Impact of Ship Emissions in the North Pacific on Arctic Air Quality

Recent measurements show notable or significant increases in atmospheric sulfate aerosol and SO2 concentrations in Alaska at the coastal Simeneof and Tuxedni Wilderness Areas and at Trapper Creek sites of the IMPROVE network, while the inland Denali National Park and Preserve site shows decreasing trends. Average concentrations are nearly double as high at the Simeneof site than at the other three sites. Recent measurements of oceanic ph-values a dramatic decrease in pH in the bottom waters inshore of the sill along the Seward line. WRF/Chem is applied to examine whether increases in ship emissions are potential causes for the affected sulfate and SO2 concentrations and increasing trends. Focus will be on differences as compared to mid-latitude ship emission impacts in behavior of chemical processes during the long white nights and dark days of Alaska.