The University of Maryland conducted flight operations in the Philadelphia, PA area for the NARSTO Northeast Corridor Oxidant and Particle Study (NE-OPS) project Fri-Sun July 13-15 performing five research flights (RF-34 through RF-37) during day and nighttime operations. The goals of these flights were identical to those listed in the July 12) update. Flight operations were plagued with a number of aircraft electrical system problems, causing several research flights to be stopped short or cancelled during the operational period, and the aircraft to be hard-down Mon-Tue July 16-17 despite weather conducive to research flight operations. These problems are being addressed at this time, and the aircraft is expected to resume research flights later this week. 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.

Under the very mild weather conditions characterizing this period air quality aloft and visibility were good to moderate throughout much of the period. However, we did perform numerous intercomparison flybys of the Millersville University balloon tethered at the NE-OPS surface site at Baxter Water Treatment Plant (BAX) and vertical survey spirals above Northeast Philadelphia airport (PNE, ~15 km NE of Philadelphia, and ~3 km NW of BAX). Despite our aircraft problems several interesting features were observed. On several of the PNE vertical survey spirals we observed clearly stratified layers in aerosol scatering coefficient (Bscat) aloft, which should make for an interesting comparison with the Penn State lidar. Altough air quality with respect to ozone was good, with ozone mostly near regional summertime background levels, substantial loadings of CO and SO₂ - relatively conserved markers of fossil fuel combustion - were observed below 2.0 Kft both upwind and downwind of the Philadelphia, PA area. All research instruments performed niminally throughout.

The upcomming weather pattern is somewhat uncertain at this stage. However, the plan is to work the Pittsburgh, PA (PIT) area on Thursday and work east to Philadelphia, PA (PHL) Friday morning where we will base through at least the coming weekend. Media activities at both locations are planned at this stage. Lingering precipitation may force cancellation of the PIT leg but the weather looks better later in the week for PHL.

Check back for an update mid-week.

Doddridge