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Environmental Monitoring


July 2011 Issue

Oil Spill Monitoring System Passes First At-Sea Tests in Italy
The early stages of ARGOMARINE, an automated marine environment monitoring system designed to detect oil spills, came to an end with the completion of the first at-sea test May 6 at the NATO Undersea Research Centre in La Spezia, Italy.

ARGOMARINE, supported by the European Commission, is scheduled to deploy by 2012 in the Mediterranean Sea. The three-year project, which has received €3.3 million in funding, aims to develop new technologies capable of constant monitoring of the seas and real-time alerts for hydrocarbon spill in the Mediterranean, where every year 60 significant accidents occur. Of those accidents, 15 involve hydrocarbon spills at sea, according to Tuscan Archipelago National Park data.

ARGOMARINE's nine partners conducted a joint experiment of the system's current instruments, which include sensors and autonomous vehicles that will interface with satellites, radar stations and computers. Part of the test simulated the unauthorized access of a craft with the potential to cause an oil spill. In the project's next phase, ARGOMARINE will receive new sensors, electronic "noses" able to sniff and catalog the emissions coming from oil spill. These sensors will be installed on floats and AUVs. For more information, visit www.argomarine.eu.

Team Uses Satellite Data to Track How Environment Affects Kelp
Scientists at University of California, Santa Barbara (UCSB), have developed new methods for studying how environmental factors and climate affect giant kelp forest ecosystems at unprecedented spatial and temporal scales.

The scientists merged data collected underwater by UCSB divers with satellite images of giant kelp canopies taken by the Landsat-5 satellite's Thematic Mapper. The findings are published in the May 16 issue of Marine Ecology Progress Series.

The team tracked the dynamics of giant kelp—the world's largest alga—throughout the entire Santa Barbara Channel at approximately six-week intervals over a period of 25 years, from 1984 through 2009.

Images from the Landsat 5 satellite provided the research team with a new window into how giant kelp changes through time. These images were relatively expensive, limiting their use in scientific research until 2009, when the entire Landsat image library was made freely available.

Having 25 years of imagery from the same satellite is unprecedented, said David Siegel, study co-author and UCSB professor of geography. Satellite missions that last longer than 10 years are rare. Landsat-5 was originally planned to last for only three years.

The scientists found the dynamics of giant kelp growing in exposed areas of the Santa Barbara Channel were largely controlled by the occurrence of large wave events. Meanwhile, kelp in protected areas was most limited by periods of low nutrient levels.

Study author and UCSB marine science graduate student Kyle C. Cavanaugh said that thanks to the satellite images, his team was able to see how the biomass of giant kelp fluctuates within and among years at a regional level for the first time.

"It varies an enormous amount," said Cavanaugh. "We know from scuba diver observations that individual kelp plants are fast-growing and short-lived, but these new data show the patterns of variability that are also present within and among years at much larger spatial scales. Entire forests can be wiped out in days but then recover in a matter of months."

For more information, visit www.ia.ucsb.edu.

Radar Spanning US West Coast Gathers Surface Circulation Data
A network of high-frequency radar systems designed for mapping ocean surface currents now provides detail of coastal ocean dynamics along thousands of kilometers of shoreline on the U.S. West Coast, a team of researchers from the Scripps Institution of Oceanography reported in May.

The report, published in the Journal of Geophysical Research: Oceans, outlined several scientific aspects of coastal surface circulation derived from what is now the world's largest radar network. Led by Sung Yong Kim, a postdoctoral researcher at Scripps, the team performed a multiyear synthesis of surface current observations, provided via a centralized data center designed and operated by Scripps.

Scientists have long known that the ocean's surface currents are governed by a complex combination of elements, including coastal tides, winds, Earth's rotation, and synoptic ocean signals and their interactions. These factors' relative contributions, however, are very location-specific and difficult to predict.

With an ability to retrieve data on kilometer-scale currents out to approximately 150 kilometers offshore and along 2,500 kilometers of shoreline, the researchers reported on how the network allows the determination of geographic differences of these dynamics. They also explained how the system is able to characterize phenomena such as the seasonal transition of alongshore surface circulation, eddies less than 70 kilometers in diameter and coastal trapped waves.

"This radar network provides the detailed coastal surface circulation and ocean dynamics at a resolution—kilometers in space and hourly in time—never before resolved," Kim said.

For more information, visit http://scrippsnews.ucsd.edu.

Chilean Ocean Radar Captures Signals From Japan's Tsunami
A radar system in Chile captured the signal of the tsunami that struck Japan in March, University of Concepcion (UC) researchers reported May 31, marking the first time an ocean radar detected an approaching tsunami.

After the 9.0-magnitude earthquake occurred in Japan on March 11, the resulting tsunami travelled across the Pacific Ocean and reached the coast of Chile within 22 hours. Upon hearing the news about the earthquake, UC professor Dante Figueroa drove to the remote WavE RAdar (WERA) ocean radar site and switched the system into a fastest operation mode, which collects real-time data every 30 seconds.

The theoretical basis for this approach is that tsunami waves generate a characteristic periodic ocean surface current pattern that can be used as the tsunami "signature," which was detected in the signal WERA recorded. Comparing measured radar signatures with nearby sea level measurements showed a high correlation between the two signals and confirmed WERA captured the signal. For more information, visit www.helzel.com.


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