October 31, 2014

Smoke in Southeast; Dust in Arizona and Wyoming

Smoke from some of the fires in the southeast mentioned in earlier posts is visible in the MODIS Aqua image of the Louisiana, Mississippi, Alabama, and Florida coasts shown below left. These fires may be contributing to the spots of Moderate AQI in this area, seen in the EPA AQI loop below right.

Also visible in the AQI loop are patches of Moderate AQI in the Pacific Northwest, Pacific Southwest, and Mid-Atlantic. The effects of the elevated AQI in southern California can be seen in the NPS webcam image from Joshua Tree National Park below left. On the right are images from the same location on clear and hazy days for comparison.

The National Weather Service issued Air Quality Alerts in northeastern Wyoming and southwestern Arizona today due to blowing dust. The NWS maps of sustained wind speed and direction, below left, and wind gusts, below right, indicate strong gusts over both areas and sustained high winds over Wyoming ready to kick up dust and keep it going.

October 30, 2014

Smoke in the Gulf of Texas; High NO2 in the Great Lakes

Today, OM2.5 levels were good in most of the US except in the western states where AirNow reported moderate levels. California, Oregon, Washington and Idaho experienced moderate levels throughout the day (top left). In the east, the Mid-Atlantic and Great Lakes registered moderate levels as well for short periods. HMS reported an area of light density remnant smoke visible moving north from the Mexico/Gulf of Mexico into southern Texas on the Gulf coast (top right). This smoke originates from the agricultural fires that have been occurring throughout the southeastern U.S. this week. High levels of NO2 were retrieved by OMI over the Great Lakes region (bottom).

SPECIAL FEATURE: Fires in the Southern United States

Large wildfires that threaten people and property--such as the September 2014 King Fire in California--capture the attention of the American public and media. They are unpredictable and menacing and have an outsized influence on our impressions of fire and smoke.
Less prominent in the public eye are the myriad smaller fires that are set for managing cropland or forested areas. However, recent research by Hsiao-Wen Lin of University of California-Irvine found that prescribed burns and cropland fires accounted for 77 percent of all fires detected in the United States by NASA's Terra satellite between 2001-2010. These managed fire types can contribute significantly to emissions of carbon and other pollutants, particularly in the South and Southeast.
On October 22, 2014, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite acquired this image of fires across the U.S. Southeast. Actively burning areas, detected by the thermal bands on MODIS, are outlined in red.
Most of the fires in this image are likely prescribed, according to Doug Morton of NASA's Goddard Space Flight Center. October is the right time and location to see burning in preparation for planting in the U.S. Southeast. The cycle includes planting of seedlings, growing and harvesting trees, and then the burning of branches and debris--collectively called slash--that are left on the ground. The burning returns the land to bare soil that can be planted with new seedlings.

October 29, 2014

Code Yellow to Red in the Western United States; Wallops Rocket explosion; Glacier Silt in the Gulf of Alaska

Moderate PM2.5 concentrations were observed along the East and West coast of the United States, as shown in the EPA Airnow animation (top left). Code Orange and Red concentrations were reported in the afternoon in northern California and along the Idaho/Nevada and Utah border. Satellite retrievals over the nation show that AOD levels exceeding values greater than 0.2, over Nevada, eastern Plains States and the Mississippi Valley.

As you all may know the Antares rocket and its cargo spacecraft suffered a catastrophic failure shortly after liftoff Tuesday evening at NASA's Wallops facility. The explosion can be seen in the GOES-13 shortwave IR animation (courtesy of Scott Bachmeier, CIMSS) The thermal signature from the explosion and fire is evident within the red circle: the IR brightness temperature was 292.2K on the 22:30 UTC image (darker black pixel), compared to 286.9 and 286.7 K on the 22:15 UTC and 22:45 UTC images, respectively. In addition satellite imagery showed a glacial silt event in the Gulf of Alaska (MODIS-Aqua rgb image). Silt is granular material of a size between sand and clay whose mineral origin is quartz and feldspar. Silt occurs as a soil or sediment mixed in suspension with water.

October 28, 2014

Dust blowing in Rocky Mountain Region. Increased NO2 over Great Lakes Region and Rocky Mountain Region

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 Southwest region. 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 the Great Lakes region as well as the Rocky Mountain Region. There is also a large increase in NO2 in southern California.

The surface PM 2.5 model, courtesy NAAPS below left, shows continuing dust blowing in the Ohio River Valley region and into the Midwest region. This model also shows an increase in the surface sulfates in the Mid Atlantic region and increased surface smoke concentrations in the Southeast region which correlates well with local fires. The AIRS Dust Score, below right, shows an increased region of blowing dust in the Rocky Mountain Region.

October 27, 2014

Prescribed Fires in SE, Wildfires in Pacific NW

The dense concentration of smoke over the Southeast continues to be a problem, measuring Moderate AQIs for the day (EPA AirNow, right). The NAAPS aerosol model (left) predicts the smoke concentration to have reached 16 ug/m^3 in the Southeast and is predicted to diffuse eastward as the week progresses. It is not clear exactly where the smoke is coming from, but part of the plumes seem to originate from small prescribed fires in the region, such as the Shenandoah National Park Fire in Virginia, which is active and has been last reported to have burned 35 acres (inciweb.nwcg.gov). Fires are also burning parts of the Pacific Northwest, except much larger than those previously discussed, such as the Malheur National Forest Fire in Oregon, which has burned up to 66,179 acres to date.

October 25, 2014

Weekend Edition: Fires in Texas, Arkansas leading to smoke in the Southeast

Two fires as streaming smoke eastward towards the US Southeast. The smoke is forecasted to cover much of the southeast in the MMM forecast. A broad band of moderate PM AQI starts in Texas and works its way northeast today.

Update: October 26, 2014

Fires continue across the south and are likely due to land clearing. A fire northeast of Houston is burning in Texas, but a number of fires are seen in the image below in Arkansas.

October 24, 2014

Moderate AQI Across Midwest

The EPA AQI loop below left shows a swath of Moderate AQI from the Great Lakes through the Great Plains and into the Mississippi Valley. This area corresponds in part to the areas of high NO2 shown in the Tropospheric NO2 image below right. There are also patches of Moderate AQI in the Pacific Southwest and Southeast.

The NPS webcam image below left shows the view from Big Bend National Park in southwest Texas, on the edge of the area of Moderate AQI shown in the image above. Images taken in clear and hazy conditions are shown below right for comparison. The image shows somewhat hazy conditions, in keeping with the AQI levels around that area.