The research component of this CAREER project focuses on developing and deploying two clusters of optical and radio equipment to study irregularities that occur in the nighttime mid-latitude F region of the upper atmosphere. The education component integrates the research conducted into the classroom through the development of modules and laboratory experiments pertaining to the instrumentation used in this study. Additionally, the PI will be developing a new course on the Global Positioning System (GPS) at the University of Illinois. Two clusters of instrumentation consisting of a wide-field ionospheric imaging system, a dual-frequency GPS receiver, and a single-frequency GPS scintillation monitor will be deployed to the Caribbean region south of the Arecibo Observatory. These instruments will augment those already in place at the Arecibo Observatory in Puerto Rico for studying ionospheric irregularities. The research project will focus on the following set of science questions: 1) What are the physical extent, seasonal properties, and lifetimes of nighttime F-region structures observed over the Caribbean? 2) What is the genesis region and mechanism for the different types of structures present in the nighttime F-region ionosphere? Do they grow locally, or are they coupled from low latitudes? What effect on trans-ionospheric radio wave propagation do these irregularities have? 3) Are the enhancements in electron density commonly seen in the American sector during severe geomagnetic storms effective in creating scintillations on critical trans-ionospheric radio links? Previous studies lacked the spatial coverage to address these questions, nor did they have instrumentation to measure the scintillation effects on critical satellite links. Both of these shortcomings are addressed in this research.
Curriculum development is an integral part of this project and will enable students at both the undergraduate and graduate level to solidify fundamental knowledge gained in the classroom through hands-on experiences. New classroom modules and laboratories will be developed. Motivated undergraduate students will be encouraged to become involved in the research program, increasing the breadth of their education. Graduate students will also participate in all aspects of this project, contributing to their development into the next generation of scientists.
This project concerned studying the midlatitude ionosphere and the conditions during which structure can develop in this region of the upper atmosphere. The experimental portion of this project involved deploying optical and radio instruments to two new observation sites in the Caribbean as well as the continued operation and analysis of data from sites in South America and Hawaii. The multi-year dataset was used in studies conducted by the research team to understand the conditions under which structuring occurs in the midlatitude ionosphere and the adverse effects this structure can have on the propagation of radiowaves transmitted by satellite communication and navigation systems. The most significant results stemming from this project were that we have: shown that, even during low solar flux conditions, the Caribbean ionosphere is under the influence of both low- and mid-latitude dynamics. Both medium-scale traveling ionospheric disturbances (MSTIDs; traditionally viewed as a mid-latitude phenomenon) and equatorial plasma bubbles (EPBs; traditionally viewed as a low-latitude phenomenon) are commonly observed there; confirmed through observations that MSTIDs can reach low latitudes during low solar flux conditions, contrary to previous reports; modeled how the electric field within a mid-latitude MSTID can act as a seeding mechanism for EPBs, demonstrating coupling across latitude regimes that have traditionally been treated separately; and presented the first ever observation of the airglow signature in the upper atmosphere caused by the passage of a tsunami. Our initial observation, made during the tsunami following the Tohoku earthquake in March 2011, has been followed up with a second observation of a much smaller tsunami caused by the Charlotte earthquake in October of 2012. These observations demonstrate the altitudinal coupling from the ocean through the upper atmosphere. In addition, several significant educational objectives were completed under this project. First, a new course on Global Navigation Satellite Systems (GNSS) was developed at the University of Illinois and is now routinely offered to upper-level undergraduate and graduate students. Second, multiple undergraduate students gained valuable hands-on research experience working with the instrumentation and resultant data collected under this project as well as presenting their results within our research group and at national conferences. Finally, several graduate students developed their research skills through their involvement in instrument deployment, operation, and data analysis as well as gaining leadership skills while mentoring the undergraduate students involved in the project.
