Aerosol-cloud interactions make up a strong but highly uncertain aspect of the projected climate response to future warming. Anthropogenic aerosols contribute a negative radiative forcing by changing the albedo and macrophysical properties of clouds, but the magnitude of this effect is not well constrained in current earth system models. Many of the physical processes driving aerosol-cloud interactions occur at subgrid scales and must be parameterized, which introduces uncertainty into model simulations. Perturbed parameter ensembles (PPEs) can address this parametric uncertainty by exploring the effects of varying multiple parameters across a range of possible values at the same time. We build a PPE using version 3 of the Energy Exascale Earth System Model (E3SMv3) under an atmosphere-only configuration. In the E3SMv3 PPE, we perturb 25 parameters related to aerosols, convective microphysics, accretion, and autoconversion in an ensemble of 125 two-year simulations of both pre-industrial and present-day aerosol forcings. Focusing on changes to the liquid water path and cloud fraction, called aerosol-cloud adjustments, we constrain the PPE output with ground-based observations from three Atmospheric Radiation Measurement (ARM) sites across the globe: Eastern North Atlantic, Ascension Island, and Southern Great Plains. We apply these constraints regionally and globally to see how well variance in the different cloud regimes across sites can explain global variance in aerosol-cloud adjustments. The E3SMv3 PPE, combined with ARM observations, may provide a better constraint on radiative forcings from aerosol-cloud interactions in the historical record and help advance our understanding of the magnitude of future radiative forcings due to aerosol-cloud interactions.