The University of Maryland aircraft performed two (2) research flights (RF-03 and RF-04) on Monday April 23 over the Richmond, VA (RIC) area. The purpose of these flights was to evaluate several pre-selected locations for vertical survey spirals that might be represetative of the lower troposphere over the VADEQ radar profiler with RASS recently installed at the Virginia Science Museum (VSM) near downtown Richmond, this under upper-level flow conditions similar to a summertime ridging pattern. Aircraft instruments mostly performed well, except for some problems with the CO analyzer - causing signal noise throughout and the loss of data for the morning traverse to RIC and one AM profile. We'll work on this problem in the lab over the next week. A brief summary of the flights is given in the "Research Flight (RF) Summaries:" section. Only moderate ozone levels (up to 60 ppbv) aloft were observed, consistent with season and the prevailing flow. The three (3) locations evaluated - forming a triangle roughly 10-15 miles around VSM - showed no substantive differences in meteorology (T, RH) and chemistry (ozone) from the surface to 2.1 Km MSL. Data for CO and SO₂ require substantial processing, and are not presently available. These preliminary data suggest profiles at the three (3) locations were remarkably consistent during the afternoon flight, when the planetary boundary layer (PBL) was nearing its fully developed state. Comparisons with the VSM profiler will be conducted when the data become available from VADEQ. No problems were encountered with air traffic control in the area during these first flights in the RIC area, and we expect to be able to perform all currently planned flight patterns in the future without air traffic problems.

Doddridge