April 17, 2015

Mostly Good Air; Dust in Southwest

The HMS fire and smoke product, below left shows only one fire in the U.S. that I can find, with three overall; a rare sight and getting rarer as we head toward the summer fire season. The EPA AQI loop below right shows some of the benefits of the fewer fires; there are only a few areas of Moderate AQI, one around the Great Lakes and more along the West and Gulf Coasts.


The NWS wind forecast below left shows low winds in the Midwest, which would have helped the aerosols to build up. The map also shows areas of high winds in the southern Rockies, which may have contributed into the dust seen in the NWS dust forecast below right. This seems to be mostly above the surface though, as it does not seem to have affected the surface air quality much.


April 15, 2015

Smoke over Minnesota; Dust Storm in Utah/Nevada; Homogeneous Boundary Layer over Baltimore

Remnant smoke plumes were observed over Minnesota and the Dakotas. The smoke is believed to have originated from the central plains. The top left image is the NOAA Hazard Mapping System Fire and Smoke Product show the locations where satellite observations located smoke and fires over this region. The top right image is the MODIS Aqua AOD retrieval over the smoke locations, yielding max values of 0.4.

Blowing dust leftover from last evenings haboob event that originated in central Nevada was observed in visible satellite imagery stretching from Colorado, New Mexico, Arizona and southern California. The animation below (courtesy of CIMSS satellite blog) is acomposite of GOES-13 (GOES-East) 0.63 µm visible channel images showing a cloud of dust moving southward across southern Nevada and parts of southern California, along and behind a strong cold frontal boundary on late Tuesady afternoon. This is the same dust storm that wreaked havoc in Utah along Interstate 80, with 1 person dead and 16 hurt, with Six semis and 11 passenger vehicles were involved in a chain-reaction crash in Tooele County, Utah. Last, in Baltimore lidar observations show a homogeneous boundary layer extending up to 1.75 km. Clouds advected as well, at heights around 6-8 km.

April 13, 2015

Smoke from Central US Fires Causing Elevated AOD in Great Lakes; Remnant Smoke from Central American Fires Reaches Southern Texas

The only concerns of Moderate to USG AQI's were noted in the northeastern, central, and southwestern US (EPA AirNow Combined AQI loop, top left). All of these areas also experienced higher concentrations of tropospheric NO2, especially in southern California, the northern Midwestern states, and the Great Lakes region (KNMI OMI Tropospheric NO, top right). Due to clouds limiting visibility over southern California and the Midwest, the only areas spotted with elevated AOD was over the Great Lakes region (MODIS Terra, middle left).

A mixture of sulfates and light remnant smoke from agricultural burnings in the central US could be what is affecting air quality over this region, as what is predicted by the NAAPS Aerosol Model (middle right). HMS claims dust might also play a role in this, stating that an aerosol load--presumably made up of elevated dust particles--was seen in GOES East imagery today headed eastbound over the Great Lakes Region, crossing over Minnesota and Wisconsin into Lake Superior. This could mistakenly be remnant smoke from the central US fires, which can be seen moving eastward from their fire sites (NOAA HMS, bottom left).

Smoke from the prescribed fires still burning in the central US are possibly the cause behind the growing spot of USG AQI's on the border of Wyoming, Colorado, and Nebraska. The high pressure system parked over the region helps aide in keeping the smoke in the lower parts of the atmosphere (NOAA Weather Map, bottom right). Other agricultural fires--like those in Central America--have caused a rather large plume of smoke to cover most of Mexico. Another remnant plume (light in density) from these fires has stretched as far north as southern Texas. Back in the US, southern California is covered heavily by Moderate to sometimes USG AQI's, presumably from urban pollution as well as a few fires burning in the area.

April 11, 2015

Weekend Edition: Smoke from Kansas moves northeastward

Daniel pointed out in Friday's post that there was smoke being generated in Kansas from agricultural activities. That smoke showed up today in MODIS's aerosol optical depth product over Iowa and the GASP loop shows the movement of the smoke. Recall that bright surfaces will give high reflectivity and cause GASP to interpret that as elevated AOD. But you can see the difference from the surface (which does not move) and smoke which does move. Watch the loop over Iowa and you will get the point.

The HMS folks at NOAA have identified multiple fires in the region and a broad area of smoke. The AIRNOW site is unfortunately offline on Saturday night but web cams at the University of Iowa show reddening in the sky at sunset (below right).

April 10, 2015

Good AQIs But Fires in Central Kansas

The HMS fire and smoke product, below left, shows many fires in eastern Kansas, some of which are shown in the MODIS Terra image below right.


The smoke also seems to be showing up in the MODIS Terra AOD image shown below.

April 8, 2015

Red Flag Warning Colorado and New Mexico; Smoke over the Gulf of Mexico; Moderate PM2.5 in Central US

The National Weather Service issued a Red Flag Warning in southern Colorado and northern New Mexico.Strong winds and very dry air this region causes extreme fire danger. Wind gusts of 40 to 50 mph are experienced across the lower elevations with winds to 60 mph in and near the Mountains. Dry grasses and other dry fuels are highly susceptible to spark or flame. Blowing dust will be an issue across the San Luis Valley and parts of the Plains in Colorado (top left image, source National Weather Service). Air quality in the Plains, Mississippi Valley and southern Great Lakes States experienced Moderate PM2.5 AQI levels (Airnow animation).

NOAA's Hazard Mapping System Fire and Smoke Product reported smoke over the Gulf of Mexico. A large area of light density was visible moving from the Yucatan and adjoining areas of Mexico towards the northern Gulf towards Texas. The smoke is believed to be smoke from remnant agricultural smoke and emissions from the oil rigs in the same area of the southwestern Gulf. In the Eastern Gulf of Mexico smoke was moving NW from the Tampa Bay area of Florida into the panhandle of the state. This smoke originates from the several agricultural burns that have been taking place around Lake Okeechobee.

In Arizona an area of hazy blowing dust was visible moving SE and extending through a majority of the state. There is a high chance that this dust is foreign, and made its way from California overnight from the Pacific Ocean. The bottom right webcam image (courtesy of television station KPHO) shows the hazy/dusty skies over East Valley, Arizona.

April 6, 2015

Asian Dust over Northern US Plains into Southern Canada

The EPA AirNow combined AQI loop (left) shows mostly good air quality today, save some concentrated areas of Moderate AQI's dotting the rest of the nation. The only troubling spot of AQI's reached USG in northern Ohio before 12:00 EDT before receding back to Moderate. This spot is believed to be from a mixture of dust (predicted by the NAAPS Aerosol Model to reach 40 µg/m3), sulfate (also predicted by NAAPS to reach 4 µg/m3), and smoke (light to moderate in density, presumably from the large amount of agricultural fires from yesterday and over the weekend in the Central Plains and Midwest regions, predicted to reach 32 µg/m3). The MODIS Terra image (right), however, notes elevated AOD over northern Wyoming, crossing over into southern Canadaa over Quebec, Ontario, and Manitoba. The HMS Fire and Smoke text believes this to be an episode of elevated Asian dust. The NAAPS Aerosol model supports this claim, predicting dust to have reached a surface concentration of over 1.26 mg/m3 in and around the area.