News Coverage
Plant
food from pollution
News and views in
brief
(Nature, Vol 433, 2005)
Iron is an essential nutrient for phytoplankton, the tiny
aquatic plants that carry out almost half of all photosynthesis on Earth.
Dust storms in northern China and Mongolia carry iron from the soil of
the Gobi desert to the northern Pacific Ocean. But the iron in desert
dust is in a mineral form that has low solubility in seawater and so is
not readily available to phytoplankton. Nicholas Meskhidze and colleagues
have found that sulphur dioxide pollution from industrial plants in China
can acidify the dust, which converts iron to a more soluble form.(Double
click on image to see the full story)
Dust
Storm Surprise: Pollution Can Convert Airborne Iron into Soluble Form
Required for Phytoplankton Growth
A surprising link may exist between ocean fertility and
air pollution over land, according to Georgia Institute of Technology
research reported in the Feb. 16 issue of the Journal of Geophysical Research
- Atmospheres. The work provides new insight into the role that ocean
fertility plays in the complex cycle involving carbon dioxide and other
greenhouse gases in global warming. (Double click
on image to see the full story)
Pollution
Can Convert Airborne Iron Into Soluble Form Required For Phytoplankton
Growth
A surprising link may exist between ocean fertility and
air pollution over land, according to Georgia Institute of Technology
research reported in the Feb. 16 issue of the Journal of Geophysical Research
— Atmospheres. The work provides new insight into the role that ocean
fertility plays in the complex cycle involving carbon dioxide and other
greenhouse gases in global warming.(Double click
on image to see the full story)
Pollution
May Feed Plankton
A surprising chain of events and chemical reactions link
a rise in air pollution over land to a decrease in a common greenhouse
gas over the sea, announced researchers at the Georgia Institute of Technology
on Thursday.
The chain includes the participation of dust storms in the Gobi Desert,
the buildup of harmful sulfur dioxide over coastal industrial zones, and
a burst in the population of tiny plants in the sea known as phytoplankton,
said the researchers. The end result is a decrease in atmospheric carbon
dioxide, they said. Carbon dioxide contributes to global warming by preventing
heat from escaping the atmosphere, the way the walls of a greenhouse prevent
heat from escaping an enclosed space. (Double click
on image to see the full story)
Research
by EAS's Nicholas Meskhidze, Postdoctoral Fellow in Athanasios Nenes'
Group*
SciTech,
(From the College of Science, Vol. 4)
Dissolved iron is one of the necessary nutrients for photosynthesis
of microscopic, single-celled marine organisms (phytoplankton) that grow
abundantly in oceans around the world. Bioavailability of iron (Fe) has
been hypothesized to play a key role in limiting phytoplankton productivity
in much of the world's ocean, particularly in high-nitrate low-chlorophyll
(HNLC) regions such as the subarctic North Pacific where airborne dust
is considered to be the main source of Fe. While only soluble Fe is bioavailable
virtually all the Fe found in sands from arid and semi-arid regions is
in a crystalline Fe(III) form. This form of Fe is insoluble in high pH
solutions such as seawater; thus for phytoplankton to utilize the Fe deposited
in mineral dust, some fraction of the Fe must be dissolved during transport
in the atmosphere. (Double click on image to see
the full story)
* should have read as:
Cover:Research by EAS's Nicholas Meskhidze, Postdoctoral Fellow with supervision
by William Chameides and a member of Athanasois Nenes' group.
Iron Injection
News and views in brief
(Nature, Vol 426, 2003)
Sulphur dioxide, a gas emitted by industrial processes and implicated in acid rain,may be a cloud with a silver lining, according to N.Meskhidze and colleagues. They propose that SO2 converts iron in mineral dust into a form that can be assimilated as a nutrient by phytoplankton, encouraging primary production in the oceans.As this process ‘fixes’ atmospheric carbon dioxide in biological tissues, it alleviates global warming. (Double click on image to see the full story)
Pollution may alter ocean photosynthesis
Science Concentrates
(Chemical & Engineering News, Vol 81, 2003)
Sulfur emitted from industrial and power plants can affect oceanic CO2 uptake [Geophys. Res. Lett., 30, 2085 (2003)]. Earth and atmospheric sciences graduate student Nicholas Meskhidze and coworkers at Georgia Institute of Technology, Atlanta, and NASA Langley Research Center, Hampton, Va., knew that large dust storms from the gobi deserts of northern China could carry iron to phytoplankton in remote regions of the North Pacific Ocean, facilitating photosynthesis and CO2 uptake. (Double click on image to see the full story)
Pollution may increase oceanic photosynthesis
(AGU Journal Highlights November,2003)
Air pollution may help increase photosynthesis of oceanic ecosystems, according to a new study that suggests man-made sulfur dioxide in the air promotes the formation of nutrients from mineral dust. Meskhidze et al. analyzed aircraft data collected over heavily polluted areas of China and propose that sulfur dioxide can enhance the production of bioavailable iron when combined with airborne dust plumes that contain insoluble iron particles. The authors believe that the sulfur dioxide emissions acidify the airborne dust commonly blown from sands and arid regions worldwide and promote the mobilization of the iron contained in the dust. (Double click on image to see the full story)
