Oahu got a taste of restless Kilauea Volcano on Friday when it experienced a blast of vog that drifted up the island chain during a lull in the tradewinds.
“It’s surprising how voggy it is,” said Robert Ballard, National Weather Service meteorologist.
The worst of the hazy air pollution from Kilauea’s volcanic emissions arrived about midmorning and hung out most of the day Friday.
The good news, Ballard said, is that the trades were expected to start back up Friday night and continue today and through the weekend.
“People are going to be a lot more comfortable,” he said.
The islands lost the tradewinds Thursday evening, resulting in light and variable winds of 5 to 10 mph through the night and most of Friday, he said.
Visibility at Daniel K. Inouye International Airport on Friday was reportedly 10 miles. That’s not bad, Ballard said, except that typical visibility is 30 or 40 miles.
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Ballard said the volcanic smog was exacerbated by the fact that the islands have experienced a surge in muggy conditions with dew points several degrees higher than normal.
Vog is primarily water vapor, carbon dioxide and sulfur dioxide gas. When sulfur dioxide is released from Kilauea’s eruptive vents, it reacts with oxygen, sunlight, moisture and other gases and particles and converts to fine particles that end up scattering sunlight and causing the hazy conditions we experience.
When the tradewinds are missing, the entire state can be enveloped by the nasty mixture. For many, that means a miserable day of coughing, a runny nose, a sore throat and headaches.
Steven Businger, University of Hawaii professor of atmospheric sciences, said the volcano has been generating much more vog since it began erupting May 3 in Leilani Estates.
Kilauea, he said, went from releasing 2,000 tons of emissions a day to 10,000 tons a day as at least 15 fissures opened up in Lower Puna and giant ash clouds have repeatedly risen from the volcano’s summit a few thousand feet into the air.
Fortunately, he said, steady tradewinds for the most part have been pushing the vog to the southwest away from the island chain.
What Oahu experienced Friday was only a small taste of Kilauea’s volcanic pollution, Businger said. If southerly winds were to pick up, the islands could really see some bad air and haze.
But Businger said wind models indicate that the trades should remain strong for the next week, with perhaps a brief break in the pattern Wednesday.