NASA is flying an airborne science laboratory through Canadian snowstorms for six weeks in support of a difficult task of the upcoming Global Precipitation Measurement (GPM) mission: measuring snowfall from space. GPM is an international satellite mission scheduled for launch in 2014 that will provide next-generation observations of worldwide rain and snow every three hours. It is the first precipitation mission designed to detect falling snow from space. NASA's DC-8 flying laboratory flew this flight path on Jan 19, 2012 in support of NASA's Global Precipitation Measurement Cold-season Precipitation Experiment (GCPEx) snow study. The GCPEx field campaign will help scientists match measurements of snow in the air and on the ground.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 18.104.22.168.0