Post by
greg_atlanta »
https://forums.nicoclub.com/greg-atlanta-u160.html
Thu Jul 22, 2004 11:44 am
from NYTimes yesterday.... 3rd paragraph should be of interest to anyone in SoCal
A Far-Reaching Fire Makes a Point About PollutionBy ANDREW C. REVKIN
Published: July 27, 2004
In 1859, the American oceanographer Matthew Fontaine Maury, one of the first scientists to describe Earth's seas and skies as integrated systems, wrote, "It is only the girdling encircling air, that flows above and around all, that makes the whole world kin."
Last week, a pair of globe-scanning NASA satellites, Terra and Aqua, reinforced that notion as they tracked the sooty remains of fire-swept Alaskan black spruce forests wafting high over coastal Louisiana and beyond.
Such measurements have increasingly been showing how pollution that was once perceived as local is, at least in part, global. By 2010, for example, scientists project that a third of the smog-forming ozone in California air will originate in the booming economies of Asia.
In this case, the link between the Far North and the Deep South started with fire-friendly conditions in Alaska. This has been one of the worst fire seasons in the state since 1950, when officials first started keeping records, with nearly four million acres burned in 492 fires so far - more than half started by people and the rest by lightning.
The moist air that usually starts sweeping in from the Bering Sea by mid-July is absent, officials said, keeping forests vulnerable. And there has been ample lightning, with some 8,000 ground strikes estimated in a two-day stretch last week, said Gil Knight, a spokesman for the Alaska Fire Service.
The emissions from all that combustion took an unusual path. A week ago, the atmosphere over North America was in a pattern more typical of winter, with high pressure sitting over the West and low pressure running from Hudson Bay nearly to the Gulf of Mexico, said Scott Stephens, a meteorologist at the Commerce Department's National Climatic Data Center in Asheville, N.C.
This sent the jet stream, essentially a speeding river of high-altitude air, veering far south of its normal Canada-spanning path, and the Alaskan smoke went along for the ride, at 100 miles an hour.
"The smoke plumes just rode that all the way down through the Mississippi Valley," Mr. Stephens said.
That was only the first leg of the journey, though.
The same satellites that recorded the smoke flowing over the Big Easy on July 19, picked it up on July 21, as winds carried it past New York City and New England, where local weather forecasters noted a milky haze.
And the smoke has wandered even farther than that. Veils from the fires were recorded heading toward Greenland, carried by air currents high in the Arctic.
