U.S. Air Quality

Layer Aloft and Homogeneous Boundary Layer

A homogeneous boundary layer was observed by ELF over Baltimore. A weak layer aloft was observed between 2.5 to 4 km during today's operation. Maryland Department of the Environment wind profiler timeseries and the NOAA HYSPLIT backtrajectory indicated that the air mass over UMBC came from northwest, shown below. Ground PM2.5 concentrations in downtown Baltimore increased from 11 to 20 ug/m3 during our observations as humid southerly winds reached our region after 18:00 UTC.