July 14, 2007
HIgh clouds
High clouds at ~11km are with us when ELF is running. There are also some low clouds at the top of the boundary layer in the afternoon. The aerosol optical depth is around 0.23 from AERONET, MD science center. The hourly PM 2.5 concentrations in the range of 5.3 (16:00, July 14th, 2007, UTC) to 23.4 ug/m3(21:00, July 14th, 2007) were recorded at Maryland's Department of the Environment Oldtown site in Baltimore during ELF's operation.
