10/25/2010

Understanding How Ice Clouds Warm the Atmosphere

Summary

DOE scientists have improved our understanding of how ice crystals form in the atmosphere and how their growth reduces the humidity of air. Ice clouds form at high altitudes, playing a critical role in Earth’s energy balance by trapping infrared radiation (heat) emitted by the Earth’s surface and from lower levels of the atmosphere leading to an overall warming of the atmosphere. Historically, ice clouds have been crudely represented in climate models largely due to inadequate in-situ observations needed to build quality parameterizations. This new research builds on improved local scale coupled process modeling of turbulence, humidity fields, and both anthropogenic and natural cloud condensation nuclei that in turn influence the evolution of ice cloud particles.

References

Gettelman, A., X. Liu, S. J. Ghan, H. Morrison, S. Park, A. Conley, S. A. Klein, J. Boyle, D. Mitchell, and J-L F Li, 2010. “Global simulations of ice nucleation and ice supersaturation with an improved cloud scheme in the community atmosphere model,” J. Geophys. Res., 115(D18216), doi:10.1029/2009JD013797.