It has over 30 years since the discovery that certain common bacteria are potent ice nuclei (IN). Two factors make this of potential importance for the atmosphere:
(i) These bacteria can be active at temperatures up to -2 degrees Celsius, thus more active than most other naturally occurring substances.
(ii) The IN active bacteria occur in high abundance on plants and may become airborne.
There are no reliable estimates of the overall contribution of biogenic ice nuclei to atmospheric processes. In view of the importance of the ice phase in cloud and precipitation processes, increased understanding of this element is highly desirable. This project will increase awareness and lead to new research activity about the atmospheric role of biogenic ice nuclei. It will support organization of, and travel for participants to attend, a session titled "Biological Ice Nucleators in the Atmosphere - at the Crossroads of Physics and Biology" that has been organized as part of the General Assembly of the International Union on Geodesy and Geophysics. The meeting is to be held in Perugia, Italy, July 2-13, 2007. The broader impact of the planned meeting and of the acceleration of research on biogenic IN is expected to be the clarification of an important biosphere-atmosphere linkage and the opening of new opportunities for interdisciplinary studies. Knowledge about the biogenic IN are also of interest to the medical field (organ preservation), to agriculture (frost prevention), desease control (winter survival of pests), the food industry (control of grain infestation) and many aspects of ecology.
