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Earth Is Twice as Dusty as in 19th Century, Research Shows

ScienceDaily (Jan. 10, 2011)}

Earth Is Twice as Dusty as in 19th Century, Research Shows

ScienceDaily (Jan. 10, 2011)

If the house seems dustier than it used to be, it may not be a reflection on your housekeeping skills. The amount of dust in the Earth’s atmosphere has doubled over the last century, according to a new study ; and the dramatic increase is influencing climate and ecology around the world.

The study, led by Natalie Mahowald, associate professor of earth and atmospheric sciences, used available data and computer modeling to estimate the amount of desert dust, or soil particles in the atmosphere, throughout the 20th century. It’s the first study to trace the fluctuation of a natural (not human-caused) aerosol around the globe over the course of a century.

To measure fluctuations in desert dust over the century, the researchers gathered existing data from ice cores, lake sediment and coral, each of which contain information about past concentrations of desert dust in the region. They then linked each sample with its likely source region and calculated the rate of dust deposition over time. Applying components of a computer modeling system known as the Community Climate System Model, the researchers reconstructed the influence of desert dust on temperature, precipitation, ocean iron deposition and terrestrial carbon uptake over time.

Among their results, the researchers found that regional changes in temperature and precipitation caused a global reduction in terrestrial carbon uptake of 6 parts per million (ppm) over the 20th century. The model also showed that dust deposited in oceans increased carbon uptake from the atmosphere by 6 percent, or 4 ppm, over the same time period

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Page publiée le 19 novembre 2011, mise à jour le 2 août 2014