This two-year award for U.S.-France cooperative research in atmospheric science involves Cesar Valladares and Dwight Decker of Boston College and Denis Alcayde and his group at the Centre D'Etude Spatiale des Rayonnements in Toulouse, France. The award provides travel and subsistence support to the U.S. investigators for trips to the United Kingdom and France. The objective of the research is to investigate the global characteristics of plasma structuring that develops in the polar cap and auroral oval. They will conduct joint analysis, interpretation, modeling of data collected by the incoherent scattering radars at Sondrestrom, Greenland, and EISCAT, Scandinavia. The project takes advantage of access to radar data from Scandinavia and of the complementary expertise of the U.S. and French investigators in modeling. The project advances understanding of plasma structure and irregularities in ionospheric density in the polar cap.