Grantee Research Project Results
1998 Progress Report: Development of Lightweight Instrumentation for Measurement of Long-Lived Trace Gases
EPA Grant Number: R825222Title: Development of Lightweight Instrumentation for Measurement of Long-Lived Trace Gases
Investigators: Avallone, Linnea M.
Institution: University of Colorado at Boulder
EPA Project Officer: Hahn, Intaek
Project Period: December 1, 1996 through November 30, 2001
Project Period Covered by this Report: December 1, 1997 through November 30, 1998
Project Amount: $466,074
RFA: Exploratory Research - Early Career Awards (1996) RFA Text | Recipients Lists
Research Category: Early Career Awards
Objective:
The primary goal of the research supported under this grant is the development, testing, and deployment of a prototype, lightweight gas chromatograph system, based on micro-GC technology. As originally conceived, this GC system would be integrated into a suite of sensors (the rest of which are funded through a grant from the NASA Atmospheric Effects of Aviation Program) to be flown on a commercial airliner. The aim of this larger project is to obtain extensive measurements of several key trace species (O3, CO2, H2O, and C2Cl4) in the upper troposphere (8-12 km altitude). This dataset can be used for a variety of purposes, including testing of global three- dimensional chemical transport models and models of ozone precursor emissions and ambient air quality, and the assessment of the effects of subsonic aviation on upper tropospheric and lower stratospheric ozone distributions.Progress Summary:
During the development and testing phase of this project, we have focused our efforts on a measurement of tetrachloroethene (C2Cl4) in the upper troposphere, as this species is of greatest interest to the anticipated community of users of the aircraft dataset. At a preliminary design review held in May '98, we were strongly discouraged from continuing our development of the proposed gas chromatograph system with an electron capture detector (ECD). It was felt that the radioactive source in an ECD would be viewed by the airline industry as a tremendous safety hazard and would not be allowed on the aircraft. A meeting was held in July '98 with representatives from a major world airline and an aircraft manufacturer to discuss the issues related to integrating our proposed package. They felt that flying an ECD was not a problem, so we have been able to proceed with our development.Since summer '98, mechanical designs for all of our sensors have been developed, based on the ARINC standards used for equipment on commercial aircraft. These standards dictate size of enclosures, mounting hardware, electrical connections, etc. A mechanical engineer has been working full-time on this aspect of the project. Parts are on order for the GC, with delivery slated for February '99. A post-doctorate will begin work in mid- January '99 to refine the chromatography, with an eye toward minimization of cycle times (that is, time between successive air samples, which includes trapping of the sample and processing on the analytic column) and gas consumption. An electrical engineer begins work in mid-January as well, focusing on the design and layout of custom circuit boards that will interface between individual sensors and the central data acquisition system and computer.
Meanwhile, significant progress has been made on the other sensors that are part of this instrument suite. Packaging designs for the ozone and carbon dioxide systems are complete. The hygrometer (a tunable-diode laser system) has been finished and test-flown on the National Center for Atmospheric Research C-130, with good results.
Future Activities:
The entire suite of instruments will be completed by summer 1999 and test-flown as a package on the NASA DC-8 or similar platform during the late summer or early fall of 1999. No further progress has been made in obtaining a "ride" on a commercial carrier as of this date. However, other options are being explored and we are confident that these instruments will be used to gather useful and exciting data.Journal Articles:
No journal articles submitted with this report: View all 17 publications for this projectSupplemental Keywords:
RFA, Scientific Discipline, Air, Environmental Chemistry, air toxics, climate change, Ecology and Ecosystems, tropospheric ozone, Atmospheric Sciences, monitoring, ambient ozone data, ozone occurrence, chemical composition, chemical transport model, gas chromatography, atmospheric chemical cycles, chemical kinetics, carbon dioxide, diode laser spectrometer, atmospheric monitoring, field measurements, lightweight instrumentation, measurement methods , three dimensional model, convective boundary layer, trace gas measurementRelevant Websites:
http://cloud1.arc.nasa.gov/solve/Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.