Assessing the Dependence of Aerosol-Cloud Interactions on Low-Cloud Mesoscale Morphology with ARM Observations

Principal Investigator: Tianle Yuan, GESTAR-II/ JCET, University of Maryland, Baltimore County

Co-Investigator: Christine Chiu, Colorado State University

Aerosol-cloud interactions in the marine boundary layer clouds and their radiative forcing remain the leading uncertainty in our climate forcing estimate. Previous investigations have shown that aerosol-cloud interactions

aerosol-cloud interaction

The interaction of airborne particles (aerosols) with clouds. Scientists study how aerosols affect clouds and how these interactions can impact the Earth's climate.

Source: DOE Source

in the marine boundary layer are state-dependent and time-dependent, which makes them hard to model in climate models and contributes to the current uncertainty. Observational investigations of aerosol-cloud interactions in the marine boundary layer often suffer from the attribution problem, i.e., it is often challenging to attribute observed cloud adjustments to aerosols

aerosols

Small particles or droplets, such as wildfire smoke, volcanic gases, or salty sea spray, that float in the air. They are emitted by both natural events and human activities.

Source: NASA Global Climate Change Source

alone. Marine boundary layer cloud morphology

morphology

The science of the form and structure of organisms (plants, animals, and other forms of life).

Source: National Cancer Institute Source

has been shown to play an important role in qualitatively determining cloud adjustments to aerosols by both observational and modeling studies. However, our understanding of the morphology-dependence of ACIs in the MBL clouds is still in its infancy.

Here we propose to synergistically combine ground-based Department of Energy Atmospheric Radiation Measurement (ARM) facility’s observations and satellite-based observations to improve our understanding of the morphology dependency of aerosol-cloud interactions in the marine boundary layer clouds. We will collocate ARM observations of marine boundary layers clouds with cloud morphology classifications and find clouds affected by ship-emitted aerosols in the ARM observations at the Eastern North Atlantic site and during other field campaigns. We will analyze the comprehensive combined dataset to answer important questions regarding aerosol-cloud interactions. Results from our investigation will contribute to the ASR program by providing observational constraints on the behavior of aerosol-cloud interactions and its dependence on cloud morphology.