Last week, principal investigators from the AC4 Program’s Nitrogen Aerosol group held their first meeting at the Gordon Research Conference on Atmospheric Chemistry in Newry, Maine. The Nitrogen Aerosol group is comprised of PI teams that started projects in FY18 with a focus on the interaction of biogenic volatile organic compounds (VOCs) and reactive nitrogen. The closely-related group of 10 projects is mostly focused on laboratory experiments that are complementary to and build on a 2013 interagency field campaign (SAS/SOAS/SENEX) in the Southeast U.S. The next PI meeting, which will include a workshop on forming closer collaborations and closer ties to other nitrogen-focused AC4-funded activities, is being planned for late winter/early spring of 2020. The first PI meeting also touched on new progress reporting requirements and best approaches to reporting diversity and inclusion accomplishments.