December 18, 2014

High NO2 concetrations Along Mississippi Valley States

PM2.5 concentrations reached Code Yellow (Moderate) AQI levels in the Pacific Northwest, Great Lakes, and the Gulf of Mexico states (Airnow animation). Clouds hindered once again AOD retrievals over the nation (top right image). Troposphere NO2 concentrations were high along the Mississippi Valley states, as light winds over this region limited pollutant dispersion.

December 17, 2014

Code Red in Portola Air Monitoring Station; High trophospheric NO2 concentrations in the Southeast

Moderate PM2.5 concentrations were experienced in the early morning hours in the Pacific Northwest and California, as high pressure in the region caused fine particulates to gradually increase. In northern California, the Portola air monitoring station reported concentrations as high as 129 ug/m3 (Code RED AQI, Unhealthy). In the East coast, strong westerly winds provided good ventilation with PM2.5 concentrations reaching GOOD AQI levels as the day progressed, with cooler and drier air moving behind a cold front. Satellite AOD in both coast was hindered by clouds. In the Southeast OMI KMNI tropospheric NO2 concentrations were high over Georgia.

December 13, 2014

Weekend Edition: Very clear in the US Southeast with Agricultural Burning

The area of the US with the highest concentrations of PM2.5 on Saturday are in the Great Lakes states of Indiana, Ohio and Pennsylvania. Unfortunately, the whole area is under cloud today so it is likely that this is due to low boundary layer heights. In the US Southeast, it is very clear and there are a large number of fires identified there in the HMS image.


The LANCE Worldview site shows one of those fires in, what we guess is Virginia. To show how sites can change on your without warning, Worldview now does not print place labels, state boundaries, etc. without you having a license for StreetView. That is not progress and will make Worldview much less useful than it was. If you cannot navigate the geography, the imagery is just that. Imagery.

Update: Sunday December 14

Overnight high PM2.5 concentrations were elevated in isolated monitors in the Pacific NW. Each of these code Reds are limited in time and only an hour or two. This indicates household heating (probably wood burning) and low boundary layer heights. There are code yellow (moderate) readings in the San Joaquin Valley and in the I-95 corridor in the mid-Atlantic.

I don't often get to write posts on a weekend from opposite coasts but there was a beautiful sunrise over Ohio today and the low stratus clouds looked like the surface of the ocean.

December 12, 2014

Moderate AQI around Great Lakes and Southeast

Spots of Moderate AQI appear in the Great Lakes, Mississippi Valley, Mid-Atlantic, Southeast, and Pacific Northwest in the Airnow AQI image shown below left. The OMI tropospheric NO2 image shown below right indicates that elevated nitrate levels may be responsible for the elevated AQIs in the Great Lakes and Mid-Atlantic, although clouds cover much of those areas. The HMS analysis indicates that the agricultural and prescribed burns in the southwest are ongoing, which might contribute to the degraded air quality in that area.


The National Weather Service has issued Air Quality Alerts for central Indiana due to the possibility of excessive fine particulate matter and for northern Kentucky along the Indiana border due to elevated ozone levels. The low winds seen in the NWS image below will not help the issue, keeping the same air in the area until the pattern changes.

December 11, 2014

Moderate AQI in California and Great Lakes


The air quality today in the US reached moderate levels in different regions. The Great Lakes, Central Plains regions, and California experienced moderate level throughout the entire day (top left). According to HMS, no areas of significant smoke and/or blowing dust seen in satellite imagery. However, a large number of agricultural and prescribed burns were observed over the Southeast US, mainly over Georgia, Alabama and Florida, which had smoke plumes that were seen moving to the south and east (top right). Some of this smoke can be seen in the GASP animations as high AOD levels were retrieved in the aforementioned states (bottom left). Monterrey Aerosol Modeling suggests the presence of Sulfate in the Mississippi Valley and smoke in the Pacific Northwest (bottom left).

December 10, 2014

Prescribed Fires in the Southeastern and Mississippi Valley States

Clouds (top left image, AQUA rgb) hindered MODIS AOD retrievals in locations where PM2.5 concentrations reached Moderate AQI levels. NOAA's Hazard Mapping System Fire and Smoke Product reported the presence of moderately dense smoke plumes across the Southeast/Mississippi Valley. The smoke plumes in the southeast can be seen in today's GASP AOD retrievals, with values ranging between 0.1 to 0.4 over Georgia/South Carolina and Florida. These prescribed fires may have contribute to the PM2.5 concentrations in the late afternoon, as shown in the Airnow animation. PM2.5 concentrations over Idaho reached Code Orange (Unhealthy for Sensitive Groups), with concentrations ranging between 17 to 87 ug/m3 at the Salmon air quality monitoring station. In California, concentrations were Moderate (Code Yellow). The Code Red concentrations might not be real as inspection of data reported by Airnowtech suggest that data before and after exceeendance was the same.

December 9, 2014

Unhealthy AQI in Caliifornia/Nevada. Most likely due to residential wood burning.

The MODIS AOD image, below left, shows low values of AOD across the country for today. There does appear to be scattered increases in AOD in the Southeast and Texas regions Large cloud coverage in the eastern portion of the country deterred retrieval efforts and there are large gaps in the AOD product. The KNMI OMI NRT NO2 product below right, shows increases in NO2 throughout the troposphere. There appears to be an increase in the NO2 in Texas and the Pacific Southwest.



Below left, courtesy NOAA National Maps, shows the synoptic surface meteorology for today. There has been a fairly persistent high pressure system east of the Sierras and west of the Rockies throughout the day that to appears to be deteriorating air quality. This high pressure system has helped to stagnate surface conditions with an temperature inversion near 300 m (from Reno, NV 12 Z sonde). Due to this stagnation, air quality has decreased from the increased trapping of local wood burning debris. Below, right courtesy NOAA HMS, shows the fire locations for the day. There are concentrated fires in the Southeast and scattered fires in California but there does not appear to be much smoke from these fires. The animation below left, shows the EPA AIRNOW AQI values for today. This shows the code red values for the surrounding region near Reno, NV. This increases is mostly due to residential wood burning and several burn bans are in place throughout the region. There does appear to be a rain/snow in the forecast for the next few days and it will hopefully bring cleaner air into the region.