On Friday, Mark Ruminski of NOAA warned us that he had detected a band of smoke north of the Great Lakes. We were down at the time and couldn't help much with imagery but there was an indication of a layer from 4-3 km aloft over Egbert Canada (thanks to the CORALNET folks, who still appear to be hanging on by their fingernails despite the press releases about major cuts to Environment Canada). On the left the visible 532nm image and on the right the 1064 nm image. The strong 1064 nm return would indicate larger particles if the backscatter is calibrated (but this may be relative backscatter).
Yesterday's AQI was moderate throughout the midwest at the temperatures start to rise from last week's chilly temperatures. There was what looked like a fire in Michigan as can be seen on the overlaid Google Earth image of the MODIS AQUA red-green-blue (RGB) image (right). However the MODIS fire counts did not see it and only a few small fires were indicated in the area.
So the smoke HMS saw remains a bit of a mystery. Several days ago, Mike Fromm of NRL was following a big blowup of a pyroCb in Siberia which started in the high troposphere. It is possible these may be related but little evidence is seen in these images.
Finally, smoke season is starting again in Mexico as intentional fires are set in preparation for the planting season. In Guerrero and Jalisco States, smoke is seen from a number of locations. In the north, in the Sierra Madre Mountains other fires are burning but are likely of lightning origin.