Sink or source? A new model to measure organic carbon in surface waters
A new carbon model allows scientists to estimate sources and losses of organic carbon in surface waters in the United States. Study results indicate that streams act as both sources and sinks for organic carbon. "Model estimates help managers and researchers track carbon transport in streams, which is information that is ultimately needed to improve our understanding of the fate of rising carbon dioxide levels in the atmosphere," said Dr. Richard Smith, a USGS hydrologist and coauthor of the study. "The study contributes new information on the role of rivers as sources and sinks for organic carbon at regional and continental scales, for which scientific knowledge is rather limited."
Findings show that in-stream photosynthesis by algae is a major contributor of organic carbon in large rivers of the United States. It is the largest source of organic carbon delivered to coastal waters from the Mississippi-Atchafalaya River Basin and the Pacific Northwest.
Terrestrial sources of carbon, such as from forests and wetlands, are dominant in all other coastal waters, including waters of the North Atlantic, the South Atlantic Gulf, California, the Texas Gulf, and the Great Lakes.
The results also provide estimates of how much of the organic carbon transported in streams is then permanently removed from the water column. The removed carbon is either sequestered in sediments over long time periods or oxidized and returned to the atmosphere as carbon dioxide. The specific fate of the carbon is not quantified in the current model.
Study findings are estimated using a hydrological mass-balance model based on long-term monitoring at 1,125 stream locations and national geospatial information, including a river network of approximately 62,000 reaches and their connecting drainages, land cover, climate, soils, and estimates of the supply of carbon to streams from primary production.
Source: United States Geological Survey
- Model predicts shifts in carbon absorption by forest canopiesWed, 31 Mar 2010, 12:18:24 EDT
- How grazing lands influence greenhouse gasTue, 18 May 2010, 11:40:35 EDT
- US rivers and streams saturated with carbonMon, 17 Oct 2011, 14:33:53 EDT
- Limitations of charcoal as an effective carbon sinkThu, 1 May 2008, 18:07:43 EDT
- Ocean plankton sponge up nearly twice the carbon currently assumedTue, 19 Mar 2013, 14:02:09 EDT
- Sink or source? A new model to measure organic carbon in surface watersfrom Science CentricSat, 5 Mar 2011, 9:40:13 EST
- Sink or source? A new model to measure organic carbon in surface watersfrom Science BlogFri, 4 Mar 2011, 9:01:26 EST
- Sink or source? A new model to measure organic carbon in surface watersfrom PhysorgFri, 4 Mar 2011, 8:31:35 EST
Latest Science NewsletterGet the latest and most popular science news articles of the week in your Inbox! It's free!
Learn more about
Check out our next project, Biology.Net
From other science news sites
Popular science news articles
- ASU researchers discover chameleons use colorful language to communicate
- The mystery of lizard breath
- Environment drives genetics in 'Evolution Canyon'; discovery sheds light on climate change
- Differences in educational achievement owe more to genetics than environment
- NASA reveals new results from inside the ozone hole