The power and the fury of the ongoing eruption of Kilauea apparently knows no bounds.
Scientists now think that the vog emanating from the volcano has the ability to change the weather.
In a study published June 16, University of Hawaii at Manoa researchers reported that last summer’s Tropical Storm Flossie exhibited no signs of lightning as it approached the Big Island, but once it had incorporated gasses and particles from the eruption, “vigorous lightning flashed.”
In a Thursday phone interview, study co-author Steven Businger, an atmospheric science professor at UH-Manoa, said that the findings based on data gathered in July 2013 were “a bit of a surprise.”
“We saw a beautiful spiral pattern in our vog model, and we thought, ‘This is interesting.’ But when we looked closer, we saw the lightning was being affected,” he said.
Businger’s vog model — which can be found at http://weather.hawaii.edu/vmap/hysplit/ — uses estimates of volcano emissions and wind forecasts to predict concentrations at various locations of sulfur dioxide gas and sulfate aerosol particles downwind of the Kilauea eruption.
“The vog has these aerosols, or very fine particles, quite a lot of them,” he said. “And liquid water droplets in the cloud form on them.”
As a result of the introduction of those fine particles into a storm system, the moisture in the clouds is spread out into many smaller droplets than normal, making them less likely to leave the cloud as rain. These droplets serve to separate the electric charge within the clouds, leading to lightning strikes.
“This is the first interaction between an active, vigorously degassing volcano and a tropical cyclone captured by a vog model run over the Hawaiian Islands — providing a unique opportunity to analyze the influence of robust volcanic emissions entrained into a tropical storm system,” Businger said.
UH-Manoa graduate assistant Andre Pattantyus, lead author of the study, said Thursday that he and Businger are excited by the findings, and they are eagerly awaiting future storms to provide more data.
“We’re definitely going to be investigating this further,” he said. “Now, we need another case to study.”
One possible implication of the study is that areas on the Big Island may be experiencing drought at least in part due to vog, Pattantyus said. Another implication could be that the Big Isle could in some small way be protected from hurricanes and cyclones because of the vog.
“A lot of people have theorized that that is possible,” he said. “We just happened to find the mechanism by which it could happen. We found it happening in nature.”
Pattantyus added that most recently, the Big Island’s experience with the remnants of Tropical Storm Wali showed some of the same results.
“We saw a ton of lightning with that, although there were other contributing factors having to do with the storm,” he said.
Outside of Hawaii, the observations of the impact of vog on Flossie also could help scientists understand how polluted air might alter hurricanes as they approach the U.S. mainland.
“The Hawaiian Islands provide a unique environment to study this interaction in relative isolation from other influences,” Businger said.
He plans to model the interaction of the vog plume and Flossie with a more complex model that integrates chemistry into the predictions to better understand the processes at work.
Email Colin M. Stewart at cstewart@hawaiitribune-herald.com.
