August 24, 2008
Stagnant conditions in Ohio River Valley clearing slowly
A front which has moved out of Canada cross Lake Michigan is trying hard to push the stagnant air out of Ohio. To some extent, we are probably lucky this happened on a weekend in summer when energy demand is somewhat lower from the Ohio River power plants and urban emissions in Ohio are lower. The PM (left) is still in the moderate range in this area and the ozone (right) is above normal with localized unhealthy for sensitive groups.
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NOAA's forecast guidance has been good for this event and shows high ozone along the Ohio River. For tomorrow, the forecast for ozone shows the highest values moving east into the Atlantic States. A few fires have blossomed up in Idaho, Wyoming and Montana and the NOAA smoke guidance shows that the smoke will be moving northward.
Tropical Storm Fay continues to be a major weather influence on the circulation and it is now over New Orleans. It has been almost three years since Katrina and Rita and this probably is bringing bad memories to those in Louisiana. The excellent CoCoRaHs observers site has reported 3-4 inches of rain over the last 24 hours (ending 7am this morning) in Shelby County, Alabama. We are also featuring this on the Mesoamerican and Caribbean Air Quality blog (MACAQ) tonight and there is an indication of high AOD trailing the storm.
Finally, while we don't often highlight this feature of IDEA, but the correlation between PM2.5 and AOD is tracked in two month segments. The MODIS (left) and GASP(right) correlation plots show good correlation (deep red colors) for much of the east and California, Low or no correlation is seen in the west where elevated smoke may be adding to AOD without affecting surface PM concentrations.
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I think one that has really helped this summer has been the installation of scrubbers for various plants along the Ohio River. I know the Clean Air Interstate Rule is no more, but since the EPA won't relax the new 24-hr PM2.5 standards in 2010, I gotta think there's going to more scrubbers one way or the other.
It'd be interesting to see what the average AOD was over the Ohio Valley this summer. We've had FAR fewer hazy days here in Eastern Ohio than I can ever remember, even going to back to really cool summers like 1993.
Posted by: Phil Creed at August 24, 2008 10:13 PMWe can run this. I'll have Hai take a look at summerizing [sic] the AOD in the ORV this year.
Thanks for the idea.
Posted by: Ray Hoff at August 24, 2008 10:32 PMRay, I had Chuanyu Xu already look at these statistics if you want to post those. I had him do that due to persistent fires in CA.
Posted by: Shobha Kondragunta at August 25, 2008 2:51 PMThanks, Shobha. Send it over and we can post it up.
Posted by: Ray Hoff at August 25, 2008 10:24 PMcontinues to be a major weather influence on the circulation and it is now over New Orleans. It has been almost three years since Katrina and Rita and this probably is bringing bad memories to those in Louisiana.correlation is seen in the west where elevated smoke may be adding to AOD without affecting surface PM concentrations.
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jnnywllms
Posted by: jnnywllms at August 29, 2008 12:25 AMThanks Jenny.
There is a post on the PyroCB listserve on Yahoo which says that there is significant high altitude smoke over Colorado last night (probably from the Utah/Idaho fires) and yes, this won't affect the ground level concentration. Thanks for following the Smog Blog.
Posted by: Ray Hoff at August 29, 2008 8:44 AMI am trying to get some images of PM2.5 plumes from gas-fired peaker plants -- or is that too difficult to image?
Posted by: Rural Canada at November 11, 2008 10:34 PMSorry we missed your comment. Generally the answer is yes, we are not going to see a PM2.5 signal from a point source in the AOD imagery. Do you know what PM2.5 concentrations (range) it may generate, i.e. how clean is the plant ?