Very unhealthy air quality (EPA AirNow) remains in Northern California. The rest of the nation is experiencing mostly moderate (code yellow) conditions. Smoke is apparent in most of the Country. More specifically, in the Northwest, smoke is likely from California fires. Refer to the MODIS AOD map (left; NOAA-UMBC GASP IDEA) for intensity. The true color MODIS image (UW MODIS Today) is on the right. Aerosol is also present over the Great Plains region; most of it is likely from fires in Canada. I may receive some images related to the fire events in Canada from a colleague. High AOD over the Northeast is likely due to regional haze, which we are familiar with this time of year. However, smoke aerosols from Canadian fires may also be contributing to that load. See Ruben’s LIDAR post; apparently some of this smoke is aloft over Maryland. Lastly, the AOD is high over the Gulf region. Again, this is probably due to lingering dust.

Overnight ELF operations were carried out to support Maryland Department of the Environment Low Level Jet (LLJ) studies. No conclusive signs of LLJ activity were observed last night, as it was for the night of June 13th. A homogeneous boundary layer, that extended up to ~2.5 km and aerosol stratification were observed throughout today's lidar timeseries. Backtrajectories for the airmass associated with the plumes aloft between 4-6 km came from Canada (right image), according to NOAA HYSPLIT calculations. These plumes could be part of the influx of Canadian smoke to the US that was covered by Nikisa in her post.

Air quality conditions continue to be dangerous for residents of northern and central California due to smoke from the numerous wildfires that have been burning for the past 10 days. PM2.5 air quality is in the Code Maroon (Hazardous) range at Auburn, Roseville-Rocklin, Sacramento, and Bakersfield this afternoon. Today’s MODIS Terra true color image for northern and central California overlaid with the 21:00 UTC AQI values (below) shows the Hazardous readings. As we have been reporting the past few days, air quality has improved in many of the regions in California impacted by the wildfires, as can be seen by the Code Green and Yellow conditions in the San Francisco metropolitan area and across the Central Valley. However, poor air quality persists in the Sacramento/Chico region.

Today’s MODIS Terra true color image of the USA1 region (below on left) shows a clear view of the smoke plumes from the California wildfires. The corresponding GASP AOD image (below on right) of Region 9 indicates the high AOD associated with smoke from the fires.

Sacramento, Roseville-Rocklin, and Auburn residents won’t get any relief from poor air quality conditions for at least another day. California air quality forecasters are predicting Code Red (Unhealthy) PM2.5 conditions in these cities for Thursday.

Across the rest of the country, air quality is mostly in the good to moderate range. There are a few reports of Code Orange (Unhealthy for Sensitive Groups) ozone scattered across the Southeast and Texas, as can be seen in the image below of the 21:00 UTC AQI values for the nation.

Many fires in California have been producing significant smoke over much of the West (see old posts on the blog). Most of these fires are, in fact, still going strong; air quality (EPA AIRNow) remains poor as smoke continues to drift northward into Oregon and Washington. Local fires in Nevada are also contributing to the smoke load in the West.

The nation is receiving another influx of intense smoke, but Canada is the source this time. Please refer to a news story from the Canadian press (archived here) for more details on the forest fires. Also, the The Canadian Interagency Forest Fire Centre (CIFFC) provides more information on current conditions. Please link to the Canadian Wildland Fire Information System (CWFIS) site for recent data maps.

Aerosol Optical Depth (AOD) data from the MODIS satellite instrument is shown on the right. The AOD (left; NOAA-UMBC GASP IDEA) provides a better understanding of aerosol intensity. We can clearly see that the aerosol load is most intense in the Northwest, Southern Canada, and North Central U.S. (smoke from Canada). The AOD is also high over the Atlantic and Gulf Coast region. This is likely due to dust transported from Africa along with regional haze. Refer to the satellite RGB images from MODIS as well (right; UW MODIS Today).

But where will all this stuff be headed? If you want the answer to this question please refer to the NOAA-UMBC GASP IDEA website. I’ve provided the animated image below for your convenience, which shows the wind vectors. A JAVA version is also available which allows the user to control the animation and layers to be displayed. In short, smoke from the California fires will likely continue to head northward and more smoke from the Canadian fire event will move further into the U.S Northern Great Plains.



If you live in the regions currently being impacted by smoke please be sure to read health guidelines provided by EPA. Breathe easy and make sure to stay linked to the smog blog!

