Measurements at NOAA's Mauna Loa Observatory stopped following the recent eruption of the Mauna Loa volcano, when lava flow blocked staff access and took out power lines to the facility.

Under an emergency agreement, NOAA and the University of Hawaii have established a temporary measurement site at the nearby Mauna Kea volcano for the critical CO2 record and other atmospheric measurements taken at the observatory.

Media can contact: Theo Stein (303) 819-7409 ( or Karin Vergoth 303-632-6413‬ (


NOAA logo National Oceanic and Atmospheric Administration (NOAA), Earth System Research Laboratory (ESRL)

What does this program measure?

Sulfur Dioxide is measured at 4,10,23,and 40 meters above the ground, in units of parts per trillion by volume.

How does this program work?

A Pulsed fluorescence method using a Thermo-Environmental Inc. model 43S (shown below) is used continuously at Mauna Loa Observatory.

Sulfur Dioxide Analyzer at MLO

Why is this research important?

This is part of an effort to monitor long-term of emissions from Kilauea and Mauna Loa volcanoes. It may provide a precursor to the next Mauna Loa eruption. These measurements also detection large sulfur dioxide pollution events from Asia.

Are there any trends in the data?

No trends. Kilauea has been in continuous eruption since 1983. Mauna Loa last erupted in 1984. Since 1994; SO2 levels from Mauna Loa have been low (<500ppt, or parts per trillion).

How does this program fit into the big picture?

What is it's role in global climate change?

The SO2 data can be used to detect periods of volcanic pollution at the observatory. This can provide a non-baseline filter for other measurements.

Comments and References


Lead Investigator(s):

David Nardini
808-933-6965 (x229)

MLO Contact(s):

David Nardini
808-933-6965 (x229)

Web Site(s)

Date Started



Related Programs
Volcanic Activity

Tower with SO2 inlet and Building with Analyzer
High Tower