April 22, 2008
Intense haze over Nebraska, South Dakota, Iowa, Wyoming, Montana, and Minnesota…the power of satellite derived Aerosol Optical Depth.
Intense haze is present over the Midwest. It is mostly noticeable over Nebraska, South Dakota, Iowa, Wyoming, Montana, and Minnesota (left image; source: UW MODIS Direct). Few in situ air quality monitors exist in this region, but we fortunately have a spaceborne perspective from MODIS where the aerosol intensity can be inferred. AOD was high over this region and reached unity where the concentrations were likely the most intense. Also, haze which was over the Great Lakes region yesterday now lingers over the Atlantic (right image; source: UW MODIS Direct). Refer to the center graphic for a visual of today’s MODIS AOD (source: NOAA-UMBC GASP IDEA).
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PM2.5 (source: EPA AIRNow – bottom image) levels remain moderate in the Midwest, Central U.S., and parts of the East. Pollution from local sources are likely responsible. Southern California also has code yellow conditions, but haze was not clearly visible in the MODIS true color image. Look carefully at the AOD picture above and you will see that the values are elevated where most code yellow conditions were reported.
Lastly, several fires are still present in the Nation. Refer to the analysis from the HMS team for identification of all hotspots (smoke indicated in gray).
Regarding the haze seen over the northern Plains and Upper Midwest...this blog post caught my attention today:
They suggest that this haze plume is due to the long-range transport of smoke from massive fires in eastern Russia, and I'm inclined to believe that hypothesis.
The animation of GOES-12 visible images shows the plume moving eastward at speeds representative of those found aloft in the middle troposphere:
and 7-day back trajectories do indeed suggest some sources from the Lake Baikal region:
Posted by: Scott Bachmeier at April 22, 2008 10:32 PMI suspect that the "haze" over the north central states may be long-range transported aerosol from Asia. The "haze" was very apparent both early in the day in the western GOES satellite imagery, and late in the day in the eastern GOES satellite data --- when the repsective angles of incidence were similar. The "haze" did not appear to have originated in the Pacific Northwest, which recently has been cool, wet and largely fire-free. The "haze" plume was also partially visible moving around the southern side of the large storm system over the northeast Pacific late Monday. I can forward two GOES images of the north central states taken around sunrise and around sunset by the GOES West and GOES East satellites, respectively, if anyone is interested.
Stephen Corfidi
NOAA Storm Prediction Center
Thank you both for the comments! I did suspect that this might be long range transport but couldn’t get back trajectories at the time or local LIDAR data. It is quite intense and is probably at high altitudes in the atmosphere. All REALM participants should be running there systems over the next few days, some of this pollution will likely pass over the east. I will make a follow up post on this event soon. Thank you again for the feedback, links, and etc!
Posted by: Nikisa Jordan at April 23, 2008 10:29 AMHi again Stephen…
This is an interesting story so please feel free to send any additional images and we can post to the blog (of course making source to give credit). Or you can provide links to this imagery where we can link to.