A series of fires in the Mississippi Valley region cause several small, light density smoke plumes to form. This can be seen by the HMS smoke and fire products in the top left. The smoke has little effect on air quality. The only observable effect is a slightly elevated Aerosol Optical Depth (AOD) in the area of the fires (NASA WorldView AOD layer, top right). Other than this, North America had a very good day in terms of air quality. There were negligible amounts of dust, low surface sulfate concentrations and the AirNow Ozone AQI loop (bottom left) shows surface ozone reaching code orange (unhealthy for sensitive groups) for only a short time in a small part of the Mississippi Valley Region, which is quite low compared to an average summer day.

The NWS ozone forecast below left shows elevated levels across the Great Lakes and Mid-Atlantic regions, prompting Air Action Days and Air Quality Alerts in those areas. The EPA ozone AQI map below right indicates that the forecast was fairly close to what happened, with several areas in Ohio and the Mid-Atlantic reaching Unhealthy for Sensitive Groups. The NWS wind speed graphic below left indicates low winds in these regions in the afternoon, which would have let ozone and its precursors build up. On a different note, the MODIS instrument on Terra caught the image shown below right of smoke in eastern Arkansas near the Tennessee-Mississippi border. The Hazards Mapping Service smoke text product indicates these are from prescribed burns.

Ozone levels reached mostly Code Yellow (Moderate) levels in the Great Lakes Region, the Mid-Atlantic, the Northeast, the Mississippi Valley, and the Southern Plains States (NOAA, top left). Code Orange (Unsafe for Sensitive Groups) as well as some Code Red (Unsafe) levels were seen in the Great Lakes region. PM 2.5 levels reached Code Yellow on the border between the Plains States and the Mississippi Valley, as well as parts of the Great lakes region. This can be seen in AirNow's PM 2.5 map, top right. Southern California also reached Code Yellow levels of PM 2.5 as well as Code Orange. California's elevated PM levels are most likely due to the Soberanes and Canyon wildfires discussed in yesterday's post. The smoke from these fires can be seen in HMS' smoke and fire map, bottom left.

A large number of agricultural, or prescribed, fires were detected in the Mississippi Valley and Southeast regions today. These fires produced thin density smoke plumes which are not seen in the HMS image, top left. However, these plumes of light smoke caused the air quality from the southern Plains to the Great Lakes region to be mostly code yellow, moderate, and in certain areas code orange, unhealthy (AirNow Image, top right). Ozone was a secondary factor that caused the air quality to reach code orange in these areas. The NOAA Average Ozone Concentration image, bottom left, shows the areas where ozone levels were elevated, and these coincide with the poorer air quality in the region. California also experienced poor air quality due to elevated ozone levels, however, a small plume of light density remnant smoke from the Soberanes and Canyon wildfires is seen aloft near Los Angeles. The extent of this smoke plume was difficult to determine due to heavy cloud coverage.

The Great lakes, Mississippi valley region, and California all experienced Moderate, Ozone and PM 2.5 combined, AQI (AirNow, top left). The Soberanes and Canyon fires in California are producing smoke that extends well off the coast and east into Nevada (HMS, top right). NASA satellite imagery captured this smoke (bottom left). Fires in Utah are also contributing to the plumes shown in the smoke product. VIIRS Aerosol Optical Depth product shows heavy aerosol loading in regions impacted by smoke (bottom right).

Throughout the nation today, we see a nice and relatively clear day. However, in the Pacific Southwest region, we see elevated aerosol optical depth (AOD) as seen in the AirNow image below (top left). EOSDIS provides us with an image (top right) of the differing levels of AOD in this south west region of California and towards central California, where yellow is moderate to light levels of AOD and orange to red is rather high levels of AOD. Fires produced heavy amounts of smoke at the origin of the fire and slowly fanned out west and east of the fires and spanning over a much larger region, as seen in the HMS image below (bottom left). We can see the actual source of the smoke and the direction it is moving in the Terra image below (bottom right). Along with the heavy smoke in the area and the rising PM, Ozone reached a moderate level from what seems to be the effect of the remnant smoke and elevated climates.

Ozone levels. These were elevated throughout the U.S. Code-yellow (moderate) levels were widespread in the West and Plains regions (see map, top left). Code-orange (unhealthy for sensitive groups) to Code-Red (Unhealthy) levels were seen along the Californian coast and in the South-central U.S. They are a result of wildfire smoke, high temperatures and some high pressure systems in the area.

Aerosol Concentrations. These were high (purple, red, yellow) along the West coast and Rocky Mountain regions due to dense smoke from wildfires (see map, top right). Throughout the rest of the U.S., concentrations remained relatively low (blue).

Wildfires. Three main wildfires in California are producing moderate-to-thick density smoke: (1) Willard wildfire in the north (2) Soberanes wildfire along the central coast and (3) Owens River wildfire in the east-central region (see map, bottom left). Smoke from these fires are traveling southwest over the Pacific Ocean and to the east into northern Nevada.
In northern and central Arizona and New Mexico, wildfires are producing light-to-moderate density smoke drifting both east and westward.
A series of fires and smoke plumes were seen scattered across Utah (Moderately dense-to-thick smoke) as well as western and southwestern Colorado.