Waves and coupling in the Earth's upper atmosphere

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This proposal supports research into the physics of the middle and upper atmosphere (between 50 and ~250 km). These heights encompass the region where the atmosphere transitions to geospace. It is characterized by large waves (tides, planetary waves and gravity waves) which propagate upward from the lower atmosphere into these heights and ionospheric current systems generated through interactions between the solar wind, Earth's magnetic field and atmospheric motions. Determining the mechanisms which cause the upward and downward flow of constituents and energy through this region is essential to understanding the Sun/Earth system. Given our growing dependence on satellite technologies and the global impact human activities are having on the composition of the atmosphere and its response to the Sun's energy, such an understanding is vital.***The proposed research has three components: the development of world class, unique optical instruments to image winds; the establishment and support of ground-based instruments in the Canadian High Arctic which probe the dynamics of the upper atmosphere and the analysis of their observations; the analysis of global data sets from models and satellites to investigate the dynamics of the middle and upper atmosphere. ***We have recently generated the first images ever of winds at a height of 95 km using interferometers to measure Doppler shifts of naturally occurring light from airglow. One component of the proposed research is to optimize and field test these instruments and then use them to remotely “see” winds and investigate the properties of waves present in the upper atmosphere. ***I currently have a wind interferometer and an all sky imager located at the Polar Environment Atmospheric Research Laboratory (PEARL) at Eureka, Nunavut which provide wind and airglow brightness at heights between 85 and 100 km. Collaborations have been set up with colleagues responsible for other instruments at Eureka and Resolute Bay which take measurements complementing these measurements. Another component of the proposed research is the maintenance and expansion of this network and the analysis of the observations so that the dynamics at these heights becomes known.***For a global perspective on the physics of the transition region, satellite observations and output from global general circulation models are needed. Observations of the dynamics of this region of the atmosphere from a sequence of satellites (several of which are Canadian) have been made since the 1990's Output from a Canadian General Circulation model covering the years from 1990 to 2010 is available. A third research component is to use our experience in working with these data sets to characterize the global dynamics and look for long term atmospheric trends**