Nitrogen (N) is essential for life, yet most of it exists as inert atmospheric N2, inaccessible to most living organisms. Only a small fraction of N – reactive N (Nr)– is biologically available and directly usable by plants and microbes. Bioavailable forms of N are exchanged between the atmosphere and terrestrial environments primarily through emission and precipitation, or wet deposition. Understandings of deposition are shifting, from a general focus on inorganic acidic solutes such as nitrate to a more complex and dynamic picture inclusive of dissolved organic N which encompasses any molecule with an organic carbon (C) backbone that also contains N. The chemical composition of precipitation can reveal landscape-scale emission sources of organic C, and by association N, to the atmosphere and the degree to which these complex organic molecules may participate in C and/or N cycles once deposited into ecosystems. The goal of this postdoctoral fellowship project is to advance the understanding of how organic C and N in precipitation originate, transform, and impact ecosystems. The research will explicitly test whether events such as forest fires, transpiration, and agricultural soil decomposition may individually or collectively drive the trends in organic matter deposition. The broader impacts of this research encompass quantifying biogeochemical links between the atmosphere and biosphere while also achieving stakeholder engagement, interdisciplinary collaboration, and teachin