The University of Maryland conducted flight operations in the Philadelphia, PA area for the NARSTO Northeast Corridor Oxidant and Particle Study (NE-OPS) project Mon-Tue July 9-10 performing five research flights (RF-29 through RF-33) during day and nighttime operations. The goals of these flights were to:
(1) place NE-OPS surface measurements at the Philadelphia Baxter Water Treatment Plant (BAX) in a regional context;
(2) evaluate BAX vertical surface sounding data: City of Philadelphia radar profiler with RASS, Penn State lidar, and Millersvile University instrumented tethered balloon;
(3) characterize regional-scale transport of pollution to the Philadelphia area; and
(4) investigate the relationship between meteorology, photochemistry and the ambient abundance of key photochemical oxidants and fine particle haze.
Flight data and vertical survey spiral detail are available in the 2001 RAMMPP research flight summary. Preliminary flight data files are available upon request from the Principal Investigator.
Although air quality aloft was good to moderate throughout much of the period (ozone 60-80 ppbv and light haze) we were able to perform multiple vertical survey spirals above Northeast Philadelphia airport (about 15 km NE of Philadelphia, and ~3 km NW of BAX). The evening flights on Monday July 9 (RF-30, 31, 32) were interesting in that a number of stratified layers characterized by elevated aerosol optical scattering were observed aloft over PNE 1.5-3.0 Km MSL, which should make for interesting comparisons with the lidar and profiler/RASS. All instruments operated nominally. A static inverter (research power) problem during RF-31 resulted in CO and SO₂ instruments being left off that entire flight.
The Tuesday July 10 AM RF-33 flight investigated regional transport to the Philadelphia area. Highly elevated SO₂ and CO - relatively conserved markers of fossil fuel combustion - was observed aloft over Summit, DE (EVY), and to a lesser extent over Pennridge, PA (N70). Moderate remnant ozone (90-95 ppbv) was also observed aloft indicating some regional oxidant load being transported into the area. Haze was marginally higher relative to the previous day.

The movement into the region of a number of convective storms prompted a premature termination of flight opeations. The Tuesday July 10 PM flight was aborted, however, due to a mechanical/electrical problem with the aircraft, a failure in the starboard engine starter, possibly a result of the same problem that caused research power problem during RF-31. The problem is being repaired presently, and future flight operations are not expected to be affected.

The next flight operational period is expected to be Friday-Sunday July 13-15 again in the Philadelphia, PA area for NE-OPS.

Doddridge