KAILUA-KONA — Vog is nothing new for Hawaii Island.
With more active eruptions at Kilauea Volcano, including a new fissure breaking out Wednesday afternoon, it could get worse before it gets better, however.
But what’s outside right now, some experts and data say, isn’t out of the norm by any stretch.
“Kona’s always been impacted with the vog, and I believe it’s going to increase due to the increased amount of emissions that are coming out,” of Kilauea Volcano, said Lisa Young, an environmental health specialist with state Department of Health’s Clean Air Branch. “Looks like there’s always been a lot of particulates there (in Kona) depending on the wind conditions, and I think it may get a bit heavier.”
What’s out there now, it’s not all that bad — at least that’s one expert’s take.
Steve Businger, chairman of the Atmospheric Sciences Department at the University of Hawaii at Manoa who heads the Vog Measurement and Prediction Project, said the levels of vog being seen on Hawaii Island are “nothing out of the ordinary” except that the emissions are distributed across three vent areas, the summit, Pu‘u ‘O‘o and Leilani Estates.
“There’s not really that much more vog being emitted by the volcano than previously, maybe it’s up 10 percent,” Businger said of levels in the wake of recent activity at Kilauea Volcano that’s resulted in 15 fissures opening in Puna.
What Kona is seeing is relatively normal, as the vog is known to cross South Point and then get caught up in sea breezes that bring it to the area.
He anticipates, based on the prediction project’s models, that there’s a “chance we’ll see a bit of vog on Friday and Saturday,” but it “doesn’t look like it’s going to be a bad episode.”
Janet Babb, with the U.S. Geological Survey’s Hawaiian Volcano Observatory, confirmed sulfur dioxide emissions — the main component of vog — from the volcano are elevated.
But she was unable to provide specific numbers because conditions have prevented the observatory from installing additional monitors near the activity on the volcano’s lower East Rift Zone. She noted that levels are highest downwind of the source, which can change quickly.
“Anytime there is an eruption, fissure or vent, sulfur dioxide comes out and that’s part of the deal,” she said.
And actually, according to the most recent air quality readings, Kona’s air is below average levels when it comes to sulfur dioxide.
As of Wednesday afternoon, air quality at the Kona monitoring was listed as green or “good,” with the concentration of sulfur dioxide in the air at 0.00 parts per million. That number ranged from 0.00 to 0.02 throughout Wednesday, according to the state Department of Health’s Short Term SO2 Advisory website.
The state considers a sulfur dioxide 24-hour block average of 0.14 and an annual average of .03 acceptable levels.
Fine particulate matter, which are 2.5 microns or smaller and includes SO4, or sulfate, was also elevated, with www.AirNow.gov labeling air quality in the Kona area as “moderate,” giving it a 55 on the index that runs from from 0 (good) to 500 (hazardous).
Moderate air quality, which is acceptable but may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution, starts at 51.
The current forecast calls for northeasterly trade winds to gradually weaken and shift to the east into tonight, providing some relief to the leeward side from vog. Thereafter, light easterly trade winds will continue over and just south of Hawaii Island, but the winds will veer out of the southeast in the area northeast of Hawaii Island and Maui County.
“The light winds may allow volcanic haze (VOG) to become more widespread on the Big Island through Friday night,” forecasters with the Honolulu-based National Weather Service said Wednesday. “It does not appear that there will be enough southeast flow to carry much of the VOG over the smaller islands.”
Thereafter, northeasterly trade winds are forecast to build back across the state. Those northeasterly trades are known to push the vog plume around South Point where it interacts with thermally generated winds that pull it up into an eddy system off Kona.