Research Projects

Project at a Glance

Project Status: complete

Title: Aircraft measurements of ozone and meteorological variables over the Sacramento Valley.

Principal Investigator / Author(s): Carroll, John J

Contractor: UC Davis

Contract Number: 92-330

Research Program Area: Atmospheric Processes

Topic Areas: Monitoring


The primary objective of this project was to use an instrumented aircraft to measure in situ vertical distributions of ozone concentrations. These data are to be used to verify profiles of ozone measured by a ground based remote sensing system. Differential absorption LIDAR (DIAL) systems can, under certain conditions, be used to measure trace gas concentrations as a function of distance from the instrument up to several kilometers. The design concept is to emit pulses electromagnetic radiation at two closely spaced frequencies, one in an absorption band of the gas to be measured and one just outside of the band. The difference in the energy backscattered to the instrument at the two wavelengths can be used to estimate the amount of absorbing gas between the source and the back-scattering aerosol particles. The Wave Propagation Laboratory (WPL) of the National Oceanographic and Atmospheric Administration (NOAA) has developed such an instrument for measuring ozone. The DIAL system was pointed upward and capable of measuring vertically to about 3,000 m (9,800 feet). Aircraft flights and DIAL operations were successfully conducted between July 14 and 22, 1993, west of Davis, California.

On two days (July 13 and 23, 1993) aircraft profiles were taken near and above the Sutter Buttes to provide information on the vertical and horizontal variability of ozone in the vicinity of a ground based ozone monitor located on South Sutter Butte near the 100m (2,300 feet) elevation. On September 9, 1993, vertical profiles and horizontal transects were flown over the Sierra foothills east of Sacramento to obtain three dimensionally distributed data to aid the ARB Control Strategy Modeling Section in analyzing results from photochemical modeling simulations. The aircraft operations and data acquired are described in this report. Data summaries are presented in graphical form.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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