Over the last weekend, the University of Maryland research aircraft
performed our 50th research flight of the summer -
big numbers considering we still have 1.5 months to go until our
projected mid-September operational termination date, and not
experiencing much of a "summer" to speak of, at least in terms of
photochemical near-surface ozone.
Over two days July 27-28 we conducted 4 research flights (RF-48 through RF-51) in the Philadelphia, PA (PHL) area as part of the EPA-sponsored NARSTO Northeast Oxidant and Particle Study (NARSTO/NE-OPS). Flights concentrated on:
(i) placing project surface measurements in a more regional context in terms of transport and planetary boundary layer (PBL) dynamics
(ii) evaluating NE-OPS lidar, tethered balloon and radar/RASS profiling tools being operated nearly continuously at the project surface site in northeast Philadelphia, PA
(iii) investigating urban center/transport corridor input to the PBL and ozone/haze production over and downwind of the urban center.
Yet again Mother Nature was uncooperative, with conditions not conducive to producing high ozone and thick haze during this period. Again during this series of flights, stratified pollution layers observed upwind and over the PHL area seemed to entrain into the developing planetary boundary layer during the course of a afternoon. Some enhancements in ozone and total aerosol scattering (a useful proxy for fine particulate haze) were observed downwind of the city center. During the ferry to PHL on July 27 (RF-48) ozone in excess of 100 ppbv (the highest during the 2-day deployment) was observed at around 3.0 Km MSL over Pennridge (N70) - the source of which is being investigated, and is possibly a remnant of a natural intrusion of stratospheric ozone as a result of a prior tropopause folding event. Flight data and vertical survey spiral details are available in the 2001 RAMMPP research flight summary. Preliminary flight data files are available upon request from the Principal Investigator.
Activities at the NE-OPS site are winding down at present, with intensive operations due to terminate within a day or so. The current research aircraft plan is to deploy to Pittsburgh, PA tomorrow, Wednesday August 1 for a final 1-day research flight in support of the DOE-sponsored Upper Ohio River Valley Project (UORVP) and EPA-sponsored 2001 Eastern Supersite intensive (ESP01).
Preliminary results from these Pittsburgh area flights and upcoming plans will be posted on this site later this week.