August 20, 2014

Smoke from Northern California Wildfires Moving East

Several wildfires in northern California continue to produce smoke, as shown in today's MODIS Aqua RGB image (top left image). The smoke is moving east (top right image, NOAA Hazard Mapping System Fire and Smoke Product), yielding high AOD values over Nevada, Oregon, and Idaho (bottom left image, MODIS Aqua AOD). The smoke is impacting the air quality in locations near the wildfires, as Moderate to Unhealthy for Sensitive Groups (Code Yellow to Orange) PM2.5 AQI levels were experienced over this region (EPA Airnow animation).

August 19, 2014

Smoke over the Northern Plains; Dust over the Southern

The EPA AQI loop, below left, shows areas of Moderate AQI across the Mid-Atlantic, Great Lakes, Southeast, Mississippi Valley, and southern Plains, as well as the Pacific Southwest, the Pacific Northwest, the northern Rocky Mountain, and the northern Plains. Spots of Unhealthy for Sensitive Groups are also visible in northern California and Idaho before disappearing in the evening, with the Idaho patch reaching Unhealthy before dropping. The HMS fire and smoke imagery, below right, shows smoke over northern California, the northern Rockies and Plains, the Great Lakes, and the Mid-Atlantic, which may be related to the higher AQIs in these regions.

The smoke plume over the northern Plains is visible in the MODIS Terra image below left. The NRL NAAPS forecast, below right, shows sulfates may be behind the elevated AQIs in the east and southeast, while dust may be responsible for those in the south.

August 18, 2014

Wildfire Smoke Pollutes Northern and Eastern US; Dust Pollutes Gulf of Mexico

The wildfires in Western Canada are still active, producing smoke spilling over into the US. The thickest smoke can be seen over British Columbia, Saskatchewan, and Manitoba, leaking over the US border into Montana and the Northern Plains States (NOAA HMS Google Earth, right). Light remnant smoke from these Canadian wildfires covers part of the East Coast, creating spots of Moderate AQIs over most of the region (EPA AirNow PM2.5 loop, left). The still burning wildfires in Northern California are producing much of the same effect; leaking smoke into Idaho and causing unhealthy amounts of PM2.5 to build up around 4:00 PM EST.

Elevated AOD can be seen off the coast of Florida (MODIS Terra, left). This is presumably unrelated to any wildfire smoke, but instead the product of Saharan dust. The EPA AirNow PM2.5 loop above shows Moderate AQIs in Southern Florida supporting this claim. The NAAPS Aerosol model (right) predicts a swath of dust transported over the Atlantic Ocean to hover over most of the Caribbean Islands and parts of Central America, Mexico, and the Gulf. This swarm of Saharan dust is forecasted to move up into Texas and across into Louisiana throughout the course of the week.

August 17, 2014

Weekend Edition: The Summer of Smoke Continues

We have been posting on the Smog Blog for almost 10 years now (September 2014) will be our tenth anniversary. We don't recall such a consistently smoky summer. We had years with major smoke events (like the Quebec fires of 2002) that impacted the US, but never continuous smoke coverage over the US and Canada. Fires in the Yukon have been burning nearly continuously since May. This week a major fire in British Columbia continues to pour smoke into the US. On Graham's post yesterday, the streamer of smoke could be seen going out to the Atlantic over the Mid-Atlantic states and we did see that high altitude smoke on the GSFC MPL lidar on Saturday. The NRL MMM forecast of smoke shows that it dominates the continent.

We had to wait until quite late on the 16th to get the full US RGB image from AQUA MODIS on the Worldview site. The smoke plume from BC is seen streaming across Canada and will probably head eastward instead of southward into the US, giving some relief from this major smoke event. In California and Oregon, however, fires continue to burn and smoke can be seen heading across Idaho.

The fires in British Columbia have produced an impressive smoke plume in the Sunday imagery, heading towards Hudson's Bay.

August 15, 2014

Smoke, Sulfates, and Dust Combine to Affect AOD and AQIs

Looking at the NOAA HMS Smoke and Fire Product (top left), the clumps of small red dots indicate masses of currently burning fires, with smoke plumes being indicated by the grey patches. The Canadian plume we have grown accustomed to this summer reaches down into Kentucky and Tennessee, although the sun angle prohibits any GOES-West imaging further east than the image indicates. It is possible that this plume stretches to the Atlantic coast, and the MODIS Terra image (top right) illustrates elevated AODs in Canada and northern parts of the US in accordance with this plume. Also, a small plume around the Northern California wildfires mentioned by Daniel yesterday was seen continuing to persist.

The EPA AIRNow combined AQI loop (bottom left) shows increased AQIs in western Canada and northern California around the wildfires, but the largest portion of moderate and USG AQIs are in the southeast United States. The current high is in Atlanta, GA (137), and the NAAPS Aerosol model (bottom right) at 1800 UTC predicts high concentrations of sulfates to affect air quality in this area. In addition, it also predicts smoke to create elevated AODs in Canada and a region of higher AODs due to dust in the Caribbean and Atlantic. This could very well be Saharan dust migrating towards North America, and looking back at the aforementioned MODIS Terra image, one can see high AODs in the southeast corner corresponding to the area of dust in the NAAPS forecasts.

August 14, 2014

Smoke over Central U.S., Fires in West

The EPA AQI loop, below left, shows the area of Unhealthy AQI in central Idaho present in the early morning before dropping to Moderate by mid-morning and disappearing entirely partway through the afternoon. There are additional patches of Moderate AQI through the Pacific Northwest, Pacific Southwest, southern Plains States, Mississippi Valley, Southeast, and Mid-Atlantic, with some spots in North Carolina and along the Texas-Oklahoma border reaching Unhealthy for Sensitive Groups. The HMS smoke product, below right, shows smoke covering the Plains, Great Lakes, ,Mid-Atlantic, and Northeast, which may account for some of the elevated AQIs.

The MODIS Aqua image of north-central California below shows a closer view of one of the smoke plumes visible in the HMS image above, spreading eastward from the Lodge Complex fires.

In another closer look, the webcam image below on the left is from Boundary Waters Canoe Area Wilderness in northeast Minnesota, which appears rather more hazy than the image on the right, taken in clear conditions.

August 12, 2014

Fires in Pacific Northwest; Moderate AQIs in East

The EPA AQI loop below (top left) shows most of the Plains States and southern Rockies clear, with some areas of Moderate AQI from the Great Lakes into the Southeast, with a few smaller spots across New England and the Mid-Atlantic. One of the areas in Georgia got up to Unhealthy for Sensitive Groups early in the day before dropping back down. The Pacific Southwest has its own areas of Moderate AQI briefly reaching Unhealthy for Sensitive Groups, while the Pacific Northwest and northern Rocky Mountains are largely at Moderate AQIs or above. There are sustained regions of Unhealthy and Unhealthy for Sensitive Groups in northern Washington and central Idaho. NWS surface smoke predictions below (top right) show regions of smoke blanketing the Pacific Northwest and southwestern Canada, which makes that a likely cause. The USDA Large Incidents report shows upward of a dozen fires in the area feeding into the smoke, shown bottom left below, lends credence to that hypothesis.

Most of the Pacific Northwest has been under Red Flag Warnings due to the dry and windy conditions, so the fires there have plenty to work with. The NWS Storm Prediction Center's Fire Weather Outlook for tomorrow, below left, shows an increased risk for fires, so it may be a while before the fires are no longer an issue. The morning radiosonde from Spokane, WA, shown below right, shows a low inversion which, if not broken by diurnal heating, would keep all the aerosols causing the elevated AQIs near the surface, prolonging the event.