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Impacts of Volcanic Degassing Emissions Across the United States
Citation:
Itahashi, S., R. Mathur, C. Hogrefe, S. Napelenok, AND Y. Zhang. Impacts of Volcanic Degassing Emissions Across the United States. EM: AIR AND WASTE MANAGEMENT ASSOCIATION'S MAGAZINE FOR ENVIRONMENTAL MANAGERS. Air & Waste Management Association, Pittsburgh, PA, October:1-5, (2021).
Impact/Purpose:
As SO2 emission controls on anthropogenic sources are reducing ambient SO42-, the portion attributable to natural sources is becoming increasingly important. Continuous SO2 emissions associated with volcanic degassing modulate the tropospheric aerosol sulfate levels. This study assesses the impacyt of these degassing emissions on large scale atmospheric aerosol sulfate levels by incorporation of estimates of volcanic degassing emissions in the Hemispheric CMAQ modeling system.
Description:
Emissions of SO2 resulting from volcanic degassing is one of the important sources that should be considered in the modeling system as it regulates tropospheric SO42- levels not only in the vicinity of the volcano but also through long-range transport that modulates background levels in downwind continents. Based on a comparison of degassing and eruptive emissions, it was estimated that volcanic activity contributed about 23 Tg/yr of SO2 from degassing while eruptive SO2 emissions ranged from 0.2 to 10 Tg/yr during 2005-2015. However, eruptive volcanic emissions can play an important role in episodically modulating tropospheric sulfur budgets. The modeling on both eruptive and degassing volcanoes are required in future updates to modeling system.
