The project aims to investigate the occurrence and distribution of intermediate scale irregularities that develop on the equatorward edge of the aurora and in the midlatitude trough. A network of six passive radio beacon receivers in the northeast United States will be used to assemble a database which will then be interrogated to establish the morphology of the intermediate scale structures. A particular goal is to determine the relation of the zonal variations of the structures to the source region, such as the auroral oval or the trough, and to the level of geomagnetic activity. The database comprises measurements of the total electron content (TEC), phase scintillations, and the rate of TEC fluctuations which will be obtained by monitoring radio beacon transmissions at 150 MHz and 400 MHz from low-Earth-orbiting satellites. Five of the receivers to be used in the investigation already exist; the project seeks to establish a sixth receiver in upstate New York. The receivers are Coherent Ionospheric Doppler Receivers, or CIDRs, and the network of six CIDRs established under this project will constitute the North East CIDR Array (NECA). The locations of four of the receivers are Cornell, SUNY-Oneonta, Siena College, and MIT. These are distributed over about 400 km of longitude at a geomagnetic latitude of ~54 degrees north. This array configuration enables measurements of the occurrence and spatial distribution characteristics of intermediate scale plasma irregularities, ranging in size from 100 m to 30 km. A southern CIDR has been deployed at Wallops Island, at roughly 4 degrees southern magnetic latitude, and a sixth CIDR will be established in the Adirondacks of Northern New York (2 degrees north magnetic latitude) in the fall of 2007. Data from the receivers will be used to determine the approximate altitude of observed scintillations and fluctuations. Once the approximate altitude has been determined, the observed scintillation can be located in geomagnetic latitude and longitude, as well as in position relative to the auroral oval, the ionospheric trough, and the storm enhanced density (SED) plumes. The broader impacts of the project are both educational and societal. The investigation will contribute to the determination of causes of space weather processes that specifically impact technologies on Earth and in near-Earth space. Ionospheric irregularities produce scintillation in radio communication and navigation systems and generate "clutter" in radar signals. Such systems are ubiquitous in the air travel industry. Since there are increasing levels of air travel near the auroral oval and ionospheric trough, the morphology and occurrence of plasma irregularities in these regions has societal implications as well as scientific merit. A central database will be established to store all the NECA observations which will be freely and publicly available. The project will involve undergraduates in all aspects of the investigation, including data acquisition, archiving, processing, and quality control. This will enable participating students to become familiar with the instrumentation and data as well as develop their scientific and technological competence.
The decades since the advent of space flight have witnessed the increasing importance and relevance of the Earthâ€™s space environment: for understanding the functioning of planet Earth within the solar system; for understanding numerous aspects of laboratory physics and astrophysics; and for understanding the Sunâ€™s influence on technological systems deployed on Earth and in space. To better understand Earthâ€™s space environment - Geospace - the State University of New York College at Oneonta, Siena College, and the Applied Research Laboratories, University of Texas at Austin operated passive radio receivers in the northeast United States to monitor beacon transmissions at 150 MHz and 400 MHz from low-earth-orbiting (LEO) satellites (see Figure 1). A primary objective of this study is to determine the occurrence and distribution of plasma irregularities/bubbles (see Figure 2) observed along the equatorward edge of the auroral zone. The proposed research also examined the causes of space weather processes that specifically impact technologies on Earth and in near-Earth space. Ionospheric irregularities/bubbles produce scintillation in radio and beacon communication and navigation systems and generate clutter in radar signals. Such systems are ubiquitous in the air travel industry. Coupled with the increasing levels of air travel near the auroral oval, the morphology and occurrence of plasma irregularities/bubbles in these regions has societal impact, as well as scientific merit. This project further addressed NSFâ€™s broader impact criteria in two significant ways. First, the data sets are available to all researchers and could enhance many other projects beyond those proposed herein. Second, the investigators on this proposal have mentored undergraduate students for years using various geophysical data sets, and we provided students with meaningful research experiences in geospace physics. Thus, the students had an opportunity to apply their experience in several mathematics and physics courses to fundamental problems in radio wave propagation and space physics. In assuming ownership of their entire project, the students gain significant experience maintaining instruments, managing the data base, data analysis and software development, while making contributions to the field (see Figure 3). Science Presentations First authored student presentations are underlined: NECA Observations of Medium Scale Structures in the Ionosphere over New England, James Akey, T. Kelley, P. Anderson, J. Benway, H. Gallagher 2, T. W. Garner, A. T. Weatherwax and A. Costner, Coupling, Energetic, and Dynamics of Atmospheric Regions workshop, Boulder, Colorado, June 20-25, 2010. The North East CIDR Array (NECA): A Chain of Ionospheric Tomography Receivers for Studying the Equatorward Edge of the Auroral Oval and the Mid-latitude Trough, H. Gallagher, P. Anderson, L. Dâ€™Imperio, T. Kelley, Michael Eramo and Scott Suriano, T. W. Garner, A. Scholze, A. T. Weatherwax and J. Akey, A. Coster, Coupling, Energetic, and Dynamics of Atmospheric Regions workshop, Boulder, Colorado, June 20-25, 2010. The NorthEast CIDR Array: A new chain of ionospheric tomography receivers for studying the equatorward edge of the auroral oval and the mid-latitude trough, H. Gallagher, P. Anderson, L. Dâ€™Imperio, T. Kelley, T. W. Garner, A Scholze, A Coster, A. T. Weatherwax and J. Akey, Coupling, Energetic, and Dynamics of Atmospheric Regions workshop, Santa Fe, New Mexico, June 28 – July 2, 2009. Observations of the auroral electrojet plasma using UHF/VHF radio beacon measurements, S Bayne, H Gallagher, T W Garner, A T Weatherwax and J Secan, Coupling, Energetic, and Dynamics of Atmospheric Regions workshop, Santa Fe, New Mexico, June 28 – July 2, 2009. Outreach Presentations First authored student presentations are underlined: The North-East CIDR Array: A New Chain of Ionospheric Tomography Receivers for Studying the Equatorward Edge of the Auroral Oval and the Mid-latitude Trough, H. A. Gallagher Jr., Peter Anderson, Luke Dâ€™Imperio, Timothy Kelly, Trevor Garner, Allan Weatherwax, James Akey, poster presented at Undergraduates Shaping New Yorkâ€™s Future: A Showcase of Scholarly Posters at the Capitol in Albany, NY April 13, 2010. The North-East CIDR Array: A New Chain of Ionospheric Tomography Receivers for Studying the Equatorward Edge of the Auroral Oval and the Mid-latitude Trough, H. A. Gallagher Jr., Peter Anderson, Luke Dâ€™Imperio, Timothy Kelly, Trevor Garner, Allan Weatherwax, James Akey, poster presented at the SUNY Oneonta Faculty Research Show, February, 2010. Role of NECA in Teaching Space Physics at SUNY Oneonta, H. Gallagher, Oral presentation at the Solar and Space Physics Undergraduate Teaching Workshop, San Francisco, CA, December, 2009. Coherent ionospheric Doppler Receiver (CIDR) Observations of Mid-Latitude Total Electron Content, Peter Anderson, Luke Dâ€™Imperio, Hugh Gallagher Jr., Trevor Garner, Allan Weatherwax (Siena College),. Poster presentation at Student Research Day, SUNY Oneonta, Oneonta, NY, March, 2009.