Nitrate aerosols play an important role in regional air quality as well as the Earth’s climate system. However, it is not well represented or even neglected in many global climate models (GCMs). The formation of coarse mode nitrate aerosols in GCMs strongly depends on the model representation of mineral dust and sea salt, and it has large uncertainties and is not well constrained by observations. In this study, we investigate the impacts of dust emission fluxes and size distributions, and mixing state between dust and sea salt particles on the mass fractions of fine and coarse mode nitrate aerosols using the U.S. DOE Energy Exascale Earth System Model version 2 (E3SMv2) with the four-mode version of the Modal Aerosol Module (MAM4) for concentrations, size distributions and mixing states of aerosol species and the Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) module for the dynamic gas-particle phase partitioning. The simulated nitrate, dust, and sea salt aerosol concentrations are evaluated against synergetic measurements in different size ranges (e.g., PM₁, PM_2.5, and PM₁₀) from long-term ground-based networks (e.g., IMPROVE, EMEP) and aircraft campaigns (e.g., ATom). We found that simulated nitrate aerosols, especially over the tropical and North Atlantic, are sensitive to the treatments of mixing state between dust and sea salt, dust emission fluxes, and emitted dust size distributions. The E3SMv2 model can capture the seasonality of near-surface nitrate aerosol concentrations over remote ocean regions influenced by sea salt and dust outflow, but it fails to capture the seasonality over coastal regions.