Ground Based Remote Sensing of the KÄ«Lauea Volcano Plume

Volcanic smog, know as ‘vog’, has been a persistent issue on the island of Hawai‘i since the eruption of Kīlauea Volcano began in 1983. Vog is composed of sulfur dioxide (SO₂), emitted directly from the volcano, and sulfate aerosols, which are a secondary pollutant that form as sulfur dioxide oxidizes.  Together these pollutants pose a significant health risk to communities surrounding the volcano and on the leeward coast of Hawai‘i.  Detailed measurements of the volcanic plume were collected downwind of Kīlauea in July 2015 using correlation spectrometers known as FLYSPEC, a simple two-channel GLOBE photometer, and off-the shelf Vaisala ceilometers to estimate the conversion rate of sulfur dioxide to sulfate aerosols. 

Also, of interest are relationships between the different observed quantities because very few SO₂ monitoring stations exist across the islands to provide confirmation of the passage of the volcanic plume.  Therefore any observation platform that may provide information on the presence of the volcanic plume are sought.  The photometer and ceilometer are good candidates since they observe the secondary sulfate aerosols that linger long after the SO₂ as been emitted, particularly on the leeward coast. These observations are important for emergency managers and public health officials in order to mitigate impacts from the vog as well as for validation of the University of Hawai‘i at Mānoa Vog Model forecasts. 

We present observations from all platforms and correlations between retrieved quantities at various distances downwind of the volcano for three days of observations.  The correlations are stronger further downwind when the plume is well mixed in the boundary layer.  Correlations suggest that further observations from ceilometers, such as those operated by the FAA, could be a valuable tool for tracking the transport and dispersion of the volcanic plume around the state of Hawai‘i.