The Ice Nucleation in Layer Clouds (ICE-L) Field Project
More than 50% of the earth's precipitation originates in the ice phase. Ice nucleation, therefore, is one of the most basic processes that lead to precipitation. The poorly understood processes of ice initiation in clouds result in large uncertainties in the modeling of precipitation production with consequences for numerical weather prediction and climate change simulation.
Recently, NSF awarded funds for the ICE-L (Layer clouds) field project, led by NCAR (MMM: Heymsfield, Field / EOL: Rogers, Stith), to study heterogeneous ice nucleation using aircraft. More than 50% of the earth's precipitation originates in the ice phase. Heterogeneous ice nucleation is the dominant method of producing ice at temperatures warmer than -40C. The project is planned for next Spring (March-April 2007) and will involve the NCAR C-130 operating in the Front Range area targeting lenticular wave clouds and altocumulus. More than 10 University groups have applied for NSF funds in support of this project and propose to study a diverse range of problems ranging from the physical location of the nucleation region to the chemical analysis of the aerosol that ice particles formed on.
Progress in deciphering the interplay between atmospheric dynamics, thermodynamics and different aerosols types will lead to a better understanding of anthropogenic impacts on ice clouds and improved prediction of the longevity of supercooled layer clouds important for aircraft icing safety.