2010 April 20: MD Baltimore: Coarse Particulate Aloft over Baltimore
While the skies over Baltimore looked clear to the human eye, the picture is quite different when observed by ELF. Today lidar observations show a homogenous boundary layer confined to the first 2 km of the atmosphere. Above the boundary layer stratified layers non-spherical particles/scatterers (lidar polarization timeseries not shown here) were observed and extended up to 10 km. The red counts after 06:00 UTC and at heights between 9 and 12 km are due to cirrus clouds. Optical column size distribution retrieved from the UMBC sunphotometer (available at NASA/AERONET site) measurements were dominated by the presence of coarse particulate matter (radius in the range of 1-10 microns) aloft. These scatterers aloft are most likely to be dust storms from the Taklimakan Desert, located in western China. NOAA Hysplit backtrajectories indicated that the air mass over the Mid-Atlantic states originated in this region. Dust storms from this location were highlighted as the MODIS Rapid Response System image of the day on April 9 and 14.
Thanks to Mike Fromm and the Naval Research Laboratory pyrocb group for alerting us of the large plume over the United States, as proper attributions to aerosols sources will be become extremely important in the following days due recent events in Europe.
Posted by Ruben Delgado at April 20, 2010 1:19 PM