Canadian scientists have developed a map of global air-particulate pollution using National Aeronautics and Space Administration satellite data, and it shows that China's air quality isvery poor compared to the rest of the world.
Shanghai's route length is 420km, but the NYC track length is 1,355km. So the two figures are different things. Track length is always a few times more than route length. Shanghai's track length should still be longer than NYC.
The map shown is the distribution of "particulate matter" with length +/- 2.5um, the so-called PM2.5 - the smallest particle size that would trap in our breathing system.
There are different sizes of sand in the desert, probably the one in Sahara and Saudi Arabia are finer than those in Australia...
發表於 2010-9-28 11:08
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