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.
Doddridge