CLARS

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

The California Laboratory for Atmospheric Remote Sensing (CLARS) built by the Jet Propulsion Laboratory (JPL) 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 (~1.7 km). It consists of a laboratory for optical instrumentation, a telescope, and a precision pointing system for the collection of atmospheric data.

The instruments at CLARS includes both point and imaging Fourier transform spectrometers (FTS). 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-FTS has been measuring GHGs and air pollutants continuously since September 2011, thus providing the longest available data record that covers the entire LA basin.