It’s been another day of Code Red (Unhealthy) and Code Orange (Unhealthy for Sensitive Groups) air quality in the west. As Ray reported yesterday, the good news is that air quality is improving along the California coast and Central Valley, but the bad news is that smoke from the California wildfires is moving north into southern and central Oregon, and air quality is degrading there as a result. The loops of today’s PM2.5 conditions in California (on left) and Oregon (on right) show the relative improvement in California’s air quality and the deteriorating conditions in Oregon, with Code Orange and Red PM2.5 across the southern portion of the state.

The 29 fires in California have burned 366,656 acres, according to the National Interagency Fire Center. Today’s MODIS Terra true color image (below) shows smoke from the fires extending from northern California into southern Oregon; it’s a bit difficult to discern the smoke in the image today with all the clouds inland and along the coastline.

Poor air quality conditions are expected to be widespread across the west on Tuesday. The image below shows the official AQI forecasts for Tuesday in Google Earth. Code Red ozone levels are expected for interior regions of the Los Angeles area, while Code Orange conditions are predicted for the Central Valley, inland San Diego, southern Oregon, and urban areas of Colorado. If you live in these areas, keep an eye on the air quality tomorrow.

Elsewhere in the nation, air quality is in the good to moderate range. A cold front is moving through the east this evening, bringing Code Green conditions in its wake. Some Code Yellow (Moderate) PM2.5 persists along the Gulf Coast, likely due to the influence of the Saharan dust that we have been discussing for the past several days. Today’s GASP AOD loop (below) shows elevated AOD associated with the Saharan dust over the Gulf of Mexico, Caribbean, and Atlantic Ocean.

Although air quality is slowly improving in California, this is only the beginning of the fire season in the west. Red Flag warnings are posted for tonight into Tuesday for much of the west, including parts of interior Washington, eastern Oregon, western Nevada, much of Utah, and southwestern Colorado. A Red Flag warning means that critical fire weather conditions are either occurring now, or will occur shortly. In this case, thunderstorms are forecast to move through the warned regions; lightning and gusty winds associated with the storms will provide the potential for ignition and explosive fire growth. If you live in the warned regions, be aware of the fire potential tonight and Tuesday.

The fires continue in the west, but offshore flow is taking the smoke to the northwest.
The NOAA forecast guidance (lower left panel) shows that the smoke will continue up the coast towards Washington and Oregon. MODIS AQUA's RGB superimposed with the local temperatures and wind barbs is shown in the figure on the right. AIRNOW's surface readings in California today are shown here.

As Ruben, Amy and Meloe have pointed out for the last few days, a big pulse of Saharan dust has been coming across from Africa and now is in the middle of the Caribbean. We are testing a new blog with our colleagues in the SERVIR project in Panama. Ruben posted the prediction of this plume on the new Mesoamerican and Caribbean Smog Blog (posted in Spanish). In the panel in the left, GASP has detected a pulse of high AOD of nearly unity near Texas. The AIRNOW concentrations for PM increased in Texas and Louisiana throughout the day.

On Friday night, Calipso had an overpass over the eastern Caribbean and the big yellow plume in this image is Saharan dust.

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And finally, congratulations to Ana Prados whose Spanish team won the Eurocup 2008!

As Amy predicted in yesterday's post, today's MODIS TERRA true color image (below, left) still shows the presence of wildfires in California (305,112 acres burnt according to the National Interagency Fire Center). We can, indeed, observe a wide spread smoke plume mostly contained over the Sacramento and San Joaquin Valleys. According to a CNN report, the smoke forced the cancellation of athletic events in Northern California and people were advised to stay inside and keep activity to a minimum.

According to this same report, changing weather brought smoke-clearing breezes and brief relief to Northern California today. This can be observed when comparing today and yesterday's mass concentration at the ground (PM2.5 values, below right). By the end of the afternoon, conditions are, at the most, unhealthy for sensitive groups from Fresno to Eureka. Scattered thunderstorms are predicted this weekend over northern California, which could also bring lightning storms similar to the ones that ignited fires a week ago.

The Saharan desert dust plume reported in yesterday's post over Southern Florida seems to have migrated further West over the Gulf of Mexico, which induced strong AOD values retrieved from the MODIS-AQUA radiometer (between 0.8 and 1 at 550 nm, below left). According to the GASP aerosol, winds and precipitation trajectory forecast (below, right), the plume could be flowing towards Southern Texas and Louisiana in the next two days.

Finally, except for the states of South Dakota and Pennsylvania ("unhealthy for sensitive groups"), the rest of the country shows "good" to "moderate" air quality conditions today around 7 PM .