The Office of Public Affairs recently featured research by Dr. David Siegel in its “News from UC Santa Barbara.” Dr. Siegel is a Professor in the Department of Geography and the Interdepartmental Graduate Program in Marine Science, as well as the Director of the Institute for Computational Earth System Science and Director of SPOT (see our June 30, 2005 news article). The press release, titled “Ocean Varies in Ability to Sequester Atmospheric Carbon, Scientists Report,” states:
The amount of atmospheric carbon that the ocean can sequester varies greatly depending on location, according to 17 scientists who have published an article in the April 27 issue of the journal Science. This variation affects models of climate change and the carbon cycle. The size of the variation is three gigatons of carbon per year, according to co-author David A. Siegel, professor of marine science at the University of California, Santa Barbara, and director of UCSB’s Institute for Computational Earth System Science. “This is huge considering the eight gigatons of carbon from fossil fuel we burn each year," said Siegel. “The only reason we discovered this variation is due to the development of new tools that accurately measure the sinking flux of carbon.” Siegel was the physical oceanographer tracking the many instruments deployed during the two experiments.
The research indicates that carbon dioxide absorbed by photosynthesizing marine plants in the sunlit ocean surface layer is often consumed by animals and bacteria and recycled in the “twilight zone” – 100 to 1,000 meters below the surface – and never reaches the deep ocean. A mere 20% percent of the total carbon in the ocean surface made it through the twilight zone off Hawaii, while 50 % did in the northwest Pacific near Japan, thus complicating scientists’ ability to predict the ocean’s role in offsetting the impacts of greenhouse gases. The full text, including a press release from the Woods Hole Oceanographic Institution, can be found at http://www.ia.ucsb.edu/pa/display.aspx?pkey=1591
