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Increase in the export of alkalinity from North America's largest river

Publication Type:

Journal Article

Source:

Science, Volume 301, Issue 5629, Number 5629, p.88-91 (2003)

ISBN:

0036-8075

Keywords:

atmospheric co2, carbon-cycle, chemistry, erosion, geochemical cycles, LAND-USE, mississippi river, rhizosphere, united-states, weathering rates

Abstract:

Chemical weathering and the subsequent export of carbonate alkalinity (HCO3- + CO3-2) from soils to rivers account for significant amounts of terrestrially sequestered atmospheric CO2. We show here that during the past half-century, the export of this alkalinity has increased dramatically from North America's largest river, the Mississippi. This increased export is in part the result of increased flow resulting from higher rainfall in the Mississippi basin. Subcatchment data from the Mississippi suggest that the increase in the export of alkalinity is also linked to amount and type of land cover. These observations have important implications for the potential management of carbon sequestration in the United States.