July 23, 2014
Blanket of Smoke of Canadian and Northwestern Fires Covers the US
An enormous amount of smoke persists over much of Canada from large wildfire complexes throughout the Northwest Territories surrounding Great Slave and Great Bear Lake. The heavy smoke is visible in the MODIS Aqua rgb image below and is captured in today's AOD retrieval as well.
Nearly all of the US remains affected by remnant smoke from fires in Northwestern US and Canada, with some contribution from fires over East central Nevada. Clear zones include, Alaska, Washington, Oregon, California, Idaho, Nevada, Arizona, the Southeast US from the Mississippi River through North Carolina including all but the Florida panhandle. In today's MODIS Aqua AOD retrieval a large area of hazy aerosols and smoke can be seen across Oklahoma, Arkansas, Missouri, Kansas and Texas. US AQI levels were Moderate for PM2.5 along states on the eastern and southern edge of the smoke cloud, discussed above.
Posted by Ruben Delgado at July 23, 2014 11:35 PM
A large part of the problem is that vegetation is dying because it is absorbing pollution. Trees are dying prematurely because they suffer cumulative damage from tropospheric ozone, which makes them more vulnerable to biotic attacks from insects, disease and fungus - all of which are epidemics around the world.
I recently bought “Global Alert” by Jack Fishman (30 years at NASA), published way back in 1990. Here is an excerpt I transcribed (and keep in mind that the background level of ozone is inexorably increasing):
“Not just smoke [referring to annual crop burning] but many other gases are being released into the atmosphere at an alarming rate. The earth is an enclosed system, with a wonderful proclivity to cleanse itself, but it is being taxed to the limit by the sheer number of humans and their waste products in the form of gases and manufactured chemicals. This is not speculation; it is already happening. These are the signs: In the autumn of 1988 the NYTimes published a story about the Jamaican palm trees in the southeastern United States being decimated by a disease known as yellowleaf fungus. The species may disappear from America by the turn of the century. Although the cause of the disease is a known fungus, the underlying cause is the increased ozone levels in the air, which, by placing the trees under stress, pave the way for the attacking fungus…Forest in parts of Germany are suffering from “early autumn” syndrome: they lose their leaves by late August and early September. The cause? Increased ozone levels in the air…During the sumer of 1988 American farmers lost between $1 billion and $2 billion in crops. The drought was a factor, but a sizable fraction of the losses from lower crop yields can be attributed to increased ozone in the atmosphere."
More on Fishman's work is posted: http://witsendnj.blogspot.com/2014/07/there-goes-neighborhood.html
See links to research here: http://scienceblogs.com/gregladen/2013/01/29/whispers-from-the-ghosting-trees/