Long-range (CAPTEX (Cross-APpalachian Tracer EXperiment)) and complex terrain (ASCOT (Atmospheric Studies of COmplex Terrain)) perfluorocarbon tracer studies
Perfluorocarbon tracer (PFT) technology, consisting of tracers, samplers, and analytical equipment, has been deployed in numerous meteorological experiments for the verification of long-range and complex terrain transport and dispersion models. The CAPTEX (Cross-APpalachain Tracer EXperiment) ''83 was conducted from mid-September through October 1983, in which seven 3-h tracer releases (5 from Dayton, Ohio, and 2 from Sudbury, Ontario) were made of a single PFT. Ground sampling occurred at 80 sites in the northeastern US and southeastern Canada at distances of 300 to 1100 km from the release sites, with a total of 3000 samples collected. Seven aircraft gathered 1600 crosswind and vertical spiral samples at distance of 200 to 900 km from the release sites. Peak ground concentrations of over 30 times background and peak aircraft values of over 150 times background were measured at the most distant sites; some typical results are shown. The branching atmospheric trajectory (BAT) long-range transport was described. The model-calculated maximum ground level PFT concentrations were compared with the measured concentration isopleths as well as through the use of scatter diagrams of concentrations, spatial errors, and frequency of space- and time-averaged concentrations. The average spatial error found for each of the 7 releases ranged from 1.3/sup 0/ to 1.7/sup 0/ lat. The crosswind standard deviations of aircraft traverses at 600 to 800 km downwind varied from 12 to 20 km which corresponded to 1.0/sup 0/ to 1.6/sup 0/ lat., indicating that the model was accurate to within one standard deviation of the real-time tracer profiles. On average, for the 7 runs, 50% of the model-calculated concentrations were within a factor of 20 of the observations, indicating that, in general, 1/sup 0/ lat. shifts can easily cause order-of-magnitude changes in observed concentrations.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA); National Oceanic and Atmospheric Administration, Silver Spring, MD (USA). Air Resources Lab.; Los Alamos National Lab., NM (USA)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6358240
- Report Number(s):
- BNL-39588; CONF-8609215-2; ON: DE87010059; TRN: 87-023740
- Resource Relation:
- Conference: Ispra courses: regional and long-range transport of air pollution, Ispra, Varese, Italy, 15 Sep 1986; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Modeling the CAPTEX vertical tracer concentration profiles
Design and analysis of Cross-Appalachian Tracer Experiment (CAPTEX) field trials. Second annual progress report. [CAPTEX]
Related Subjects
AIR POLLUTION
LONG-RANGE TRANSPORT
PLUMES
DIFFUSION
COMPLEX TERRAIN
EARTH ATMOSPHERE
METEOROLOGY
NAPAP
ORGANIC FLUORINE COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
TRACER TECHNIQUES
ENVIRONMENTAL TRANSPORT
ISOTOPE APPLICATIONS
MASS TRANSFER
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
POLLUTION
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)