November 2, 2008
Midwest haze continues and is likely to persist
The midwest haze identified over the last few days is holding on and not moving quickly. The left panel below shows the PM2.5 levels throughout the middle of the country. On the right, I have posted the November 1 tropospheric nitrogen dioxide columns from the OMI satellite. NO2 is a source of ammonium nitrate which can be a major contributor to haze during cooler, winter months. It is possible that this haze event has a significant nitrate component.
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The high PM concentrations in Houston (120 ug/m3) and Beaumont, Texas, (107 ug/m3) are likely due to smoke from fires in the area (left panel, below). NOAA's forecast guidance system is showing elevated smoke levels for the next 12 hours in the south and midwest, with the smoke moving from south to north.
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