Snow grain size is an essential property required for many applications: cold regions hydrology, polar and mountain climatology, optical and microwave remote sensing, snow chemistry, etc. However, field and laboratory measurements of snow grain size are notoriously difficult and impaired by the coexistence of inconsistent definitions. Several instruments and methods based on very different physical principles (optical, gas adsorption, tomography, stereology) have been developed in the last decade, with differences in terms of reproducibility, acquisition time and vertical and horizontal resolution in the field. In recent years, grain size measurements have been conducted by different groups in a wide variety of environments. However, little is known about the accuracy of these methods due to the lack of an approved reference method and the insufficient number of inter-comparison exercises.
The *main objectives *of the meeting is to gather snow grain size specialists to:
1. Present established and new methods of measurements.
2. Discuss about the accuracy, comparability and quality of existing measurement methods,
3. Identify areas where action at the international level is needed to improve the situation.
Emphasis is deliberately placed on field or laboratory methods together with their theoretical relation to a particular definition of snow grain size. Development and applications related to grain size in the field of remote sensing, snowpack modeling and data assimilation are also welcome and open for discussion.
The 4-day workshop will include keynote lectures, oral presentations, poster presentations, discussions and one-day field trip near Grenoble. The objective of this field day is to demonstrate the instruments brought by the participants to the others and to potentially initiate an inter-comparison.
This workshop is the first meeting associated to the working group "From quantitative stratigraphy to microstructure-based modeling of snow" which will be supported by the International Association of Cryospheric Sciences (http://www.cryosphericsciences.org/).