Cloud-aerosol-precipitation interactions

 
Poster PDF

Authors

Steven J. Ghan — Pacific Northwest National Laboratory
Robert Wood — University of Washington

Category

Aerosol-Cloud-Radiation Interactions

Description

Aerosol particles, cloud particles, and precipitating particles form a continuum of particles that interact through a variety of complex mechanisms that affect the distribution and climate impacts of all particles. Aerosol particles affect clouds and precipitation by serving as the seeds for nucleation of droplets and crystals and by absorbing sunlight and thereby heating the air, suppressing condensation, changing the atmospheric circulation, and reducing turbulent transport of water from the surface into clouds. Clouds and precipitation affect the aerosol by transporting aerosol and their precursor gases upward and downward, by hosting aqueous chemistry that produces aerosol mass within cloud droplets, and by removing aerosol from the atmosphere when clouds precipitate. Observations and theoretical models suggest that full cloud-aerosol-precipitation interactions can lead to dramatic transitions from relatively polluted slowly precipitating clouds to much cleaner rapidly precipitating clouds, but these transitions are poorly understood. The Atmospheric Radiation Measurement (ARM) Climate Research Facility and the Atmospheric System Research (ASR) program together can provide the measurements, analysis, and modeling needed to address the many challenges of representing these interactions in climate models. In this poster/presentation we will summarize current understanding of cloud-aerosol-precipitation interactions and provide a vision for future directions of ARM and ASR measurements, analysis, and modeling to improve understanding and representation of the interactions in climate models.