Evidence of liquid dependent ice nucleation in high-latitude stratiform clouds from surface remote sensors

• Published in: Geophysical Research Letters
• Other Authors: de Boer, G. (author), Morrison, Hugh (author), Shupe, M. (author), Hildner, R. (author)
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2011
• Subjects: Arctic; Arctic Ocean; Canada; Eureka; Barrow; Alaska
• Online Access: http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-512; https://doi.org/10.1029/2010GL046016

Ground-based lidar, radar and microwave radiometer observations at Eureka, Canada, Barrow, Alaska and over the western Arctic Ocean measure physical characteristics and morphology of stratiform clouds. Despite transition of a cold atmosphere (−15 C)through ice supersaturated conditions, ice is not observed until soon after a liquid layer. Several cases illustrating this phenomenon are presented in addition to long-term observations from three measurement sites characterizing cloud phase frequency. This analysis demonstrates that clouds composed entirely of ice occur less frequently than liquid-topped mixed-phase clouds at temperatures warmer than −25 to −30 C. These results indicate ice formation generally occurs in conjunction with liquid at these temperatures, and suggest the importance of liquid-dependent ice nucleation mechanisms.