Progress and challenges in understanding and simulating ice-nucleating particle concentrations for global climate models

Aerosols contribute globally not only to the direct radiative forcing of climate and impacts on warm clouds via cloud condensation nuclei, but also to populations of ice-nucleating particles (INPs) and their impacts on mixed-phase and ice clouds.  Cloud and climate models increasingly aim to represent the complex interactions of INPs with cloud processes by implementing aerosol-aware parameterizations ofice nucleation.

While these developments are exciting, aerosol-aware cloud and climate models are also susceptible to biases in simulated atmospheric INP populations.  Until recently, ice nucleation parameterizations and simulated INPs had not been systematically challenged with field observations.

This talk will provide an overview of several research efforts during the past decade that have advanced our fundamental understanding of the sources of atmospheric INPs, as well as our ability to simulate them in atmospheric models.  I will discuss the significant advances that have been made, especially surrounding the understanding of biological and biogenic particles that act as INPs.  Additionally, I will highlight some remaining challenges and identify future research needs.

Note: This seminar is part of the CESM Land Model / Biogeochemistry Working Group Meeting. For details on this meeting, or to register to receive the link to join online, please visit the website.