ESRL Global Monitoring Laboratory - Mauna Loa Observatory

Measurements at the Mauna Loa Observatory stopped after the 2022 eruption of the Mauna Loa volcano, when lava flow crossed the access road and took out power lines to the facility. The observatory remains inaccessible by vehicle and without power from the local utility company.

Observatory staff has established limited solar power in four observatory buildings and restored approximately 33 percent of the measurements onsite, including the Global Monitoring Laboratory and Scripps critical CO₂ records and other atmospheric measurements.

Media can contact: Theo Stein (303) 819-7409 (theo.stein@noaa.gov) or Karin Vergoth 303-632-6413‬ (karin.vergoth@noaa.gov)

Organization(s):

NASA logo National Aeronautics and Space Administration (NASA), Goddard Space Flight Center

What does this program measure?

Aerosol Optical Depth (AOD) – No units

How does this program work?

A sunphotometer is used to measure the extinction of direct beam spectral solar radiation. Robots approximately 18" high with a 1-foot diameter base are used in conjunction with a data logger, data transmission device, batteries, solar panels, and antenna for data transmission. The system runs continuously and automatically at MLO.

Why is this research important?

AERONET can provide continuous measurements of aerosol optical depth (AOD), an important climate forcing agent. AOD is needed in satellite validation and atmospheric correction, and MLO is used to calibrate the instruments since the low and stable AOD are ideal for this purpose. AERONET can provide long term comparisons between the in situ CMDL measurements of size distribution at Bondville, IL and the retrievals measured from the CIMEL automatic sunphotometers. The MLO instrument will periodically be swapped with a field instrument to provide a well calibration instrument for field intercomparisons. Long term particle size distribution comparisons will provide validation of the radiometric inversion scheme.

Are there any trends in the data?

The trends are seasonal at MLO, with a maximum in spring (March-May) resulting from aerosols transported from Asia. No inter-annual long term trends have been detected at MLO.

How does this program fit into the big picture?

What is it's role in global climate change?

AERONET is a global network of sun/sky radiometers that is monitoring AOD and aerosol optical properties for AOD trend analysis, optical properties characterization, and for validation of satellite retrievals. Aerosol radiative forcings are one of the largest uncertainties in climate change studies.