The awardee will operate and manage the Poker Flat and Resolute Bay Advanced Modular Incoherent Scatter Radar (AMISR) facilities. AMISR is a new incoherent scatter radar system designed and built through National Science Foundation support. Over the last four decades, incoherent scatter radar is the primary technique for measuring basic properties of the upper atmosphere and ionosphere. The AMISR has significant scientific advantages over existing incoherent scatter radars, largely due to the rapid steering provided by the phased array antenna. The pulse-to-pulse steering capability promises to resolve many of the temporal/spatial ambiguities inherent in measurements from mechanically steered dish-based systems. In operating and managing the AMISR systems in Alaska and Canada, the awardee will focus on assisting the research community by 1) directing use of a state-of-the-art facility in unique parts of the world, 2) providing access to a knowledgeable staff of scientists and engineers for consultation and collaboration, 3) providing logistics support for campaigns and long-term measurement programs, 4) providing easy access to various levels of processed and analyzed radar data, and 5) participating in the training of students and assisting student advisors. Scientific activities related to the AMISR observations will focus on Earth's upper atmosphere, ionosphere, and magnetosphere, and their coupling to the solar wind. Although, knowledge of the Earth's geospace environment has advanced significantly during the second half of the twentieth century, detailed understanding of even the most basic processes remains somewhat vague. At times, important temporal scales can range from seconds through days. Similarly, the relevant spatial scales range from submeters through thousands of kilometers. AMISR fills the needs of the atmospheric science and magnetospheric science communities to study the dynamic processes that occur at high latitudes. There is evidence that much of the variability is due to advection of horizontally inhomogeneous structures, but it is also clear that the structures evolve with time. A phased array system such as AMISR would essentially support the short timescale imaging of such structures and the tracking of their evolution. A similar argument applies to the probing of auroral ionization structures. Another important attribute of the AMISR facilities is that they are remotely accessible, and the radar and ancillary instruments will be designed to produce real-time processed data that will be made publicly available and distributed to the user community over the Internet. The provision of user-friendly data and display capabilities, which meet the community's research needs, is an important part of AMISR operations. Support of a strong, distributed, and trained user community is very important to the overall scientific success of the AMISR project. The AMISR management team will work directly with graduate and undergraduate students and their advisors to assist with student training, experiment planning, and scheduling. It will also maintain a repository for contributed course materials, technical data, and facility instrument information.
This project resulted in more than 60 publications in peer-reviewed journals, spanning a range of research topics. The primary instruments involved in the research were two incoherent scatter radars, called Advanced Modular Incoherent Scatter Radars or AMISRs, which were used to probe the upper reaches of the Earth’s atmosphere and ionosphere. The AMISR systems have been operating at arctic locations in central Alaska (near Fairbanks) and northern Canada (near Resolute Bay, Nunavut) to investigate the region in and to the north of the Aurora Borealis. This part of the upper atmosphere is critical to understanding the way particles and fields in the solar wind interact with the Earth. One of the main innovations incorporated into the AMISR design allows three-dimensional imaging of the ionized, or invisible, part of the aurora. Several studies compared this three-dimensional ionization structure with images collected from cameras located at the same site. This direct comparison of the characteristics of the ionization and the optically measured auroral forms has expanded our understanding of different phases of auroral arc evolution. In particular, we are seeing, at shorter and shorter time and distances scales, how the ionization itself affects the motion of the plasma by shielding out electric fields that would otherwise drive the plasma. Another extremely useful capability of the AMISR technology is operation in a reduced power mode. Starting with the International Polar Year, this has allowed the Alaska system to run nearly continuously for almost the entire duration of this project without excessive costs. Operating all the time has meant that the AMISR system has seen the ionospheric impact of almost all the solar activity for the past five years. This has allowed, for instance, the investigation of regions on the sun called co-rotating interaction regions, which rotate with the sun’s surface, and the discovery that they directly heat the ionospheric plasma at the Earth. The extensive data set generated by this project are available to all researchers via the internet through the Madrigal database.
