Tropical cyclones (TCs) are the leading cause of weather-related economic loss in the U.S., accounting for $938.2 billion between 1980-2019.  Into the future, coastal regions are expected to face compounding challenges from TCs and sea-level rise. Despite the societal and economic risk TCs pose, grand challenges remain including a lack of consensus on future change in global TC number and uncertainty in the magnitude of regional change in TC intensity and precipitation. This knowledge gap stems from the lack of a theory to explain what constrains annual TC numbers and a limited understanding of how various coupled atmosphere-ocean processes alter TC intensity in different climate states. The urgency of addressing the challenge to make reliable future TC projections is escalating with increasing coastal development and population growth, the high economic output of U.S. coastal regions, the vulnerability of infrastructure to coastal flooding, and sea-level rise. This research will (1) quantify how local-scale processes and atmosphere-ocean interactions shape TC intensity in a changing climate (e.g., TC intensity and associated wind-driven ocean mixing, TC precipitation and associated freshwater flux to the ocean, and upper-ocean thermal and salinity conditions); (2) determine the primary large-scale physical drivers that control the spatial and temporal statistics of landfalling TCs (e.g., inter-basin and intra-basin ocean temperature gradients, greenhouse gas and aerosol forcings, TC steering flow, and TC precursors); and (3) translate the knowledge developed in 1 and 2, together with sea-level rise projections, into coastal impacts due to the combination of storm surge, heavy precipitation, and strong winds associated with TCs. We will address these problems using observations and climate models including the DOE Energy Exascale Earth System Model (E3SM), a convection-permitting atmosphere-ocean regional climate model, and a storm surge model. This research will advance the resilience of North American coastal systems to climate change by determining how local coupled processes and large-scale drivers control historical and future TC characteristics.