Volcanic aerosol impacts on Hawai'i Island rainfall

While it is clear that volcanic emissions can create hazardous air quality for Hawaiian communities, the impacts on rainfall are less clear. Here we investigate the impact of volcanic aerosol emissions on Hawai'i Island rainfall.

Based on observed daily rainfall and SO2 emissions, it is found that days with high SO2 emissions have on average 8 mm day(-1) less rainfall downstream of the Kilauea volcano. Sensitivity studies with varying volcanic aerosol emission sources from the Kilauea vent locations have also been conducted by the Weather Research and Forecasting (WRF) Model in order to examine the detailed physical processes. Consistent with SO2 air quality observations, it is found that the diurnal change in aerosol number concentration is strongly dependent on the diurnal variation of local circulations.