10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Ice Nuclei and Their Impact on Clouds in Alaska

GIJS DE BOER, Matthew Norgren, Jessie Creamean, Amy Solomon, Maximilian Maahn, Fan Mei, Hagen Telg, Allison McComiskey, CIRES/NOAA

     Abstract Number: 95
     Working Group: Unraveling the Many Facets of Ice Nucleating Particles and Their Interactions with Clouds

Abstract
Northern Alaska is signifcantly influenced by the presence of ice nucleating particles (INP). These particles have a strong impact on hydrometeor properties in the region, introducing influence on cloud radiative properties, precipitation intensity, and cloud lifetime. While critical to the accurate projection of future climate states, the roles of these particles remain a challenge to understand and quantify. The Arctic is particularly sensitive to these interactions because small changes to the impacts of clouds on surface energy exchange can have large implications on a region known for extensive cloud cover whose atmospheric state exhibits large sensitivities to the surface energy budget, and where small shifts in temperature may result in dramatic departures in the surface energy budget through modification of surface albedos. To better understand the role that INP particles play in this puzzle and the sources of aerosols involved, we are using a variety of observational and modeling tools to gain new insight into the importance of these particles.

In this work, we will present observational analyses that shed light on the interplay between aerosols and cloud microphysical and radiative properties in Northern Alaska. Using measurements from surface-based US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program observatories at Oliktok Point and Utquiagvik (formerly Barrow) Alaska, together with airborne measurements, we will cover:

1) Observations of INP in northern Alaska and the potential sources of these particles,
2) An observational study demonstrating that aerosol loading plays a role in the modulation of precipitation from mixed-phase clouds, thereby impacting surface albedo and cloud dynamics, and
3) Modeling work demonstrating that small changes to the balance of INP and Cloud Condensation Nuclei (CCN) can impact mixed-phase cloud structure and lifetime.

This combination of studies will highlight the need to further our understanding of INP in this part of the world.