June 28, 2007
Hazy day with a shower in the afternoon
We get hazy day again today. ELF was run 24 hours from yesterday. There are some scattered high clouds and low clouds around all the time and a short time shower in today's afternoon. The aerosol optical depth is around 0.8 from AERONET, MD science center. The hourly PM 2.5 concentrations in the range of 15.7 (7:00, Jun 28th, 2007, UTC) to 42.7 ug/m3(18:00, June 27th, 2007, UTC) were recorded at Maryland's Department of the Environment Oldtown site in Baltimore during ELF's operation.
