Aerosols are an important component of our atmosphere, and representing them correctly in simulations is key to understanding their impact on air quality, climate systems, and human health. A new study, supported in part by the Climate Program Office’s Atmospheric Chemistry, Carbon Cycle and Climate (AC4) Program, assesses aerosol concentration results from a global chemical transport model by comparing them to observations made during the NASA Atmospheric Tomography Mission (ATom). The findings, published in JGR Atmospheres, show an overestimation of aerosols in the Northern Hemisphere during the winter season which was improved by updating the representation of wet scavenging, or the process by which aerosols are collected by falling precipitation (e.g. rain). This adjustment improves estimation of the amount of time aerosols spend in the atmosphere, which is important for accurate understanding and mitigation of air quality impacts. This study contributes to the AC4 Program’s initiative to investigate the processes affecting aerosols in the atmosphere and provides essential insight into the accurate representation of aerosols and thus precipitation in models.