saw, and this is what really was there.”
Researchers can use space-borne imagery to track sediment down the Columbia River, and then distinguish it from phytoplankton blooms in the Pacific.
It can reveal near-shore eddies, currents, and the influence of coastal streams entering the ocean. Imagery also will help scientists monitor events like oil spills and analyze effects of climate change.
HICO can map the ocean floor in water as deep as 50 to 60 feet, he said.
Why focus on the Columbia?
Researchers have taken a few images of Puget Sound, but that Northwest water feature is not a focus of the project.
“We’re not having much luck there getting images, because of clouds,” he said.
And, OHSU’s Center for Coastal Margin Observation & Prediction has a reliable baseline of Columbia River estuary data.
“We look at the Columbia River a lot more, because we have more ‘ground truth’ and can understand the data,” Davis said. “In the Puget Sound, nobody is collecting data.”
Scientists have to conserve their opportunities. Transmission of the enormous data files takes time, so NASA limits the scanning system to one image per orbit, or a maximum of about 15 images a day.
However, it typically gets only five or six good images of targeted areas each day because of cloud cover, darkness and the orbital path of the space station.
Each image shows a slice of coastline measuring about 30 miles by 120 miles.
Images have 10 times the resolution of previous technology. A photo of the mouth of the Columbia River, taken from 200 miles up, is sharp enough to show cargo ships and the Astoria-Megler Bridge.
The imaging system, developed by the Naval Research Laboratory, was transported to the space station in September 2009 on a Japanese rocket and is housed on a “space porch” attached to Japan’s science lab.
And now, Japan has become a timely subject for research.
“We hope to begin imaging the area around Sendai,” Davis said, to learn what they can about the area devastated by the recent earthquake and tsunami.
Tom Vogt: 360-735-4558; tom.vogt@columbian.com.
