July 6, 2007
Running when there is no clouds
There is no clouds when ELF is running. The aerosol optical depth is around 0.25 from AERONET, MD science center. The hourly PM 2.5 concentrations in the range of 19.7 (18:00, July 6th, 2007, UTC) to28.5 ug/m3(22:00, July 6th, 2007, UTC) were recorded at Maryland's Department of the Environment Oldtown site in Baltimore during ELF's operation.
