03/09/2009
New Model Describes Links Between Vertical Air Motion and Arctic Cloud Properties
Summary
DOE scientists have developed a model that explains aspects of the life-cycle of low-altitude Arctic clouds using ground-based measurements from the Atmospheric Radiation Measurement (ARM) user facility. These clouds are often called mixed-phase clouds because of the co-existence of both water and ice. Lifting of air in these clouds leads to formation of liquid and ice particles. Subsequent descending air motion nearly eliminates the ice phase through sublimation and particles falling out of the clouds. It is important to understand the role of vertical air motion in determining the distribution of liquid and ice particles in these clouds because of their direct impact on Arctic climate through changes in the surface and atmospheric radiation budgets. These findings pave the way for improved representation of clouds in climate models.
References
Shupe, M. D., P. Kollias, P. O. G. Persson, and G. M. McFarquhar, 2008: Vertical motions in Arctic mixed-phase stratiform clouds. J. Atmos. Sci. 65, 1304-1322.