July 22, 2016

Unknown Aerosol in Mississippi Valley; Saharan Dust Spreads into Puerto Rico

Seen below (top left) in the MODIS Aerosol Optical Depth figure, there are zones of high concentrations of aerosols (reds, oranges, and yellows) in the Mississippi Valley and few areas of high concentration in the Great Lakes Region. From the NOAA HMS Smoke Analysis Team, we find that the composition of this aerosol is still unknown.
Also in the top left figure, there are areas in the northern central states with a high AOD.
This is caused by the light to medium density smoke found in the NOAA Smoke Product figure (top right). The smoke is thought to be a product of wildfires occurring in north and west central Wyoming.
In the Dust AOD figure (below left), Saharan dust is found spanning over the Caribbean and Puerto Rico. Using the NOAA HYSPLIT Backward Trajectory Model over San Juan, Puerto Rico (below right), winds seem to be carrying the aerosol towards the southeast.

July 21, 2016

Ozone spreads across East Coast

PM 2.5 levels reached Code Yellow (Moderate) levels today in many places across the nation, as seen in AirNow's Air Quality Index, top left. The elevated PM 2.5 levels were mostly concentrated in the Great Lakes Region, the Mississippi Valley, and the Mid-Atlantic. Ozone levels also reached Code Yellow in the Mid-Atlantic, the Great Lakes Region, the Mississippi Valley, and the Pacific Southwest (NOAA, top right). Ozone levels also reached Code Orange (Unhealthy for Sensitive Groups) levels in the Mid-Atlantic and Southern California, with some Code Red (Unhealthy) levels showing up in the same area of Southern California as well.

The elevated levels of Ozone in these areas were partially due to high summer temperatures across the nation, as seen in the Nation Weather Service's temperature map, mid-left. The Ozone in the Mid-Atlantic was most likely also due to high pressure systems spread throughout the Eastern part of the United States (NOAA, mid right). The Ozone seen over Southern California was most likely also a result of low wind speeds and stagnant winds over California (National Weather Service, bottom left).


In the elastic Lidar (355 nm) image below (left) we see, what we believe to be, smoke at 2 different altitudes, one at about 2000 to 2500 meters and the other at 3500 to 4500 meters. In the HMS overlay image below (right), we see smoke originating from fires earlier in the week in Alaska and Northwestern territories with smoke spanning across Canada and making its way to Northeastern US. The HYSPLIT overlay image shows 2 different air mass trajectories for July 21st and the 20th for the 2 different altitudes (2-2.5 km and 3.5-4.5 km) that we see smoke in our Lidar observations.

July 20, 2016

Smoke over Baltimore and Ozone in the Midwest and Western US

Early today we began seeing what we believed to be a thin layer of smoke over Baltimore, Maryland between 2.5 to 3.5 Kilometers of altitude. We kept track of it with our Lidar system (top left) and saw that the plume began to thicken up a little bit, but also it began to merge in with the PBL slowly as the morning went on. By about 1 PM, local time, the plume had dissipated and seemingly merged fully with the PBL. This small plume of light density smoke, we believe, was carried into our area from the large plume of light to medium density smoke that has traveled into the Great Lakes and Northeast regions from the ongoing Alaskan and Canadian fires. The Google Earth image, top right, shows an overlay of smoke coverage from the 19th and the 20th as well as a 24 hour Hysplit backward trajectory from Baltimore. This shows the direction in which the winds traveled at altitudes of 2,500 meter, 3,000 meters, and 3,500 meters, the altitude of the aforementioned plume, showing that the light plume over our area was indeed light smoke.
The rest of the nation saw moderate, code yellow, air quality in several regions with a few areas seeing unhealthy levels; the remainder of the nation enjoyed good levels of air quality. Parts of the Midwest and Western states experienced elevated ozone levels, as seen in the NOAA Ozone Concentration map (mid left). These elevated levels were due in part to excessive heat in those areas, seen in pink, dark pink, maroon, and salmon colors in the National Weather Service map (mid right). Also, dust remains aloft spanning from New Mexico into the Southern Plains and traveling north, as seen in the surface dust image, bottom left.


In the elastic lidar (355 nm)image below (left) we see smoke aloft over Baltimore at a height of 3000 to 4000 meters. It is believed to be smoke from fires in Alaska and Northwestern territories. HMS and HYSPLIT overlay shows the location of the smoke between July 17-19 with the back trajectory of the air mass at 3-4 km seen in the lidar observations.

July 18, 2016

Remnant smoke in Alaska and across Canada, Saharan dust in Plain states

Wildfire activity continues in North-central Alaska and Northwest territories (HMS, left) contributing moderate to dense remnant smoke across the region. Fires reported in Northern Arizona and Colorado producing moderately dense smoke traveling east towards the plain states. Ozone levels were good across the nation today with moderate to high levels in the northeast region of the United States. PM2.5, believed to be Saharan dust is seen in Missouri and Plain States (AirNow, Right).

HYSPLIT trajectories (top left) shows that although smoke was present west of the reported PM2.5, wind trajectory originates from the Gulf of Mexico where in the Copernicus image below (top right), Saharan dust was reported in the Gulf of Mexico with great density over Northern Texas. It is believed that wind carried Saharan dust from the Gulf of Mexico North to the Plain states, contributing to the elevated levels of PM2.5 in the Plain States. EOSDIS image below (bottom) shows today's image of the density of dust over the Plain States, specifically Kansas, Missouri, Arkansas and Oklahoma.

July 17, 2016


Smoke from heavy wildfire activity in Alaska combines with smoke from wildfires in the Northwest Territories to create a large area of light, medium and heavy density smoke in Northern North America; it extends from Alaska, eastward, into Nunavut. The smoke appears to be moving southeast, because light and medium density remnants from these fires are seen moving into Northern Minnesota (HMS, top left). Judging by the HYSPLIT trajectory model, It's likely the smoke will continue to move in this direction, it may even reach the East Coast of the United states (top right).
Besides the areas affected by smoke, AOD remained relatively low across the US (blues and purples) (NASA WorldView AOD Layer, bottom left). Ozone levels, on the other hand, peaked at code red (unhealthy) in Southern California, with scattered code orange (unhealthy for sensitive groups) (AirNow Daily Ozone, bottom right).