Forecast Discussion
VOG Forecast Discussion for 9:30 AM HST Friday December 30th 2011
Current Measured Conditions:
Light to moderate trades should continue to decrease throughout the day. Decreasing winds and sea breeze development should begin to shift higher sulfur dioxide concentrations near the summit over the next 24 hours. For the latest sulfur dioxide emissions rates, please refer to the USGS eruption update. For the latest sulfur dioxide and aerosol concentrations, please refer to the current conditions table.
Island of Hawaii Forecast:
The pressure gradient has continued to weaken with the approaching front and weakening high pressure north of the state. Weather models indicate light trades will give way to light and variable winds with land and sea breezes by tomorrow. The vog model predicts increasing sulfur dioxide concentrations near the summit today and moderate aerosol concentrations near Hilo tomorrow. With variable winds and sea breezes expected, all locations on the Island of Hawaii can expect increasing concentrations of both pollutants lasting through Monday. Light trades should return by Tuesday which should begin to lower sulfur dioxide concentrations near the summit and sulfate aerosol concentrations for the east portion of the island. Until then, expect increasing concentrations of both pollutants and voggy conditions over the New Years weekend.
Western Hawaiian Islands Forecast:
Light variable winds and sea breezes should allow the Kilauea plume to shift north later today as indicated by the custom vog model. Sulfate aerosol concentrations should increase from east to west near Maui and then Oahu by tomorrow. This trend should continue through Monday before light trades are forecast to return on Tuesday and shift the plume south of the smaller islands.
Model Performance and Biases:
Over the last 24 hours the vog model has predicted increase concentrations of both pollutants near Pahala. Kailua-Kona has additional sources of sulfate aerosols which contribute to higher observed aerosol values than what is predicted. All other locations have ambient sources of aerosols which can cause observed values to be slightly higher as well but to a lesser degree. Known biases in the model include higher predicted concentrations of sulfate aerosols in Pahala and lower predicted concentrations of sulfate aerosols than those observed in Kailua-Kona. Please refer to the Model Performance page for graphical analysis of model performance.
Forecast issued by: Roy Huff
The following models are part of an experiment being conducted by the School of Ocean and Earth Science and Technology at the University of Hawai`i at Manoa. The information should not be relied upon.
Vog Measurement and Prediction
"Vog" is a mixture of gasses mainly composed of surfur dioxide (SO2) and sulfate (SO4) emitted from volcanos or vents. SO2 reacts with moisture and oxygen to produce a visible aerosol of SO4. The term vog comes from the combination of "volcanic" and "smog".
Kilauea, one of the world’s most active volcanos, has been erupting continuosly since 1983 and vents gas and vog from three locations: Halema`uma`u Crater, Pu“u O`o, and from the coastline where the lava flows into the ocean. Typically, Hawai`i’s tradewinds blow most of this pollution out to sea and away from civilization. However, the poisonous gasses sometimes blanket the Big Island, especially during times of slack winds. Even worse occurs when southerly Kona winds push the vog over the Big Island, sometimes drifting across the other neighboring islands of Maui, Lana`i, and Moloka`i, rarely reaching O`ahu, Kaua`i, and Ni`ihau.
Not only can the chemicals in vog damage the environment, but humans, other animals, and even plants can be harmed by these gasses.
