Today Friday July 6 the University of Maryland performed three research flights (RF-26, -27, -28) in support of the EPA-sponsored 2001 Eastern Supersite intensive (ESP01) and the DOE-sponsored Upper Ohio River Valley Project (UORVP).

The AM Flight combined a ferry from MD to the Pittsburgh, PA (PIT) area with ongoing profiler/RASS evaluation work at Fort Meade, MD (FME) and a vertical survey over the UOVRP primary surface site at Stubenville, OH (2G2). Conditions were clear with light planetary boundary layer (PBL) haze. Air quality was generally good until we reached industrial areas west of PIT where SO₂ and B_scat increased substantially in the lower PBL downwind of multiple local sources visible from the air.
The aircraft then landed at Allegheny Co. Airport (AGC) for a meeting with Bob Jacko (Purdue University) and Larry Waskow (WI State DNR), who each operate other aircraft involved involved in regional ozone/haze research and supporting ESP01, to plan an airborne intercomparison of meteorology (T, RH); trace gas (ozone) and aerosol optical properties (sub-micron Dp B_scat). The airborne intercomparison experiment involved all three aicraft to fly in formation at similar altitude west of AGC and perform two 15-20 constant altitude N-S transects between Harrison Co. (8G6) and Tri-City (3G6) airports at 3.5 Kft MSL (northbound) and 8.5 Kft (southbound). Preliminary results communicated between aircraft during flight indicated quite reasonable agreement in all scalars compared between the three aircraft.
After refueling at AGC, the Maryland aicraft continued characterizing the PIT urban center during the PM Flight performing spirals over West Penn/Rock (9G1) and Rostraver (P53). During the early afternoon some scattered fair-weather cumulus clouds had developed under otherwise clear skies. A high loading of SO₂ was observed throughout the PBL during both profiles, and a surprisingly high amount of CO was observed near-surface at 9G1 (~4 ppmv!), with P53 also showing elevated CO near the surface. On the ferry from PIT back to MD the PBL haze was observed to increase, although visibility remained high at ~20 miles. An additional profile over FME was performed before landing at College Park, MD.

The planned flights in support of NE-OPS have been postponed due to deteriorating weather conditions (NW to NE winds aloft and possibility of PM storms) forecast over eastern PA for the weekend. The situation is being evaluated daily. Check back for updates and future flight planning.

Doddridge