The goal of this investigation is to understand the wave-driven circulation and variability of the polar atmosphere through an integrated study that combines satellite measurements, lidar measurements, meteorological analyses, and model simulations will be conducted. This study is an international collaboration between investigators at six institutions in Germany, Japan and the United States. An international network of four Rayleigh lidars located in observatories at Andoya, Norway (69Â°N, 16Â°E), Chatanika, Alaska (65Â°N, 147Â°W), Kangarlussuaq, Greenland (67Â°N, 51Â°W) and KÃ¼hlungsborn, Germany (54Â°N, 12Â°E) provide a chain of measurements from the eastern Arctic to the western Arctic under distinct synoptic regimes (i.e., the Arctic stratospheric vortex, the Aleutian anticyclone, the stratospheric surf-zone). The lidars will yield high-resolution temperature and density measurements that allow characterization of the planetary waves, tides, and gravity waves. The satellite observations yield synoptic-scale temperature measurements of the mesosphere and upper stratosphere while the meteorological soundings and analyses provide synoptic-scale measurements of the troposphere and lower stratosphere. We have three specific goals; i) to extend the scope of current Rayleigh lidar measurements to characterize a wider range of waves than previously measured ii) to combine lower-resolution global data from satellite observations and meteorological analyses with higher-resolution data from Arctic Rayleigh lidar systems to document both the synoptic conditions and wave activity. iii) to investigate the observed wave behavior using a comprehensive general circulation model to understand the wave mean-flow interactions. The proposed activity will provide a comprehensive analysis of the circulation of the Arctic atmosphere that will directly address the following specific studies; coupling and feedbacks between waves and large-scale circulation; the structure; evolution, and variability of polar vortices and anticyclones; links between the middle and lower atmosphere; and atmospheric tele-connections. The study will advance our understanding of wave mean-flow interactions both regionally and globally that is critical for understanding dynamical driving of the circulation and the evolution of the climate. This study will provide data and analyses in support of studies of ozone depletion, stratospheric climate, and long-range horizontal and vertical transport in the Arctic. The observations, analyses and results of this activity will contribute to the CAWSES, CEDAR, SEARCH, and SPARC programs.