Geoscience Reference
In-Depth Information
In a study published in the February 22, 2008 Journal of Geophysical Research ,
Ronald van der A, a senior project scientist at the Royal Netherlands Meteorological
Institute, and his colleagues reviewed satellite data from 1996 to 2006 for NO 2 and
found that some areas in China had seen an average annual increase of up to 29%. Por-
tions of India, Iran, Russia, South Africa, and the central US also had annual increases.
But pollution reduction efforts may have contributed to small annual decreases in
much of Europe and portions of the eastern US and the Philippines.
In a presentation at the July 2006 Third Annual Dragon Programme Symposium in
Lijiang, China, van der A and colleagues including Jeroen Kuenen reported that NO x
emissions from China alone between 1997 and 2005 contributed to a small but impor-
tant increase in ground-level ozone around the entire northern hemisphere, averaging
roughly 0.3-0.5 ppb by volume when the air mass reached western North America,
and about 0.2 ppb by volume when it drifted to Greenland, Europe, and northern
Africa.
Several studies have found a strong correlation between satellite measurements
and ground-level concentrations of NO 2 , says Randall Martin, an associate professor
of physics and atmospheric science at Dalhousie University in Halifax, Nova Scotia.
However, he says more study is needed to cross-check satellite data with ground moni-
tors, develop better algorithms, and better address variables such as geographic loca-
tion, seasonal effects, and atmospheric conditions. But Martin and colleague Lok Nath
Lamsal say they're getting close to more accurately determining ground-level concen-
trations via satellite, having developed algorithms that resulted in an 86% correlation
between satellite and ground measurements of NO 2 in favorable circumstances. Their
report of these data has been accepted for publication in the Journal of Geophysical
Research.
Figure 4. This image sequence taken over an 18-day period in September 2005 shows CO from
agricultural fires blooming repeatedly over the Amazon basin, then traveling across the Atlantic
Ocean, where it meets CO from fires in sub-Saharan Africa. These images came from the Atmospheric
Infrared Sounder Experiment, whose visible, infrared, and microwave detectors provide a three-
dimensional map of temperature, humidity, cloud cover, greenhouse gases, and other atmospheric
phenomena.
Source : NASA/JPL
 
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