California Laboratory for Atmospheric Remote Sensing (CLARS)

CLARS picture and results
Left: The CLARS facility overlooks the Los Angeles basin with visibility from the San Bernardino Mountains in the east to the Pacific coast in the west, and from the base of the San Gabriel Mountains in the north to Long Beach Harbor and Orange County in the south. Photo credit: R. Duren  Right: Example of a map from CLARS data showing the ratio of CH4 to CO2 over the Los Angeles basin for all data from 2011-2017. The units are ppb/ppm. “Hot spots” in the central part of the figure are likely associated with methane emissions from landfills.

The California Laboratory for Atmospheric Remote Sensing (CLARS) is an observing facility for the measurement of greenhouse gases and pollutant emissions from sources in the South Coast Air Basin. The facility also serves as a testbed for new optical instruments for future NASA satellite missions. CLARS is located on Mt. Wilson, California, overlooking the Los Angeles basin at an altitude of 5700 ft. It consists of a laboratory for optical instrumentation, a telescope and precision pointing system for collection of atmospheric data.

The instruments at CLARS includes both point and imaging Fourier transform spectrometers (FTS) built by JPL. These instruments operate autonomously, measuring dry air mixing ratios of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), water vapor (H2O, HDO), nitrous oxide (N2O), and aerosols.

The CLARS facility also hosts atmospheric monitoring equipment that is part of California Air Resources Board’s permanent air quality network in California. This equipment acquires measurements that are complementary to those obtained by the FTS instruments at CLARS.

Ongoing Research Projects: 
  • Measurement of greenhouse gas emissions (CH4, CO2, N2O) in the LA basin
  • Studies of the distributions and sources of air pollutants including CO and aerosols
  • Development of new instruments for satellite remote sensing of atmospheric composition