As Peter pointed out yesterday, Texas is being influenced by smoke from the south. Today, air quality was degraded in Brownsville giving an orange or Unhealthy for Sensitive Groups reading. The image on the left below shows the MODIS RGB image superimposed with the AIRNOW AQI readings as well as the VIIRS fire counts (red dots) showing fires in Northern Texas. A much larger fire was seen in North Dakota within the last six hours. Scott Bachmeir of CIMSS sent out a message asking whether the northern fire might have developed into a "pyroCb". That will take some further analysis to confirm.

HMS clearly shows the extent of the smoke reaching Texas as being from the Yucatan fires. Ellen asked yesterday whether the eruption of Pococapeptl Volcano could be adding ash to this mix? That's an excellent question. While there was SO2 detected as coming from the volcano two days ago, below that is the Aerosol Index at the same time. The emission is mostly SO2. Over the course of two days, nearly 1/2 of the SO2 could convert to sulfate. To determine whether there is enough sulfate to change the AOD will take correlative ground measurements. Today's RGB from Mexico shows considerable haze along the west coast of Mexico but almost nothing in the way of haze near Popocapeptl. It is not likely that Texas is being affected by direct ash emissions from the volcano.

Weekend update: May 19, 2013 22:00 EDT

Smoke continues to stream out of Mexico and Guatemala. This band of smoke continues up through Texas (see VIIRS AOD plot below right). The result is moderate air quality throughout the Mississippi Valley up into southern Canada. AOD and recognizable smoke can be seen whereever there is clear air. It appears that this will arrive in the East over the next couple of days.

The image on the left, taken from the US EPA's AIRNow website, shows significant areas of moderate air quality throughout the Mississippi River valley, Southeastern states, and Mid Atlantic states and Texas. A patch of code orange, unhealthy for sensitive groups, appeared over the Texas coast in the afternoon. Patches of moderate air quality were observed throughout the rest of the nation during the afternoon. A patch of moderate air quality persisted over California.
The image on the right showing HMS data indicates some scattered fires are burning throughout the nation, particularly in the Northern Plains and Southeast Coast. Two small smoke plumes were observed over Georgia and South Carolina. A massive smoke plume covered the Texas and Louisiana as well as the western Gulf of Mexico. This smoke plume appears to originate from agricultural fires in Mexico.

Smoke originating from fires in Minnesota tracked southeast today, towards southern Michigan and across Great Lakes. In addition, the HMS analysis team reports moderately dense smoke plumes near Arkansas, Oklahoma, and easternTexas. These plumes are believed to have originated from agricultural fires burning in Central America (plumes also visible). It is suspected that the plume across the southern Plain states extends further, over Louisiana and Texas but is not detectable due to clouds surrounding a large weather system (top left). Today's VIRRS AOD and RGB imagery shows the expansive clouds associated with this weather system, as well as a slight signature of elevated AOD over Michigan and Lake Michigan (top right). Widespread Code Yellow (Moderate) air quality in terms of PM2.5 were recored today across the United States (bottom left). The worst conditions, Code Orange (Unhealthy for Sensitive Groups) were experienced near the Great Lakes through western Pennsylvania, West Virginia, and Maryland (bottom right).

The first image below, courtesy NOAA HMS, shows the fire locations across the United States. The red dots correspond to active fires, and the grey areas are plumes. There are small plumes and a high concentration of fires in the Southeast region and Texas. These fires have been burning steadily for the past few days with no large plumes. There is also a large concentration of fires in southern Mexico, which the plume has been steadily moving northward.The second image below, courtesy of GASP East (Goes EAST), shows the retrieved AOD animation for the country today. You can see that most of these raised values correspond to more optically thick areas, which correspond to the fires and smoke debris throughout the nation. You can see raised values off the western coast of the Southeast region and the Gulf of Mexico that may be due to the concentration of fires in the region. Additionally, there is some isolated regions of high AOD in the Plains region that have not shown any surface presence at this time. This could be smoke layers aloft (CALIPSO image not available at this time).

The first image, courtesy EPA AIRNOW, shows the AQI values for San Bernardino, CA today. The code orange has been forecasted for favorable ozone formation parameters (Temperature reaching 90 F, 10% cloud coverage mixed with the urban/VOC aerosol environment). The second image is from a GEOS-5 0 UTC modeled run for the AOD due to all aerosols. You can see that the smoke plumes in near the Gulf will most likely head northwards, so air quality may be affected in the coming days.

Moderate to Unhealthy Ozone concentrations were reported across the Southern United States, as shown in EPA's Airnow animation. A high pressure system over this region (top right image, courtesy of NOAA Hydrometeorological Prediction Center), limited pollutant dispersion as light winds, sunny skies and warm temperatures enhanced ozone formation.

NOAA's Hazard Mapping System Fire and Smoke Product shows several fires across the southeastern US. Smoke from these fires is clearly visible in today's VIIRS rgb image (bottom left image, Goggle Earth overlay of NOAA HMS fire product with IDEA's VIIRS RGB product). Smoke from these fires led to higher AOD values recorded along this region. Here in Baltimore, clouds prevailed throughout today's lidar observations. The cloud capped boundary layer extended up to 2.5 km.

Actually, it is Chris Hadfield who is on his way down this evening. But he is coming down with Tom Marshburn so David Bowie was pretty prescient.

But if you haven't heard his music video released today, you should give it a listen. His son, Evan, says it is truly the first music video made in orbit.

Overall, ozone is good on Saturday and there is only a patch of moderate PM readings in the northern San Joaquin Valley. HMS has identified fires throughout the prairie provinces of Canada and this afternoon's AQUA overpass shows moderate aerosol optical depth as far south as Nebraska.

In orbit, this afternoon Chris Cassidy and Tom Marshburn took a spacewalk to repair an ammonia leak which risked overheating a solar panel. When back inside, Chris Hadfield sent this absolutely stunning image down:

Image credit: Chris Hadfield CSA-ASC and NASA.